From 6ebbe0ef50667af7a6ddb5ba674a6ab5e0827be1 Mon Sep 17 00:00:00 2001 From: Mark Simulacrum Date: Mon, 8 May 2017 05:33:43 -0600 Subject: [PATCH] Re-add LALR grammar. --- src/grammar/.gitignore | 3 + src/grammar/lexer.l | 343 ++++ src/grammar/parser-lalr-main.c | 203 ++ src/grammar/parser-lalr.y | 1945 +++++++++++++++++++ src/grammar/raw-string-literal-ambiguity.md | 64 + src/grammar/testparser.py | 76 + src/grammar/tokens.h | 91 + 7 files changed, 2725 insertions(+) create mode 100644 src/grammar/.gitignore create mode 100644 src/grammar/lexer.l create mode 100644 src/grammar/parser-lalr-main.c create mode 100644 src/grammar/parser-lalr.y create mode 100644 src/grammar/raw-string-literal-ambiguity.md create mode 100755 src/grammar/testparser.py create mode 100644 src/grammar/tokens.h diff --git a/src/grammar/.gitignore b/src/grammar/.gitignore new file mode 100644 index 00000000000..3e449875943 --- /dev/null +++ b/src/grammar/.gitignore @@ -0,0 +1,3 @@ +*.class +*.java +*.tokens diff --git a/src/grammar/lexer.l b/src/grammar/lexer.l new file mode 100644 index 00000000000..77737c99496 --- /dev/null +++ b/src/grammar/lexer.l @@ -0,0 +1,343 @@ +%{ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#include +#include + +static int num_hashes; +static int end_hashes; +static int saw_non_hash; + +%} + +%option stack +%option yylineno + +%x str +%x rawstr +%x rawstr_esc_begin +%x rawstr_esc_body +%x rawstr_esc_end +%x byte +%x bytestr +%x rawbytestr +%x rawbytestr_nohash +%x pound +%x shebang_or_attr +%x ltorchar +%x linecomment +%x doc_line +%x blockcomment +%x doc_block +%x suffix + +ident [a-zA-Z\x80-\xff_][a-zA-Z0-9\x80-\xff_]* + +%% + +{ident} { BEGIN(INITIAL); } +(.|\n) { yyless(0); BEGIN(INITIAL); } + +[ \n\t\r] { } + +\xef\xbb\xbf { + // UTF-8 byte order mark (BOM), ignore if in line 1, error otherwise + if (yyget_lineno() != 1) { + return -1; + } +} + +\/\/(\/|\!) { BEGIN(doc_line); yymore(); } +\n { BEGIN(INITIAL); + yyleng--; + yytext[yyleng] = 0; + return ((yytext[2] == '!') ? INNER_DOC_COMMENT : OUTER_DOC_COMMENT); + } +[^\n]* { yymore(); } + +\/\/|\/\/\/\/ { BEGIN(linecomment); } +\n { BEGIN(INITIAL); } +[^\n]* { } + +\/\*(\*|\!)[^*] { yy_push_state(INITIAL); yy_push_state(doc_block); yymore(); } +\/\* { yy_push_state(doc_block); yymore(); } +\*\/ { + yy_pop_state(); + if (yy_top_state() == doc_block) { + yymore(); + } else { + return ((yytext[2] == '!') ? INNER_DOC_COMMENT : OUTER_DOC_COMMENT); + } +} +(.|\n) { yymore(); } + +\/\* { yy_push_state(blockcomment); } +\/\* { yy_push_state(blockcomment); } +\*\/ { yy_pop_state(); } +(.|\n) { } + +_ { return UNDERSCORE; } +as { return AS; } +box { return BOX; } +break { return BREAK; } +const { return CONST; } +continue { return CONTINUE; } +crate { return CRATE; } +else { return ELSE; } +enum { return ENUM; } +extern { return EXTERN; } +false { return FALSE; } +fn { return FN; } +for { return FOR; } +if { return IF; } +impl { return IMPL; } +in { return IN; } +let { return LET; } +loop { return LOOP; } +match { return MATCH; } +mod { return MOD; } +move { return MOVE; } +mut { return MUT; } +priv { return PRIV; } +proc { return PROC; } +pub { return PUB; } +ref { return REF; } +return { return RETURN; } +self { return SELF; } +static { return STATIC; } +struct { return STRUCT; } +trait { return TRAIT; } +true { return TRUE; } +type { return TYPE; } +typeof { return TYPEOF; } +unsafe { return UNSAFE; } +use { return USE; } +where { return WHERE; } +while { return WHILE; } + +{ident} { return IDENT; } + +0x[0-9a-fA-F_]+ { BEGIN(suffix); return LIT_INTEGER; } +0o[0-8_]+ { BEGIN(suffix); return LIT_INTEGER; } +0b[01_]+ { BEGIN(suffix); return LIT_INTEGER; } +[0-9][0-9_]* { BEGIN(suffix); return LIT_INTEGER; } +[0-9][0-9_]*\.(\.|[a-zA-Z]) { yyless(yyleng - 2); BEGIN(suffix); return LIT_INTEGER; } + +[0-9][0-9_]*\.[0-9_]*([eE][-\+]?[0-9_]+)? { BEGIN(suffix); return LIT_FLOAT; } +[0-9][0-9_]*(\.[0-9_]*)?[eE][-\+]?[0-9_]+ { BEGIN(suffix); return LIT_FLOAT; } + +; { return ';'; } +, { return ','; } +\.\.\. { return DOTDOTDOT; } +\.\. { return DOTDOT; } +\. { return '.'; } +\( { return '('; } +\) { return ')'; } +\{ { return '{'; } +\} { return '}'; } +\[ { return '['; } +\] { return ']'; } +@ { return '@'; } +# { BEGIN(pound); yymore(); } +\! { BEGIN(shebang_or_attr); yymore(); } +\[ { + BEGIN(INITIAL); + yyless(2); + return SHEBANG; +} +[^\[\n]*\n { + // Since the \n was eaten as part of the token, yylineno will have + // been incremented to the value 2 if the shebang was on the first + // line. This yyless undoes that, setting yylineno back to 1. + yyless(yyleng - 1); + if (yyget_lineno() == 1) { + BEGIN(INITIAL); + return SHEBANG_LINE; + } else { + BEGIN(INITIAL); + yyless(2); + return SHEBANG; + } +} +. { BEGIN(INITIAL); yyless(1); return '#'; } + +\~ { return '~'; } +:: { return MOD_SEP; } +: { return ':'; } +\$ { return '$'; } +\? { return '?'; } + +== { return EQEQ; } +=> { return FAT_ARROW; } += { return '='; } +\!= { return NE; } +\! { return '!'; } +\<= { return LE; } +\<\< { return SHL; } +\<\<= { return SHLEQ; } +\< { return '<'; } +\>= { return GE; } +\>\> { return SHR; } +\>\>= { return SHREQ; } +\> { return '>'; } + +\x27 { BEGIN(ltorchar); yymore(); } +static { BEGIN(INITIAL); return STATIC_LIFETIME; } +{ident} { BEGIN(INITIAL); return LIFETIME; } +\\[nrt\\\x27\x220]\x27 { BEGIN(suffix); return LIT_CHAR; } +\\x[0-9a-fA-F]{2}\x27 { BEGIN(suffix); return LIT_CHAR; } +\\u\{[0-9a-fA-F]?{6}\}\x27 { BEGIN(suffix); return LIT_CHAR; } +.\x27 { BEGIN(suffix); return LIT_CHAR; } +[\x80-\xff]{2,4}\x27 { BEGIN(suffix); return LIT_CHAR; } +<> { BEGIN(INITIAL); return -1; } + +b\x22 { BEGIN(bytestr); yymore(); } +\x22 { BEGIN(suffix); return LIT_BYTE_STR; } + +<> { return -1; } +\\[n\nrt\\\x27\x220] { yymore(); } +\\x[0-9a-fA-F]{2} { yymore(); } +\\u\{[0-9a-fA-F]?{6}\} { yymore(); } +\\[^n\nrt\\\x27\x220] { return -1; } +(.|\n) { yymore(); } + +br\x22 { BEGIN(rawbytestr_nohash); yymore(); } +\x22 { BEGIN(suffix); return LIT_BYTE_STR_RAW; } +(.|\n) { yymore(); } +<> { return -1; } + +br/# { + BEGIN(rawbytestr); + yymore(); + num_hashes = 0; + saw_non_hash = 0; + end_hashes = 0; +} +# { + if (!saw_non_hash) { + num_hashes++; + } else if (end_hashes != 0) { + end_hashes++; + if (end_hashes == num_hashes) { + BEGIN(INITIAL); + return LIT_BYTE_STR_RAW; + } + } + yymore(); +} +\x22# { + end_hashes = 1; + if (end_hashes == num_hashes) { + BEGIN(INITIAL); + return LIT_BYTE_STR_RAW; + } + yymore(); +} +(.|\n) { + if (!saw_non_hash) { + saw_non_hash = 1; + } + if (end_hashes != 0) { + end_hashes = 0; + } + yymore(); +} +<> { return -1; } + +b\x27 { BEGIN(byte); yymore(); } +\\[nrt\\\x27\x220]\x27 { BEGIN(INITIAL); return LIT_BYTE; } +\\x[0-9a-fA-F]{2}\x27 { BEGIN(INITIAL); return LIT_BYTE; } +\\u[0-9a-fA-F]{4}\x27 { BEGIN(INITIAL); return LIT_BYTE; } +\\U[0-9a-fA-F]{8}\x27 { BEGIN(INITIAL); return LIT_BYTE; } +.\x27 { BEGIN(INITIAL); return LIT_BYTE; } +<> { BEGIN(INITIAL); return -1; } + +r\x22 { BEGIN(rawstr); yymore(); } +\x22 { BEGIN(suffix); return LIT_STR_RAW; } +(.|\n) { yymore(); } +<> { return -1; } + +r/# { + BEGIN(rawstr_esc_begin); + yymore(); + num_hashes = 0; + saw_non_hash = 0; + end_hashes = 0; +} + +# { + num_hashes++; + yymore(); +} +\x22 { + BEGIN(rawstr_esc_body); + yymore(); +} +(.|\n) { return -1; } + +\x22/# { + BEGIN(rawstr_esc_end); + yymore(); + } +(.|\n) { + yymore(); + } + +# { + end_hashes++; + if (end_hashes == num_hashes) { + BEGIN(INITIAL); + return LIT_STR_RAW; + } + yymore(); + } +[^#] { + end_hashes = 0; + BEGIN(rawstr_esc_body); + yymore(); + } + +<> { return -1; } + +\x22 { BEGIN(str); yymore(); } +\x22 { BEGIN(suffix); return LIT_STR; } + +<> { return -1; } +\\[n\nr\rt\\\x27\x220] { yymore(); } +\\x[0-9a-fA-F]{2} { yymore(); } +\\u\{[0-9a-fA-F]?{6}\} { yymore(); } +\\[^n\nrt\\\x27\x220] { return -1; } +(.|\n) { yymore(); } + +\<- { return LARROW; } +-\> { return RARROW; } +- { return '-'; } +-= { return MINUSEQ; } +&& { return ANDAND; } +& { return '&'; } +&= { return ANDEQ; } +\|\| { return OROR; } +\| { return '|'; } +\|= { return OREQ; } +\+ { return '+'; } +\+= { return PLUSEQ; } +\* { return '*'; } +\*= { return STAREQ; } +\/ { return '/'; } +\/= { return SLASHEQ; } +\^ { return '^'; } +\^= { return CARETEQ; } +% { return '%'; } +%= { return PERCENTEQ; } + +<> { return 0; } + +%% diff --git a/src/grammar/parser-lalr-main.c b/src/grammar/parser-lalr-main.c new file mode 100644 index 00000000000..db88a1f2999 --- /dev/null +++ b/src/grammar/parser-lalr-main.c @@ -0,0 +1,203 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#include +#include +#include +#include + +extern int yylex(); +extern int rsparse(); + +#define PUSHBACK_LEN 4 + +static char pushback[PUSHBACK_LEN]; +static int verbose; + +void print(const char* format, ...) { + va_list args; + va_start(args, format); + if (verbose) { + vprintf(format, args); + } + va_end(args); +} + +// If there is a non-null char at the head of the pushback queue, +// dequeue it and shift the rest of the queue forwards. Otherwise, +// return the token from calling yylex. +int rslex() { + if (pushback[0] == '\0') { + return yylex(); + } else { + char c = pushback[0]; + memmove(pushback, pushback + 1, PUSHBACK_LEN - 1); + pushback[PUSHBACK_LEN - 1] = '\0'; + return c; + } +} + +// Note: this does nothing if the pushback queue is full. As long as +// there aren't more than PUSHBACK_LEN consecutive calls to push_back +// in an action, this shouldn't be a problem. +void push_back(char c) { + for (int i = 0; i < PUSHBACK_LEN; ++i) { + if (pushback[i] == '\0') { + pushback[i] = c; + break; + } + } +} + +extern int rsdebug; + +struct node { + struct node *next; + struct node *prev; + int own_string; + char const *name; + int n_elems; + struct node *elems[]; +}; + +struct node *nodes = NULL; +int n_nodes; + +struct node *mk_node(char const *name, int n, ...) { + va_list ap; + int i = 0; + unsigned sz = sizeof(struct node) + (n * sizeof(struct node *)); + struct node *nn, *nd = (struct node *)malloc(sz); + + print("# New %d-ary node: %s = %p\n", n, name, nd); + + nd->own_string = 0; + nd->prev = NULL; + nd->next = nodes; + if (nodes) { + nodes->prev = nd; + } + nodes = nd; + + nd->name = name; + nd->n_elems = n; + + va_start(ap, n); + while (i < n) { + nn = va_arg(ap, struct node *); + print("# arg[%d]: %p\n", i, nn); + print("# (%s ...)\n", nn->name); + nd->elems[i++] = nn; + } + va_end(ap); + n_nodes++; + return nd; +} + +struct node *mk_atom(char *name) { + struct node *nd = mk_node((char const *)strdup(name), 0); + nd->own_string = 1; + return nd; +} + +struct node *mk_none() { + return mk_atom(""); +} + +struct node *ext_node(struct node *nd, int n, ...) { + va_list ap; + int i = 0, c = nd->n_elems + n; + unsigned sz = sizeof(struct node) + (c * sizeof(struct node *)); + struct node *nn; + + print("# Extending %d-ary node by %d nodes: %s = %p", + nd->n_elems, c, nd->name, nd); + + if (nd->next) { + nd->next->prev = nd->prev; + } + if (nd->prev) { + nd->prev->next = nd->next; + } + nd = realloc(nd, sz); + nd->prev = NULL; + nd->next = nodes; + nodes->prev = nd; + nodes = nd; + + print(" ==> %p\n", nd); + + va_start(ap, n); + while (i < n) { + nn = va_arg(ap, struct node *); + print("# arg[%d]: %p\n", i, nn); + print("# (%s ...)\n", nn->name); + nd->elems[nd->n_elems++] = nn; + ++i; + } + va_end(ap); + return nd; +} + +int const indent_step = 4; + +void print_indent(int depth) { + while (depth) { + if (depth-- % indent_step == 0) { + print("|"); + } else { + print(" "); + } + } +} + +void print_node(struct node *n, int depth) { + int i = 0; + print_indent(depth); + if (n->n_elems == 0) { + print("%s\n", n->name); + } else { + print("(%s\n", n->name); + for (i = 0; i < n->n_elems; ++i) { + print_node(n->elems[i], depth + indent_step); + } + print_indent(depth); + print(")\n"); + } +} + +int main(int argc, char **argv) { + if (argc == 2 && strcmp(argv[1], "-v") == 0) { + verbose = 1; + } else { + verbose = 0; + } + int ret = 0; + struct node *tmp; + memset(pushback, '\0', PUSHBACK_LEN); + ret = rsparse(); + print("--- PARSE COMPLETE: ret:%d, n_nodes:%d ---\n", ret, n_nodes); + if (nodes) { + print_node(nodes, 0); + } + while (nodes) { + tmp = nodes; + nodes = tmp->next; + if (tmp->own_string) { + free((void*)tmp->name); + } + free(tmp); + } + return ret; +} + +void rserror(char const *s) { + fprintf(stderr, "%s\n", s); +} diff --git a/src/grammar/parser-lalr.y b/src/grammar/parser-lalr.y new file mode 100644 index 00000000000..c9fcdf7647b --- /dev/null +++ b/src/grammar/parser-lalr.y @@ -0,0 +1,1945 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +%{ +#define YYERROR_VERBOSE +#define YYSTYPE struct node * +struct node; +extern int yylex(); +extern void yyerror(char const *s); +extern struct node *mk_node(char const *name, int n, ...); +extern struct node *mk_atom(char *text); +extern struct node *mk_none(); +extern struct node *ext_node(struct node *nd, int n, ...); +extern void push_back(char c); +extern char *yytext; +%} +%debug + +%token SHL +%token SHR +%token LE +%token EQEQ +%token NE +%token GE +%token ANDAND +%token OROR +%token SHLEQ +%token SHREQ +%token MINUSEQ +%token ANDEQ +%token OREQ +%token PLUSEQ +%token STAREQ +%token SLASHEQ +%token CARETEQ +%token PERCENTEQ +%token DOTDOT +%token DOTDOTDOT +%token MOD_SEP +%token RARROW +%token LARROW +%token FAT_ARROW +%token LIT_BYTE +%token LIT_CHAR +%token LIT_INTEGER +%token LIT_FLOAT +%token LIT_STR +%token LIT_STR_RAW +%token LIT_BYTE_STR +%token LIT_BYTE_STR_RAW +%token IDENT +%token UNDERSCORE +%token LIFETIME + +// keywords +%token SELF +%token STATIC +%token AS +%token BREAK +%token CRATE +%token ELSE +%token ENUM +%token EXTERN +%token FALSE +%token FN +%token FOR +%token IF +%token IMPL +%token IN +%token LET +%token LOOP +%token MATCH +%token MOD +%token MOVE +%token MUT +%token PRIV +%token PUB +%token REF +%token RETURN +%token STRUCT +%token TRUE +%token TRAIT +%token TYPE +%token UNSAFE +%token DEFAULT +%token USE +%token WHILE +%token CONTINUE +%token PROC +%token BOX +%token CONST +%token WHERE +%token TYPEOF +%token INNER_DOC_COMMENT +%token OUTER_DOC_COMMENT + +%token SHEBANG +%token SHEBANG_LINE +%token STATIC_LIFETIME + + /* + Quoting from the Bison manual: + + "Finally, the resolution of conflicts works by comparing the precedence + of the rule being considered with that of the lookahead token. If the + token's precedence is higher, the choice is to shift. If the rule's + precedence is higher, the choice is to reduce. If they have equal + precedence, the choice is made based on the associativity of that + precedence level. The verbose output file made by ‘-v’ (see Invoking + Bison) says how each conflict was resolved" + */ + +// We expect no shift/reduce or reduce/reduce conflicts in this grammar; +// all potential ambiguities are scrutinized and eliminated manually. +%expect 0 + +// fake-precedence symbol to cause '|' bars in lambda context to parse +// at low precedence, permit things like |x| foo = bar, where '=' is +// otherwise lower-precedence than '|'. Also used for proc() to cause +// things like proc() a + b to parse as proc() { a + b }. +%precedence LAMBDA + +%precedence SELF + +// MUT should be lower precedence than IDENT so that in the pat rule, +// "& MUT pat" has higher precedence than "binding_mode ident [@ pat]" +%precedence MUT + +// IDENT needs to be lower than '{' so that 'foo {' is shifted when +// trying to decide if we've got a struct-construction expr (esp. in +// contexts like 'if foo { .') +// +// IDENT also needs to be lower precedence than '<' so that '<' in +// 'foo:bar . <' is shifted (in a trait reference occurring in a +// bounds list), parsing as foo:(bar) rather than (foo:bar). +%precedence IDENT + +// A couple fake-precedence symbols to use in rules associated with + +// and < in trailing type contexts. These come up when you have a type +// in the RHS of operator-AS, such as "foo as bar". The "<" there +// has to be shifted so the parser keeps trying to parse a type, even +// though it might well consider reducing the type "bar" and then +// going on to "<" as a subsequent binop. The "+" case is with +// trailing type-bounds ("foo as bar:A+B"), for the same reason. +%precedence SHIFTPLUS + +%precedence MOD_SEP +%precedence RARROW ':' + +// In where clauses, "for" should have greater precedence when used as +// a higher ranked constraint than when used as the beginning of a +// for_in_type (which is a ty) +%precedence FORTYPE +%precedence FOR + +// Binops & unops, and their precedences +%precedence BOX +%precedence BOXPLACE +%nonassoc DOTDOT + +// RETURN needs to be lower-precedence than tokens that start +// prefix_exprs +%precedence RETURN + +%right '=' SHLEQ SHREQ MINUSEQ ANDEQ OREQ PLUSEQ STAREQ SLASHEQ CARETEQ PERCENTEQ +%right LARROW +%left OROR +%left ANDAND +%left EQEQ NE +%left '<' '>' LE GE +%left '|' +%left '^' +%left '&' +%left SHL SHR +%left '+' '-' +%precedence AS +%left '*' '/' '%' +%precedence '!' + +%precedence '{' '[' '(' '.' + +%precedence RANGE + +%start crate + +%% + +//////////////////////////////////////////////////////////////////////// +// Part 1: Items and attributes +//////////////////////////////////////////////////////////////////////// + +crate +: maybe_shebang inner_attrs maybe_mod_items { mk_node("crate", 2, $2, $3); } +| maybe_shebang maybe_mod_items { mk_node("crate", 1, $2); } +; + +maybe_shebang +: SHEBANG_LINE +| %empty +; + +maybe_inner_attrs +: inner_attrs +| %empty { $$ = mk_none(); } +; + +inner_attrs +: inner_attr { $$ = mk_node("InnerAttrs", 1, $1); } +| inner_attrs inner_attr { $$ = ext_node($1, 1, $2); } +; + +inner_attr +: SHEBANG '[' meta_item ']' { $$ = mk_node("InnerAttr", 1, $3); } +| INNER_DOC_COMMENT { $$ = mk_node("InnerAttr", 1, mk_node("doc-comment", 1, mk_atom(yytext))); } +; + +maybe_outer_attrs +: outer_attrs +| %empty { $$ = mk_none(); } +; + +outer_attrs +: outer_attr { $$ = mk_node("OuterAttrs", 1, $1); } +| outer_attrs outer_attr { $$ = ext_node($1, 1, $2); } +; + +outer_attr +: '#' '[' meta_item ']' { $$ = $3; } +| OUTER_DOC_COMMENT { $$ = mk_node("doc-comment", 1, mk_atom(yytext)); } +; + +meta_item +: ident { $$ = mk_node("MetaWord", 1, $1); } +| ident '=' lit { $$ = mk_node("MetaNameValue", 2, $1, $3); } +| ident '(' meta_seq ')' { $$ = mk_node("MetaList", 2, $1, $3); } +| ident '(' meta_seq ',' ')' { $$ = mk_node("MetaList", 2, $1, $3); } +; + +meta_seq +: %empty { $$ = mk_none(); } +| meta_item { $$ = mk_node("MetaItems", 1, $1); } +| meta_seq ',' meta_item { $$ = ext_node($1, 1, $3); } +; + +maybe_mod_items +: mod_items +| %empty { $$ = mk_none(); } +; + +mod_items +: mod_item { $$ = mk_node("Items", 1, $1); } +| mod_items mod_item { $$ = ext_node($1, 1, $2); } +; + +attrs_and_vis +: maybe_outer_attrs visibility { $$ = mk_node("AttrsAndVis", 2, $1, $2); } +; + +mod_item +: attrs_and_vis item { $$ = mk_node("Item", 2, $1, $2); } +; + +// items that can appear outside of a fn block +item +: stmt_item +| item_macro +; + +// items that can appear in "stmts" +stmt_item +: item_static +| item_const +| item_type +| block_item +| view_item +; + +item_static +: STATIC ident ':' ty '=' expr ';' { $$ = mk_node("ItemStatic", 3, $2, $4, $6); } +| STATIC MUT ident ':' ty '=' expr ';' { $$ = mk_node("ItemStatic", 3, $3, $5, $7); } +; + +item_const +: CONST ident ':' ty '=' expr ';' { $$ = mk_node("ItemConst", 3, $2, $4, $6); } +; + +item_macro +: path_expr '!' maybe_ident parens_delimited_token_trees ';' { $$ = mk_node("ItemMacro", 3, $1, $3, $4); } +| path_expr '!' maybe_ident braces_delimited_token_trees { $$ = mk_node("ItemMacro", 3, $1, $3, $4); } +| path_expr '!' maybe_ident brackets_delimited_token_trees ';'{ $$ = mk_node("ItemMacro", 3, $1, $3, $4); } +; + +view_item +: use_item +| extern_fn_item +| EXTERN CRATE ident ';' { $$ = mk_node("ViewItemExternCrate", 1, $3); } +| EXTERN CRATE ident AS ident ';' { $$ = mk_node("ViewItemExternCrate", 2, $3, $5); } +; + +extern_fn_item +: EXTERN maybe_abi item_fn { $$ = mk_node("ViewItemExternFn", 2, $2, $3); } +; + +use_item +: USE view_path ';' { $$ = mk_node("ViewItemUse", 1, $2); } +; + +view_path +: path_no_types_allowed { $$ = mk_node("ViewPathSimple", 1, $1); } +| path_no_types_allowed MOD_SEP '{' '}' { $$ = mk_node("ViewPathList", 2, $1, mk_atom("ViewPathListEmpty")); } +| MOD_SEP '{' '}' { $$ = mk_node("ViewPathList", 1, mk_atom("ViewPathListEmpty")); } +| path_no_types_allowed MOD_SEP '{' idents_or_self '}' { $$ = mk_node("ViewPathList", 2, $1, $4); } +| MOD_SEP '{' idents_or_self '}' { $$ = mk_node("ViewPathList", 1, $3); } +| path_no_types_allowed MOD_SEP '{' idents_or_self ',' '}' { $$ = mk_node("ViewPathList", 2, $1, $4); } +| MOD_SEP '{' idents_or_self ',' '}' { $$ = mk_node("ViewPathList", 1, $3); } +| path_no_types_allowed MOD_SEP '*' { $$ = mk_node("ViewPathGlob", 1, $1); } +| '{' '}' { $$ = mk_atom("ViewPathListEmpty"); } +| '{' idents_or_self '}' { $$ = mk_node("ViewPathList", 1, $2); } +| '{' idents_or_self ',' '}' { $$ = mk_node("ViewPathList", 1, $2); } +| path_no_types_allowed AS ident { $$ = mk_node("ViewPathSimple", 2, $1, $3); } +; + +block_item +: item_fn +| item_unsafe_fn +| item_mod +| item_foreign_mod { $$ = mk_node("ItemForeignMod", 1, $1); } +| item_struct +| item_enum +| item_trait +| item_impl +; + +maybe_ty_ascription +: ':' ty_sum { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +maybe_init_expr +: '=' expr { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +// structs +item_struct +: STRUCT ident generic_params maybe_where_clause struct_decl_args +{ + $$ = mk_node("ItemStruct", 4, $2, $3, $4, $5); +} +| STRUCT ident generic_params struct_tuple_args maybe_where_clause ';' +{ + $$ = mk_node("ItemStruct", 4, $2, $3, $4, $5); +} +| STRUCT ident generic_params maybe_where_clause ';' +{ + $$ = mk_node("ItemStruct", 3, $2, $3, $4); +} +; + +struct_decl_args +: '{' struct_decl_fields '}' { $$ = $2; } +| '{' struct_decl_fields ',' '}' { $$ = $2; } +; + +struct_tuple_args +: '(' struct_tuple_fields ')' { $$ = $2; } +| '(' struct_tuple_fields ',' ')' { $$ = $2; } +; + +struct_decl_fields +: struct_decl_field { $$ = mk_node("StructFields", 1, $1); } +| struct_decl_fields ',' struct_decl_field { $$ = ext_node($1, 1, $3); } +| %empty { $$ = mk_none(); } +; + +struct_decl_field +: attrs_and_vis ident ':' ty_sum { $$ = mk_node("StructField", 3, $1, $2, $4); } +; + +struct_tuple_fields +: struct_tuple_field { $$ = mk_node("StructFields", 1, $1); } +| struct_tuple_fields ',' struct_tuple_field { $$ = ext_node($1, 1, $3); } +; + +struct_tuple_field +: attrs_and_vis ty_sum { $$ = mk_node("StructField", 2, $1, $2); } +; + +// enums +item_enum +: ENUM ident generic_params maybe_where_clause '{' enum_defs '}' { $$ = mk_node("ItemEnum", 0); } +| ENUM ident generic_params maybe_where_clause '{' enum_defs ',' '}' { $$ = mk_node("ItemEnum", 0); } +; + +enum_defs +: enum_def { $$ = mk_node("EnumDefs", 1, $1); } +| enum_defs ',' enum_def { $$ = ext_node($1, 1, $3); } +| %empty { $$ = mk_none(); } +; + +enum_def +: attrs_and_vis ident enum_args { $$ = mk_node("EnumDef", 3, $1, $2, $3); } +; + +enum_args +: '{' struct_decl_fields '}' { $$ = mk_node("EnumArgs", 1, $2); } +| '{' struct_decl_fields ',' '}' { $$ = mk_node("EnumArgs", 1, $2); } +| '(' maybe_ty_sums ')' { $$ = mk_node("EnumArgs", 1, $2); } +| '=' expr { $$ = mk_node("EnumArgs", 1, $2); } +| %empty { $$ = mk_none(); } +; + +item_mod +: MOD ident ';' { $$ = mk_node("ItemMod", 1, $2); } +| MOD ident '{' maybe_mod_items '}' { $$ = mk_node("ItemMod", 2, $2, $4); } +| MOD ident '{' inner_attrs maybe_mod_items '}' { $$ = mk_node("ItemMod", 3, $2, $4, $5); } +; + +item_foreign_mod +: EXTERN maybe_abi '{' maybe_foreign_items '}' { $$ = mk_node("ItemForeignMod", 1, $4); } +| EXTERN maybe_abi '{' inner_attrs maybe_foreign_items '}' { $$ = mk_node("ItemForeignMod", 2, $4, $5); } +; + +maybe_abi +: str +| %empty { $$ = mk_none(); } +; + +maybe_foreign_items +: foreign_items +| %empty { $$ = mk_none(); } +; + +foreign_items +: foreign_item { $$ = mk_node("ForeignItems", 1, $1); } +| foreign_items foreign_item { $$ = ext_node($1, 1, $2); } +; + +foreign_item +: attrs_and_vis STATIC item_foreign_static { $$ = mk_node("ForeignItem", 2, $1, $3); } +| attrs_and_vis item_foreign_fn { $$ = mk_node("ForeignItem", 2, $1, $2); } +| attrs_and_vis UNSAFE item_foreign_fn { $$ = mk_node("ForeignItem", 2, $1, $3); } +; + +item_foreign_static +: maybe_mut ident ':' ty ';' { $$ = mk_node("StaticItem", 3, $1, $2, $4); } +; + +item_foreign_fn +: FN ident generic_params fn_decl_allow_variadic maybe_where_clause ';' { $$ = mk_node("ForeignFn", 4, $2, $3, $4, $5); } +; + +fn_decl_allow_variadic +: fn_params_allow_variadic ret_ty { $$ = mk_node("FnDecl", 2, $1, $2); } +; + +fn_params_allow_variadic +: '(' ')' { $$ = mk_none(); } +| '(' params ')' { $$ = $2; } +| '(' params ',' ')' { $$ = $2; } +| '(' params ',' DOTDOTDOT ')' { $$ = $2; } +; + +visibility +: PUB { $$ = mk_atom("Public"); } +| %empty { $$ = mk_atom("Inherited"); } +; + +idents_or_self +: ident_or_self { $$ = mk_node("IdentsOrSelf", 1, $1); } +| ident_or_self AS ident { $$ = mk_node("IdentsOrSelf", 2, $1, $3); } +| idents_or_self ',' ident_or_self { $$ = ext_node($1, 1, $3); } +; + +ident_or_self +: ident +| SELF { $$ = mk_atom(yytext); } +; + +item_type +: TYPE ident generic_params maybe_where_clause '=' ty_sum ';' { $$ = mk_node("ItemTy", 4, $2, $3, $4, $6); } +; + +for_sized +: FOR '?' ident { $$ = mk_node("ForSized", 1, $3); } +| FOR ident '?' { $$ = mk_node("ForSized", 1, $2); } +| %empty { $$ = mk_none(); } +; + +item_trait +: maybe_unsafe TRAIT ident generic_params for_sized maybe_ty_param_bounds maybe_where_clause '{' maybe_trait_items '}' +{ + $$ = mk_node("ItemTrait", 7, $1, $3, $4, $5, $6, $7, $9); +} +; + +maybe_trait_items +: trait_items +| %empty { $$ = mk_none(); } +; + +trait_items +: trait_item { $$ = mk_node("TraitItems", 1, $1); } +| trait_items trait_item { $$ = ext_node($1, 1, $2); } +; + +trait_item +: trait_const +| trait_type +| trait_method +; + +trait_const +: maybe_outer_attrs CONST ident maybe_ty_ascription maybe_const_default ';' { $$ = mk_node("ConstTraitItem", 4, $1, $3, $4, $5); } +; + +maybe_const_default +: '=' expr { $$ = mk_node("ConstDefault", 1, $2); } +| %empty { $$ = mk_none(); } +; + +trait_type +: maybe_outer_attrs TYPE ty_param ';' { $$ = mk_node("TypeTraitItem", 2, $1, $3); } +; + +maybe_unsafe +: UNSAFE { $$ = mk_atom("Unsafe"); } +| %empty { $$ = mk_none(); } +; + +maybe_default_maybe_unsafe +: DEFAULT UNSAFE { $$ = mk_atom("DefaultUnsafe"); } +| DEFAULT { $$ = mk_atom("Default"); } +| UNSAFE { $$ = mk_atom("Unsafe"); } +| %empty { $$ = mk_none(); } + +trait_method +: type_method { $$ = mk_node("Required", 1, $1); } +| method { $$ = mk_node("Provided", 1, $1); } +; + +type_method +: attrs_and_vis maybe_unsafe FN ident generic_params fn_decl_with_self_allow_anon_params maybe_where_clause ';' +{ + $$ = mk_node("TypeMethod", 6, $1, $2, $4, $5, $6, $7); +} +| attrs_and_vis maybe_unsafe EXTERN maybe_abi FN ident generic_params fn_decl_with_self_allow_anon_params maybe_where_clause ';' +{ + $$ = mk_node("TypeMethod", 7, $1, $2, $4, $6, $7, $8, $9); +} +; + +method +: attrs_and_vis maybe_unsafe FN ident generic_params fn_decl_with_self_allow_anon_params maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("Method", 7, $1, $2, $4, $5, $6, $7, $8); +} +| attrs_and_vis maybe_unsafe EXTERN maybe_abi FN ident generic_params fn_decl_with_self_allow_anon_params maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("Method", 8, $1, $2, $4, $6, $7, $8, $9, $10); +} +; + +impl_method +: attrs_and_vis maybe_unsafe FN ident generic_params fn_decl_with_self maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("Method", 7, $1, $2, $4, $5, $6, $7, $8); +} +| attrs_and_vis maybe_unsafe EXTERN maybe_abi FN ident generic_params fn_decl_with_self maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("Method", 8, $1, $2, $4, $6, $7, $8, $9, $10); +} +; + +// There are two forms of impl: +// +// impl (<...>)? TY { ... } +// impl (<...>)? TRAIT for TY { ... } +// +// Unfortunately since TY can begin with '<' itself -- as part of a +// TyQualifiedPath type -- there's an s/r conflict when we see '<' after IMPL: +// should we reduce one of the early rules of TY (such as maybe_once) +// or shall we continue shifting into the generic_params list for the +// impl? +// +// The production parser disambiguates a different case here by +// permitting / requiring the user to provide parens around types when +// they are ambiguous with traits. We do the same here, regrettably, +// by splitting ty into ty and ty_prim. +item_impl +: maybe_default_maybe_unsafe IMPL generic_params ty_prim_sum maybe_where_clause '{' maybe_inner_attrs maybe_impl_items '}' +{ + $$ = mk_node("ItemImpl", 6, $1, $3, $4, $5, $7, $8); +} +| maybe_default_maybe_unsafe IMPL generic_params '(' ty ')' maybe_where_clause '{' maybe_inner_attrs maybe_impl_items '}' +{ + $$ = mk_node("ItemImpl", 6, $1, $3, 5, $6, $9, $10); +} +| maybe_default_maybe_unsafe IMPL generic_params trait_ref FOR ty_sum maybe_where_clause '{' maybe_inner_attrs maybe_impl_items '}' +{ + $$ = mk_node("ItemImpl", 6, $3, $4, $6, $7, $9, $10); +} +| maybe_default_maybe_unsafe IMPL generic_params '!' trait_ref FOR ty_sum maybe_where_clause '{' maybe_inner_attrs maybe_impl_items '}' +{ + $$ = mk_node("ItemImplNeg", 7, $1, $3, $5, $7, $8, $10, $11); +} +| maybe_default_maybe_unsafe IMPL generic_params trait_ref FOR DOTDOT '{' '}' +{ + $$ = mk_node("ItemImplDefault", 3, $1, $3, $4); +} +| maybe_default_maybe_unsafe IMPL generic_params '!' trait_ref FOR DOTDOT '{' '}' +{ + $$ = mk_node("ItemImplDefaultNeg", 3, $1, $3, $4); +} +; + +maybe_impl_items +: impl_items +| %empty { $$ = mk_none(); } +; + +impl_items +: impl_item { $$ = mk_node("ImplItems", 1, $1); } +| impl_item impl_items { $$ = ext_node($1, 1, $2); } +; + +impl_item +: impl_method +| attrs_and_vis item_macro { $$ = mk_node("ImplMacroItem", 2, $1, $2); } +| impl_const +| impl_type +; + +impl_const +: attrs_and_vis item_const { $$ = mk_node("ImplConst", 1, $1, $2); } +; + +impl_type +: attrs_and_vis TYPE ident generic_params '=' ty_sum ';' { $$ = mk_node("ImplType", 4, $1, $3, $4, $6); } +; + +item_fn +: FN ident generic_params fn_decl maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("ItemFn", 5, $2, $3, $4, $5, $6); +} +; + +item_unsafe_fn +: UNSAFE FN ident generic_params fn_decl maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("ItemUnsafeFn", 5, $3, $4, $5, $6, $7); +} +| UNSAFE EXTERN maybe_abi FN ident generic_params fn_decl maybe_where_clause inner_attrs_and_block +{ + $$ = mk_node("ItemUnsafeFn", 6, $3, $5, $6, $7, $8, $9); +} +; + +fn_decl +: fn_params ret_ty { $$ = mk_node("FnDecl", 2, $1, $2); } +; + +fn_decl_with_self +: fn_params_with_self ret_ty { $$ = mk_node("FnDecl", 2, $1, $2); } +; + +fn_decl_with_self_allow_anon_params +: fn_anon_params_with_self ret_ty { $$ = mk_node("FnDecl", 2, $1, $2); } +; + +fn_params +: '(' maybe_params ')' { $$ = $2; } +; + +fn_anon_params +: '(' anon_param anon_params_allow_variadic_tail ')' { $$ = ext_node($2, 1, $3); } +| '(' ')' { $$ = mk_none(); } +; + +fn_params_with_self +: '(' maybe_mut SELF maybe_ty_ascription maybe_comma_params ')' { $$ = mk_node("SelfValue", 3, $2, $4, $5); } +| '(' '&' maybe_mut SELF maybe_ty_ascription maybe_comma_params ')' { $$ = mk_node("SelfRegion", 3, $3, $5, $6); } +| '(' '&' lifetime maybe_mut SELF maybe_ty_ascription maybe_comma_params ')' { $$ = mk_node("SelfRegion", 4, $3, $4, $6, $7); } +| '(' maybe_params ')' { $$ = mk_node("SelfStatic", 1, $2); } +; + +fn_anon_params_with_self +: '(' maybe_mut SELF maybe_ty_ascription maybe_comma_anon_params ')' { $$ = mk_node("SelfValue", 3, $2, $4, $5); } +| '(' '&' maybe_mut SELF maybe_ty_ascription maybe_comma_anon_params ')' { $$ = mk_node("SelfRegion", 3, $3, $5, $6); } +| '(' '&' lifetime maybe_mut SELF maybe_ty_ascription maybe_comma_anon_params ')' { $$ = mk_node("SelfRegion", 4, $3, $4, $6, $7); } +| '(' maybe_anon_params ')' { $$ = mk_node("SelfStatic", 1, $2); } +; + +maybe_params +: params +| params ',' +| %empty { $$ = mk_none(); } +; + +params +: param { $$ = mk_node("Args", 1, $1); } +| params ',' param { $$ = ext_node($1, 1, $3); } +; + +param +: pat ':' ty_sum { $$ = mk_node("Arg", 2, $1, $3); } +; + +inferrable_params +: inferrable_param { $$ = mk_node("InferrableParams", 1, $1); } +| inferrable_params ',' inferrable_param { $$ = ext_node($1, 1, $3); } +; + +inferrable_param +: pat maybe_ty_ascription { $$ = mk_node("InferrableParam", 2, $1, $2); } +; + +maybe_unboxed_closure_kind +: %empty +| ':' +| '&' maybe_mut ':' +; + +maybe_comma_params +: ',' { $$ = mk_none(); } +| ',' params { $$ = $2; } +| ',' params ',' { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +maybe_comma_anon_params +: ',' { $$ = mk_none(); } +| ',' anon_params { $$ = $2; } +| ',' anon_params ',' { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +maybe_anon_params +: anon_params +| anon_params ',' +| %empty { $$ = mk_none(); } +; + +anon_params +: anon_param { $$ = mk_node("Args", 1, $1); } +| anon_params ',' anon_param { $$ = ext_node($1, 1, $3); } +; + +// anon means it's allowed to be anonymous (type-only), but it can +// still have a name +anon_param +: named_arg ':' ty { $$ = mk_node("Arg", 2, $1, $3); } +| ty +; + +anon_params_allow_variadic_tail +: ',' DOTDOTDOT { $$ = mk_none(); } +| ',' anon_param anon_params_allow_variadic_tail { $$ = mk_node("Args", 2, $2, $3); } +| %empty { $$ = mk_none(); } +; + +named_arg +: ident +| UNDERSCORE { $$ = mk_atom("PatWild"); } +| '&' ident { $$ = $2; } +| '&' UNDERSCORE { $$ = mk_atom("PatWild"); } +| ANDAND ident { $$ = $2; } +| ANDAND UNDERSCORE { $$ = mk_atom("PatWild"); } +| MUT ident { $$ = $2; } +; + +ret_ty +: RARROW '!' { $$ = mk_none(); } +| RARROW ty { $$ = mk_node("ret-ty", 1, $2); } +| %prec IDENT %empty { $$ = mk_none(); } +; + +generic_params +: '<' lifetimes '>' { $$ = mk_node("Generics", 2, $2, mk_none()); } +| '<' lifetimes ',' '>' { $$ = mk_node("Generics", 2, $2, mk_none()); } +| '<' lifetimes SHR { push_back('>'); $$ = mk_node("Generics", 2, $2, mk_none()); } +| '<' lifetimes ',' SHR { push_back('>'); $$ = mk_node("Generics", 2, $2, mk_none()); } +| '<' lifetimes ',' ty_params '>' { $$ = mk_node("Generics", 2, $2, $4); } +| '<' lifetimes ',' ty_params ',' '>' { $$ = mk_node("Generics", 2, $2, $4); } +| '<' lifetimes ',' ty_params SHR { push_back('>'); $$ = mk_node("Generics", 2, $2, $4); } +| '<' lifetimes ',' ty_params ',' SHR { push_back('>'); $$ = mk_node("Generics", 2, $2, $4); } +| '<' ty_params '>' { $$ = mk_node("Generics", 2, mk_none(), $2); } +| '<' ty_params ',' '>' { $$ = mk_node("Generics", 2, mk_none(), $2); } +| '<' ty_params SHR { push_back('>'); $$ = mk_node("Generics", 2, mk_none(), $2); } +| '<' ty_params ',' SHR { push_back('>'); $$ = mk_node("Generics", 2, mk_none(), $2); } +| %empty { $$ = mk_none(); } +; + +maybe_where_clause +: %empty { $$ = mk_none(); } +| where_clause +; + +where_clause +: WHERE where_predicates { $$ = mk_node("WhereClause", 1, $2); } +| WHERE where_predicates ',' { $$ = mk_node("WhereClause", 1, $2); } +; + +where_predicates +: where_predicate { $$ = mk_node("WherePredicates", 1, $1); } +| where_predicates ',' where_predicate { $$ = ext_node($1, 1, $3); } +; + +where_predicate +: maybe_for_lifetimes lifetime ':' bounds { $$ = mk_node("WherePredicate", 3, $1, $2, $4); } +| maybe_for_lifetimes ty ':' ty_param_bounds { $$ = mk_node("WherePredicate", 3, $1, $2, $4); } +; + +maybe_for_lifetimes +: FOR '<' lifetimes '>' { $$ = mk_none(); } +| %prec FORTYPE %empty { $$ = mk_none(); } + +ty_params +: ty_param { $$ = mk_node("TyParams", 1, $1); } +| ty_params ',' ty_param { $$ = ext_node($1, 1, $3); } +; + +// A path with no type parameters; e.g. `foo::bar::Baz` +// +// These show up in 'use' view-items, because these are processed +// without respect to types. +path_no_types_allowed +: ident { $$ = mk_node("ViewPath", 1, $1); } +| MOD_SEP ident { $$ = mk_node("ViewPath", 1, $2); } +| SELF { $$ = mk_node("ViewPath", 1, mk_atom("Self")); } +| MOD_SEP SELF { $$ = mk_node("ViewPath", 1, mk_atom("Self")); } +| path_no_types_allowed MOD_SEP ident { $$ = ext_node($1, 1, $3); } +; + +// A path with a lifetime and type parameters, with no double colons +// before the type parameters; e.g. `foo::bar<'a>::Baz` +// +// These show up in "trait references", the components of +// type-parameter bounds lists, as well as in the prefix of the +// path_generic_args_and_bounds rule, which is the full form of a +// named typed expression. +// +// They do not have (nor need) an extra '::' before '<' because +// unlike in expr context, there are no "less-than" type exprs to +// be ambiguous with. +path_generic_args_without_colons +: %prec IDENT + ident { $$ = mk_node("components", 1, $1); } +| %prec IDENT + ident generic_args { $$ = mk_node("components", 2, $1, $2); } +| %prec IDENT + ident '(' maybe_ty_sums ')' ret_ty { $$ = mk_node("components", 2, $1, $3); } +| %prec IDENT + path_generic_args_without_colons MOD_SEP ident { $$ = ext_node($1, 1, $3); } +| %prec IDENT + path_generic_args_without_colons MOD_SEP ident generic_args { $$ = ext_node($1, 2, $3, $4); } +| %prec IDENT + path_generic_args_without_colons MOD_SEP ident '(' maybe_ty_sums ')' ret_ty { $$ = ext_node($1, 2, $3, $5); } +; + +generic_args +: '<' generic_values '>' { $$ = $2; } +| '<' generic_values SHR { push_back('>'); $$ = $2; } +| '<' generic_values GE { push_back('='); $$ = $2; } +| '<' generic_values SHREQ { push_back('>'); push_back('='); $$ = $2; } +// If generic_args starts with "<<", the first arg must be a +// TyQualifiedPath because that's the only type that can start with a +// '<'. This rule parses that as the first ty_sum and then continues +// with the rest of generic_values. +| SHL ty_qualified_path_and_generic_values '>' { $$ = $2; } +| SHL ty_qualified_path_and_generic_values SHR { push_back('>'); $$ = $2; } +| SHL ty_qualified_path_and_generic_values GE { push_back('='); $$ = $2; } +| SHL ty_qualified_path_and_generic_values SHREQ { push_back('>'); push_back('='); $$ = $2; } +; + +generic_values +: maybe_lifetimes maybe_ty_sums_and_or_bindings { $$ = mk_node("GenericValues", 2, $1, $2); } +; + +maybe_ty_sums_and_or_bindings +: ty_sums +| ty_sums ',' +| ty_sums ',' bindings { $$ = mk_node("TySumsAndBindings", 2, $1, $3); } +| bindings +| bindings ',' +| %empty { $$ = mk_none(); } +; + +maybe_bindings +: ',' bindings { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +//////////////////////////////////////////////////////////////////////// +// Part 2: Patterns +//////////////////////////////////////////////////////////////////////// + +pat +: UNDERSCORE { $$ = mk_atom("PatWild"); } +| '&' pat { $$ = mk_node("PatRegion", 1, $2); } +| '&' MUT pat { $$ = mk_node("PatRegion", 1, $3); } +| ANDAND pat { $$ = mk_node("PatRegion", 1, mk_node("PatRegion", 1, $2)); } +| '(' ')' { $$ = mk_atom("PatUnit"); } +| '(' pat_tup ')' { $$ = mk_node("PatTup", 1, $2); } +| '(' pat_tup ',' ')' { $$ = mk_node("PatTup", 1, $2); } +| '[' pat_vec ']' { $$ = mk_node("PatVec", 1, $2); } +| lit_or_path +| lit_or_path DOTDOTDOT lit_or_path { $$ = mk_node("PatRange", 2, $1, $3); } +| path_expr '{' pat_struct '}' { $$ = mk_node("PatStruct", 2, $1, $3); } +| path_expr '(' DOTDOT ')' { $$ = mk_node("PatEnum", 1, $1); } +| path_expr '(' pat_tup ')' { $$ = mk_node("PatEnum", 2, $1, $3); } +| path_expr '!' maybe_ident delimited_token_trees { $$ = mk_node("PatMac", 3, $1, $3, $4); } +| binding_mode ident { $$ = mk_node("PatIdent", 2, $1, $2); } +| ident '@' pat { $$ = mk_node("PatIdent", 3, mk_node("BindByValue", 1, mk_atom("MutImmutable")), $1, $3); } +| binding_mode ident '@' pat { $$ = mk_node("PatIdent", 3, $1, $2, $4); } +| BOX pat { $$ = mk_node("PatUniq", 1, $2); } +| '<' ty_sum maybe_as_trait_ref '>' MOD_SEP ident { $$ = mk_node("PatQualifiedPath", 3, $2, $3, $6); } +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident maybe_as_trait_ref '>' MOD_SEP ident +{ + $$ = mk_node("PatQualifiedPath", 3, mk_node("PatQualifiedPath", 3, $2, $3, $6), $7, $10); +} +; + +pats_or +: pat { $$ = mk_node("Pats", 1, $1); } +| pats_or '|' pat { $$ = ext_node($1, 1, $3); } +; + +binding_mode +: REF { $$ = mk_node("BindByRef", 1, mk_atom("MutImmutable")); } +| REF MUT { $$ = mk_node("BindByRef", 1, mk_atom("MutMutable")); } +| MUT { $$ = mk_node("BindByValue", 1, mk_atom("MutMutable")); } +; + +lit_or_path +: path_expr { $$ = mk_node("PatLit", 1, $1); } +| lit { $$ = mk_node("PatLit", 1, $1); } +| '-' lit { $$ = mk_node("PatLit", 1, $2); } +; + +pat_field +: ident { $$ = mk_node("PatField", 1, $1); } +| binding_mode ident { $$ = mk_node("PatField", 2, $1, $2); } +| BOX ident { $$ = mk_node("PatField", 2, mk_atom("box"), $2); } +| BOX binding_mode ident { $$ = mk_node("PatField", 3, mk_atom("box"), $2, $3); } +| ident ':' pat { $$ = mk_node("PatField", 2, $1, $3); } +| binding_mode ident ':' pat { $$ = mk_node("PatField", 3, $1, $2, $4); } +; + +pat_fields +: pat_field { $$ = mk_node("PatFields", 1, $1); } +| pat_fields ',' pat_field { $$ = ext_node($1, 1, $3); } +; + +pat_struct +: pat_fields { $$ = mk_node("PatStruct", 2, $1, mk_atom("false")); } +| pat_fields ',' { $$ = mk_node("PatStruct", 2, $1, mk_atom("false")); } +| pat_fields ',' DOTDOT { $$ = mk_node("PatStruct", 2, $1, mk_atom("true")); } +| DOTDOT { $$ = mk_node("PatStruct", 1, mk_atom("true")); } +; + +pat_tup +: pat { $$ = mk_node("pat_tup", 1, $1); } +| pat_tup ',' pat { $$ = ext_node($1, 1, $3); } +; + +pat_vec +: pat_vec_elts { $$ = mk_node("PatVec", 2, $1, mk_none()); } +| pat_vec_elts ',' { $$ = mk_node("PatVec", 2, $1, mk_none()); } +| pat_vec_elts DOTDOT { $$ = mk_node("PatVec", 2, $1, mk_none()); } +| pat_vec_elts ',' DOTDOT { $$ = mk_node("PatVec", 2, $1, mk_none()); } +| pat_vec_elts DOTDOT ',' pat_vec_elts { $$ = mk_node("PatVec", 2, $1, $4); } +| pat_vec_elts DOTDOT ',' pat_vec_elts ',' { $$ = mk_node("PatVec", 2, $1, $4); } +| pat_vec_elts ',' DOTDOT ',' pat_vec_elts { $$ = mk_node("PatVec", 2, $1, $5); } +| pat_vec_elts ',' DOTDOT ',' pat_vec_elts ',' { $$ = mk_node("PatVec", 2, $1, $5); } +| DOTDOT ',' pat_vec_elts { $$ = mk_node("PatVec", 2, mk_none(), $3); } +| DOTDOT ',' pat_vec_elts ',' { $$ = mk_node("PatVec", 2, mk_none(), $3); } +| DOTDOT { $$ = mk_node("PatVec", 2, mk_none(), mk_none()); } +| %empty { $$ = mk_node("PatVec", 2, mk_none(), mk_none()); } +; + +pat_vec_elts +: pat { $$ = mk_node("PatVecElts", 1, $1); } +| pat_vec_elts ',' pat { $$ = ext_node($1, 1, $3); } +; + +//////////////////////////////////////////////////////////////////////// +// Part 3: Types +//////////////////////////////////////////////////////////////////////// + +ty +: ty_prim +| ty_closure +| '<' ty_sum maybe_as_trait_ref '>' MOD_SEP ident { $$ = mk_node("TyQualifiedPath", 3, $2, $3, $6); } +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident maybe_as_trait_ref '>' MOD_SEP ident { $$ = mk_node("TyQualifiedPath", 3, mk_node("TyQualifiedPath", 3, $2, $3, $6), $7, $10); } +| '(' ty_sums ')' { $$ = mk_node("TyTup", 1, $2); } +| '(' ty_sums ',' ')' { $$ = mk_node("TyTup", 1, $2); } +| '(' ')' { $$ = mk_atom("TyNil"); } +; + +ty_prim +: %prec IDENT path_generic_args_without_colons { $$ = mk_node("TyPath", 2, mk_node("global", 1, mk_atom("false")), $1); } +| %prec IDENT MOD_SEP path_generic_args_without_colons { $$ = mk_node("TyPath", 2, mk_node("global", 1, mk_atom("true")), $2); } +| %prec IDENT SELF MOD_SEP path_generic_args_without_colons { $$ = mk_node("TyPath", 2, mk_node("self", 1, mk_atom("true")), $3); } +| BOX ty { $$ = mk_node("TyBox", 1, $2); } +| '*' maybe_mut_or_const ty { $$ = mk_node("TyPtr", 2, $2, $3); } +| '&' ty { $$ = mk_node("TyRptr", 2, mk_atom("MutImmutable"), $2); } +| '&' MUT ty { $$ = mk_node("TyRptr", 2, mk_atom("MutMutable"), $3); } +| ANDAND ty { $$ = mk_node("TyRptr", 1, mk_node("TyRptr", 2, mk_atom("MutImmutable"), $2)); } +| ANDAND MUT ty { $$ = mk_node("TyRptr", 1, mk_node("TyRptr", 2, mk_atom("MutMutable"), $3)); } +| '&' lifetime maybe_mut ty { $$ = mk_node("TyRptr", 3, $2, $3, $4); } +| ANDAND lifetime maybe_mut ty { $$ = mk_node("TyRptr", 1, mk_node("TyRptr", 3, $2, $3, $4)); } +| '[' ty ']' { $$ = mk_node("TyVec", 1, $2); } +| '[' ty ',' DOTDOT expr ']' { $$ = mk_node("TyFixedLengthVec", 2, $2, $5); } +| '[' ty ';' expr ']' { $$ = mk_node("TyFixedLengthVec", 2, $2, $4); } +| TYPEOF '(' expr ')' { $$ = mk_node("TyTypeof", 1, $3); } +| UNDERSCORE { $$ = mk_atom("TyInfer"); } +| ty_bare_fn +| ty_proc +| for_in_type +; + +ty_bare_fn +: FN ty_fn_decl { $$ = $2; } +| UNSAFE FN ty_fn_decl { $$ = $3; } +| EXTERN maybe_abi FN ty_fn_decl { $$ = $4; } +| UNSAFE EXTERN maybe_abi FN ty_fn_decl { $$ = $5; } +; + +ty_fn_decl +: generic_params fn_anon_params ret_ty { $$ = mk_node("TyFnDecl", 3, $1, $2, $3); } +; + +ty_closure +: UNSAFE '|' anon_params '|' maybe_bounds ret_ty { $$ = mk_node("TyClosure", 3, $3, $5, $6); } +| '|' anon_params '|' maybe_bounds ret_ty { $$ = mk_node("TyClosure", 3, $2, $4, $5); } +| UNSAFE OROR maybe_bounds ret_ty { $$ = mk_node("TyClosure", 2, $3, $4); } +| OROR maybe_bounds ret_ty { $$ = mk_node("TyClosure", 2, $2, $3); } +; + +ty_proc +: PROC generic_params fn_params maybe_bounds ret_ty { $$ = mk_node("TyProc", 4, $2, $3, $4, $5); } +; + +for_in_type +: FOR '<' maybe_lifetimes '>' for_in_type_suffix { $$ = mk_node("ForInType", 2, $3, $5); } +; + +for_in_type_suffix +: ty_proc +| ty_bare_fn +| trait_ref +| ty_closure +; + +maybe_mut +: MUT { $$ = mk_atom("MutMutable"); } +| %prec MUT %empty { $$ = mk_atom("MutImmutable"); } +; + +maybe_mut_or_const +: MUT { $$ = mk_atom("MutMutable"); } +| CONST { $$ = mk_atom("MutImmutable"); } +| %empty { $$ = mk_atom("MutImmutable"); } +; + +ty_qualified_path_and_generic_values +: ty_qualified_path maybe_bindings +{ + $$ = mk_node("GenericValues", 3, mk_none(), mk_node("TySums", 1, mk_node("TySum", 1, $1)), $2); +} +| ty_qualified_path ',' ty_sums maybe_bindings +{ + $$ = mk_node("GenericValues", 3, mk_none(), mk_node("TySums", 2, $1, $3), $4); +} +; + +ty_qualified_path +: ty_sum AS trait_ref '>' MOD_SEP ident { $$ = mk_node("TyQualifiedPath", 3, $1, $3, $6); } +| ty_sum AS trait_ref '>' MOD_SEP ident '+' ty_param_bounds { $$ = mk_node("TyQualifiedPath", 3, $1, $3, $6); } +; + +maybe_ty_sums +: ty_sums +| ty_sums ',' +| %empty { $$ = mk_none(); } +; + +ty_sums +: ty_sum { $$ = mk_node("TySums", 1, $1); } +| ty_sums ',' ty_sum { $$ = ext_node($1, 1, $3); } +; + +ty_sum +: ty { $$ = mk_node("TySum", 1, $1); } +| ty '+' ty_param_bounds { $$ = mk_node("TySum", 2, $1, $3); } +; + +ty_prim_sum +: ty_prim { $$ = mk_node("TySum", 1, $1); } +| ty_prim '+' ty_param_bounds { $$ = mk_node("TySum", 2, $1, $3); } +; + +maybe_ty_param_bounds +: ':' ty_param_bounds { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +ty_param_bounds +: boundseq +| %empty { $$ = mk_none(); } +; + +boundseq +: polybound +| boundseq '+' polybound { $$ = ext_node($1, 1, $3); } +; + +polybound +: FOR '<' maybe_lifetimes '>' bound { $$ = mk_node("PolyBound", 2, $3, $5); } +| bound +| '?' bound { $$ = $2; } +; + +bindings +: binding { $$ = mk_node("Bindings", 1, $1); } +| bindings ',' binding { $$ = ext_node($1, 1, $3); } +; + +binding +: ident '=' ty { mk_node("Binding", 2, $1, $3); } +; + +ty_param +: ident maybe_ty_param_bounds maybe_ty_default { $$ = mk_node("TyParam", 3, $1, $2, $3); } +| ident '?' ident maybe_ty_param_bounds maybe_ty_default { $$ = mk_node("TyParam", 4, $1, $3, $4, $5); } +; + +maybe_bounds +: %prec SHIFTPLUS + ':' bounds { $$ = $2; } +| %prec SHIFTPLUS %empty { $$ = mk_none(); } +; + +bounds +: bound { $$ = mk_node("bounds", 1, $1); } +| bounds '+' bound { $$ = ext_node($1, 1, $3); } +; + +bound +: lifetime +| trait_ref +; + +maybe_ltbounds +: %prec SHIFTPLUS + ':' ltbounds { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +ltbounds +: lifetime { $$ = mk_node("ltbounds", 1, $1); } +| ltbounds '+' lifetime { $$ = ext_node($1, 1, $3); } +; + +maybe_ty_default +: '=' ty_sum { $$ = mk_node("TyDefault", 1, $2); } +| %empty { $$ = mk_none(); } +; + +maybe_lifetimes +: lifetimes +| lifetimes ',' +| %empty { $$ = mk_none(); } +; + +lifetimes +: lifetime_and_bounds { $$ = mk_node("Lifetimes", 1, $1); } +| lifetimes ',' lifetime_and_bounds { $$ = ext_node($1, 1, $3); } +; + +lifetime_and_bounds +: LIFETIME maybe_ltbounds { $$ = mk_node("lifetime", 2, mk_atom(yytext), $2); } +| STATIC_LIFETIME { $$ = mk_atom("static_lifetime"); } +; + +lifetime +: LIFETIME { $$ = mk_node("lifetime", 1, mk_atom(yytext)); } +| STATIC_LIFETIME { $$ = mk_atom("static_lifetime"); } +; + +trait_ref +: %prec IDENT path_generic_args_without_colons +| %prec IDENT MOD_SEP path_generic_args_without_colons { $$ = $2; } +; + +//////////////////////////////////////////////////////////////////////// +// Part 4: Blocks, statements, and expressions +//////////////////////////////////////////////////////////////////////// + +inner_attrs_and_block +: '{' maybe_inner_attrs maybe_stmts '}' { $$ = mk_node("ExprBlock", 2, $2, $3); } +; + +block +: '{' maybe_stmts '}' { $$ = mk_node("ExprBlock", 1, $2); } +; + +maybe_stmts +: stmts +| stmts nonblock_expr { $$ = ext_node($1, 1, $2); } +| nonblock_expr +| %empty { $$ = mk_none(); } +; + +// There are two sub-grammars within a "stmts: exprs" derivation +// depending on whether each stmt-expr is a block-expr form; this is to +// handle the "semicolon rule" for stmt sequencing that permits +// writing +// +// if foo { bar } 10 +// +// as a sequence of two stmts (one if-expr stmt, one lit-10-expr +// stmt). Unfortunately by permitting juxtaposition of exprs in +// sequence like that, the non-block expr grammar has to have a +// second limited sub-grammar that excludes the prefix exprs that +// are ambiguous with binops. That is to say: +// +// {10} - 1 +// +// should parse as (progn (progn 10) (- 1)) not (- (progn 10) 1), that +// is to say, two statements rather than one, at least according to +// the mainline rust parser. +// +// So we wind up with a 3-way split in exprs that occur in stmt lists: +// block, nonblock-prefix, and nonblock-nonprefix. +// +// In non-stmts contexts, expr can relax this trichotomy. +// +// There is also one other expr subtype: nonparen_expr disallows exprs +// surrounded by parens (including tuple expressions), this is +// necessary for BOX (place) expressions, so a parens expr following +// the BOX is always parsed as the place. + +stmts +: stmt { $$ = mk_node("stmts", 1, $1); } +| stmts stmt { $$ = ext_node($1, 1, $2); } +; + +stmt +: let +| stmt_item +| PUB stmt_item { $$ = $2; } +| outer_attrs stmt_item { $$ = $2; } +| outer_attrs PUB stmt_item { $$ = $3; } +| full_block_expr +| block +| nonblock_expr ';' +| ';' { $$ = mk_none(); } +; + +maybe_exprs +: exprs +| exprs ',' +| %empty { $$ = mk_none(); } +; + +maybe_expr +: expr +| %empty { $$ = mk_none(); } +; + +exprs +: expr { $$ = mk_node("exprs", 1, $1); } +| exprs ',' expr { $$ = ext_node($1, 1, $3); } +; + +path_expr +: path_generic_args_with_colons +| MOD_SEP path_generic_args_with_colons { $$ = $2; } +| SELF MOD_SEP path_generic_args_with_colons { $$ = mk_node("SelfPath", 1, $3); } +; + +// A path with a lifetime and type parameters with double colons before +// the type parameters; e.g. `foo::bar::<'a>::Baz::` +// +// These show up in expr context, in order to disambiguate from "less-than" +// expressions. +path_generic_args_with_colons +: ident { $$ = mk_node("components", 1, $1); } +| path_generic_args_with_colons MOD_SEP ident { $$ = ext_node($1, 1, $3); } +| path_generic_args_with_colons MOD_SEP generic_args { $$ = ext_node($1, 1, $3); } +; + +// the braces-delimited macro is a block_expr so it doesn't appear here +macro_expr +: path_expr '!' maybe_ident parens_delimited_token_trees { $$ = mk_node("MacroExpr", 3, $1, $3, $4); } +| path_expr '!' maybe_ident brackets_delimited_token_trees { $$ = mk_node("MacroExpr", 3, $1, $3, $4); } +; + +nonblock_expr +: lit { $$ = mk_node("ExprLit", 1, $1); } +| %prec IDENT + path_expr { $$ = mk_node("ExprPath", 1, $1); } +| SELF { $$ = mk_node("ExprPath", 1, mk_node("ident", 1, mk_atom("self"))); } +| macro_expr { $$ = mk_node("ExprMac", 1, $1); } +| path_expr '{' struct_expr_fields '}' { $$ = mk_node("ExprStruct", 2, $1, $3); } +| nonblock_expr '.' path_generic_args_with_colons { $$ = mk_node("ExprField", 2, $1, $3); } +| nonblock_expr '.' LIT_INTEGER { $$ = mk_node("ExprTupleIndex", 1, $1); } +| nonblock_expr '[' maybe_expr ']' { $$ = mk_node("ExprIndex", 2, $1, $3); } +| nonblock_expr '(' maybe_exprs ')' { $$ = mk_node("ExprCall", 2, $1, $3); } +| '[' vec_expr ']' { $$ = mk_node("ExprVec", 1, $2); } +| '(' maybe_exprs ')' { $$ = mk_node("ExprParen", 1, $2); } +| CONTINUE { $$ = mk_node("ExprAgain", 0); } +| CONTINUE lifetime { $$ = mk_node("ExprAgain", 1, $2); } +| RETURN { $$ = mk_node("ExprRet", 0); } +| RETURN expr { $$ = mk_node("ExprRet", 1, $2); } +| BREAK { $$ = mk_node("ExprBreak", 0); } +| BREAK lifetime { $$ = mk_node("ExprBreak", 1, $2); } +| nonblock_expr LARROW expr { $$ = mk_node("ExprInPlace", 2, $1, $3); } +| nonblock_expr '=' expr { $$ = mk_node("ExprAssign", 2, $1, $3); } +| nonblock_expr SHLEQ expr { $$ = mk_node("ExprAssignShl", 2, $1, $3); } +| nonblock_expr SHREQ expr { $$ = mk_node("ExprAssignShr", 2, $1, $3); } +| nonblock_expr MINUSEQ expr { $$ = mk_node("ExprAssignSub", 2, $1, $3); } +| nonblock_expr ANDEQ expr { $$ = mk_node("ExprAssignBitAnd", 2, $1, $3); } +| nonblock_expr OREQ expr { $$ = mk_node("ExprAssignBitOr", 2, $1, $3); } +| nonblock_expr PLUSEQ expr { $$ = mk_node("ExprAssignAdd", 2, $1, $3); } +| nonblock_expr STAREQ expr { $$ = mk_node("ExprAssignMul", 2, $1, $3); } +| nonblock_expr SLASHEQ expr { $$ = mk_node("ExprAssignDiv", 2, $1, $3); } +| nonblock_expr CARETEQ expr { $$ = mk_node("ExprAssignBitXor", 2, $1, $3); } +| nonblock_expr PERCENTEQ expr { $$ = mk_node("ExprAssignRem", 2, $1, $3); } +| nonblock_expr OROR expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiOr"), $1, $3); } +| nonblock_expr ANDAND expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAnd"), $1, $3); } +| nonblock_expr EQEQ expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiEq"), $1, $3); } +| nonblock_expr NE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiNe"), $1, $3); } +| nonblock_expr '<' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLt"), $1, $3); } +| nonblock_expr '>' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGt"), $1, $3); } +| nonblock_expr LE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLe"), $1, $3); } +| nonblock_expr GE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGe"), $1, $3); } +| nonblock_expr '|' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitOr"), $1, $3); } +| nonblock_expr '^' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitXor"), $1, $3); } +| nonblock_expr '&' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitAnd"), $1, $3); } +| nonblock_expr SHL expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShl"), $1, $3); } +| nonblock_expr SHR expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShr"), $1, $3); } +| nonblock_expr '+' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAdd"), $1, $3); } +| nonblock_expr '-' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiSub"), $1, $3); } +| nonblock_expr '*' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiMul"), $1, $3); } +| nonblock_expr '/' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiDiv"), $1, $3); } +| nonblock_expr '%' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiRem"), $1, $3); } +| nonblock_expr DOTDOT { $$ = mk_node("ExprRange", 2, $1, mk_none()); } +| nonblock_expr DOTDOT expr { $$ = mk_node("ExprRange", 2, $1, $3); } +| DOTDOT expr { $$ = mk_node("ExprRange", 2, mk_none(), $2); } +| DOTDOT { $$ = mk_node("ExprRange", 2, mk_none(), mk_none()); } +| nonblock_expr AS ty { $$ = mk_node("ExprCast", 2, $1, $3); } +| BOX nonparen_expr { $$ = mk_node("ExprBox", 1, $2); } +| %prec BOXPLACE BOX '(' maybe_expr ')' nonblock_expr { $$ = mk_node("ExprBox", 2, $3, $5); } +| expr_qualified_path +| nonblock_prefix_expr +; + +expr +: lit { $$ = mk_node("ExprLit", 1, $1); } +| %prec IDENT + path_expr { $$ = mk_node("ExprPath", 1, $1); } +| SELF { $$ = mk_node("ExprPath", 1, mk_node("ident", 1, mk_atom("self"))); } +| macro_expr { $$ = mk_node("ExprMac", 1, $1); } +| path_expr '{' struct_expr_fields '}' { $$ = mk_node("ExprStruct", 2, $1, $3); } +| expr '.' path_generic_args_with_colons { $$ = mk_node("ExprField", 2, $1, $3); } +| expr '.' LIT_INTEGER { $$ = mk_node("ExprTupleIndex", 1, $1); } +| expr '[' maybe_expr ']' { $$ = mk_node("ExprIndex", 2, $1, $3); } +| expr '(' maybe_exprs ')' { $$ = mk_node("ExprCall", 2, $1, $3); } +| '(' maybe_exprs ')' { $$ = mk_node("ExprParen", 1, $2); } +| '[' vec_expr ']' { $$ = mk_node("ExprVec", 1, $2); } +| CONTINUE { $$ = mk_node("ExprAgain", 0); } +| CONTINUE ident { $$ = mk_node("ExprAgain", 1, $2); } +| RETURN { $$ = mk_node("ExprRet", 0); } +| RETURN expr { $$ = mk_node("ExprRet", 1, $2); } +| BREAK { $$ = mk_node("ExprBreak", 0); } +| BREAK ident { $$ = mk_node("ExprBreak", 1, $2); } +| expr LARROW expr { $$ = mk_node("ExprInPlace", 2, $1, $3); } +| expr '=' expr { $$ = mk_node("ExprAssign", 2, $1, $3); } +| expr SHLEQ expr { $$ = mk_node("ExprAssignShl", 2, $1, $3); } +| expr SHREQ expr { $$ = mk_node("ExprAssignShr", 2, $1, $3); } +| expr MINUSEQ expr { $$ = mk_node("ExprAssignSub", 2, $1, $3); } +| expr ANDEQ expr { $$ = mk_node("ExprAssignBitAnd", 2, $1, $3); } +| expr OREQ expr { $$ = mk_node("ExprAssignBitOr", 2, $1, $3); } +| expr PLUSEQ expr { $$ = mk_node("ExprAssignAdd", 2, $1, $3); } +| expr STAREQ expr { $$ = mk_node("ExprAssignMul", 2, $1, $3); } +| expr SLASHEQ expr { $$ = mk_node("ExprAssignDiv", 2, $1, $3); } +| expr CARETEQ expr { $$ = mk_node("ExprAssignBitXor", 2, $1, $3); } +| expr PERCENTEQ expr { $$ = mk_node("ExprAssignRem", 2, $1, $3); } +| expr OROR expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiOr"), $1, $3); } +| expr ANDAND expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAnd"), $1, $3); } +| expr EQEQ expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiEq"), $1, $3); } +| expr NE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiNe"), $1, $3); } +| expr '<' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLt"), $1, $3); } +| expr '>' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGt"), $1, $3); } +| expr LE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLe"), $1, $3); } +| expr GE expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGe"), $1, $3); } +| expr '|' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitOr"), $1, $3); } +| expr '^' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitXor"), $1, $3); } +| expr '&' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitAnd"), $1, $3); } +| expr SHL expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShl"), $1, $3); } +| expr SHR expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShr"), $1, $3); } +| expr '+' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAdd"), $1, $3); } +| expr '-' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiSub"), $1, $3); } +| expr '*' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiMul"), $1, $3); } +| expr '/' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiDiv"), $1, $3); } +| expr '%' expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiRem"), $1, $3); } +| expr DOTDOT { $$ = mk_node("ExprRange", 2, $1, mk_none()); } +| expr DOTDOT expr { $$ = mk_node("ExprRange", 2, $1, $3); } +| DOTDOT expr { $$ = mk_node("ExprRange", 2, mk_none(), $2); } +| DOTDOT { $$ = mk_node("ExprRange", 2, mk_none(), mk_none()); } +| expr AS ty { $$ = mk_node("ExprCast", 2, $1, $3); } +| BOX nonparen_expr { $$ = mk_node("ExprBox", 1, $2); } +| %prec BOXPLACE BOX '(' maybe_expr ')' expr { $$ = mk_node("ExprBox", 2, $3, $5); } +| expr_qualified_path +| block_expr +| block +| nonblock_prefix_expr +; + +nonparen_expr +: lit { $$ = mk_node("ExprLit", 1, $1); } +| %prec IDENT + path_expr { $$ = mk_node("ExprPath", 1, $1); } +| SELF { $$ = mk_node("ExprPath", 1, mk_node("ident", 1, mk_atom("self"))); } +| macro_expr { $$ = mk_node("ExprMac", 1, $1); } +| path_expr '{' struct_expr_fields '}' { $$ = mk_node("ExprStruct", 2, $1, $3); } +| nonparen_expr '.' path_generic_args_with_colons { $$ = mk_node("ExprField", 2, $1, $3); } +| nonparen_expr '.' LIT_INTEGER { $$ = mk_node("ExprTupleIndex", 1, $1); } +| nonparen_expr '[' maybe_expr ']' { $$ = mk_node("ExprIndex", 2, $1, $3); } +| nonparen_expr '(' maybe_exprs ')' { $$ = mk_node("ExprCall", 2, $1, $3); } +| '[' vec_expr ']' { $$ = mk_node("ExprVec", 1, $2); } +| CONTINUE { $$ = mk_node("ExprAgain", 0); } +| CONTINUE ident { $$ = mk_node("ExprAgain", 1, $2); } +| RETURN { $$ = mk_node("ExprRet", 0); } +| RETURN expr { $$ = mk_node("ExprRet", 1, $2); } +| BREAK { $$ = mk_node("ExprBreak", 0); } +| BREAK ident { $$ = mk_node("ExprBreak", 1, $2); } +| nonparen_expr LARROW nonparen_expr { $$ = mk_node("ExprInPlace", 2, $1, $3); } +| nonparen_expr '=' nonparen_expr { $$ = mk_node("ExprAssign", 2, $1, $3); } +| nonparen_expr SHLEQ nonparen_expr { $$ = mk_node("ExprAssignShl", 2, $1, $3); } +| nonparen_expr SHREQ nonparen_expr { $$ = mk_node("ExprAssignShr", 2, $1, $3); } +| nonparen_expr MINUSEQ nonparen_expr { $$ = mk_node("ExprAssignSub", 2, $1, $3); } +| nonparen_expr ANDEQ nonparen_expr { $$ = mk_node("ExprAssignBitAnd", 2, $1, $3); } +| nonparen_expr OREQ nonparen_expr { $$ = mk_node("ExprAssignBitOr", 2, $1, $3); } +| nonparen_expr PLUSEQ nonparen_expr { $$ = mk_node("ExprAssignAdd", 2, $1, $3); } +| nonparen_expr STAREQ nonparen_expr { $$ = mk_node("ExprAssignMul", 2, $1, $3); } +| nonparen_expr SLASHEQ nonparen_expr { $$ = mk_node("ExprAssignDiv", 2, $1, $3); } +| nonparen_expr CARETEQ nonparen_expr { $$ = mk_node("ExprAssignBitXor", 2, $1, $3); } +| nonparen_expr PERCENTEQ nonparen_expr { $$ = mk_node("ExprAssignRem", 2, $1, $3); } +| nonparen_expr OROR nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiOr"), $1, $3); } +| nonparen_expr ANDAND nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAnd"), $1, $3); } +| nonparen_expr EQEQ nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiEq"), $1, $3); } +| nonparen_expr NE nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiNe"), $1, $3); } +| nonparen_expr '<' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLt"), $1, $3); } +| nonparen_expr '>' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGt"), $1, $3); } +| nonparen_expr LE nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiLe"), $1, $3); } +| nonparen_expr GE nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiGe"), $1, $3); } +| nonparen_expr '|' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitOr"), $1, $3); } +| nonparen_expr '^' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitXor"), $1, $3); } +| nonparen_expr '&' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitAnd"), $1, $3); } +| nonparen_expr SHL nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShl"), $1, $3); } +| nonparen_expr SHR nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiShr"), $1, $3); } +| nonparen_expr '+' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiAdd"), $1, $3); } +| nonparen_expr '-' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiSub"), $1, $3); } +| nonparen_expr '*' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiMul"), $1, $3); } +| nonparen_expr '/' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiDiv"), $1, $3); } +| nonparen_expr '%' nonparen_expr { $$ = mk_node("ExprBinary", 3, mk_atom("BiRem"), $1, $3); } +| nonparen_expr DOTDOT { $$ = mk_node("ExprRange", 2, $1, mk_none()); } +| nonparen_expr DOTDOT nonparen_expr { $$ = mk_node("ExprRange", 2, $1, $3); } +| DOTDOT nonparen_expr { $$ = mk_node("ExprRange", 2, mk_none(), $2); } +| DOTDOT { $$ = mk_node("ExprRange", 2, mk_none(), mk_none()); } +| nonparen_expr AS ty { $$ = mk_node("ExprCast", 2, $1, $3); } +| BOX nonparen_expr { $$ = mk_node("ExprBox", 1, $2); } +| %prec BOXPLACE BOX '(' maybe_expr ')' expr { $$ = mk_node("ExprBox", 1, $3, $5); } +| expr_qualified_path +| block_expr +| block +| nonblock_prefix_expr +; + +expr_nostruct +: lit { $$ = mk_node("ExprLit", 1, $1); } +| %prec IDENT + path_expr { $$ = mk_node("ExprPath", 1, $1); } +| SELF { $$ = mk_node("ExprPath", 1, mk_node("ident", 1, mk_atom("self"))); } +| macro_expr { $$ = mk_node("ExprMac", 1, $1); } +| expr_nostruct '.' path_generic_args_with_colons { $$ = mk_node("ExprField", 2, $1, $3); } +| expr_nostruct '.' LIT_INTEGER { $$ = mk_node("ExprTupleIndex", 1, $1); } +| expr_nostruct '[' maybe_expr ']' { $$ = mk_node("ExprIndex", 2, $1, $3); } +| expr_nostruct '(' maybe_exprs ')' { $$ = mk_node("ExprCall", 2, $1, $3); } +| '[' vec_expr ']' { $$ = mk_node("ExprVec", 1, $2); } +| '(' maybe_exprs ')' { $$ = mk_node("ExprParen", 1, $2); } +| CONTINUE { $$ = mk_node("ExprAgain", 0); } +| CONTINUE ident { $$ = mk_node("ExprAgain", 1, $2); } +| RETURN { $$ = mk_node("ExprRet", 0); } +| RETURN expr { $$ = mk_node("ExprRet", 1, $2); } +| BREAK { $$ = mk_node("ExprBreak", 0); } +| BREAK ident { $$ = mk_node("ExprBreak", 1, $2); } +| expr_nostruct LARROW expr_nostruct { $$ = mk_node("ExprInPlace", 2, $1, $3); } +| expr_nostruct '=' expr_nostruct { $$ = mk_node("ExprAssign", 2, $1, $3); } +| expr_nostruct SHLEQ expr_nostruct { $$ = mk_node("ExprAssignShl", 2, $1, $3); } +| expr_nostruct SHREQ expr_nostruct { $$ = mk_node("ExprAssignShr", 2, $1, $3); } +| expr_nostruct MINUSEQ expr_nostruct { $$ = mk_node("ExprAssignSub", 2, $1, $3); } +| expr_nostruct ANDEQ expr_nostruct { $$ = mk_node("ExprAssignBitAnd", 2, $1, $3); } +| expr_nostruct OREQ expr_nostruct { $$ = mk_node("ExprAssignBitOr", 2, $1, $3); } +| expr_nostruct PLUSEQ expr_nostruct { $$ = mk_node("ExprAssignAdd", 2, $1, $3); } +| expr_nostruct STAREQ expr_nostruct { $$ = mk_node("ExprAssignMul", 2, $1, $3); } +| expr_nostruct SLASHEQ expr_nostruct { $$ = mk_node("ExprAssignDiv", 2, $1, $3); } +| expr_nostruct CARETEQ expr_nostruct { $$ = mk_node("ExprAssignBitXor", 2, $1, $3); } +| expr_nostruct PERCENTEQ expr_nostruct { $$ = mk_node("ExprAssignRem", 2, $1, $3); } +| expr_nostruct OROR expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiOr"), $1, $3); } +| expr_nostruct ANDAND expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiAnd"), $1, $3); } +| expr_nostruct EQEQ expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiEq"), $1, $3); } +| expr_nostruct NE expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiNe"), $1, $3); } +| expr_nostruct '<' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiLt"), $1, $3); } +| expr_nostruct '>' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiGt"), $1, $3); } +| expr_nostruct LE expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiLe"), $1, $3); } +| expr_nostruct GE expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiGe"), $1, $3); } +| expr_nostruct '|' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitOr"), $1, $3); } +| expr_nostruct '^' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitXor"), $1, $3); } +| expr_nostruct '&' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiBitAnd"), $1, $3); } +| expr_nostruct SHL expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiShl"), $1, $3); } +| expr_nostruct SHR expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiShr"), $1, $3); } +| expr_nostruct '+' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiAdd"), $1, $3); } +| expr_nostruct '-' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiSub"), $1, $3); } +| expr_nostruct '*' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiMul"), $1, $3); } +| expr_nostruct '/' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiDiv"), $1, $3); } +| expr_nostruct '%' expr_nostruct { $$ = mk_node("ExprBinary", 3, mk_atom("BiRem"), $1, $3); } +| expr_nostruct DOTDOT %prec RANGE { $$ = mk_node("ExprRange", 2, $1, mk_none()); } +| expr_nostruct DOTDOT expr_nostruct { $$ = mk_node("ExprRange", 2, $1, $3); } +| DOTDOT expr_nostruct { $$ = mk_node("ExprRange", 2, mk_none(), $2); } +| DOTDOT { $$ = mk_node("ExprRange", 2, mk_none(), mk_none()); } +| expr_nostruct AS ty { $$ = mk_node("ExprCast", 2, $1, $3); } +| BOX nonparen_expr { $$ = mk_node("ExprBox", 1, $2); } +| %prec BOXPLACE BOX '(' maybe_expr ')' expr_nostruct { $$ = mk_node("ExprBox", 1, $3, $5); } +| expr_qualified_path +| block_expr +| block +| nonblock_prefix_expr_nostruct +; + +nonblock_prefix_expr_nostruct +: '-' expr_nostruct { $$ = mk_node("ExprUnary", 2, mk_atom("UnNeg"), $2); } +| '!' expr_nostruct { $$ = mk_node("ExprUnary", 2, mk_atom("UnNot"), $2); } +| '*' expr_nostruct { $$ = mk_node("ExprUnary", 2, mk_atom("UnDeref"), $2); } +| '&' maybe_mut expr_nostruct { $$ = mk_node("ExprAddrOf", 2, $2, $3); } +| ANDAND maybe_mut expr_nostruct { $$ = mk_node("ExprAddrOf", 1, mk_node("ExprAddrOf", 2, $2, $3)); } +| lambda_expr_nostruct +| MOVE lambda_expr_nostruct { $$ = $2; } +| proc_expr_nostruct +; + +nonblock_prefix_expr +: '-' expr { $$ = mk_node("ExprUnary", 2, mk_atom("UnNeg"), $2); } +| '!' expr { $$ = mk_node("ExprUnary", 2, mk_atom("UnNot"), $2); } +| '*' expr { $$ = mk_node("ExprUnary", 2, mk_atom("UnDeref"), $2); } +| '&' maybe_mut expr { $$ = mk_node("ExprAddrOf", 2, $2, $3); } +| ANDAND maybe_mut expr { $$ = mk_node("ExprAddrOf", 1, mk_node("ExprAddrOf", 2, $2, $3)); } +| lambda_expr +| MOVE lambda_expr { $$ = $2; } +| proc_expr +; + +expr_qualified_path +: '<' ty_sum maybe_as_trait_ref '>' MOD_SEP ident maybe_qpath_params +{ + $$ = mk_node("ExprQualifiedPath", 4, $2, $3, $6, $7); +} +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident maybe_as_trait_ref '>' MOD_SEP ident +{ + $$ = mk_node("ExprQualifiedPath", 3, mk_node("ExprQualifiedPath", 3, $2, $3, $6), $7, $10); +} +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident generic_args maybe_as_trait_ref '>' MOD_SEP ident +{ + $$ = mk_node("ExprQualifiedPath", 3, mk_node("ExprQualifiedPath", 4, $2, $3, $6, $7), $8, $11); +} +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident maybe_as_trait_ref '>' MOD_SEP ident generic_args +{ + $$ = mk_node("ExprQualifiedPath", 4, mk_node("ExprQualifiedPath", 3, $2, $3, $6), $7, $10, $11); +} +| SHL ty_sum maybe_as_trait_ref '>' MOD_SEP ident generic_args maybe_as_trait_ref '>' MOD_SEP ident generic_args +{ + $$ = mk_node("ExprQualifiedPath", 4, mk_node("ExprQualifiedPath", 4, $2, $3, $6, $7), $8, $11, $12); +} + +maybe_qpath_params +: MOD_SEP generic_args { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +maybe_as_trait_ref +: AS trait_ref { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +lambda_expr +: %prec LAMBDA + OROR ret_ty expr { $$ = mk_node("ExprFnBlock", 3, mk_none(), $2, $3); } +| %prec LAMBDA + '|' maybe_unboxed_closure_kind '|' ret_ty expr { $$ = mk_node("ExprFnBlock", 3, mk_none(), $4, $5); } +| %prec LAMBDA + '|' inferrable_params '|' ret_ty expr { $$ = mk_node("ExprFnBlock", 3, $2, $4, $5); } +| %prec LAMBDA + '|' '&' maybe_mut ':' inferrable_params '|' ret_ty expr { $$ = mk_node("ExprFnBlock", 3, $5, $7, $8); } +| %prec LAMBDA + '|' ':' inferrable_params '|' ret_ty expr { $$ = mk_node("ExprFnBlock", 3, $3, $5, $6); } +; + +lambda_expr_nostruct +: %prec LAMBDA + OROR expr_nostruct { $$ = mk_node("ExprFnBlock", 2, mk_none(), $2); } +| %prec LAMBDA + '|' maybe_unboxed_closure_kind '|' expr_nostruct { $$ = mk_node("ExprFnBlock", 2, mk_none(), $4); } +| %prec LAMBDA + '|' inferrable_params '|' expr_nostruct { $$ = mk_node("ExprFnBlock", 2, $2, $4); } +| %prec LAMBDA + '|' '&' maybe_mut ':' inferrable_params '|' expr_nostruct { $$ = mk_node("ExprFnBlock", 2, $5, $7); } +| %prec LAMBDA + '|' ':' inferrable_params '|' expr_nostruct { $$ = mk_node("ExprFnBlock", 2, $3, $5); } + +; + +proc_expr +: %prec LAMBDA + PROC '(' ')' expr { $$ = mk_node("ExprProc", 2, mk_none(), $4); } +| %prec LAMBDA + PROC '(' inferrable_params ')' expr { $$ = mk_node("ExprProc", 2, $3, $5); } +; + +proc_expr_nostruct +: %prec LAMBDA + PROC '(' ')' expr_nostruct { $$ = mk_node("ExprProc", 2, mk_none(), $4); } +| %prec LAMBDA + PROC '(' inferrable_params ')' expr_nostruct { $$ = mk_node("ExprProc", 2, $3, $5); } +; + +vec_expr +: maybe_exprs +| exprs ';' expr { $$ = mk_node("VecRepeat", 2, $1, $3); } +; + +struct_expr_fields +: field_inits +| field_inits ',' +| maybe_field_inits default_field_init { $$ = ext_node($1, 1, $2); } +; + +maybe_field_inits +: field_inits +| field_inits ',' +| %empty { $$ = mk_none(); } +; + +field_inits +: field_init { $$ = mk_node("FieldInits", 1, $1); } +| field_inits ',' field_init { $$ = ext_node($1, 1, $3); } +; + +field_init +: ident ':' expr { $$ = mk_node("FieldInit", 2, $1, $3); } +; + +default_field_init +: DOTDOT expr { $$ = mk_node("DefaultFieldInit", 1, $2); } +; + +block_expr +: expr_match +| expr_if +| expr_if_let +| expr_while +| expr_while_let +| expr_loop +| expr_for +| UNSAFE block { $$ = mk_node("UnsafeBlock", 1, $2); } +| path_expr '!' maybe_ident braces_delimited_token_trees { $$ = mk_node("Macro", 3, $1, $3, $4); } +; + +full_block_expr +: block_expr +| full_block_expr '.' path_generic_args_with_colons %prec IDENT { $$ = mk_node("ExprField", 2, $1, $3); } +| full_block_expr '.' path_generic_args_with_colons '[' maybe_expr ']' { $$ = mk_node("ExprIndex", 3, $1, $3, $5); } +| full_block_expr '.' path_generic_args_with_colons '(' maybe_exprs ')' { $$ = mk_node("ExprCall", 3, $1, $3, $5); } +| full_block_expr '.' LIT_INTEGER { $$ = mk_node("ExprTupleIndex", 1, $1); } +; + +expr_match +: MATCH expr_nostruct '{' '}' { $$ = mk_node("ExprMatch", 1, $2); } +| MATCH expr_nostruct '{' match_clauses '}' { $$ = mk_node("ExprMatch", 2, $2, $4); } +| MATCH expr_nostruct '{' match_clauses nonblock_match_clause '}' { $$ = mk_node("ExprMatch", 2, $2, ext_node($4, 1, $5)); } +| MATCH expr_nostruct '{' nonblock_match_clause '}' { $$ = mk_node("ExprMatch", 2, $2, mk_node("Arms", 1, $4)); } +; + +match_clauses +: match_clause { $$ = mk_node("Arms", 1, $1); } +| match_clauses match_clause { $$ = ext_node($1, 1, $2); } +; + +match_clause +: nonblock_match_clause ',' +| block_match_clause +| block_match_clause ',' +; + +nonblock_match_clause +: maybe_outer_attrs pats_or maybe_guard FAT_ARROW nonblock_expr { $$ = mk_node("Arm", 4, $1, $2, $3, $5); } +| maybe_outer_attrs pats_or maybe_guard FAT_ARROW full_block_expr { $$ = mk_node("Arm", 4, $1, $2, $3, $5); } +; + +block_match_clause +: maybe_outer_attrs pats_or maybe_guard FAT_ARROW block { $$ = mk_node("Arm", 4, $1, $2, $3, $5); } +; + +maybe_guard +: IF expr_nostruct { $$ = $2; } +| %empty { $$ = mk_none(); } +; + +expr_if +: IF expr_nostruct block { $$ = mk_node("ExprIf", 2, $2, $3); } +| IF expr_nostruct block ELSE block_or_if { $$ = mk_node("ExprIf", 3, $2, $3, $5); } +; + +expr_if_let +: IF LET pat '=' expr_nostruct block { $$ = mk_node("ExprIfLet", 3, $3, $5, $6); } +| IF LET pat '=' expr_nostruct block ELSE block_or_if { $$ = mk_node("ExprIfLet", 4, $3, $5, $6, $8); } +; + +block_or_if +: block +| expr_if +| expr_if_let +; + +expr_while +: maybe_label WHILE expr_nostruct block { $$ = mk_node("ExprWhile", 3, $1, $3, $4); } +; + +expr_while_let +: maybe_label WHILE LET pat '=' expr_nostruct block { $$ = mk_node("ExprWhileLet", 4, $1, $4, $6, $7); } +; + +expr_loop +: maybe_label LOOP block { $$ = mk_node("ExprLoop", 2, $1, $3); } +; + +expr_for +: maybe_label FOR pat IN expr_nostruct block { $$ = mk_node("ExprForLoop", 4, $1, $3, $5, $6); } +; + +maybe_label +: lifetime ':' +| %empty { $$ = mk_none(); } +; + +let +: LET pat maybe_ty_ascription maybe_init_expr ';' { $$ = mk_node("DeclLocal", 3, $2, $3, $4); } +; + +//////////////////////////////////////////////////////////////////////// +// Part 5: Macros and misc. rules +//////////////////////////////////////////////////////////////////////// + +lit +: LIT_BYTE { $$ = mk_node("LitByte", 1, mk_atom(yytext)); } +| LIT_CHAR { $$ = mk_node("LitChar", 1, mk_atom(yytext)); } +| LIT_INTEGER { $$ = mk_node("LitInteger", 1, mk_atom(yytext)); } +| LIT_FLOAT { $$ = mk_node("LitFloat", 1, mk_atom(yytext)); } +| TRUE { $$ = mk_node("LitBool", 1, mk_atom(yytext)); } +| FALSE { $$ = mk_node("LitBool", 1, mk_atom(yytext)); } +| str +; + +str +: LIT_STR { $$ = mk_node("LitStr", 1, mk_atom(yytext), mk_atom("CookedStr")); } +| LIT_STR_RAW { $$ = mk_node("LitStr", 1, mk_atom(yytext), mk_atom("RawStr")); } +| LIT_BYTE_STR { $$ = mk_node("LitByteStr", 1, mk_atom(yytext), mk_atom("ByteStr")); } +| LIT_BYTE_STR_RAW { $$ = mk_node("LitByteStr", 1, mk_atom(yytext), mk_atom("RawByteStr")); } +; + +maybe_ident +: %empty { $$ = mk_none(); } +| ident +; + +ident +: IDENT { $$ = mk_node("ident", 1, mk_atom(yytext)); } +; + +unpaired_token +: SHL { $$ = mk_atom(yytext); } +| SHR { $$ = mk_atom(yytext); } +| LE { $$ = mk_atom(yytext); } +| EQEQ { $$ = mk_atom(yytext); } +| NE { $$ = mk_atom(yytext); } +| GE { $$ = mk_atom(yytext); } +| ANDAND { $$ = mk_atom(yytext); } +| OROR { $$ = mk_atom(yytext); } +| LARROW { $$ = mk_atom(yytext); } +| SHLEQ { $$ = mk_atom(yytext); } +| SHREQ { $$ = mk_atom(yytext); } +| MINUSEQ { $$ = mk_atom(yytext); } +| ANDEQ { $$ = mk_atom(yytext); } +| OREQ { $$ = mk_atom(yytext); } +| PLUSEQ { $$ = mk_atom(yytext); } +| STAREQ { $$ = mk_atom(yytext); } +| SLASHEQ { $$ = mk_atom(yytext); } +| CARETEQ { $$ = mk_atom(yytext); } +| PERCENTEQ { $$ = mk_atom(yytext); } +| DOTDOT { $$ = mk_atom(yytext); } +| DOTDOTDOT { $$ = mk_atom(yytext); } +| MOD_SEP { $$ = mk_atom(yytext); } +| RARROW { $$ = mk_atom(yytext); } +| FAT_ARROW { $$ = mk_atom(yytext); } +| LIT_BYTE { $$ = mk_atom(yytext); } +| LIT_CHAR { $$ = mk_atom(yytext); } +| LIT_INTEGER { $$ = mk_atom(yytext); } +| LIT_FLOAT { $$ = mk_atom(yytext); } +| LIT_STR { $$ = mk_atom(yytext); } +| LIT_STR_RAW { $$ = mk_atom(yytext); } +| LIT_BYTE_STR { $$ = mk_atom(yytext); } +| LIT_BYTE_STR_RAW { $$ = mk_atom(yytext); } +| IDENT { $$ = mk_atom(yytext); } +| UNDERSCORE { $$ = mk_atom(yytext); } +| LIFETIME { $$ = mk_atom(yytext); } +| SELF { $$ = mk_atom(yytext); } +| STATIC { $$ = mk_atom(yytext); } +| AS { $$ = mk_atom(yytext); } +| BREAK { $$ = mk_atom(yytext); } +| CRATE { $$ = mk_atom(yytext); } +| ELSE { $$ = mk_atom(yytext); } +| ENUM { $$ = mk_atom(yytext); } +| EXTERN { $$ = mk_atom(yytext); } +| FALSE { $$ = mk_atom(yytext); } +| FN { $$ = mk_atom(yytext); } +| FOR { $$ = mk_atom(yytext); } +| IF { $$ = mk_atom(yytext); } +| IMPL { $$ = mk_atom(yytext); } +| IN { $$ = mk_atom(yytext); } +| LET { $$ = mk_atom(yytext); } +| LOOP { $$ = mk_atom(yytext); } +| MATCH { $$ = mk_atom(yytext); } +| MOD { $$ = mk_atom(yytext); } +| MOVE { $$ = mk_atom(yytext); } +| MUT { $$ = mk_atom(yytext); } +| PRIV { $$ = mk_atom(yytext); } +| PUB { $$ = mk_atom(yytext); } +| REF { $$ = mk_atom(yytext); } +| RETURN { $$ = mk_atom(yytext); } +| STRUCT { $$ = mk_atom(yytext); } +| TRUE { $$ = mk_atom(yytext); } +| TRAIT { $$ = mk_atom(yytext); } +| TYPE { $$ = mk_atom(yytext); } +| UNSAFE { $$ = mk_atom(yytext); } +| USE { $$ = mk_atom(yytext); } +| WHILE { $$ = mk_atom(yytext); } +| CONTINUE { $$ = mk_atom(yytext); } +| PROC { $$ = mk_atom(yytext); } +| BOX { $$ = mk_atom(yytext); } +| CONST { $$ = mk_atom(yytext); } +| WHERE { $$ = mk_atom(yytext); } +| TYPEOF { $$ = mk_atom(yytext); } +| INNER_DOC_COMMENT { $$ = mk_atom(yytext); } +| OUTER_DOC_COMMENT { $$ = mk_atom(yytext); } +| SHEBANG { $$ = mk_atom(yytext); } +| STATIC_LIFETIME { $$ = mk_atom(yytext); } +| ';' { $$ = mk_atom(yytext); } +| ',' { $$ = mk_atom(yytext); } +| '.' { $$ = mk_atom(yytext); } +| '@' { $$ = mk_atom(yytext); } +| '#' { $$ = mk_atom(yytext); } +| '~' { $$ = mk_atom(yytext); } +| ':' { $$ = mk_atom(yytext); } +| '$' { $$ = mk_atom(yytext); } +| '=' { $$ = mk_atom(yytext); } +| '?' { $$ = mk_atom(yytext); } +| '!' { $$ = mk_atom(yytext); } +| '<' { $$ = mk_atom(yytext); } +| '>' { $$ = mk_atom(yytext); } +| '-' { $$ = mk_atom(yytext); } +| '&' { $$ = mk_atom(yytext); } +| '|' { $$ = mk_atom(yytext); } +| '+' { $$ = mk_atom(yytext); } +| '*' { $$ = mk_atom(yytext); } +| '/' { $$ = mk_atom(yytext); } +| '^' { $$ = mk_atom(yytext); } +| '%' { $$ = mk_atom(yytext); } +; + +token_trees +: %empty { $$ = mk_node("TokenTrees", 0); } +| token_trees token_tree { $$ = ext_node($1, 1, $2); } +; + +token_tree +: delimited_token_trees +| unpaired_token { $$ = mk_node("TTTok", 1, $1); } +; + +delimited_token_trees +: parens_delimited_token_trees +| braces_delimited_token_trees +| brackets_delimited_token_trees +; + +parens_delimited_token_trees +: '(' token_trees ')' +{ + $$ = mk_node("TTDelim", 3, + mk_node("TTTok", 1, mk_atom("(")), + $2, + mk_node("TTTok", 1, mk_atom(")"))); +} +; + +braces_delimited_token_trees +: '{' token_trees '}' +{ + $$ = mk_node("TTDelim", 3, + mk_node("TTTok", 1, mk_atom("{")), + $2, + mk_node("TTTok", 1, mk_atom("}"))); +} +; + +brackets_delimited_token_trees +: '[' token_trees ']' +{ + $$ = mk_node("TTDelim", 3, + mk_node("TTTok", 1, mk_atom("[")), + $2, + mk_node("TTTok", 1, mk_atom("]"))); +} +; \ No newline at end of file diff --git a/src/grammar/raw-string-literal-ambiguity.md b/src/grammar/raw-string-literal-ambiguity.md new file mode 100644 index 00000000000..c909f233314 --- /dev/null +++ b/src/grammar/raw-string-literal-ambiguity.md @@ -0,0 +1,64 @@ +Rust's lexical grammar is not context-free. Raw string literals are the source +of the problem. Informally, a raw string literal is an `r`, followed by `N` +hashes (where N can be zero), a quote, any characters, then a quote followed +by `N` hashes. Critically, once inside the first pair of quotes, +another quote cannot be followed by `N` consecutive hashes. e.g. +`r###""###"###` is invalid. + +This grammar describes this as best possible: + + R -> 'r' S + S -> '"' B '"' + S -> '#' S '#' + B -> . B + B -> ε + +Where `.` represents any character, and `ε` the empty string. Consider the +string `r#""#"#`. This string is not a valid raw string literal, but can be +accepted as one by the above grammar, using the derivation: + + R : #""#"# + S : ""#" + S : "# + B : # + B : ε + +(Where `T : U` means the rule `T` is applied, and `U` is the remainder of the +string.) The difficulty arises from the fact that it is fundamentally +context-sensitive. In particular, the context needed is the number of hashes. + +To prove that Rust's string literals are not context-free, we will use +the fact that context-free languages are closed under intersection with +regular languages, and the +[pumping lemma for context-free languages](https://en.wikipedia.org/wiki/Pumping_lemma_for_context-free_languages). + +Consider the regular language `R = r#+""#*"#+`. If Rust's raw string literals are +context-free, then their intersection with `R`, `R'`, should also be context-free. +Therefore, to prove that raw string literals are not context-free, +it is sufficient to prove that `R'` is not context-free. + +The language `R'` is `{r#^n""#^m"#^n | m < n}`. + +Assume `R'` *is* context-free. Then `R'` has some pumping length `p > 0` for which +the pumping lemma applies. Consider the following string `s` in `R'`: + +`r#^p""#^{p-1}"#^p` + +e.g. for `p = 2`: `s = r##""#"##` + +Then `s = uvwxy` for some choice of `uvwxy` such that `vx` is non-empty, +`|vwx| < p+1`, and `uv^iwx^iy` is in `R'` for all `i >= 0`. + +Neither `v` nor `x` can contain a `"` or `r`, as the number of these characters +in any string in `R'` is fixed. So `v` and `x` contain only hashes. +Consequently, of the three sequences of hashes, `v` and `x` combined +can only pump two of them. +If we ever choose the central sequence of hashes, then one of the outer sequences +will not grow when we pump, leading to an imbalance between the outer sequences. +Therefore, we must pump both outer sequences of hashes. However, +there are `p+2` characters between these two sequences of hashes, and `|vwx|` must +be less than `p+1`. Therefore we have a contradiction, and `R'` must not be +context-free. + +Since `R'` is not context-free, it follows that the Rust's raw string literals +must not be context-free. diff --git a/src/grammar/testparser.py b/src/grammar/testparser.py new file mode 100755 index 00000000000..37be41b935f --- /dev/null +++ b/src/grammar/testparser.py @@ -0,0 +1,76 @@ +#!/usr/bin/env python +# +# Copyright 2015 The Rust Project Developers. See the COPYRIGHT +# file at the top-level directory of this distribution and at +# http://rust-lang.org/COPYRIGHT. +# +# Licensed under the Apache License, Version 2.0 or the MIT license +# , at your +# option. This file may not be copied, modified, or distributed +# except according to those terms. + +# ignore-tidy-linelength + +import sys + +import os +import subprocess +import argparse + +# usage: testparser.py [-h] [-p PARSER [PARSER ...]] -s SOURCE_DIR + +# Parsers should read from stdin and return exit status 0 for a +# successful parse, and nonzero for an unsuccessful parse + +parser = argparse.ArgumentParser() +parser.add_argument('-p', '--parser', nargs='+') +parser.add_argument('-s', '--source-dir', nargs=1, required=True) +args = parser.parse_args(sys.argv[1:]) + +total = 0 +ok = {} +bad = {} +for parser in args.parser: + ok[parser] = 0 + bad[parser] = [] +devnull = open(os.devnull, 'w') +print("\n") + +for base, dirs, files in os.walk(args.source_dir[0]): + for f in filter(lambda p: p.endswith('.rs'), files): + p = os.path.join(base, f) + parse_fail = 'parse-fail' in p + if sys.version_info.major == 3: + lines = open(p, encoding='utf-8').readlines() + else: + lines = open(p).readlines() + if any('ignore-test' in line or 'ignore-lexer-test' in line for line in lines): + continue + total += 1 + for parser in args.parser: + if subprocess.call(parser, stdin=open(p), stderr=subprocess.STDOUT, stdout=devnull) == 0: + if parse_fail: + bad[parser].append(p) + else: + ok[parser] += 1 + else: + if parse_fail: + ok[parser] += 1 + else: + bad[parser].append(p) + parser_stats = ', '.join(['{}: {}'.format(parser, ok[parser]) for parser in args.parser]) + sys.stdout.write("\033[K\r total: {}, {}, scanned {}" + .format(total, os.path.relpath(parser_stats), os.path.relpath(p))) + +devnull.close() + +print("\n") + +for parser in args.parser: + filename = os.path.basename(parser) + '.bad' + print("writing {} files that did not yield the correct result with {} to {}".format(len(bad[parser]), parser, filename)) + with open(filename, "w") as f: + for p in bad[parser]: + f.write(p) + f.write("\n") diff --git a/src/grammar/tokens.h b/src/grammar/tokens.h new file mode 100644 index 00000000000..081bd050259 --- /dev/null +++ b/src/grammar/tokens.h @@ -0,0 +1,91 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +enum Token { + SHL = 257, // Parser generators reserve 0-256 for char literals + SHR, + LE, + EQEQ, + NE, + GE, + ANDAND, + OROR, + SHLEQ, + SHREQ, + MINUSEQ, + ANDEQ, + OREQ, + PLUSEQ, + STAREQ, + SLASHEQ, + CARETEQ, + PERCENTEQ, + DOTDOT, + DOTDOTDOT, + MOD_SEP, + RARROW, + FAT_ARROW, + LIT_BYTE, + LIT_CHAR, + LIT_INTEGER, + LIT_FLOAT, + LIT_STR, + LIT_STR_RAW, + LIT_BYTE_STR, + LIT_BYTE_STR_RAW, + IDENT, + UNDERSCORE, + LIFETIME, + + // keywords + SELF, + STATIC, + AS, + BREAK, + CRATE, + ELSE, + ENUM, + EXTERN, + FALSE, + FN, + FOR, + IF, + IMPL, + IN, + LET, + LOOP, + MATCH, + MOD, + MOVE, + MUT, + PRIV, + PUB, + REF, + RETURN, + STRUCT, + TRUE, + TRAIT, + TYPE, + UNSAFE, + USE, + WHILE, + CONTINUE, + PROC, + BOX, + CONST, + WHERE, + TYPEOF, + INNER_DOC_COMMENT, + OUTER_DOC_COMMENT, + + SHEBANG, + SHEBANG_LINE, + STATIC_LIFETIME +};