Make keyword table in reference reflect reality more closely
And remove the part about reserved words.
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Marijn Haverbeke
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a08e589390
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87a488048d
68
doc/rust.md
68
doc/rust.md
@ -102,12 +102,12 @@ Productions](#special-unicode-productions).
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Some rules in the grammar -- notably [unary
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operators](#unary-operator-expressions), [binary
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operators](#binary-operator-expressions), [keywords](#keywords) and [reserved
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words](#reserved-words) -- are given in a simplified form: as a listing of a
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table of unquoted, printable whitespace-separated strings. These cases form a
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subset of the rules regarding the [token](#tokens) rule, and are assumed to be
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the result of a lexical-analysis phase feeding the parser, driven by a DFA,
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operating over the disjunction of all such string table entries.
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operators](#binary-operator-expressions), and [keywords](#keywords) --
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are given in a simplified form: as a listing of a table of unquoted,
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printable whitespace-separated strings. These cases form a subset of
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the rules regarding the [token](#tokens) rule, and are assumed to be
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the result of a lexical-analysis phase feeding the parser, driven by a
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DFA, operating over the disjunction of all such string table entries.
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When such a string enclosed in double-quotes (`"`) occurs inside the
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grammar, it is an implicit reference to a single member of such a string table
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@ -139,8 +139,7 @@ The `ident` production is any nonempty Unicode string of the following form:
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- The first character has property `XID_start`
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- The remaining characters have property `XID_continue`
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that does _not_ occur in the set of [keywords](#keywords) or [reserved
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words](#reserved-words).
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that does _not_ occur in the set of [keywords](#keywords).
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Note: `XID_start` and `XID_continue` as character properties cover the
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character ranges used to form the more familiar C and Java language-family
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@ -190,7 +189,7 @@ with any other legal whitespace element, such as a single space character.
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## Tokens
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~~~~~~~~ {.ebnf .gram}
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simple_token : keyword | reserved | unop | binop ;
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simple_token : keyword | unop | binop ;
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token : simple_token | ident | literal | symbol | whitespace token ;
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~~~~~~~~
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@ -204,52 +203,32 @@ grammar as double-quoted strings. Other tokens have exact rules given.
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The keywords in [crate files](#crate-files) are the following strings:
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~~~~~~~~ {.keyword}
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import export use mod dir
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import export use mod
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~~~~~~~~
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The keywords in [source files](#source-files) are the following strings:
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*TODO* split these between type keywords and regular (value) keywords,
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and define two different `identifier` productions for the different
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contexts.
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~~~~~~~~ {.keyword}
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alt any as assert
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be bind block bool break
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char check claim const cont
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alt assert
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be break
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check claim class const cont copy
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do
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else enum export
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f32 f64 fail false float fn for
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i16 i32 i64 i8 if iface impl import in int
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fail false fn for
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if iface impl import
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let log
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mod mutable
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native note
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of
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prove pure
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native
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pure
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resource ret
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self str syntax
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true type
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u16 u32 u64 u8 uint unchecked unsafe use
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vec
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unsafe use
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while
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~~~~~~~~
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Any of these have special meaning in their respective grammars, and are
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excluded from the `ident` rule.
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### Reserved words
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The reserved words are the following strings:
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~~~~~~~~ {.reserved}
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m32 m64 m128
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f80 f16 f128
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class trait
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~~~~~~~~
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Any of these may have special meaning in future versions of the language, so
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are excluded from the `ident` rule.
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### Literals
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A literal is an expression consisting of a single token, rather than a
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@ -389,10 +368,6 @@ literal. There are three floating-point suffixes: `f` (for the base
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`float` type), `f32`, and `f64` (the 32-bit and 64-bit floating point
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types).
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A set of suffixes are also reserved to accommodate literal support for
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types corresponding to reserved tokens. The reserved suffixes are `f16`,
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`f80`, `f128`, `m`, `m32`, `m64` and `m128`.
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Examples of floating-point literals of various forms:
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~~~~
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@ -421,8 +396,7 @@ Symbols are a general class of printable [token](#tokens) that play structural
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roles in a variety of grammar productions. They are catalogued here for
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completeness as the set of remaining miscellaneous printable tokens that do not
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otherwise appear as [unary operators](#unary-operator-expressions), [binary
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operators](#binary-operator-expressions), [keywords](#keywords) or [reserved
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words](#reserved-words).
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operators](#binary-operator-expressions), or [keywords](#keywords).
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## Paths
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@ -1431,9 +1405,9 @@ rec_expr : '{' ident ':' expr
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A _[record](#record-types) expression_ is one or more comma-separated
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name-value pairs enclosed by braces. A fieldname can be any identifier
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(including reserved words), and is separated from its value expression
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by a colon. To indicate that a field is mutable, the `mutable` keyword
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is written before its name.
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(including keywords), and is separated from its value expression by a
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colon. To indicate that a field is mutable, the `mutable` keyword is
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written before its name.
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~~~~
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{x: 10f, y: 20f};
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@ -147,12 +147,12 @@ fn new_parser(sess: parse_sess, cfg: ast::crate_cfg, rdr: reader,
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// interpreted as a specific kind of statement, which would be confusing.
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fn bad_expr_word_table() -> hashmap<str, ()> {
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let words = new_str_hash();
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for word in ["mod", "if", "else", "while", "do", "alt", "for", "break",
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"cont", "ret", "be", "fail", "type", "resource", "check",
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"assert", "claim", "native", "fn", "pure",
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"unsafe", "import", "export", "let", "const",
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"log", "copy", "impl", "iface", "enum",
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"class", "trait"] {
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for word in ["alt", "assert", "be", "break", "check", "claim",
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"class", "const", "cont", "copy", "do", "else", "enum",
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"export", "fail", "fn", "for", "if", "iface", "impl",
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"import", "let", "log", "mod", "mutable", "native", "pure",
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"resource", "ret", "trait", "type", "unchecked", "unsafe",
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"while"] {
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words.insert(word, ());
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}
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words
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