auto merge of #11228 : sfackler/rust/syntaxenv, r=pcwalton
I'd really like to be able to do something like
```rust
struct MapChain<'next, K, V> {
info: BlockInfo,
map: HashMap<K, V>,
next: Option<&'next mut MapChain<'next, K, V>
}
```
but I can't get the lifetimes to work out.
This commit is contained in:
bors
commit
b9c39c6a27
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@ -155,57 +155,48 @@ pub enum SyntaxExtension {
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// The SyntaxEnv is the environment that's threaded through the expansion
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// of macros. It contains bindings for macros, and also a special binding
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// for " block" (not a legal identifier) that maps to a BlockInfo
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pub type SyntaxEnv = @mut MapChain<Name, Transformer>;
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// Transformer : the codomain of SyntaxEnvs
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pub enum Transformer {
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// this identifier maps to a syntax extension or macro
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SE(SyntaxExtension),
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// blockinfo : this is ... well, it's simpler than threading
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// another whole data stack-structured data structure through
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// expansion. Basically, there's an invariant that every
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// map must contain a binding for " block".
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BlockInfo(BlockInfo)
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}
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pub type SyntaxEnv = MapChain<Name, SyntaxExtension>;
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pub struct BlockInfo {
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// should macros escape from this scope?
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macros_escape : bool,
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// what are the pending renames?
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pending_renames : @mut RenameList
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pending_renames : RenameList
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}
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impl BlockInfo {
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pub fn new() -> BlockInfo {
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BlockInfo {
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macros_escape: false,
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pending_renames: ~[]
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}
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}
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}
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// a list of ident->name renamings
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type RenameList = ~[(ast::Ident,Name)];
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pub type RenameList = ~[(ast::Ident,Name)];
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// The base map of methods for expanding syntax extension
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// AST nodes into full ASTs
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pub fn syntax_expander_table() -> SyntaxEnv {
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// utility function to simplify creating NormalTT syntax extensions
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fn builtin_normal_tt_no_ctxt(f: SyntaxExpanderTTFunNoCtxt)
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-> @Transformer {
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@SE(NormalTT(@SyntaxExpanderTT{
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-> SyntaxExtension {
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NormalTT(@SyntaxExpanderTT{
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expander: SyntaxExpanderTTExpanderWithoutContext(f),
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span: None,
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} as @SyntaxExpanderTTTrait,
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None))
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None)
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}
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let mut syntax_expanders = HashMap::new();
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// NB identifier starts with space, and can't conflict with legal idents
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syntax_expanders.insert(intern(&" block"),
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@BlockInfo(BlockInfo{
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macros_escape : false,
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pending_renames : @mut ~[]
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}));
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let mut syntax_expanders = MapChain::new();
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syntax_expanders.insert(intern(&"macro_rules"),
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@SE(IdentTT(@SyntaxExpanderTTItem {
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IdentTT(@SyntaxExpanderTTItem {
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expander: SyntaxExpanderTTItemExpanderWithContext(
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ext::tt::macro_rules::add_new_extension),
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span: None,
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} as @SyntaxExpanderTTItemTrait,
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None)));
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None));
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syntax_expanders.insert(intern(&"fmt"),
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builtin_normal_tt_no_ctxt(
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ext::fmt::expand_syntax_ext));
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@ -231,8 +222,7 @@ pub fn syntax_expander_table() -> SyntaxEnv {
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builtin_normal_tt_no_ctxt(
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ext::log_syntax::expand_syntax_ext));
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syntax_expanders.insert(intern(&"deriving"),
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@SE(ItemDecorator(
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ext::deriving::expand_meta_deriving)));
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ItemDecorator(ext::deriving::expand_meta_deriving));
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// Quasi-quoting expanders
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syntax_expanders.insert(intern(&"quote_tokens"),
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@ -287,7 +277,7 @@ pub fn syntax_expander_table() -> SyntaxEnv {
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syntax_expanders.insert(intern(&"trace_macros"),
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builtin_normal_tt_no_ctxt(
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ext::trace_macros::expand_trace_macros));
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MapChain::new(~syntax_expanders)
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syntax_expanders
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}
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// One of these is made during expansion and incrementally updated as we go;
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@ -298,11 +288,6 @@ pub struct ExtCtxt {
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cfg: ast::CrateConfig,
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backtrace: Option<@ExpnInfo>,
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// These two @mut's should really not be here,
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// but the self types for CtxtRepr are all wrong
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// and there are bugs in the code for object
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// types that make this hard to get right at the
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// moment. - nmatsakis
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mod_path: ~[ast::Ident],
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trace_mac: bool
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}
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@ -324,7 +309,7 @@ impl ExtCtxt {
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match e.node {
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ast::ExprMac(..) => {
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let mut expander = expand::MacroExpander {
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extsbox: @mut syntax_expander_table(),
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extsbox: syntax_expander_table(),
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cx: self,
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};
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e = expand::expand_expr(e, &mut expander);
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@ -459,11 +444,7 @@ pub fn get_exprs_from_tts(cx: &ExtCtxt,
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// we want to implement the notion of a transformation
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// environment.
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// This environment maps Names to Transformers.
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// Initially, this includes macro definitions and
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// block directives.
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// This environment maps Names to SyntaxExtensions.
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// Actually, the following implementation is parameterized
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// by both key and value types.
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@ -478,169 +459,98 @@ pub fn get_exprs_from_tts(cx: &ExtCtxt,
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// able to refer to a macro that was added to an enclosing
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// scope lexically later than the deeper scope.
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// Note on choice of representation: I've been pushed to
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// use a top-level managed pointer by some difficulties
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// with pushing and popping functionally, and the ownership
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// issues. As a result, the values returned by the table
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// also need to be managed; the &'a ... type that Maps
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// return won't work for things that need to get outside
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// of that managed pointer. The easiest way to do this
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// is just to insist that the values in the tables are
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// managed to begin with.
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// a transformer env is either a base map or a map on top
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// of another chain.
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pub enum MapChain<K,V> {
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BaseMapChain(~HashMap<K,@V>),
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ConsMapChain(~HashMap<K,@V>,@mut MapChain<K,V>)
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// Only generic to make it easy to test
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struct MapChainFrame<K, V> {
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info: BlockInfo,
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map: HashMap<K, V>,
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}
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// get the map from an env frame
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impl <K: Eq + Hash + IterBytes + 'static, V: 'static> MapChain<K,V>{
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// Constructor. I don't think we need a zero-arg one.
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pub fn new(init: ~HashMap<K,@V>) -> @mut MapChain<K,V> {
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@mut BaseMapChain(init)
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}
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// add a new frame to the environment (functionally)
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pub fn push_frame (@mut self) -> @mut MapChain<K,V> {
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@mut ConsMapChain(~HashMap::new() ,self)
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}
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// no need for pop, it'll just be functional.
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// utility fn...
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// ugh: can't get this to compile with mut because of the
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// lack of flow sensitivity.
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pub fn get_map<'a>(&'a self) -> &'a HashMap<K,@V> {
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match *self {
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BaseMapChain (~ref map) => map,
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ConsMapChain (~ref map,_) => map
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}
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}
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// traits just don't work anywhere...?
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//impl Map<Name,SyntaxExtension> for MapChain {
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pub fn contains_key (&self, key: &K) -> bool {
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match *self {
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BaseMapChain (ref map) => map.contains_key(key),
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ConsMapChain (ref map,ref rest) =>
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(map.contains_key(key)
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|| rest.contains_key(key))
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}
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}
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// should each_key and each_value operate on shadowed
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// names? I think not.
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// delaying implementing this....
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pub fn each_key (&self, _f: |&K| -> bool) {
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fail!("unimplemented 2013-02-15T10:01");
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}
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pub fn each_value (&self, _f: |&V| -> bool) {
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fail!("unimplemented 2013-02-15T10:02");
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}
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// Returns a copy of the value that the name maps to.
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// Goes down the chain 'til it finds one (or bottom out).
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pub fn find (&self, key: &K) -> Option<@V> {
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match self.get_map().find (key) {
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Some(ref v) => Some(**v),
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None => match *self {
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BaseMapChain (_) => None,
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ConsMapChain (_,ref rest) => rest.find(key)
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}
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}
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}
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pub fn find_in_topmost_frame(&self, key: &K) -> Option<@V> {
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let map = match *self {
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BaseMapChain(ref map) => map,
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ConsMapChain(ref map,_) => map
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};
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// strip one layer of indirection off the pointer.
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map.find(key).map(|r| {*r})
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}
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// insert the binding into the top-level map
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pub fn insert (&mut self, key: K, ext: @V) -> bool {
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// can't abstract over get_map because of flow sensitivity...
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match *self {
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BaseMapChain (~ref mut map) => map.insert(key, ext),
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ConsMapChain (~ref mut map,_) => map.insert(key,ext)
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}
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}
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// insert the binding into the topmost frame for which the binding
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// associated with 'n' exists and satisfies pred
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// ... there are definitely some opportunities for abstraction
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// here that I'm ignoring. (e.g., manufacturing a predicate on
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// the maps in the chain, and using an abstract "find".
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pub fn insert_into_frame(&mut self,
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key: K,
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ext: @V,
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n: K,
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pred: |&@V| -> bool) {
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match *self {
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BaseMapChain (~ref mut map) => {
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if satisfies_pred(map,&n,pred) {
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map.insert(key,ext);
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} else {
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fail!("expected map chain containing satisfying frame")
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}
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},
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ConsMapChain (~ref mut map, rest) => {
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if satisfies_pred(map,&n,|v|pred(v)) {
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map.insert(key,ext);
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} else {
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rest.insert_into_frame(key,ext,n,pred)
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}
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}
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}
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}
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// Only generic to make it easy to test
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pub struct MapChain<K, V> {
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priv chain: ~[MapChainFrame<K, V>],
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}
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// returns true if the binding for 'n' satisfies 'pred' in 'map'
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fn satisfies_pred<K:Eq + Hash + IterBytes,
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V>(
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map: &mut HashMap<K,V>,
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n: &K,
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pred: |&V| -> bool)
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-> bool {
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match map.find(n) {
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Some(ref v) => (pred(*v)),
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None => false
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impl<K: Hash+Eq, V> MapChain<K, V> {
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pub fn new() -> MapChain<K, V> {
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let mut map = MapChain { chain: ~[] };
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map.push_frame();
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map
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}
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pub fn push_frame(&mut self) {
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self.chain.push(MapChainFrame {
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info: BlockInfo::new(),
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map: HashMap::new(),
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});
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}
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pub fn pop_frame(&mut self) {
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assert!(self.chain.len() > 1, "too many pops on MapChain!");
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self.chain.pop();
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}
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fn find_escape_frame<'a>(&'a mut self) -> &'a mut MapChainFrame<K, V> {
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for (i, frame) in self.chain.mut_iter().enumerate().invert() {
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if !frame.info.macros_escape || i == 0 {
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return frame
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}
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}
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unreachable!()
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}
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pub fn find<'a>(&'a self, k: &K) -> Option<&'a V> {
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for frame in self.chain.iter().invert() {
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match frame.map.find(k) {
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Some(v) => return Some(v),
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None => {}
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}
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}
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None
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}
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pub fn insert(&mut self, k: K, v: V) {
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self.find_escape_frame().map.insert(k, v);
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}
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pub fn info<'a>(&'a mut self) -> &'a mut BlockInfo {
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&mut self.chain[self.chain.len()-1].info
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}
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}
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#[cfg(test)]
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mod test {
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use super::MapChain;
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use std::hashmap::HashMap;
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#[test]
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fn testenv() {
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let mut a = HashMap::new();
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a.insert (@"abc",@15);
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let m = MapChain::new(~a);
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m.insert (@"def",@16);
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assert_eq!(m.find(&@"abc"),Some(@15));
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assert_eq!(m.find(&@"def"),Some(@16));
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assert_eq!(*(m.find(&@"abc").unwrap()),15);
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assert_eq!(*(m.find(&@"def").unwrap()),16);
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let n = m.push_frame();
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// old bindings are still present:
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assert_eq!(*(n.find(&@"abc").unwrap()),15);
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assert_eq!(*(n.find(&@"def").unwrap()),16);
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n.insert (@"def",@17);
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// n shows the new binding
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assert_eq!(*(n.find(&@"abc").unwrap()),15);
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assert_eq!(*(n.find(&@"def").unwrap()),17);
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// ... but m still has the old ones
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assert_eq!(m.find(&@"abc"),Some(@15));
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assert_eq!(m.find(&@"def"),Some(@16));
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assert_eq!(*(m.find(&@"abc").unwrap()),15);
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assert_eq!(*(m.find(&@"def").unwrap()),16);
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let mut m = MapChain::new();
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let (a,b,c,d) = ("a", "b", "c", "d");
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m.insert(1, a);
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assert_eq!(Some(&a), m.find(&1));
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m.push_frame();
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m.info().macros_escape = true;
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m.insert(2, b);
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assert_eq!(Some(&a), m.find(&1));
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assert_eq!(Some(&b), m.find(&2));
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m.pop_frame();
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assert_eq!(Some(&a), m.find(&1));
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assert_eq!(Some(&b), m.find(&2));
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m.push_frame();
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m.push_frame();
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m.info().macros_escape = true;
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m.insert(3, c);
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assert_eq!(Some(&c), m.find(&3));
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m.pop_frame();
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assert_eq!(Some(&c), m.find(&3));
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m.pop_frame();
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assert_eq!(None, m.find(&3));
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m.push_frame();
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m.insert(4, d);
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m.pop_frame();
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assert_eq!(None, m.find(&4));
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}
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}
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|
|
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|
|
@ -53,13 +53,13 @@ pub fn expand_expr(e: @ast::Expr, fld: &mut MacroExpander) -> @ast::Expr {
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let extname = &pth.segments[0].identifier;
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let extnamestr = ident_to_str(extname);
|
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// leaving explicit deref here to highlight unbox op:
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match (*fld.extsbox).find(&extname.name) {
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match fld.extsbox.find(&extname.name) {
|
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None => {
|
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fld.cx.span_fatal(
|
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pth.span,
|
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format!("macro undefined: '{}'", extnamestr))
|
||||
}
|
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Some(@SE(NormalTT(expandfun, exp_span))) => {
|
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Some(&NormalTT(expandfun, exp_span)) => {
|
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fld.cx.bt_push(ExpnInfo {
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call_site: e.span,
|
||||
callee: NameAndSpan {
|
||||
|
|
@ -221,8 +221,8 @@ pub fn expand_mod_items(module_: &ast::_mod, fld: &mut MacroExpander) -> ast::_m
|
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item.attrs.rev_iter().fold(~[*item], |items, attr| {
|
||||
let mname = attr.name();
|
||||
|
||||
match (*fld.extsbox).find(&intern(mname)) {
|
||||
Some(@SE(ItemDecorator(dec_fn))) => {
|
||||
match fld.extsbox.find(&intern(mname)) {
|
||||
Some(&ItemDecorator(dec_fn)) => {
|
||||
fld.cx.bt_push(ExpnInfo {
|
||||
call_site: attr.span,
|
||||
callee: NameAndSpan {
|
||||
|
|
@ -249,19 +249,14 @@ pub fn expand_mod_items(module_: &ast::_mod, fld: &mut MacroExpander) -> ast::_m
|
|||
// eval $e with a new exts frame:
|
||||
macro_rules! with_exts_frame (
|
||||
($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
|
||||
({let extsbox = $extsboxexpr;
|
||||
let oldexts = *extsbox;
|
||||
*extsbox = oldexts.push_frame();
|
||||
extsbox.insert(intern(special_block_name),
|
||||
@BlockInfo(BlockInfo{macros_escape:$macros_escape,pending_renames:@mut ~[]}));
|
||||
({$extsboxexpr.push_frame();
|
||||
$extsboxexpr.info().macros_escape = $macros_escape;
|
||||
let result = $e;
|
||||
*extsbox = oldexts;
|
||||
$extsboxexpr.pop_frame();
|
||||
result
|
||||
})
|
||||
)
|
||||
|
||||
static special_block_name : &'static str = " block";
|
||||
|
||||
// When we enter a module, record it, for the sake of `module!`
|
||||
pub fn expand_item(it: @ast::item, fld: &mut MacroExpander)
|
||||
-> SmallVector<@ast::item> {
|
||||
|
|
@ -302,11 +297,11 @@ pub fn expand_item_mac(it: @ast::item, fld: &mut MacroExpander)
|
|||
let extname = &pth.segments[0].identifier;
|
||||
let extnamestr = ident_to_str(extname);
|
||||
let fm = fresh_mark();
|
||||
let expanded = match (*fld.extsbox).find(&extname.name) {
|
||||
let expanded = match fld.extsbox.find(&extname.name) {
|
||||
None => fld.cx.span_fatal(pth.span,
|
||||
format!("macro undefined: '{}!'", extnamestr)),
|
||||
|
||||
Some(@SE(NormalTT(expander, span))) => {
|
||||
Some(&NormalTT(expander, span)) => {
|
||||
if it.ident.name != parse::token::special_idents::invalid.name {
|
||||
fld.cx.span_fatal(pth.span,
|
||||
format!("macro {}! expects no ident argument, \
|
||||
|
|
@ -326,7 +321,7 @@ pub fn expand_item_mac(it: @ast::item, fld: &mut MacroExpander)
|
|||
let marked_ctxt = new_mark(fm,ctxt);
|
||||
expander.expand(fld.cx, it.span, marked_before, marked_ctxt)
|
||||
}
|
||||
Some(@SE(IdentTT(expander, span))) => {
|
||||
Some(&IdentTT(expander, span)) => {
|
||||
if it.ident.name == parse::token::special_idents::invalid.name {
|
||||
fld.cx.span_fatal(pth.span,
|
||||
format!("macro {}! expects an ident argument",
|
||||
|
|
@ -369,7 +364,7 @@ pub fn expand_item_mac(it: @ast::item, fld: &mut MacroExpander)
|
|||
MRDef(ref mdef) => {
|
||||
// yikes... no idea how to apply the mark to this. I'm afraid
|
||||
// we're going to have to wait-and-see on this one.
|
||||
insert_macro(*fld.extsbox,intern(mdef.name), @SE((*mdef).ext));
|
||||
fld.extsbox.insert(intern(mdef.name), (*mdef).ext);
|
||||
SmallVector::zero()
|
||||
}
|
||||
};
|
||||
|
|
@ -377,23 +372,6 @@ pub fn expand_item_mac(it: @ast::item, fld: &mut MacroExpander)
|
|||
return items;
|
||||
}
|
||||
|
||||
|
||||
// insert a macro into the innermost frame that doesn't have the
|
||||
// macro_escape tag.
|
||||
fn insert_macro(exts: SyntaxEnv, name: ast::Name, transformer: @Transformer) {
|
||||
let is_non_escaping_block =
|
||||
|t : &@Transformer| -> bool{
|
||||
match t {
|
||||
&@BlockInfo(BlockInfo {macros_escape:false,..}) => true,
|
||||
&@BlockInfo(BlockInfo {..}) => false,
|
||||
_ => fail!("special identifier {:?} was bound to a non-BlockInfo",
|
||||
special_block_name)
|
||||
}
|
||||
};
|
||||
exts.insert_into_frame(name,transformer,intern(special_block_name),
|
||||
is_non_escaping_block)
|
||||
}
|
||||
|
||||
// expand a stmt
|
||||
pub fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<@Stmt> {
|
||||
// why the copying here and not in expand_expr?
|
||||
|
|
@ -414,12 +392,12 @@ pub fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<@Stmt> {
|
|||
}
|
||||
let extname = &pth.segments[0].identifier;
|
||||
let extnamestr = ident_to_str(extname);
|
||||
let fully_expanded: SmallVector<@Stmt> = match (*fld.extsbox).find(&extname.name) {
|
||||
let fully_expanded: SmallVector<@Stmt> = match fld.extsbox.find(&extname.name) {
|
||||
None => {
|
||||
fld.cx.span_fatal(pth.span, format!("macro undefined: '{}'", extnamestr))
|
||||
}
|
||||
|
||||
Some(@SE(NormalTT(expandfun, exp_span))) => {
|
||||
Some(&NormalTT(expandfun, exp_span)) => {
|
||||
fld.cx.bt_push(ExpnInfo {
|
||||
call_site: s.span,
|
||||
callee: NameAndSpan {
|
||||
|
|
@ -497,8 +475,6 @@ fn expand_non_macro_stmt(s: &Stmt, fld: &mut MacroExpander)
|
|||
span: stmt_span
|
||||
},
|
||||
node_id) => {
|
||||
let block_info = get_block_info(*fld.extsbox);
|
||||
let pending_renames = block_info.pending_renames;
|
||||
|
||||
// take it apart:
|
||||
let @Local {
|
||||
|
|
@ -522,12 +498,16 @@ fn expand_non_macro_stmt(s: &Stmt, fld: &mut MacroExpander)
|
|||
let new_name = fresh_name(ident);
|
||||
new_pending_renames.push((*ident,new_name));
|
||||
}
|
||||
let mut rename_fld = renames_to_fold(new_pending_renames);
|
||||
// rewrite the pattern using the new names (the old ones
|
||||
// have already been applied):
|
||||
let rewritten_pat = rename_fld.fold_pat(expanded_pat);
|
||||
let rewritten_pat = {
|
||||
let mut rename_fld = renames_to_fold(new_pending_renames);
|
||||
// rewrite the pattern using the new names (the old ones
|
||||
// have already been applied):
|
||||
rename_fld.fold_pat(expanded_pat)
|
||||
};
|
||||
// add them to the existing pending renames:
|
||||
for pr in new_pending_renames.iter() {pending_renames.push(*pr)}
|
||||
for pr in new_pending_renames.iter() {
|
||||
fld.extsbox.info().pending_renames.push(*pr)
|
||||
}
|
||||
// also, don't forget to expand the init:
|
||||
let new_init_opt = init.map(|e| fld.fold_expr(e));
|
||||
let rewritten_local =
|
||||
|
|
@ -618,16 +598,23 @@ pub fn expand_block(blk: &Block, fld: &mut MacroExpander) -> P<Block> {
|
|||
|
||||
// expand the elements of a block.
|
||||
pub fn expand_block_elts(b: &Block, fld: &mut MacroExpander) -> P<Block> {
|
||||
let block_info = get_block_info(*fld.extsbox);
|
||||
let pending_renames = block_info.pending_renames;
|
||||
let mut rename_fld = renames_to_fold(pending_renames);
|
||||
let new_view_items = b.view_items.map(|x| fld.fold_view_item(x));
|
||||
let new_stmts = b.stmts.iter()
|
||||
.map(|x| rename_fld.fold_stmt(*x)
|
||||
.expect_one("rename_fold didn't return one value"))
|
||||
.map(|x| {
|
||||
let pending_renames = &mut fld.extsbox.info().pending_renames;
|
||||
let mut rename_fld = renames_to_fold(pending_renames);
|
||||
rename_fld.fold_stmt(*x).expect_one("rename_fold didn't return one value")
|
||||
})
|
||||
.flat_map(|x| fld.fold_stmt(x).move_iter())
|
||||
.collect();
|
||||
let new_expr = b.expr.map(|x| fld.fold_expr(rename_fld.fold_expr(x)));
|
||||
let new_expr = b.expr.map(|x| {
|
||||
let expr = {
|
||||
let pending_renames = &mut fld.extsbox.info().pending_renames;
|
||||
let mut rename_fld = renames_to_fold(pending_renames);
|
||||
rename_fld.fold_expr(x)
|
||||
};
|
||||
fld.fold_expr(expr)
|
||||
});
|
||||
P(Block {
|
||||
view_items: new_view_items,
|
||||
stmts: new_stmts,
|
||||
|
|
@ -638,20 +625,11 @@ pub fn expand_block_elts(b: &Block, fld: &mut MacroExpander) -> P<Block> {
|
|||
})
|
||||
}
|
||||
|
||||
// get the (innermost) BlockInfo from an exts stack
|
||||
fn get_block_info(exts : SyntaxEnv) -> BlockInfo {
|
||||
match exts.find_in_topmost_frame(&intern(special_block_name)) {
|
||||
Some(@BlockInfo(bi)) => bi,
|
||||
_ => fail!("special identifier {:?} was bound to a non-BlockInfo",
|
||||
@" block")
|
||||
}
|
||||
struct IdentRenamer<'a> {
|
||||
renames: &'a mut RenameList,
|
||||
}
|
||||
|
||||
struct IdentRenamer {
|
||||
renames: @mut ~[(ast::Ident,ast::Name)],
|
||||
}
|
||||
|
||||
impl ast_fold for IdentRenamer {
|
||||
impl<'a> ast_fold for IdentRenamer<'a> {
|
||||
fn fold_ident(&mut self, id: ast::Ident) -> ast::Ident {
|
||||
let new_ctxt = self.renames.iter().fold(id.ctxt, |ctxt, &(from, to)| {
|
||||
new_rename(from, to, ctxt)
|
||||
|
|
@ -665,7 +643,7 @@ impl ast_fold for IdentRenamer {
|
|||
|
||||
// given a mutable list of renames, return a tree-folder that applies those
|
||||
// renames.
|
||||
pub fn renames_to_fold(renames: @mut ~[(ast::Ident,ast::Name)]) -> IdentRenamer {
|
||||
pub fn renames_to_fold<'a>(renames: &'a mut RenameList) -> IdentRenamer<'a> {
|
||||
IdentRenamer {
|
||||
renames: renames,
|
||||
}
|
||||
|
|
@ -931,7 +909,7 @@ pub fn inject_std_macros(parse_sess: @mut parse::ParseSess,
|
|||
}
|
||||
|
||||
pub struct MacroExpander<'a> {
|
||||
extsbox: @mut SyntaxEnv,
|
||||
extsbox: SyntaxEnv,
|
||||
cx: &'a mut ExtCtxt,
|
||||
}
|
||||
|
||||
|
|
@ -964,15 +942,9 @@ impl<'a> ast_fold for MacroExpander<'a> {
|
|||
pub fn expand_crate(parse_sess: @mut parse::ParseSess,
|
||||
cfg: ast::CrateConfig,
|
||||
c: Crate) -> Crate {
|
||||
// adding *another* layer of indirection here so that the block
|
||||
// visitor can swap out one exts table for another for the duration
|
||||
// of the block. The cleaner alternative would be to thread the
|
||||
// exts table through the fold, but that would require updating
|
||||
// every method/element of AstFoldFns in fold.rs.
|
||||
let extsbox = syntax_expander_table();
|
||||
let mut cx = ExtCtxt::new(parse_sess, cfg.clone());
|
||||
let mut expander = MacroExpander {
|
||||
extsbox: @mut extsbox,
|
||||
extsbox: syntax_expander_table(),
|
||||
cx: &mut cx,
|
||||
};
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue