parser comments

parser comments

Author: jbclements

src/libsyntax/parse/attr.rs

@@ -62,12 +62,14 @@ impl parser_attr for Parser {
         return attrs;
     }
 
+    // matches attribute = # attribute_naked
     fn parse_attribute(&self, style: ast::attr_style) -> ast::attribute {
         let lo = self.span.lo;
         self.expect(&token::POUND);
         return self.parse_attribute_naked(style, lo);
     }
 
+    // matches attribute_naked = [ meta_item ]
     fn parse_attribute_naked(&self, style: ast::attr_style, lo: BytePos) ->
         ast::attribute {
         self.expect(&token::LBRACKET);
@@ -86,6 +88,7 @@ impl parser_attr for Parser {
     // is an inner attribute of the containing item or an outer attribute of
     // the first contained item until we see the semi).
 
+    // matches inner_attrs* outer_attr?
     // you can make the 'next' field an Option, but the result is going to be
     // more useful as a vector.
     fn parse_inner_attrs_and_next(&self) ->
@@ -134,6 +137,9 @@ impl parser_attr for Parser {
         (inner_attrs, next_outer_attrs)
     }
 
+    // matches meta_item = IDENT
+    // | IDENT = lit
+    // | IDENT meta_seq
     fn parse_meta_item(&self) -> @ast::meta_item {
         let lo = self.span.lo;
         let name = self.id_to_str(self.parse_ident());
@@ -156,6 +162,7 @@ impl parser_attr for Parser {
         }
     }
 
+    // matches meta_seq = ( COMMASEP(meta_item) )
     fn parse_meta_seq(&self) -> ~[@ast::meta_item] {
         copy self.parse_seq(
             &token::LPAREN,

src/libsyntax/parse/parser.rs

@@ -870,6 +870,7 @@ pub impl Parser {
         }
     }
 
+    // matches token_lit = LIT_INT | ...
     fn lit_from_token(&self, tok: &token::Token) -> lit_ {
         match *tok {
             token::LIT_INT(i, it) => lit_int(i, it),
@@ -884,6 +885,7 @@ pub impl Parser {
         }
     }
 
+    // matches lit = true | false | token_lit
     fn parse_lit(&self) -> lit {
         let lo = self.span.lo;
         let lit = if self.eat_keyword(&~"true") {
@@ -2762,8 +2764,6 @@ pub impl Parser {
     // matches optbounds = ( ( : ( boundseq )? )? )
     // where   boundseq  = ( bound + boundseq ) | bound
     // and     bound     = ( 'static ) | ty
-    // you might want to insist on the boundseq having seen the colon, but
-    // that's not currently in place.
     fn parse_optional_ty_param_bounds(&self) -> @OptVec<TyParamBound> {
         if !self.eat(&token::COLON) {
             return @opt_vec::Empty;
@@ -3085,6 +3085,7 @@ pub impl Parser {
         }
     }
 
+    // matches fn_header = IDENT generics
     // parse the name and optional generic types of a function header.
     fn parse_fn_header(&self) -> (ident, ast::Generics) {
         let id = self.parse_ident();
@@ -3436,7 +3437,7 @@ pub impl Parser {
         let attrs_remaining_len = attrs_remaining.len();
 
         // looks like this code depends on the invariant that
-        // outer attributes can't occur on view items (or macros
+        // outer attributes can't occur on view items (or macro
         // invocations?)
         let mut first = true;
         while *self.token != term {
@@ -3449,9 +3450,9 @@ pub impl Parser {
                    attrs);
             match self.parse_item_or_view_item(
                 /*bad*/ copy attrs,
-                true,
-                false,
-                true
+                true, // items allowed
+                false, // foreign items allowed
+                true // macros allowed
             ) {
               iovi_item(item) => items.push(item),
               iovi_view_item(view_item) => {
@@ -3706,6 +3707,7 @@ pub impl Parser {
         }
     }
 
+    // parse extern mod foo { ... } or extern { ... }
     fn parse_item_foreign_mod(&self,
                               lo: BytePos,
                               opt_abis: Option<AbiSet>,

src/libsyntax/syntax.rc

@@ -8,6 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+/*! This module contains the Rust parser. It maps source text
+ *  to token trees and to ASTs. It contains code for expanding
+ *  macros.
+ */
+
 #[link(name = "syntax",
        vers = "0.7-pre",
        uuid = "9311401b-d6ea-4cd9-a1d9-61f89499c645")];