syntax: Extract attribute parsing to its own mod

Author: brson

src/librustsyntax/parse.rs

@@ -86,7 +86,7 @@ fn parse_crate_from_crate_file(input: str, cfg: ast::crate_cfg,
     let p = new_parser_from_file(sess, cfg, input, parser::CRATE_FILE);
     let lo = p.span.lo;
     let prefix = path::dirname(p.reader.filemap.name);
-    let leading_attrs = parser::parse_inner_attrs_and_next(p);
+    let leading_attrs = attr::parse_inner_attrs_and_next(p);
     let crate_attrs = leading_attrs.inner;
     let first_cdir_attr = leading_attrs.next;
     let cdirs = parser::parse_crate_directives(

src/librustsyntax/parse/attr.rs

@@ -0,0 +1,123 @@
+import either::{either, left, right};
+import parser::{parse_seq,
+                seq_sep,
+                expect,
+                parse_lit,
+                parse_ident,
+                parse_syntax_ext_naked,
+                spanned};
+
+export attr_or_ext;
+export parse_outer_attributes;
+export parse_outer_attrs_or_ext;
+export parse_inner_attrs_and_next;
+export parse_optional_meta;
+
+// A type to distingush between the parsing of item attributes or syntax
+// extensions, which both begin with token.POUND
+type attr_or_ext = option<either<[ast::attribute], @ast::expr>>;
+
+fn parse_outer_attrs_or_ext(
+    p: parser,
+    first_item_attrs: [ast::attribute]) -> attr_or_ext {
+    let expect_item_next = vec::is_not_empty(first_item_attrs);
+    if p.token == token::POUND {
+        let lo = p.span.lo;
+        if p.look_ahead(1u) == token::LBRACKET {
+            p.bump();
+            let first_attr = parse_attribute_naked(p, ast::attr_outer, lo);
+            ret some(left([first_attr] + parse_outer_attributes(p)));
+        } else if !(p.look_ahead(1u) == token::LT
+                    || p.look_ahead(1u) == token::LBRACKET
+                    || expect_item_next) {
+            p.bump();
+            ret some(right(parse_syntax_ext_naked(p, lo)));
+        } else { ret none; }
+    } else { ret none; }
+}
+
+// Parse attributes that appear before an item
+fn parse_outer_attributes(p: parser) -> [ast::attribute] {
+    let mut attrs: [ast::attribute] = [];
+    while p.token == token::POUND {
+        attrs += [parse_attribute(p, ast::attr_outer)];
+    }
+    ret attrs;
+}
+
+fn parse_attribute(p: parser, style: ast::attr_style) -> ast::attribute {
+    let lo = p.span.lo;
+    expect(p, token::POUND);
+    ret parse_attribute_naked(p, style, lo);
+}
+
+fn parse_attribute_naked(p: parser, style: ast::attr_style, lo: uint) ->
+   ast::attribute {
+    expect(p, token::LBRACKET);
+    let meta_item = parse_meta_item(p);
+    expect(p, token::RBRACKET);
+    let mut hi = p.span.hi;
+    ret spanned(lo, hi, {style: style, value: *meta_item});
+}
+
+// Parse attributes that appear after the opening of an item, each terminated
+// by a semicolon. In addition to a vector of inner attributes, this function
+// also returns a vector that may contain the first outer attribute of the
+// next item (since we can't know whether the attribute is an inner attribute
+// of the containing item or an outer attribute of the first contained item
+// until we see the semi).
+fn parse_inner_attrs_and_next(p: parser) ->
+   {inner: [ast::attribute], next: [ast::attribute]} {
+    let mut inner_attrs: [ast::attribute] = [];
+    let mut next_outer_attrs: [ast::attribute] = [];
+    while p.token == token::POUND {
+        if p.look_ahead(1u) != token::LBRACKET {
+            // This is an extension
+            break;
+        }
+        let attr = parse_attribute(p, ast::attr_inner);
+        if p.token == token::SEMI {
+            p.bump();
+            inner_attrs += [attr];
+        } else {
+            // It's not really an inner attribute
+            let outer_attr =
+                spanned(attr.span.lo, attr.span.hi,
+                        {style: ast::attr_outer, value: attr.node.value});
+            next_outer_attrs += [outer_attr];
+            break;
+        }
+    }
+    ret {inner: inner_attrs, next: next_outer_attrs};
+}
+
+fn parse_meta_item(p: parser) -> @ast::meta_item {
+    let lo = p.span.lo;
+    let ident = parse_ident(p);
+    alt p.token {
+      token::EQ {
+        p.bump();
+        let lit = parse_lit(p);
+        let mut hi = p.span.hi;
+        ret @spanned(lo, hi, ast::meta_name_value(ident, lit));
+      }
+      token::LPAREN {
+        let inner_items = parse_meta_seq(p);
+        let mut hi = p.span.hi;
+        ret @spanned(lo, hi, ast::meta_list(ident, inner_items));
+      }
+      _ {
+        let mut hi = p.span.hi;
+        ret @spanned(lo, hi, ast::meta_word(ident));
+      }
+    }
+}
+
+fn parse_meta_seq(p: parser) -> [@ast::meta_item] {
+    ret parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA),
+                  parse_meta_item, p).node;
+}
+
+fn parse_optional_meta(p: parser) -> [@ast::meta_item] {
+    alt p.token { token::LPAREN { ret parse_meta_seq(p); } _ { ret []; } }
+}

src/librustsyntax/parse/eval.rs

@@ -1,7 +1,6 @@
-import attr;
 import parser::{parser,
-                parse_inner_attrs_and_next,
                 parse_mod_items, SOURCE_FILE};
+import attr::parse_inner_attrs_and_next;
 
 export eval_crate_directives_to_mod;
 
@@ -81,7 +80,7 @@ fn parse_companion_mod(cx: ctx, prefix: str, suffix: option<str>)
 }
 
 fn cdir_path_opt(id: str, attrs: [ast::attribute]) -> str {
-    alt attr::first_attr_value_str_by_name(attrs, "path") {
+    alt ::attr::first_attr_value_str_by_name(attrs, "path") {
       some(d) {
         ret d;
       }

src/librustsyntax/parse/parser.rs

@@ -8,6 +8,10 @@ import ast::spanned;
 import ast_util::{mk_sp, ident_to_path};
 import lexer::reader;
 import prec::{op_spec, as_prec};
+import attr::{parse_outer_attrs_or_ext,
+              parse_inner_attrs_and_next,
+              parse_outer_attributes,
+              parse_optional_meta};
 
 export expect;
 export file_type;
@@ -17,14 +21,19 @@ export parser;
 export parse_crate_directives;
 export parse_crate_mod;
 export parse_expr;
-export parse_inner_attrs_and_next;
 export parse_item;
 export parse_mod_items;
-export parse_outer_attributes;
 export parse_pat;
+export parse_seq;
 export parse_stmt;
 export parse_ty;
 
+export spanned;
+export seq_sep;
+export parse_lit;
+export parse_ident;
+export parse_syntax_ext_naked;
+
 // FIXME: #ast expects to find this here but it's actually defined in `parse`
 // Fixing this will be easier when we have export decls on individual items --
 // then parse can export this publicly, and everything else crate-visibly.
@@ -2385,115 +2394,6 @@ fn parse_item(p: parser, attrs: [ast::attribute]) -> option<@ast::item> {
 else { ret none; }
 }
 
-// A type to distingush between the parsing of item attributes or syntax
-// extensions, which both begin with token.POUND
-type attr_or_ext = option<either<[ast::attribute], @ast::expr>>;
-
-fn parse_outer_attrs_or_ext(
-    p: parser,
-    first_item_attrs: [ast::attribute]) -> attr_or_ext {
-    let expect_item_next = vec::is_not_empty(first_item_attrs);
-    if p.token == token::POUND {
-        let lo = p.span.lo;
-        if p.look_ahead(1u) == token::LBRACKET {
-            p.bump();
-            let first_attr = parse_attribute_naked(p, ast::attr_outer, lo);
-            ret some(left([first_attr] + parse_outer_attributes(p)));
-        } else if !(p.look_ahead(1u) == token::LT
-                    || p.look_ahead(1u) == token::LBRACKET
-                    || expect_item_next) {
-            p.bump();
-            ret some(right(parse_syntax_ext_naked(p, lo)));
-        } else { ret none; }
-    } else { ret none; }
-}
-
-// Parse attributes that appear before an item
-fn parse_outer_attributes(p: parser) -> [ast::attribute] {
-    let mut attrs: [ast::attribute] = [];
-    while p.token == token::POUND {
-        attrs += [parse_attribute(p, ast::attr_outer)];
-    }
-    ret attrs;
-}
-
-fn parse_attribute(p: parser, style: ast::attr_style) -> ast::attribute {
-    let lo = p.span.lo;
-    expect(p, token::POUND);
-    ret parse_attribute_naked(p, style, lo);
-}
-
-fn parse_attribute_naked(p: parser, style: ast::attr_style, lo: uint) ->
-   ast::attribute {
-    expect(p, token::LBRACKET);
-    let meta_item = parse_meta_item(p);
-    expect(p, token::RBRACKET);
-    let mut hi = p.span.hi;
-    ret spanned(lo, hi, {style: style, value: *meta_item});
-}
-
-// Parse attributes that appear after the opening of an item, each terminated
-// by a semicolon. In addition to a vector of inner attributes, this function
-// also returns a vector that may contain the first outer attribute of the
-// next item (since we can't know whether the attribute is an inner attribute
-// of the containing item or an outer attribute of the first contained item
-// until we see the semi).
-fn parse_inner_attrs_and_next(p: parser) ->
-   {inner: [ast::attribute], next: [ast::attribute]} {
-    let mut inner_attrs: [ast::attribute] = [];
-    let mut next_outer_attrs: [ast::attribute] = [];
-    while p.token == token::POUND {
-        if p.look_ahead(1u) != token::LBRACKET {
-            // This is an extension
-            break;
-        }
-        let attr = parse_attribute(p, ast::attr_inner);
-        if p.token == token::SEMI {
-            p.bump();
-            inner_attrs += [attr];
-        } else {
-            // It's not really an inner attribute
-            let outer_attr =
-                spanned(attr.span.lo, attr.span.hi,
-                        {style: ast::attr_outer, value: attr.node.value});
-            next_outer_attrs += [outer_attr];
-            break;
-        }
-    }
-    ret {inner: inner_attrs, next: next_outer_attrs};
-}
-
-fn parse_meta_item(p: parser) -> @ast::meta_item {
-    let lo = p.span.lo;
-    let ident = parse_ident(p);
-    alt p.token {
-      token::EQ {
-        p.bump();
-        let lit = parse_lit(p);
-        let mut hi = p.span.hi;
-        ret @spanned(lo, hi, ast::meta_name_value(ident, lit));
-      }
-      token::LPAREN {
-        let inner_items = parse_meta_seq(p);
-        let mut hi = p.span.hi;
-        ret @spanned(lo, hi, ast::meta_list(ident, inner_items));
-      }
-      _ {
-        let mut hi = p.span.hi;
-        ret @spanned(lo, hi, ast::meta_word(ident));
-      }
-    }
-}
-
-fn parse_meta_seq(p: parser) -> [@ast::meta_item] {
-    ret parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA),
-                  parse_meta_item, p).node;
-}
-
-fn parse_optional_meta(p: parser) -> [@ast::meta_item] {
-    alt p.token { token::LPAREN { ret parse_meta_seq(p); } _ { ret []; } }
-}
-
 fn parse_use(p: parser) -> ast::view_item_ {
     let ident = parse_ident(p);
     let metadata = parse_optional_meta(p);

src/librustsyntax/rustsyntax.rc

@@ -28,12 +28,14 @@ mod parse {
     export comments;
     export prec;
     export classify;
+    export attr;
 
     mod eval;
     mod lexer;
     mod parser;
     mod token;
     mod comments;
+    mod attr;
 
     #[doc = "Functions dealing with operator precedence"]
     mod prec;

src/rustdoc/attr_parser.rs

@@ -38,7 +38,7 @@ mod test {
         let parser = parse::new_parser_from_source_str(
             parse_sess, [], "-", codemap::fss_none, @source);
 
-        parser::parse_outer_attributes(parser)
+        parse::attr::parse_outer_attributes(parser)
     }
 }