syntax: Extract attribute parsing to its own mod

This commit is contained in:
Brian Anderson 2012-04-19 20:51:31 -07:00
parent 3d6c79109e
commit 628e80d525
6 changed files with 140 additions and 116 deletions

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@ -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(

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@ -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 []; } }
}

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@ -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;
}

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@ -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);

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@ -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;

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@ -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)
}
}