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path: root/crates/ra_mbe/src/mbe_parser.rs
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-rw-r--r--crates/ra_mbe/src/mbe_parser.rs24
1 files changed, 12 insertions, 12 deletions
diff --git a/crates/ra_mbe/src/mbe_parser.rs b/crates/ra_mbe/src/mbe_parser.rs
index ee1b11091..d067e5248 100644
--- a/crates/ra_mbe/src/mbe_parser.rs
+++ b/crates/ra_mbe/src/mbe_parser.rs
@@ -1,10 +1,10 @@
1/// This module parses a raw `tt::TokenStream` into macro-by-example token 1/// This module parses a raw `tt::TokenStream` into macro-by-example token
2/// stream. This is a *mostly* identify function, expect for handling of 2/// stream. This is a *mostly* identify function, expect for handling of
3/// `$var:tt_kind` and `$(repeat),*` constructs. 3/// `$var:tt_kind` and `$(repeat),*` constructs.
4use crate::{MacroRulesError, Result}; 4use crate::ParseError;
5use crate::tt_cursor::TtCursor; 5use crate::tt_cursor::TtCursor;
6 6
7pub(crate) fn parse(tt: &tt::Subtree) -> Result<crate::MacroRules> { 7pub(crate) fn parse(tt: &tt::Subtree) -> Result<crate::MacroRules, ParseError> {
8 let mut parser = TtCursor::new(tt); 8 let mut parser = TtCursor::new(tt);
9 let mut rules = Vec::new(); 9 let mut rules = Vec::new();
10 while !parser.is_eof() { 10 while !parser.is_eof() {
@@ -19,7 +19,7 @@ pub(crate) fn parse(tt: &tt::Subtree) -> Result<crate::MacroRules> {
19 Ok(crate::MacroRules { rules }) 19 Ok(crate::MacroRules { rules })
20} 20}
21 21
22fn parse_rule(p: &mut TtCursor) -> Result<crate::Rule> { 22fn parse_rule(p: &mut TtCursor) -> Result<crate::Rule, ParseError> {
23 let lhs = parse_subtree(p.eat_subtree()?)?; 23 let lhs = parse_subtree(p.eat_subtree()?)?;
24 p.expect_char('=')?; 24 p.expect_char('=')?;
25 p.expect_char('>')?; 25 p.expect_char('>')?;
@@ -28,14 +28,14 @@ fn parse_rule(p: &mut TtCursor) -> Result<crate::Rule> {
28 Ok(crate::Rule { lhs, rhs }) 28 Ok(crate::Rule { lhs, rhs })
29} 29}
30 30
31fn parse_subtree(tt: &tt::Subtree) -> Result<crate::Subtree> { 31fn parse_subtree(tt: &tt::Subtree) -> Result<crate::Subtree, ParseError> {
32 let mut token_trees = Vec::new(); 32 let mut token_trees = Vec::new();
33 let mut p = TtCursor::new(tt); 33 let mut p = TtCursor::new(tt);
34 while let Ok(tt) = p.eat() { 34 while let Some(tt) = p.eat() {
35 let child: crate::TokenTree = match tt { 35 let child: crate::TokenTree = match tt {
36 tt::TokenTree::Leaf(leaf) => match leaf { 36 tt::TokenTree::Leaf(leaf) => match leaf {
37 tt::Leaf::Punct(tt::Punct { char: '$', .. }) => { 37 tt::Leaf::Punct(tt::Punct { char: '$', .. }) => {
38 if p.at_ident().is_ok() { 38 if p.at_ident().is_some() {
39 crate::Leaf::from(parse_var(&mut p)?).into() 39 crate::Leaf::from(parse_var(&mut p)?).into()
40 } else { 40 } else {
41 parse_repeat(&mut p)?.into() 41 parse_repeat(&mut p)?.into()
@@ -56,12 +56,12 @@ fn parse_subtree(tt: &tt::Subtree) -> Result<crate::Subtree> {
56 Ok(crate::Subtree { token_trees, delimiter: tt.delimiter }) 56 Ok(crate::Subtree { token_trees, delimiter: tt.delimiter })
57} 57}
58 58
59fn parse_var(p: &mut TtCursor) -> Result<crate::Var> { 59fn parse_var(p: &mut TtCursor) -> Result<crate::Var, ParseError> {
60 let ident = p.eat_ident().unwrap(); 60 let ident = p.eat_ident().unwrap();
61 let text = ident.text.clone(); 61 let text = ident.text.clone();
62 let kind = if p.at_char(':') { 62 let kind = if p.at_char(':') {
63 p.bump(); 63 p.bump();
64 if let Ok(ident) = p.eat_ident() { 64 if let Some(ident) = p.eat_ident() {
65 Some(ident.text.clone()) 65 Some(ident.text.clone())
66 } else { 66 } else {
67 p.rev_bump(); 67 p.rev_bump();
@@ -73,21 +73,21 @@ fn parse_var(p: &mut TtCursor) -> Result<crate::Var> {
73 Ok(crate::Var { text, kind }) 73 Ok(crate::Var { text, kind })
74} 74}
75 75
76fn parse_repeat(p: &mut TtCursor) -> Result<crate::Repeat> { 76fn parse_repeat(p: &mut TtCursor) -> Result<crate::Repeat, ParseError> {
77 let subtree = p.eat_subtree().unwrap(); 77 let subtree = p.eat_subtree().unwrap();
78 let mut subtree = parse_subtree(subtree)?; 78 let mut subtree = parse_subtree(subtree)?;
79 subtree.delimiter = crate::Delimiter::None; 79 subtree.delimiter = crate::Delimiter::None;
80 let sep = p.eat_punct()?; 80 let sep = p.eat_punct().ok_or(ParseError::ParseError)?;
81 let (separator, rep) = match sep.char { 81 let (separator, rep) = match sep.char {
82 '*' | '+' | '?' => (None, sep.char), 82 '*' | '+' | '?' => (None, sep.char),
83 char => (Some(char), p.eat_punct()?.char), 83 char => (Some(char), p.eat_punct().ok_or(ParseError::ParseError)?.char),
84 }; 84 };
85 85
86 let kind = match rep { 86 let kind = match rep {
87 '*' => crate::RepeatKind::ZeroOrMore, 87 '*' => crate::RepeatKind::ZeroOrMore,
88 '+' => crate::RepeatKind::OneOrMore, 88 '+' => crate::RepeatKind::OneOrMore,
89 '?' => crate::RepeatKind::ZeroOrOne, 89 '?' => crate::RepeatKind::ZeroOrOne,
90 _ => return Err(MacroRulesError::ParseError), 90 _ => return Err(ParseError::ParseError),
91 }; 91 };
92 p.bump(); 92 p.bump();
93 Ok(crate::Repeat { subtree, kind, separator }) 93 Ok(crate::Repeat { subtree, kind, separator })