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-rw-r--r--crates/ide/src/syntax_highlighting/macro_.rs129
1 files changed, 129 insertions, 0 deletions
diff --git a/crates/ide/src/syntax_highlighting/macro_.rs b/crates/ide/src/syntax_highlighting/macro_.rs
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+++ b/crates/ide/src/syntax_highlighting/macro_.rs
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1//! Syntax highlighting for macro_rules!.
2use syntax::{SyntaxElement, SyntaxKind, SyntaxToken, TextRange, T};
3
4use crate::{HlRange, HlTag};
5
6#[derive(Default)]
7pub(super) struct MacroHighlighter {
8 state: Option<MacroMatcherParseState>,
9}
10
11impl MacroHighlighter {
12 pub(super) fn init(&mut self) {
13 self.state = Some(MacroMatcherParseState::default());
14 }
15
16 pub(super) fn advance(&mut self, token: &SyntaxToken) {
17 if let Some(state) = self.state.as_mut() {
18 update_macro_state(state, token);
19 }
20 }
21
22 pub(super) fn highlight(&self, element: SyntaxElement) -> Option<HlRange> {
23 if let Some(state) = self.state.as_ref() {
24 if matches!(state.rule_state, RuleState::Matcher | RuleState::Expander) {
25 if let Some(range) = is_metavariable(element) {
26 return Some(HlRange {
27 range,
28 highlight: HlTag::UnresolvedReference.into(),
29 binding_hash: None,
30 });
31 }
32 }
33 }
34 None
35 }
36}
37
38struct MacroMatcherParseState {
39 /// Opening and corresponding closing bracket of the matcher or expander of the current rule
40 paren_ty: Option<(SyntaxKind, SyntaxKind)>,
41 paren_level: usize,
42 rule_state: RuleState,
43 /// Whether we are inside the outer `{` `}` macro block that holds the rules
44 in_invoc_body: bool,
45}
46
47impl Default for MacroMatcherParseState {
48 fn default() -> Self {
49 MacroMatcherParseState {
50 paren_ty: None,
51 paren_level: 0,
52 in_invoc_body: false,
53 rule_state: RuleState::None,
54 }
55 }
56}
57
58#[derive(Copy, Clone, Debug, PartialEq)]
59enum RuleState {
60 Matcher,
61 Expander,
62 Between,
63 None,
64}
65
66impl RuleState {
67 fn transition(&mut self) {
68 *self = match self {
69 RuleState::Matcher => RuleState::Between,
70 RuleState::Expander => RuleState::None,
71 RuleState::Between => RuleState::Expander,
72 RuleState::None => RuleState::Matcher,
73 };
74 }
75}
76
77fn update_macro_state(state: &mut MacroMatcherParseState, tok: &SyntaxToken) {
78 if !state.in_invoc_body {
79 if tok.kind() == T!['{'] || tok.kind() == T!['('] {
80 state.in_invoc_body = true;
81 }
82 return;
83 }
84
85 match state.paren_ty {
86 Some((open, close)) => {
87 if tok.kind() == open {
88 state.paren_level += 1;
89 } else if tok.kind() == close {
90 state.paren_level -= 1;
91 if state.paren_level == 0 {
92 state.rule_state.transition();
93 state.paren_ty = None;
94 }
95 }
96 }
97 None => {
98 match tok.kind() {
99 T!['('] => {
100 state.paren_ty = Some((T!['('], T![')']));
101 }
102 T!['{'] => {
103 state.paren_ty = Some((T!['{'], T!['}']));
104 }
105 T!['['] => {
106 state.paren_ty = Some((T!['['], T![']']));
107 }
108 _ => (),
109 }
110 if state.paren_ty.is_some() {
111 state.paren_level = 1;
112 state.rule_state.transition();
113 }
114 }
115 }
116}
117
118fn is_metavariable(element: SyntaxElement) -> Option<TextRange> {
119 let tok = element.as_token()?;
120 match tok.kind() {
121 kind if kind == SyntaxKind::IDENT || kind.is_keyword() => {
122 if let Some(_dollar) = tok.prev_token().filter(|t| t.kind() == T![$]) {
123 return Some(tok.text_range());
124 }
125 }
126 _ => (),
127 };
128 None
129}