feat(parser): add built-in patterns

watcol · Jul 26, 2022 · 43ab3f6 · 43ab3f6
1 parent 19768d0
commit 43ab3f6
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Showing 3 changed files with 33 additions and 6 deletions.
diff --git a/drake-parser/src/pattern.rs b/drake-parser/src/pattern.rs
@@ -3,17 +3,21 @@
 mod tests;
 
 use drake_types::ast::{Pattern, PatternKind};
-use drake_types::token::Token;
+use drake_types::token::{Symbol, Token};
 use somen::prelude::*;
 
 use crate::key::key;
+use crate::token::symbol;
 
 /// A parser for patterns
 pub fn pattern<'a, I>() -> impl Parser<I, Output = Pattern<I::Locator>> + 'a
 where
  I: Input<Ok = Token> + 'a,
 {
- choice((key().map(PatternKind::Key),))
- .with_position()
- .map(|(kind, span)| Pattern { kind, span })
+ choice((
+ symbol(Symbol::At).prefix(key()).map(PatternKind::Builtin),
+ key().map(PatternKind::Key),
+ ))
+ .with_position()
+ .map(|(kind, span)| Pattern { kind, span })
 }
diff --git a/drake-parser/src/pattern/tests.rs b/drake-parser/src/pattern/tests.rs
@@ -1,6 +1,6 @@
 use alloc::string::String;
 use drake_types::ast::{Key, KeyKind, Pattern, PatternKind};
-use drake_types::token::{Identifier, IdentifierKind, Token};
+use drake_types::token::{Identifier, IdentifierKind, Symbol, Token};
 use somen::prelude::*;
 
 use crate::test_utils::test_parser;
@@ -10,6 +10,23 @@ fn pattern() {
  test_parser(
  super::pattern().complete(),
  &[
+ (
+ &[
+ Token::Symbol(Symbol::At),
+ Token::Identifier(Identifier {
+ kind: IdentifierKind::Bare,
+ name: String::from("abc"),
+ }),
+ ],
+ Some(Pattern {
+ kind: PatternKind::Builtin(Key {
+ kind: KeyKind::Normal,
+ name: String::from("abc"),
+ span: 1..2,
+ }),
+ span: 0..2,
+ }),
+ ),
  (
  &[Token::Identifier(Identifier {
  kind: IdentifierKind::Bare,

diff --git a/drake-types/src/ast.rs b/drake-types/src/ast.rs
@@ -48,6 +48,8 @@ pub struct Pattern<L> {
 pub enum PatternKind<L> {
  /// A key pattern
  Key(Key<L>),
+ /// A built-in pattern
+ Builtin(Key<L>),
 }
 
 /// Keys
@@ -154,13 +156,17 @@ impl<L> fmt::Display for Pattern<L> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self.kind {
  PatternKind::Key(ref key) => key.fmt(f),
+ PatternKind::Builtin(ref key) => write!(f, "@{key}"),
  }
  }
 }
 
 impl<L> fmt::Display for Key<L> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- self.name.fmt(f)
+ match self.kind {
+ KeyKind::Normal => self.name.fmt(f),
+ KeyKind::Local => write!(f, "_{}", self.name),
+ }
  }
 }