From c5983b85fc9e520208684a8c625cdb96bb219b31 Mon Sep 17 00:00:00 2001
From: Edwin Cheng <edwin0cheng@gmail.com>
Date: Fri, 19 Apr 2019 21:21:47 +0800
Subject: Add literal matcher
---
crates/ra_mbe/src/lib.rs | 12 ++++++++++++
crates/ra_mbe/src/mbe_expander.rs | 9 +++++++++
crates/ra_mbe/src/tt_cursor.rs | 14 ++++++++++++++
3 files changed, 35 insertions(+)
(limited to 'crates/ra_mbe')
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index a143eaa36..b9dd22dc9 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -797,4 +797,16 @@ MACRO_ITEMS@[0; 40)
);
assert_expansion(&rules, r#"foo!{'a}"#, r#"struct Ref < 'a > {s : & 'a str}"#);
}
+
+ #[test]
+ fn test_literal() {
+ let rules = create_rules(
+ r#"
+ macro_rules! foo {
+ ($ type:ty $ lit:literal) => { const VALUE: $ type = $ lit;};
+ }
+"#,
+ );
+ assert_expansion(&rules, r#"foo!(u8 0)"#, r#"const VALUE: u8 = 0;"#);
+ }
}
diff --git a/crates/ra_mbe/src/mbe_expander.rs b/crates/ra_mbe/src/mbe_expander.rs
index cacc3da19..548b15535 100644
--- a/crates/ra_mbe/src/mbe_expander.rs
+++ b/crates/ra_mbe/src/mbe_expander.rs
@@ -185,6 +185,15 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
input.eat_lifetime().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(lifetime.into()));
}
+ "literal" => {
+ let literal =
+ input.eat_literal().ok_or(ExpandError::UnexpectedToken)?.clone();
+ res.inner.insert(
+ text.clone(),
+ Binding::Simple(tt::Leaf::from(literal).into()),
+ );
+ }
+
_ => return Err(ExpandError::UnexpectedToken),
}
}
diff --git a/crates/ra_mbe/src/tt_cursor.rs b/crates/ra_mbe/src/tt_cursor.rs
index 9c49648fa..6184fb31f 100644
--- a/crates/ra_mbe/src/tt_cursor.rs
+++ b/crates/ra_mbe/src/tt_cursor.rs
@@ -41,6 +41,13 @@ impl<'a> TtCursor<'a> {
}
}
+ pub(crate) fn at_literal(&mut self) -> Option<&'a tt::Literal> {
+ match self.current() {
+ Some(tt::TokenTree::Leaf(tt::Leaf::Literal(i))) => Some(i),
+ _ => None,
+ }
+ }
+
pub(crate) fn bump(&mut self) {
self.pos += 1;
}
@@ -79,6 +86,13 @@ impl<'a> TtCursor<'a> {
})
}
+ pub(crate) fn eat_literal(&mut self) -> Option<&'a tt::Literal> {
+ self.at_literal().map(|i| {
+ self.bump();
+ i
+ })
+ }
+
pub(crate) fn eat_path(&mut self) -> Option<tt::TokenTree> {
let parser = Parser::new(&mut self.pos, self.subtree);
parser.parse_path()
--
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