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authorEdwin Cheng <[email protected]>2020-12-11 09:59:04 +0000
committerEdwin Cheng <[email protected]>2020-12-11 09:59:04 +0000
commit175229ab3d3243991aebfad6cf7052c1b5bc4ecf (patch)
treee396b930e21ec66524ba5b69a0e8b385643c5412 /crates/mbe/src
parent41321d96789ed918eebda02ada76758765d19d16 (diff)
negative sign matching in mbe matching for literal
Diffstat (limited to 'crates/mbe/src')
-rw-r--r--crates/mbe/src/mbe_expander/matcher.rs32
-rw-r--r--crates/mbe/src/tests.rs13
2 files changed, 39 insertions, 6 deletions
diff --git a/crates/mbe/src/mbe_expander/matcher.rs b/crates/mbe/src/mbe_expander/matcher.rs
index 3f8445897..4860b242d 100644
--- a/crates/mbe/src/mbe_expander/matcher.rs
+++ b/crates/mbe/src/mbe_expander/matcher.rs
@@ -356,6 +356,18 @@ impl<'a> TtIter<'a> {
356 ExpandResult { value: _, err: Some(_) } => None, 356 ExpandResult { value: _, err: Some(_) } => None,
357 } 357 }
358 } 358 }
359
360 pub(crate) fn eat_char(&mut self) -> Option<tt::TokenTree> {
361 let mut fork = self.clone();
362 match fork.expect_char('-') {
363 Ok(_) => {
364 let tt = self.next().cloned();
365 *self = fork;
366 tt
367 }
368 Err(_) => None,
369 }
370 }
359} 371}
360 372
361pub(super) fn match_repeat( 373pub(super) fn match_repeat(
@@ -447,10 +459,22 @@ fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragmen
447 .expect_lifetime() 459 .expect_lifetime()
448 .map(|tt| Some(tt)) 460 .map(|tt| Some(tt))
449 .map_err(|()| err!("expected lifetime")), 461 .map_err(|()| err!("expected lifetime")),
450 "literal" => input 462 "literal" => {
451 .expect_literal() 463 let neg = input.eat_char();
452 .map(|literal| Some(tt::Leaf::from(literal.clone()).into())) 464 input
453 .map_err(|()| err!()), 465 .expect_literal()
466 .map(|literal| {
467 let lit = tt::Leaf::from(literal.clone());
468 match neg {
469 None => Some(lit.into()),
470 Some(neg) => Some(tt::TokenTree::Subtree(tt::Subtree {
471 delimiter: None,
472 token_trees: vec![neg, lit.into()],
473 })),
474 }
475 })
476 .map_err(|()| err!())
477 }
454 // `vis` is optional 478 // `vis` is optional
455 "vis" => match input.eat_vis() { 479 "vis" => match input.eat_vis() {
456 Some(vis) => Ok(Some(vis)), 480 Some(vis) => Ok(Some(vis)),
diff --git a/crates/mbe/src/tests.rs b/crates/mbe/src/tests.rs
index 0796ceee1..843054fe8 100644
--- a/crates/mbe/src/tests.rs
+++ b/crates/mbe/src/tests.rs
@@ -1008,11 +1008,20 @@ fn test_literal() {
1008 parse_macro( 1008 parse_macro(
1009 r#" 1009 r#"
1010 macro_rules! foo { 1010 macro_rules! foo {
1011 ($ type:ty $ lit:literal) => { const VALUE: $ type = $ lit;}; 1011 ($ type:ty , $ lit:literal) => { const VALUE: $ type = $ lit;};
1012 } 1012 }
1013"#, 1013"#,
1014 ) 1014 )
1015 .assert_expand_items(r#"foo!(u8 0);"#, r#"const VALUE : u8 = 0 ;"#); 1015 .assert_expand_items(r#"foo!(u8,0);"#, r#"const VALUE : u8 = 0 ;"#);
1016
1017 parse_macro(
1018 r#"
1019 macro_rules! foo {
1020 ($ type:ty , $ lit:literal) => { const VALUE: $ type = $ lit;};
1021 }
1022"#,
1023 )
1024 .assert_expand_items(r#"foo!(i32,-1);"#, r#"const VALUE : i32 = - 1 ;"#);
1016} 1025}
1017 1026
1018#[test] 1027#[test]