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authorNadrieril2019-03-05 12:19:15 +0100
committerNadrieril2019-03-05 12:19:15 +0100
commit29b62de572ba756d162671e3cd16eb8b11408b00 (patch)
tree6ffad0317aab87962098c7e18436139e9991890f /dhall
parent4314421924c256ab13f5a630aff2596c480f6a66 (diff)
Allow empty match in match_children!
Diffstat (limited to 'dhall')
-rw-r--r--dhall/src/lib.rs1
-rw-r--r--dhall/src/parser.rs10
2 files changed, 8 insertions, 3 deletions
diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs
index 9dbd3a6..7cc96e1 100644
--- a/dhall/src/lib.rs
+++ b/dhall/src/lib.rs
@@ -1,4 +1,5 @@
#![feature(box_patterns)]
+#![feature(trace_macros)]
pub mod context;
mod core;
diff --git a/dhall/src/parser.rs b/dhall/src/parser.rs
index 6c7c0c5..ba96a09 100644
--- a/dhall/src/parser.rs
+++ b/dhall/src/parser.rs
@@ -135,7 +135,7 @@ macro_rules! match_iter {
};
// Check no elements remain
- (@match 0, $iter:expr) => {
+ (@match 0, $iter:expr $(,)*) => {
match $iter.next() {
Some(_) => break Err(IterMatchError::TooManyItems),
None => {},
@@ -190,7 +190,11 @@ macro_rules! match_children {
(@collect, $pairs:expr, ($($args:tt)*), $body:expr, ($($acc:tt)*), ($x:ident* : $ty:ident, $($rest:tt)*)) => {
match_children!(@collect, $pairs, ($($args)*), $body, ($($acc)*, $x??), ($($rest)*))
};
- (@collect, $pairs:expr, ($($args:tt)*), $body:expr, (,$($acc:tt)*), ()) => {
+ // Catch extra comma if exists
+ (@collect, $pairs:expr, ($($args:tt)*), $body:expr, (,$($acc:tt)*), ($(,)*)) => {
+ match_children!(@collect, $pairs, ($($args)*), $body, ($($acc)*), ())
+ };
+ (@collect, $pairs:expr, ($($args:tt)*), $body:expr, ($($acc:tt)*), ($(,)*)) => {
let matched: Result<_, IterMatchError<ParseError>> =
match_iter!(@get_err, $pairs; ($($acc)*) => {
match_children!(@parse, $pairs, $($args)*);
@@ -228,7 +232,7 @@ macro_rules! match_children {
};
match_children!(@parse, $pairs $($rest)*);
};
- (@parse, $pairs:expr) => {};
+ (@parse, $pairs:expr $(,)*) => {};
// Entrypoint
($pair:expr; $( ($($args:tt)*) => $body:expr ),* $(,)*) => {