From c6f4a06b4297f498da4bc2cd747aa38effb855b0 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sun, 18 Feb 2018 01:06:48 +0300
Subject: G: value_parameters, patterns & let statement

---
 src/parser/grammar/patterns.rs | 52 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 src/parser/grammar/patterns.rs

(limited to 'src/parser/grammar/patterns.rs')

diff --git a/src/parser/grammar/patterns.rs b/src/parser/grammar/patterns.rs
new file mode 100644
index 000000000..6e4f2236b
--- /dev/null
+++ b/src/parser/grammar/patterns.rs
@@ -0,0 +1,52 @@
+use super::*;
+
+pub(super) fn pattern(p: &mut Parser) {
+    match p.current() {
+        UNDERSCORE => placeholder_pat(p),
+        AMPERSAND => ref_pat(p),
+        IDENT | REF_KW => bind_pat(p),
+        _ => p.err_and_bump("expected pattern"),
+    }
+}
+
+// test placeholder_pat
+// fn main() { let _ = (); }
+fn placeholder_pat(p: &mut Parser) {
+    assert!(p.at(UNDERSCORE));
+    let m = p.start();
+    p.bump();
+    m.complete(p, PLACEHOLDER_PAT);
+}
+
+// test ref_pat
+// fn main() {
+//     let &a = ();
+//     let &mut b = ();
+// }
+fn ref_pat(p: &mut Parser) {
+    assert!(p.at(AMPERSAND));
+    let m = p.start();
+    p.bump();
+    p.eat(MUT_KW);
+    pattern(p);
+    m.complete(p, REF_PAT);
+}
+
+// test bind_pat
+// fn main() {
+//     let a = ();
+//     let ref b = ();
+//     let ref mut c = ();
+//     let d @ _ = ();
+// }
+fn bind_pat(p: &mut Parser) {
+    let m = p.start();
+    if p.eat(REF_KW) {
+        p.eat(MUT_KW);
+    }
+    name(p);
+    if p.eat(AT) {
+        pattern(p);
+    }
+    m.complete(p, BIND_PAT);
+}
-- 
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