From ad03579035c2418958d4945e46e05fca54c44a99 Mon Sep 17 00:00:00 2001
From: misterfish <allen@netherrealm.net>
Date: Sat, 4 Jun 2016 18:12:41 +0200
Subject: [PATCH] Throw compile-time error if a label is used with a curried
 function (resolves #751)

---
 lib/ast.js          | 3 +++
 src/ast.ls          | 1 +
 test/compilation.ls | 1 +
 3 files changed, 5 insertions(+)

diff --git a/lib/ast.js b/lib/ast.js
index e2d7240a3..77fde28a5 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -4219,6 +4219,9 @@ exports.Label = Label = (function(superclass){
     var fun;
     this.label = label || '_';
     this.it = it;
+    if (this.it.curried) {
+      this.carp("can't use label with a curried function (attempted label '" + this.label + "')");
+    }
     if (fun = (it instanceof Fun || it instanceof Class) && it || it.calling && it.it.head) {
       fun.name || (fun.name = this.label, fun.labeled = true);
       return it;
diff --git a/src/ast.ls b/src/ast.ls
index fe66ffffe..86d873622 100644
--- a/src/ast.ls
+++ b/src/ast.ls
@@ -2674,6 +2674,7 @@ class exports.If extends Node
 # A labeled block or statement.
 class exports.Label extends Node
     (@label or \_, @it) ->
+        @carp "can't use label with a curried function (attempted label '#{@label}')" if @it.curried
         if fun = it instanceof [Fun, Class] and it or
              it.calling and it.it.head
             fun.name or fun <<< {name: @label, +labeled}
diff --git a/test/compilation.ls b/test/compilation.ls
index 5a12ddd65..01c395ad4 100644
--- a/test/compilation.ls
+++ b/test/compilation.ls
@@ -35,6 +35,7 @@ compileThrows 'unmatched `]`' 3 '[{\n\n]}'
 
 compileThrows 'missing `)CALL`' 1 'f('
 
+compileThrows "can't use label with a curried function (attempted label 'abc')" 1 ':abc (a, b) --> a + b'
 
 throws '''
   empty range on line 1