fixes #285: filtered comprehensions over ranges

michaelficarra · Mar 22, 2014 · f8df1d7 · f8df1d7
1 parent 31b8751
commit f8df1d7
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diff --git a/lib/compiler.js b/lib/compiler.js
diff --git a/src/compiler.coffee b/src/compiler.coffee
@@ -452,6 +452,8 @@ class exports.Compiler
  ((@target.right.instanceof CS.Int) or ((@target.right.instanceof CS.UnaryNegateOp) and @target.right.expression.instanceof CS.Int))
  varDeclaration = new JS.AssignmentExpression '=', i, compile @target.left
  update = new JS.UpdateExpression '++', yes, i
+ if @filter?
+ block.body.unshift stmt new JS.IfStatement (new JS.UnaryExpression '!', filter), new JS.ContinueStatement
  if keyAssignee?
  k = genSym 'k'
  varDeclaration = new JS.SequenceExpression [(new JS.AssignmentExpression '=', k, new JS.Literal 0), varDeclaration]

diff --git a/test/comprehensions.coffee b/test/comprehensions.coffee
@@ -21,3 +21,16 @@ suite 'Comprehensions', ->
  arrayEq [a..b], (fn() for in [a..b])
  c = 0
  arrayEq [a...b], (fn() for in [a...b])
+
+ test 'filtered comprehensions', ->
+ list = [0..5]
+ filtered = (a for a in list when a & 1)
+ arrayEq filtered, [1, 3, 5]
+ filtered = (a for a in list when a < 4)
+ arrayEq filtered, [0..3]
+
+ test '#285: filtered comprehensions over ranges', ->
+ filtered = (a for a in [0..5] when a & 1)
+ arrayEq filtered, [1, 3, 5]
+ filtered = (a for a in [0..5] when a < 4)
+ arrayEq filtered, [0..3]