Lazy consumption of generators zipped with other iterables

Author: adamsol

src/transpiler.py

@@ -1190,11 +1190,11 @@ def transpileStmtFor(self, node):
                     update = v.Call('safe_advance', iterator, end, abs_step)
 
             conditions.append(cond)
-            updates.append(update)
+            updates.append(f'({update}, {cond})')
             getters.append(getter)
 
         condition = ' && '.join(str(cond) for cond in conditions)
-        update = ', '.join(str(update) for update in updates)
+        update = ' && '.join(str(update) for update in updates)
 
         with self.loop(partial(c.For, '', condition, update), node.get('label')):
             if len(vars) == 1 and len(types) > 1:

test/good/generators/generator11.out

@@ -0,0 +1,6 @@
+2
+1
+4
+2 1 4
+3
+null 1 1

test/good/generators/generator11.px

@@ -0,0 +1,9 @@
+
+func range(a, b): Int... def
+    for x in a..b do
+        print x
+        yield x
+    print null, a, b
+
+for x, y, z in range(2, 3), range(1, 1), range(4, 5) do
+    print x, y, z

test/good/generators/var03.out

@@ -7,3 +7,11 @@ true
 4
 5
 [5]
+true
+1
+2
+[1, 2, 3]
+3
+4
+5
+[4, 5]

test/good/generators/var03.px

@@ -11,3 +11,9 @@ print false
 print [for v, i in r, 0...3 yield v]
 # 4 is lost here, Python behaves the same way.
 print [...r]
+
+r = counter(5)
+
+print [for i, v in 0...3, r yield v]
+# But with another order of iterables, 4 is consumed properly.
+print [...r]

version.txt

@@ -1 +1 @@
-0.12.0.dev
+0.13.0