From 6dba4d66724594abdfcf49ae31aded29ebf6d304 Mon Sep 17 00:00:00 2001
From: Armin Ronacher <armin.ronacher@active-4.com>
Date: Mon, 21 May 2007 23:41:36 +0200
Subject: [PATCH] [svn] checked in changes regarding variable length iteration

--HG--
branch : trunk
---
 CHANGES                |  4 ++++
 jinja/datastructure.py |  9 ++++++++-
 tests/test_forloop.py  | 10 ++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index bda176c..dd45ed0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -99,6 +99,10 @@ Version 1.1
   be an expression. As soon as you specify an expression as second argument
   the closing tag has to be omitted.
 
+- It's now possible to iterate over iterators additionally to sequences.
+  If the iterator is inifite it will crash however, so makes sure you don't
+  pass something like that to a template!
+
 
 Version 1.0
 -----------
diff --git a/jinja/datastructure.py b/jinja/datastructure.py
index daa2e27..22864b5 100644
--- a/jinja/datastructure.py
+++ b/jinja/datastructure.py
@@ -326,10 +326,17 @@ class LoopContext(object):
         """
         if seq in (Undefined, None):
             seq = ()
+            length = 0
+        else:
+            try:
+                length = len(seq)
+            except TypeError:
+                seq = list(seq)
+                length = len(seq)
         self._stack.append({
             'index':            -1,
             'seq':              seq,
-            'length':           len(seq)
+            'length':           length
         })
         return self
 
diff --git a/tests/test_forloop.py b/tests/test_forloop.py
index af8afce..ca50020 100644
--- a/tests/test_forloop.py
+++ b/tests/test_forloop.py
@@ -17,6 +17,7 @@ CONTEXTVARS = '''{% for item in seq %}\
 CYCLING = '''{% for item in seq %}{% cycle '<1>', '<2>' %}{% endfor %}\
 {% for item in seq %}{% cycle through %}{% endfor %}'''
 SCOPE = '''{% for item in seq %}{% endfor %}{{ item }}'''
+VARLEN = '''{% for item in iter %}{{ item }}{% endfor %}'''
 
 
 def test_simple(env):
@@ -63,3 +64,12 @@ def test_scope(env):
     tmpl = env.from_string(SCOPE)
     output = tmpl.render(seq=range(10))
     assert not output
+
+
+def test_varlen(env):
+    def inner():
+        for item in range(5):
+            yield item
+    tmpl = env.from_string(VARLEN)
+    output = tmpl.render(iter=inner())
+    assert output == '01234'
-- 
2.26.2