Clean up List use in Compass helpers and compiler.

3 files changed, 16 insertions, 41 deletions

diff --git a/scss/__init__.py b/scss/__init__.py
index 85ca173..e95051f 100644
--- a/scss/__init__.py
+++ b/scss/__init__.py
@@ -69,7 +69,7 @@ from scss.expression import Calculator
 from scss.functions import ALL_BUILTINS_LIBRARY
 from scss.functions.compass.sprites import sprite_map
 from scss.rule import UnparsedBlock, SassRule
-from scss.types import BooleanValue, ListValue, Null, NumberValue, StringValue
+from scss.types import BooleanValue, List, Null, NumberValue, StringValue
 from scss.util import depar, dequote, normalize_var, split_params, to_str, profile, print_timing
 
 log = logging.getLogger(__name__)
@@ -995,18 +995,17 @@ class Scss(object):
         """
         Implements @each
         """
-        var, _, name = block.argument.partition(' in ')
+        var, _, valuestring = block.argument.partition(' in ')
         calculator = Calculator(rule.namespace)
-        name = calculator.calculate(name)
+        values = calculator.calculate(valuestring)
         if not name:
             return
 
-        iterable = ListValue(name)
         var = var.strip()
         var = calculator.do_glob_math(var)
         var = normalize_var(var)
 
-        for v in iterable:
+        for v in List.from_maybe(values):
             inner_rule = rule.copy()
             inner_rule.namespace = inner_rule.namespace.derive()
             inner_rule.unparsed_contents = block.unparsed_contents
diff --git a/scss/functions/compass/helpers.py b/scss/functions/compass/helpers.py
index 6a864ed..861adab 100644
--- a/scss/functions/compass/helpers.py
+++ b/scss/functions/compass/helpers.py
@@ -79,15 +79,8 @@ def compact(*args):
 @register('reject')
 def reject(lst, *values):
     """Removes the given values from the list"""
-    if not isinstance(lst, List):
-        lst = List(lst)
-
-    if len(values) == 1:
-        values = values[0]
-        if isinstance(values, (list, tuple, List)):
-            values = frozenset(values)
-        else:
-            values = frozenset([values])
+    lst = List.from_maybe(lst)
+    values = frozenset(List.from_maybe_starargs(values))
 
     ret = []
     for item in lst:
@@ -112,12 +105,7 @@ def first_value_of(lst):
 
 @register('-compass-list')
 def dash_compass_list(*args):
-    use_comma = False
-    if len(args) == 1 and isinstance(args[0], (list, tuple, List)):
-        args = args[0]
-    if isinstance(args, List):
-        use_comma = args.use_comma
-    return List(args, use_comma=use_comma)
+    return List.from_maybe_starargs(args)
 
 
 @register('-compass-space-list')
@@ -150,14 +138,9 @@ def dash_compass_slice(lst, start_index, end_index=None):
 @register('prefixed')
 def prefixed(prefix, *args):
     to_fnct_str = 'to_' + to_str(prefix).replace('-', '_')
-    for arg in args:
-        if isinstance(arg, List):
-            for iarg in arg:
-                if hasattr(iarg, to_fnct_str):
-                    return BooleanValue(True)
-        else:
-            if hasattr(arg, to_fnct_str):
-                return BooleanValue(True)
+    for arg in List.from_maybe_starargs(args):
+        if hasattr(arg, to_fnct_str):
+            return BooleanValue(True)
     return BooleanValue(False)
 
 
@@ -380,10 +363,7 @@ OPPOSITE_POSITIONS = dict(
 )
 
 def _position(opposite, positions):
-    if isinstance(positions, List):
-        positions = positions.value
-    else:
-        positions = [positions]
+    positions = List.from_maybe(positions)
 
     ret = []
     for pos in positions:
@@ -415,10 +395,7 @@ def _position(opposite, positions):
         warnings.warn("Can't find opposite for position %r" % (pos,))
         ret.append(pos)
 
-    if len(ret) == 1:
-        return ret[0]
-    else:
-        return List(ret, use_comma=False)
+    return List(ret, use_comma=False).maybe()
 
 
 @register('position')
@@ -482,8 +459,7 @@ def _font_url(path, only_path=False, cache_buster=True, inline=False):
 
 
 def _font_files(args, inline):
-    if len(args) == 1 and isinstance(args[0], (list, tuple, List)):
-        args = list(args[0])
+    args = List.from_maybe_starargs(args)
     n = 0
     params = [[], []]
     for arg in args:
diff --git a/scss/types.py b/scss/types.py
index 9fe0d8b..889cf49 100644
--- a/scss/types.py
+++ b/scss/types.py
@@ -449,7 +449,7 @@ class List(Value):
         return cls(values, use_comma=use_comma)
 
     @classmethod
-    def from_maybe_starargs(cls, args):
+    def from_maybe_starargs(cls, args, use_comma=True):
         """If `args` has one element which appears to be a list, return it.
         Otherwise, return a list as normal.
 
@@ -461,9 +461,9 @@ class List(Value):
             if isinstance(args[0], cls):
                 return args[0]
             elif isinstance(args[0], (list, tuple)):
-                return cls(args[0])
+                return cls(args[0], use_comma=use_comma)
 
-        return cls(args)
+        return cls(args, use_comma=use_comma)
 
     @property
     def separator(self):