Remove calculator's reliance on config.FATAL_UNDEFINED.

3 files changed, 17 insertions, 7 deletions

diff --git a/scss/compiler.py b/scss/compiler.py
index 20a78dd..ac89a58 100644
--- a/scss/compiler.py
+++ b/scss/compiler.py
@@ -97,6 +97,7 @@ class Compiler(object):
             live_errors=False, warn_unused_imports=False,
             ignore_parse_errors=False,
             loops_have_own_scopes=True,
+            undefined_variables_fatal=True,
             super_selector='',
         ):
         """Configure a compiler.
@@ -144,6 +145,7 @@ class Compiler(object):
         self.warn_unused_imports = warn_unused_imports
         self.ignore_parse_errors = ignore_parse_errors
         self.loops_have_own_scopes = loops_have_own_scopes
+        self.undefined_variables_fatal = undefined_variables_fatal
         self.super_selector = super_selector
 
     def normalize_path(self, path):
@@ -313,6 +315,7 @@ class Compilation(object):
         return Calculator(
             namespace,
             ignore_parse_errors=self.ignore_parse_errors,
+            undefined_variables_fatal=self.compiler.undefined_variables_fatal,
         )
 
     # @print_timing(4)
diff --git a/scss/expression.py b/scss/expression.py
index 18ada87..465dfe4 100644
--- a/scss/expression.py
+++ b/scss/expression.py
@@ -34,13 +34,18 @@ class Calculator(object):
 
     ast_cache = {}
 
-    def __init__(self, namespace=None, ignore_parse_errors=False):
+    def __init__(
+            self, namespace=None,
+            ignore_parse_errors=False,
+            undefined_variables_fatal=True,
+            ):
         if namespace is None:
             self.namespace = Namespace()
         else:
             self.namespace = namespace
 
         self.ignore_parse_errors = ignore_parse_errors
+        self.undefined_variables_fatal = undefined_variables_fatal
 
     def _pound_substitute(self, result):
         expr = result.group(1)
@@ -85,7 +90,7 @@ class Calculator(object):
                     try:
                         v = self.namespace.variable(n)
                     except KeyError:
-                        if config.FATAL_UNDEFINED:
+                        if self.undefined_variables_fatal:
                             raise SyntaxError("Undefined variable: '%s'." % n)
                         else:
                             log.error("Undefined variable '%s'", n, extra={'stack': True})
@@ -356,12 +361,13 @@ class Literal(Expression):
         return '<%s(%s)>' % (self.__class__.__name__, repr(self.value))
 
     def __init__(self, value):
-        if isinstance(value, Undefined) and config.FATAL_UNDEFINED:
-            raise SyntaxError("Undefined literal.")
-        else:
-            self.value = value
+        self.value = value
 
     def evaluate(self, calculator, divide=False):
+        if (isinstance(self.value, Undefined) and
+                calculator.undefined_variables_fatal):
+            raise SyntaxError("Undefined literal.")
+
         return self.value
 
 
@@ -376,7 +382,7 @@ class Variable(Expression):
         try:
             value = calculator.namespace.variable(self.name)
         except KeyError:
-            if config.FATAL_UNDEFINED:
+            if calculator.undefined_variables_fatal:
                 raise SyntaxError("Undefined variable: '%s'." % self.name)
             else:
                 log.error("Undefined variable '%s'", self.name, extra={'stack': True})
diff --git a/scss/legacy.py b/scss/legacy.py
index cd74895..1b7da84 100644
--- a/scss/legacy.py
+++ b/scss/legacy.py
@@ -138,6 +138,7 @@ class Scss(object):
             warn_unused_imports=self._scss_opts.get('warn_unused', False),
             ignore_parse_errors=config.DEBUG,
             loops_have_own_scopes=config.CONTROL_SCOPING,
+            undefined_variables_fatal=config.FATAL_UNDEFINED,
             super_selector=super_selector or self.super_selector,
         )
         # Gonna add the source files manually