At last, real parsing for url(). Partly. #192

3 files changed, 64 insertions, 18 deletions

diff --git a/scss/expression.py b/scss/expression.py
index bb2fd01..034a007 100644
--- a/scss/expression.py
+++ b/scss/expression.py
@@ -15,7 +15,7 @@ import scss.config as config
 from scss.cssdefs import COLOR_NAMES, is_builtin_css_function, _expr_glob_re, _interpolate_re
 from scss.errors import SassError, SassEvaluationError, SassParseError
 from scss.rule import Namespace
-from scss.types import Boolean, Color, List, Map, Null, Number, String, Undefined, Value
+from scss.types import Boolean, Color, List, Map, Null, Number, String, Undefined, Url, Value
 from scss.util import dequote, normalize_var
 
 ################################################################################
@@ -576,6 +576,9 @@ class Parser(object):
 class SassExpressionScanner(Scanner):
     patterns = None
     _patterns = [
+        ('"\'"', "'"),
+        ('"\\""', '"'),
+        ('"url"', 'url'),
         ('":"', ':'),
         ('","', ','),
         ('[ \r\t\n]+', '[ \r\t\n]+'),
@@ -614,6 +617,7 @@ class SassExpressionScanner(Scanner):
         ('KWID', '[-a-zA-Z_][-a-zA-Z0-9_]*(?=\\s*:)'),
         ('ID', '[-a-zA-Z_][-a-zA-Z0-9_]*'),
         ('BANG_IMPORTANT', '!important'),
+        ('URL', '(?:[\\\\].|[^\'"()\\x00-\\x08\\x0b\\x0e-\\x1f\\x7f])*'),
     ]
 
     def __init__(self, input=None):
@@ -837,6 +841,25 @@ class SassExpression(Parser):
                 v = expr_lst
             RPAR = self._scan('RPAR')
             return Parentheses(v)
+        elif _token_ == '"url"':
+            self._scan('"url"')
+            LPAR = self._scan('LPAR')
+            _token_ = self._peek(self.atom_rsts_)
+            if _token_ == 'URL':
+                URL = self._scan('URL')
+                quotes = None
+            elif _token_ == '"\\""':
+                self._scan('"\\""')
+                URL = self._scan('URL')
+                self._scan('"\\""')
+                quotes = '"'
+            else:  # == '"\'"'
+                self._scan('"\'"')
+                URL = self._scan('URL')
+                self._scan('"\'"')
+                quotes = "'"
+            RPAR = self._scan('RPAR')
+            return Literal(Url(URL, quotes=quotes))
         elif _token_ == 'FNCT':
             FNCT = self._scan('FNCT')
             LPAR = self._scan('LPAR')
@@ -852,7 +875,7 @@ class SassExpression(Parser):
         elif _token_ == 'NUM':
             NUM = self._scan('NUM')
             UNITS = None
-            if self._peek(self.atom_rsts_) == 'UNITS':
+            if self._peek(self.atom_rsts__) == 'UNITS':
                 UNITS = self._scan('UNITS')
             return Literal(Number(float(NUM), unit=UNITS))
         elif _token_ == 'STR':
@@ -894,32 +917,33 @@ class SassExpression(Parser):
             KWVAR = self._scan('KWVAR')
             return Variable(KWVAR)
 
-    u_expr_chks = set(['LPAR', 'COLOR', 'QSTR', 'NUM', 'FNCT', 'STR', 'VAR', 'BANG_IMPORTANT', 'ID'])
-    m_expr_rsts = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'MUL', 'DIV', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
+    u_expr_chks = set(['"url"', 'LPAR', 'COLOR', 'QSTR', 'NUM', 'FNCT', 'STR', 'VAR', 'BANG_IMPORTANT', 'ID'])
+    m_expr_rsts = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'MUL', 'DIV', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', '"url"', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
     argspec_items_rsts = set(['RPAR', 'END', '","'])
     expr_map_rsts = set(['RPAR', '","'])
-    argspec_items_rsts__ = set(['KWVAR', 'LPAR', 'QSTR', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
+    argspec_items_rsts__ = set(['KWVAR', 'LPAR', 'QSTR', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'SIGN', 'VAR', 'ADD', 'NUM', '"url"', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
     kwatom_rsts = set(['KWVAR', 'KWID', 'KWSTR', 'KWQSTR', 'KWCOLOR', '":"', 'KWNUM'])
-    argspec_item_chks = set(['LPAR', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
+    argspec_item_chks = set(['"url"', 'LPAR', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
     a_expr_chks = set(['ADD', 'SUB'])
-    expr_slst_rsts = set(['LPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID', '","'])
-    or_expr_rsts = set(['LPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'ID', 'BANG_IMPORTANT', 'OR', '","'])
-    and_expr_rsts = set(['AND', 'LPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'ID', 'BANG_IMPORTANT', 'OR', '","'])
-    comparison_rsts = set(['LPAR', 'QSTR', 'RPAR', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', 'GT', 'END', 'SIGN', 'ADD', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'GE', 'NOT', 'OR', '","'])
+    expr_slst_rsts = set(['"url"', 'LPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID', '","'])
+    atom_rsts__ = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'VAR', 'MUL', 'DIV', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', '"url"', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'UNITS', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
+    or_expr_rsts = set(['"url"', 'LPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'ID', 'BANG_IMPORTANT', 'OR', '","'])
+    and_expr_rsts = set(['AND', 'LPAR', 'RPAR', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', '"url"', 'FNCT', 'STR', 'NOT', 'ID', 'BANG_IMPORTANT', 'OR', '","'])
+    comparison_rsts = set(['LPAR', 'QSTR', 'RPAR', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', '"url"', 'GT', 'END', 'SIGN', 'ADD', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'GE', 'NOT', 'OR', '","'])
     argspec_chks = set(['DOTDOTDOT', 'SLURPYVAR'])
-    atom_rsts_ = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'VAR', 'MUL', 'DIV', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'UNITS', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
+    atom_rsts_ = set(['URL', '"\\""', '"\'"'])
     expr_map_rsts_ = set(['KWVAR', 'KWID', 'KWSTR', 'KWQSTR', 'RPAR', 'KWCOLOR', '":"', 'KWNUM', '","'])
-    u_expr_rsts = set(['LPAR', 'COLOR', 'QSTR', 'SIGN', 'ADD', 'NUM', 'FNCT', 'STR', 'VAR', 'BANG_IMPORTANT', 'ID'])
+    u_expr_rsts = set(['"url"', 'LPAR', 'COLOR', 'QSTR', 'SIGN', 'ADD', 'NUM', 'FNCT', 'STR', 'VAR', 'BANG_IMPORTANT', 'ID'])
     comparison_chks = set(['GT', 'GE', 'NE', 'LT', 'LE', 'EQ'])
-    argspec_items_rsts_ = set(['KWVAR', 'LPAR', 'QSTR', 'END', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'SIGN', 'VAR', 'ADD', 'NUM', 'RPAR', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
-    a_expr_rsts = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
+    argspec_items_rsts_ = set(['KWVAR', 'LPAR', 'RPAR', 'QSTR', 'END', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'SIGN', 'VAR', 'ADD', 'NUM', '"url"', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
+    a_expr_rsts = set(['LPAR', 'SUB', 'QSTR', 'RPAR', 'BANG_IMPORTANT', 'LE', 'COLOR', 'NE', 'LT', 'NUM', '"url"', 'GT', 'END', 'SIGN', 'GE', 'FNCT', 'STR', 'VAR', 'EQ', 'ID', 'AND', 'ADD', 'NOT', 'OR', '","'])
     m_expr_chks = set(['MUL', 'DIV'])
     kwatom_rsts_ = set(['UNITS', '":"'])
-    argspec_items_chks = set(['KWVAR', 'LPAR', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
-    argspec_rsts = set(['KWVAR', 'LPAR', 'BANG_IMPORTANT', 'END', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'RPAR', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'QSTR', 'SIGN', 'ID'])
-    atom_rsts = set(['KWVAR', 'KWID', 'KWSTR', 'BANG_IMPORTANT', 'LPAR', 'COLOR', 'KWQSTR', 'SIGN', 'RPAR', 'KWCOLOR', 'VAR', 'ADD', 'NUM', '":"', 'STR', 'NOT', 'QSTR', 'KWNUM', 'ID', 'FNCT'])
+    argspec_items_chks = set(['KWVAR', '"url"', 'LPAR', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'BANG_IMPORTANT', 'ID'])
+    argspec_rsts = set(['KWVAR', 'LPAR', 'BANG_IMPORTANT', 'END', 'SLURPYVAR', 'COLOR', 'DOTDOTDOT', 'RPAR', 'VAR', 'ADD', 'NUM', '"url"', 'FNCT', 'STR', 'NOT', 'QSTR', 'SIGN', 'ID'])
+    atom_rsts = set(['KWVAR', 'KWID', 'KWSTR', 'BANG_IMPORTANT', 'LPAR', 'COLOR', 'KWQSTR', 'SIGN', 'RPAR', 'KWCOLOR', 'VAR', 'ADD', 'NUM', '"url"', '":"', 'STR', 'NOT', 'QSTR', 'KWNUM', 'ID', 'FNCT'])
     argspec_chks_ = set(['END', 'RPAR'])
-    argspec_rsts_ = set(['KWVAR', 'LPAR', 'BANG_IMPORTANT', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', 'FNCT', 'STR', 'NOT', 'RPAR', 'ID'])
+    argspec_rsts_ = set(['KWVAR', 'LPAR', 'BANG_IMPORTANT', 'END', 'COLOR', 'QSTR', 'SIGN', 'VAR', 'ADD', 'NUM', '"url"', 'FNCT', 'STR', 'NOT', 'RPAR', 'ID'])
 
 
 ### Grammar ends.
diff --git a/scss/src/grammar/grammar.g b/scss/src/grammar/grammar.g
index 135d594..58489aa 100644
--- a/scss/src/grammar/grammar.g
+++ b/scss/src/grammar/grammar.g
@@ -40,6 +40,10 @@ parser SassExpression:
     token KWID: "[-a-zA-Z_][-a-zA-Z0-9_]*(?=\s*:)"
     token ID: "[-a-zA-Z_][-a-zA-Z0-9_]*"
     token BANG_IMPORTANT: "!important"
+    # http://dev.w3.org/csswg/css-syntax-3/#consume-a-url-token0
+    # URLs may not contain quotes, parentheses, or unprintables
+    # TODO reify escapes, for this and for strings
+    token URL: "(?:[\\\\].|[^'\"()\\x00-\\x08\\x0b\\x0e-\\x1f\\x7f])*"
 
     # Goals:
     rule goal:          expr_lst END                {{ return expr_lst }}
@@ -152,6 +156,17 @@ parser SassExpression:
             | expr_map              {{ v = expr_map }}
             | expr_lst              {{ v = expr_lst }}
         ) RPAR                      {{ return Parentheses(v) }}
+        # Special functions.  Note that these technically overlap with the
+        # regular function rule, which makes this not quite LL -- but they're
+        # different tokens so yapps can't tell, and it resolves the conflict by
+        # picking the first one.
+        | "url" LPAR
+            (
+                URL                 {{ quotes = None }}
+                | "\"" URL "\""     {{ quotes = '"' }}
+                | "'" URL "'"       {{ quotes = "'" }}
+            )
+            RPAR                    {{ return Literal(Url(URL, quotes=quotes)) }}
         | FNCT LPAR argspec RPAR    {{ return CallOp(FNCT, argspec) }}
         | BANG_IMPORTANT            {{ return Literal(String(BANG_IMPORTANT, quotes=None)) }}
         | ID                        {{ return Literal(parse_bareword(ID)) }}
diff --git a/scss/types.py b/scss/types.py
index ef28748..27528e2 100644
--- a/scss/types.py
+++ b/scss/types.py
@@ -1062,6 +1062,13 @@ class String(Value):
         return self.__str__()
 
 
+class Url(String):
+    def render(self, compress=False):
+        # TODO url-escape whatever needs escaping
+        # TODO does that mean we should un-url-escape when parsing?  probably
+        return "url({0})".format(super(String, self).render(compress))
+
+
 class Map(Value):
     sass_type_name = six.u('map')