anchor.diff:  %%
   parser SassExpression:
       ignore: "[ \r\t\n]+"
  -    token COMMA: ","
       token LPAR: "\\(|\\["
       token RPAR: "\\)|\\]"
       token END: "$"
  
positive.code:     token UNITS: "(?<!\s)(?:[a-zA-Z]+|%)(?![-\w])"
      token NUM: "(?:\d+(?:\.\d*)?|\.\d+)"
      token COLOR: "#(?:[a-fA-F0-9]{6}|[a-fA-F0-9]{3})(?![a-fA-F0-9])"
      token VAR: "\$[-a-zA-Z0-9_]+"
      token FNCT: "[-a-zA-Z_][-a-zA-Z0-9_]*(?=\()"
      token ID: "[-a-zA-Z_][-a-zA-Z0-9_]*"
  
negative.code: 
      rule argspec:       argspec_item                {{ v = [argspec_item] }}
                          (
                              ","
                              argspec_item            {{ v.append(argspec_item) }}
                          )*                          {{ return ArgspecLiteral(v) }}
  
      rule argspec_item:
                          KWVAR ":" expr_slst         {{ return (KWVAR, expr_slst) }}
                          | expr_slst                 {{ return (None, expr_slst) }}
  
      rule expr_lst:      expr_slst                   {{ v = [expr_slst] }}
                          (
                              ","
                              expr_slst               {{ v.append(expr_slst) }}
                          )*                          {{ return ListLiteral(v) if len(v) > 1 else v[0] }}
  
  