The first version of csspp which with 100% coverage tests is now out. The .tar.gz is not yet available because SourceForge.net still has a few problems... but you can grab the source from the GIT repository.

The library (and thus command line tool) include support for a very large number of internal functions, variables, user defined functions (without support for the @return yet), nested rules, nested attributes, C/C++ like expressions, arrays, maps, color operations, etc.

The expression support the following types:

• Integer (numbers without a period)
• Decimal number
• Percentage
• Boolean (the identifiers "true" or "false", result of relational comparisons)
• String
• Color, as hash definitions (#121212) or an identifier naming a color (teal, chocolate, marron, etc.)
• Unicode Range
• URL
• NULL

Most of the operators are supported:

• - and + -- unary operators to negate or compute the entity; these require spaces
• ** -- the power operator works on numbers
• * -- multiply numbers, duplicate strings, compute unicode range intersections
• / -- divide numbers; some fields do not support this operator unless written between parenthesis or as the identifier div
• % -- compute modulos
• + -- add numbers, concatenate strings
• - -- subtract numbers
• <, <=, >, >= -- relational operators work on numbers, booleans, and strings
• =, != -- equality operators work on numbers, booleans, strings, and colors
• &&, || -- logical and and or operators; work on booleans, numbers, etc.
• ?: -- the C/C++ conditional operator
• := -- variable assignment
• () -- array and map definitions

And expressions support many internal functions (still to be grown!):

• algebra: abs, ceil, floor, log, max, min, random, round, sign, sqrt
• boolean: not
• color: alpha, blue, frgb, frgba, green, hsl, hsla, hue, lightness, red, rgb, rgba, saturation
• conversion: decimal_number, identifier, integer, percentage, string, unit
• string: str_length, unique_id
• system: function_exists, global_variable_exists, if, inspect, type_of, variable_exists
• trigonometry: acos, asin, atan, cos, sin, tan