# -*- coding: utf-8 -*- """ CleverCSS ~~~~~~~~~ The Pythonic way of CSS files. To convert this into a normal css file just call the `convert` function in the clevercss module. It's that easy :-) Example:: base_padding = 2px background_color = #eee text_color = #111 link_color = #ff0000 body: font-family: serif, sans-serif, 'Verdana', 'Times New Roman' color: $text_color padding-> top: $base_padding + 2 right: $base_padding + 3 left: $base_padding + 3 bottom: $base_padding + 2 background-color: $background_color div.foo: width: "Hello World".length() * 20px foo: (foo, bar, baz, 42).join('/') a: color: $link_color &:hover: color: $link_color.darken(30%) &:active: color: $link_color.brighten(10%) div.navigation: height: 1.2em padding: 0.2em ul: margin: 0 padding: 0 list-style: none li: float: left height: 1.2em a: display: block height: 1em padding: 0.1em foo: (1 2 3).string() __END__ this is ignored, but __END__ as such is completely optional. To get the converted example module as css just run this file as script with the "--eigen-test" parameter. Literals -------- CleverCSS supports most of the standard CSS literals. Some syntax elements are not supported by now, some will probably never. Strings: everything (except of dangling method calls and whitespace) that cannot be parsed with a different rule is considered being a string. If you want to have whitespace in your strings or use something as string that would otherwise have a different semantic you can use double or single quotes. these are all valid strings:: = foo-bar-baz "blub" 'foo bar baz' Verdana Numbers Numbers are just that. Numbers with unit postfix are values. Values Values are numbers with an associated unit. Most obvious difference between those two are the different semantics in arithmetic operations. Some units can be converted, some are just not compatible (for example you won't be able to convert 1em in percent because there is no fixed conversion possible) Additionally to the CSS supported colors this module supports the netscape color codes. Colors Colors are so far only supported in hexadecimal notation. You can also use the `rgb()` literal to some amount. But that means you cannot use "orange" as color. URLs: URLs work like strings, the only difference is that the syntax looks like ``url(...)``. Variables: variables are quite simple. Once they are defined in the root section you can use them in every expression:: foo = 42px div: width: $foo * 100; Lists: Sometimes you want to assign more than one element to a CSS rule. For example if you work with font families. In that situation just use the comma operator to define a list:: font-family: Verdana, Arial, sans-serif Additionally lists have methods, you can for example do this (although probably completely useless in real world cases):: width: (1, 2, 3, 4).length() * 20 Implicit Concatenation ---------------------- CleverCSS ignores whitespace. But whitespace keeps the tokens apart. If the parser now stumbles upon something it doesn't know how to handle, it assumes that there was a whitespace. In some situations CSS even requires that behavior:: padding: 2px 3px But because CleverCSS has expressions this could lead to this situation:: padding: $x + 1 $x + 2 This if course works too because ``$x + 1`` is one expression and ``$x + 2`` another one. This however can lead to code that is harder to read. In that situation it's recommended to parentize the expressions:: padding: ($x + 1) ($x + 2) or remove the whitespace between the operators:: padding: $x+1 $x+2 Operators --------- ``+`` add two numbers, a number and a value or two compatible values (for example ``1cm + 12mm``). This also works as concatenate operator for strings. Using this operator on color objects allows some basic color composition. ``-`` subtract one number from another, a number from a value or a value from a compatible one. Like the plus operator this also works on colors. ``*`` Multiply numbers, numbers with a value. Multiplying strings repeats it. (eg: ``= * 5`` gives '=====') ``/`` divide one number or value by a number. ``%`` do a modulo division on a number or value by a number. Keep in mind that whitespace matters. For example ``20% 10`` is something completely different than ``20 % 10``. The first one is an implicit concatenation expression with the values 20% and 10, the second one a modulo epression. The same applies to ``no-wrap`` versus ``no - wrap`` and others. Additionally there are two operators used to keep list items apart. The comma (``,``) and semicolon (``;``) operator both keep list items apart. If you want to group expressions you can use parentheses. Methods ------- Objects have some methods you can call: - `Number.abs()` get the absolute value of the number - `Number.round(places)` round to (default = 0) places - `Value.abs()` get the absolute value for this value - `Value.round(places)` round the value to (default = 0) places - `Color.brighten(amount)` brighten the color by amount percent of the current lightness, or by 0 - 100. brighening by 100 will result in white. - `Color.darken(amount)` darken the color by amount percent of the current lightness, or by 0 - 100. darkening by 100 will result in black. - `String.length()` the length of the string. - `String.upper()` uppercase version of the string. - `String.lower()` lowercase version of the string. - `String.strip()` version with leading an trailing whitespace removed. - `String.split(delim)` return a list of substrings, splitted by whitespace or delim. - `String.eval()` eval a css rule inside of a string. For example a string "42" would return the number 42 when parsed. But this can also contain complex expressions such as "(1 + 2) * 3px". - `String.string()` just return the string itself. - `List.length()` number of elements in a list. - `List.join(delim)` join a list by space char or delim. Additionally all objects and expressions have a `.string()` method that converts the object into a string, and a `.type()` method that returns the type of the object as string. If you have implicit concatenated expressions you can convert them into a list using the `list` method:: (1 2 3 4 5).list() does the same as:: 1, 2, 3, 4, 5 :copyright: Copyright 2007 by Armin Ronacher, Georg Brandl. :license: BSD License """ import re import colorsys import operator VERSION = '0.1' __all__ = ['convert'] # regular expresssions for the normal parser _var_def_re = re.compile(r'^([a-zA-Z_][a-zA-Z0-9_]*)\s*=\s*(.+)') _def_re = re.compile(r'^([a-zA-Z-]+)\s*:\s*(.+)') _line_comment_re = re.compile(r'//.*?$') # list of operators _operators = ['+', '-', '*', '/', '%', '(', ')', ';', ','] # units and conversions _units = ['em', 'ex', 'px', 'cm', 'mm', 'in', 'pt', 'pc', 'deg', 'rad' 'grad', 'ms', 's', 'Hz', 'kHz', '%'] _conv = { 'length': { 'mm': 1.0, 'cm': 10.0, 'in': 25.4, 'pt': 25.4 / 72, 'pc': 25.4 / 6 }, 'time': { 'ms': 1.0, 's': 1000.0 }, 'freq': { 'Hz': 1.0, 'kHz': 1000.0 } } _conv_mapping = {} for t, m in _conv.items(): for k in m: _conv_mapping[k] = t del t, m, k # color literals _colors = { 'aliceblue': '#f0f8ff', 'antiquewhite': '#faebd7', 'aqua': '#00ffff', 'aquamarine': '#7fffd4', 'azure': '#f0ffff', 'beige': '#f5f5dc', 'bisque': '#ffe4c4', 'black': '#000000', 'blanchedalmond': '#ffebcd', 'blue': '#0000ff', 'blueviolet': '#8a2be2', 'brown': '#a52a2a', 'burlywood': '#deb887', 'cadetblue': '#5f9ea0', 'chartreuse': '#7fff00', 'chocolate': '#d2691e', 'coral': '#ff7f50', 'cornflowerblue': '#6495ed', 'cornsilk': '#fff8dc', 'crimson': '#dc143c', 'cyan': '#00ffff', 'darkblue': '#00008b', 'darkcyan': '#008b8b', 'darkgoldenrod': '#b8860b', 'darkgray': '#a9a9a9', 'darkgreen': '#006400', 'darkkhaki': '#bdb76b', 'darkmagenta': '#8b008b', 'darkolivegreen': '#556b2f', 'darkorange': '#ff8c00', 'darkorchid': '#9932cc', 'darkred': '#8b0000', 'darksalmon': '#e9967a', 'darkseagreen': '#8fbc8f', 'darkslateblue': '#483d8b', 'darkslategray': '#2f4f4f', 'darkturquoise': '#00ced1', 'darkviolet': '#9400d3', 'deeppink': '#ff1493', 'deepskyblue': '#00bfff', 'dimgray': '#696969', 'dodgerblue': '#1e90ff', 'firebrick': '#b22222', 'floralwhite': '#fffaf0', 'forestgreen': '#228b22', 'fuchsia': '#ff00ff', 'gainsboro': '#dcdcdc', 'ghostwhite': '#f8f8ff', 'gold': '#ffd700', 'goldenrod': '#daa520', 'gray': '#808080', 'green': '#008000', 'greenyellow': '#adff2f', 'honeydew': '#f0fff0', 'hotpink': '#ff69b4', 'indianred': '#cd5c5c', 'indigo': '#4b0082', 'ivory': '#fffff0', 'khaki': '#f0e68c', 'lavender': '#e6e6fa', 'lavenderblush': '#fff0f5', 'lawngreen': '#7cfc00', 'lemonchiffon': '#fffacd', 'lightblue': '#add8e6', 'lightcoral': '#f08080', 'lightcyan': '#e0ffff', 'lightgoldenrodyellow': '#fafad2', 'lightgreen': '#90ee90', 'lightgrey': '#d3d3d3', 'lightpink': '#ffb6c1', 'lightsalmon': '#ffa07a', 'lightseagreen': '#20b2aa', 'lightskyblue': '#87cefa', 'lightslategray': '#778899', 'lightsteelblue': '#b0c4de', 'lightyellow': '#ffffe0', 'lime': '#00ff00', 'limegreen': '#32cd32', 'linen': '#faf0e6', 'magenta': '#ff00ff', 'maroon': '#800000', 'mediumaquamarine': '#66cdaa', 'mediumblue': '#0000cd', 'mediumorchid': '#ba55d3', 'mediumpurple': '#9370db', 'mediumseagreen': '#3cb371', 'mediumslateblue': '#7b68ee', 'mediumspringgreen': '#00fa9a', 'mediumturquoise': '#48d1cc', 'mediumvioletred': '#c71585', 'midnightblue': '#191970', 'mintcream': '#f5fffa', 'mistyrose': '#ffe4e1', 'moccasin': '#ffe4b5', 'navajowhite': '#ffdead', 'navy': '#000080', 'oldlace': '#fdf5e6', 'olive': '#808000', 'olivedrab': '#6b8e23', 'orange': '#ffa500', 'orangered': '#ff4500', 'orchid': '#da70d6', 'palegoldenrod': '#eee8aa', 'palegreen': '#98fb98', 'paleturquoise': '#afeeee', 'palevioletred': '#db7093', 'papayawhip': '#ffefd5', 'peachpuff': '#ffdab9', 'peru': '#cd853f', 'pink': '#ffc0cb', 'plum': '#dda0dd', 'powderblue': '#b0e0e6', 'purple': '#800080', 'red': '#ff0000', 'rosybrown': '#bc8f8f', 'royalblue': '#4169e1', 'saddlebrown': '#8b4513', 'salmon': '#fa8072', 'sandybrown': '#f4a460', 'seagreen': '#2e8b57', 'seashell': '#fff5ee', 'sienna': '#a0522d', 'silver': '#c0c0c0', 'skyblue': '#87ceeb', 'slateblue': '#6a5acd', 'slategray': '#708090', 'snow': '#fffafa', 'springgreen': '#00ff7f', 'steelblue': '#4682b4', 'tan': '#d2b48c', 'teal': '#008080', 'thistle': '#d8bfd8', 'tomato': '#ff6347', 'turquoise': '#40e0d0', 'violet': '#ee82ee', 'wheat': '#f5deb3', 'white': '#ffffff', 'whitesmoke': '#f5f5f5', 'yellow': '#ffff00', 'yellowgreen': '#9acd32' } _reverse_colors = dict((v, k) for k, v in _colors.items()) # partial regular expressions for the expr parser _r_number = '\d+(?:\.\d+)?' _r_string = r"(?:'(?:[^'\\]*(?:\\.[^'\\]*)*)'|" \ r'\"(?:[^"\\]*(?:\\.[^"\\]*)*)")' _r_call = r'([a-zA-Z_][a-zA-Z0-9_]*)\(' # regular expressions for the expr parser _operator_re = re.compile('|'.join(re.escape(x) for x in _operators)) _whitespace_re = re.compile(r'\s+') _number_re = re.compile(_r_number + '(?![a-zA-Z0-9_])') _value_re = re.compile(r'(%s)(%s)(?![a-zA-Z0-9_])' % (_r_number, '|'.join(_units))) _color_re = re.compile(r'#' + ('[a-fA-f0-9]{1,2}' * 3)) _string_re = re.compile('%s|([^\s*/();,.+$]+|\.(?!%s))+' % (_r_string, _r_call)) _url_re = re.compile(r'url\(\s*(%s|.*?)\s*\)' % _r_string) _var_re = re.compile(r'(?>> li = LineIterator(u'foo\nbar\n\n/* foo */bar') >>> li.next() 1, u'foo' >>> li.next() 2, 'bar' >>> li.next() 4, 'bar' >>> li.next() Traceback (most recent call last): File "", line 1, in StopIteration """ def __init__(self, source, emit_endmarker=False): """ If `emit_endmarkers` is set to `True` the line iterator will send the string ``'__END__'`` before closing down. """ lines = source.splitlines() self.lineno = 0 self.lines = len(lines) self.emit_endmarker = emit_endmarker self._lineiter = iter(lines) def __iter__(self): return self def _read_line(self): """Read the next non empty line. This strips line comments.""" line = '' while not line.strip(): line += _line_comment_re.sub('', next(self._lineiter)).rstrip() self.lineno += 1 return line def _next(self): """ Get the next line without mutliline comments. """ # XXX: this fails for a line like this: "/* foo */bar/*" line = self._read_line() comment_start = line.find('/*') if comment_start < 0: return self.lineno, line stripped_line = line[:comment_start] comment_end = line.find('*/', comment_start) if comment_end >= 0: return self.lineno, stripped_line + line[comment_end + 2:] start_lineno = self.lineno try: while True: line = self._read_line() comment_end = line.find('*/') if comment_end >= 0: stripped_line += line[comment_end + 2:] break except StopIteration: raise ParserError(self.lineno, 'missing end of multiline comment') return start_lineno, stripped_line def __next__(self): """ Get the next line without multiline comments and emit the endmarker if we reached the end of the sourcecode and endmarkers were requested. """ try: return self._next() except StopIteration: if self.emit_endmarker: self.emit_endmarker = False return self.lineno, '__END__' raise class Engine(object): """ The central object that brings parser and evaluation together. Usually nobody uses this because the `convert` function wraps it. """ def __init__(self, source): self._parser = p = Parser() self.rules, self._vars = p.parse(source) def evaluate(self, context=None): """Evaluate code.""" expr = None context = {} for key, value in context.items(): expr = self._parser.parse_expr(1, value) context[key] = expr context.update(self._vars) for selectors, defs in self.rules: yield selectors, [(key, expr.to_string(context)) for key, expr in defs] def to_css(self, context=None): """Evaluate the code and generate a CSS file.""" blocks = [] for selectors, defs in self.evaluate(context): block = [] block.append(',\n'.join(selectors) + ' {') for key, value in defs: block.append(' %s: %s;' % (key, value)) block.append('}') blocks.append('\n'.join(block)) return '\n\n'.join(blocks) class TokenStream(object): """ This is used by the expression parser to manage the tokens. """ def __init__(self, lineno, gen): self.lineno = lineno self.gen = gen next(self) def __next__(self): try: self.current = next(self.gen) except StopIteration: self.current = None, 'eof' def expect(self, value, token): if self.current != (value, token): raise ParserError(self.lineno, "expected '%s', got '%s'." % (value, self.current[0])) next(self) class Expr(object): """ Baseclass for all expressions. """ #: name for exceptions name = 'expression' #: empty iterable of dict with methods methods = () def __init__(self, lineno=None): self.lineno = lineno def evaluate(self, context): return self def add(self, other, context): return String(self.to_string(context) + other.to_string(context)) def sub(self, other, context): raise EvalException(self.lineno, 'cannot substract %s from %s' % (self.name, other.name)) def mul(self, other, context): raise EvalException(self.lineno, 'cannot multiply %s with %s' % (self.name, other.name)) def div(self, other, context): raise EvalException(self.lineno, 'cannot divide %s by %s' % (self.name, other.name)) def mod(self, other, context): raise EvalException(self.lineno, 'cannot use the modulo operator for ' '%s and %s. Misplaced unit symbol?' % (self.name, other.name)) def neg(self, context): raise EvalException(self.lineno, 'cannot negate %s by %s' % self.name) def to_string(self, context): return self.evaluate(context).to_string(context) def call(self, name, args, context): if name == 'string': if isinstance(self, String): return self return String(self.to_string(context)) elif name == 'type': return String(self.name) if name not in self.methods: raise EvalException(self.lineno, '%s objects don\'t have a method' ' called "%s". If you want to use this' ' construct as string, quote it.' % (self.name, name)) return self.methods[name](self, context, *args) def __repr__(self): return '%s(%s)' % ( self.__class__.__name__, ', '.join('%s=%r' % item for item in self.__dict__.items()) ) class ImplicitConcat(Expr): """ Holds multiple expressions that are delimited by whitespace. """ name = 'concatenated' methods = { 'list': lambda x, c: List(x.nodes) } def __init__(self, nodes, lineno=None): Expr.__init__(self, lineno) self.nodes = nodes def to_string(self, context): return ' '.join(x.to_string(context) for x in self.nodes) class Bin(Expr): def __init__(self, left, right, lineno=None): Expr.__init__(self, lineno) self.left = left self.right = right class Add(Bin): def evaluate(self, context): return self.left.evaluate(context).add( self.right.evaluate(context), context) class Sub(Bin): def evaluate(self, context): return self.left.evaluate(context).sub( self.right.evaluate(context), context) class Mul(Bin): def evaluate(self, context): return self.left.evaluate(context).mul( self.right.evaluate(context), context) class Div(Bin): def evaluate(self, context): return self.left.evaluate(context).div( self.right.evaluate(context), context) class Mod(Bin): def evaluate(self, context): return self.left.evaluate(context).mod( self.right.evaluate(context), context) class Neg(Expr): def __init__(self, node, lineno=None): Expr.__init__(self, lineno) self.node = node def evaluate(self, context): return self.node.evaluate(context).neg(context) class Call(Expr): def __init__(self, node, method, args, lineno=None): Expr.__init__(self, lineno) self.node = node self.method = method self.args = args def evaluate(self, context): return self.node.evaluate(context) \ .call(self.method, [x.evaluate(context) for x in self.args], context) class Literal(Expr): def __init__(self, value, lineno=None): Expr.__init__(self, lineno) self.value = value def to_string(self, context): rv = str(self.value) if len(rv.split(None, 1)) > 1: return "'%s'" % rv.replace('\\', '\\\\') \ .replace('\n', '\\\n') \ .replace('\t', '\\\t') \ .replace('\'', '\\\'') return rv class Number(Literal): name = 'number' methods = { 'abs': lambda x, c: Number(abs(x.value)), 'round': lambda x, c, p=0: Number(round(x.value, p)) } def __init__(self, value, lineno=None): Literal.__init__(self, float(value), lineno) def add(self, other, context): if isinstance(other, Number): return Number(self.value + other.value, lineno=self.lineno) elif isinstance(other, Value): return Value(self.value + other.value, other.unit, lineno=self.lineno) return Literal.add(self, other, context) def sub(self, other, context): if isinstance(other, Number): return Number(self.value - other.value, lineno=self.lineno) elif isinstance(other, Value): return Value(self.value - other.value, other.unit, lineno=self.lineno) return Literal.sub(self, other, context) def mul(self, other, context): if isinstance(other, Number): return Number(self.value * other.value, lineno=self.lineno) elif isinstance(other, Value): return Value(self.value * other.value, other.unit, lineno=self.lineno) return Literal.mul(self, other, context) def div(self, other, context): try: if isinstance(other, Number): return Number(self.value / other.value, lineno=self.lineno) elif isinstance(other, Value): return Value(self.value / other.value, other.unit, lineno=self.lineno) return Literal.div(self, other, context) except ZeroDivisionError: raise EvalException(self.lineno, 'cannot divide by zero') def mod(self, other, context): try: if isinstance(other, Number): return Number(self.value % other.value, lineno=self.lineno) elif isinstance(other, Value): return Value(self.value % other.value, other.unit, lineno=self.lineno) return Literal.mod(self, other, context) except ZeroDivisionError: raise EvalException(self.lineno, 'cannot divide by zero') def neg(self, context): return Number(-self.value) def to_string(self, context): return number_repr(self.value) class Value(Literal): name = 'value' methods = { 'abs': lambda x, c: Value(abs(x.value), x.unit), 'round': lambda x, c, p=0: Value(round(x.value, p), x.unit) } def __init__(self, value, unit, lineno=None): Literal.__init__(self, float(value), lineno) self.unit = unit def add(self, other, context): return self._conv_calc(other, context, operator.add, Literal.add, 'cannot add %s and %s') def sub(self, other, context): return self._conv_calc(other, context, operator.sub, Literal.sub, 'cannot subtract %s from %s') def mul(self, other, context): if isinstance(other, Number): return Value(self.value * other.value, self.unit, lineno=self.lineno) return Literal.mul(self, other, context) def div(self, other, context): if isinstance(other, Number): try: return Value(self.value / other.value, self.unit, lineno=self.lineno) except ZeroDivisionError: raise EvalException(self.lineno, 'cannot divide by zero', lineno=self.lineno) return Literal.div(self, other, context) def mod(self, other, context): if isinstance(other, Number): try: return Value(self.value % other.value, self.unit, lineno=self.lineno) except ZeroDivisionError: raise EvalException(self.lineno, 'cannot divide by zero') return Literal.mod(self, other, context) def _conv_calc(self, other, context, calc, fallback, msg): if isinstance(other, Number): return Value(calc(self.value, other.value), self.unit) elif isinstance(other, Value): if self.unit == other.unit: return Value(self.value + other.value, other.unit, lineno=self.lineno) self_unit_type = _conv_mapping.get(self.unit) other_unit_type = _conv_mapping.get(other.unit) if not self_unit_type or not other_unit_type or \ self_unit_type != other_unit_type: raise EvalException(self.lineno, msg % (self.unit, other.unit) + ' because the two units are ' 'not compatible.') self_unit = _conv[self_unit_type][self.unit] other_unit = _conv[other_unit_type][other.unit] if self_unit > other_unit: return Value(calc(self.value / other_unit * self_unit, other.value), other.unit, lineno=self.lineno) return Value(calc(other.value / self_unit * other_unit, self.value), self.unit, lineno=self.lineno) return fallback(self, other, context) def neg(self, context): return Value(-self.value, self.unit, lineno=self.lineno) def to_string(self, context): return number_repr(self.value) + self.unit def brighten_color(color, context, amount=None): if amount is None: amount = Value(10.0, '%') hue, lightness, saturation = rgb_to_hls(*color.value) if isinstance(amount, Value): if amount.unit == '%': if not amount.value: return color lightness *= 1.0 + amount.value / 100.0 else: raise EvalException(self.lineno, 'invalid unit %s for color ' 'calculations.' % amount.unit) elif isinstance(amount, Number): lightness += (amount.value / 100.0) if lightness > 1: lightness = 1.0 return Color(hls_to_rgb(hue, lightness, saturation)) def darken_color(color, context, amount=None): if amount is None: amount = Value(10.0, '%') hue, lightness, saturation = rgb_to_hls(*color.value) if isinstance(amount, Value): if amount.unit == '%': if not amount.value: return color lightness *= amount.value / 100.0 else: raise EvalException(self.lineno, 'invalid unit %s for color ' 'calculations.' % amount.unit) elif isinstance(amount, Number): lightness -= (amount.value / 100.0) if lightness < 0: lightness = 0.0 return Color(hls_to_rgb(hue, lightness, saturation)) class Color(Literal): name = 'color' methods = { 'brighten': brighten_color, 'darken': darken_color, 'hex': lambda x, c: Color(x.value, x.lineno) } def __init__(self, value, lineno=None): self.from_name = False if isinstance(value, str): if not value.startswith('#'): value = _colors.get(value) if not value: raise ParserError(lineno, 'unknown color name') self.from_name = True try: if len(value) == 4: value = [int(x * 2, 16) for x in value[1:]] elif len(value) == 7: value = [int(value[i:i + 2], 16) for i in range(1, 7, 2)] else: raise ValueError() except ValueError as e: raise ParserError(lineno, 'invalid color value') Literal.__init__(self, tuple(value), lineno) def add(self, other, context): if isinstance(other, (Color, Number)): return self._calc(other, operator.add) return Literal.add(self, other, context) def sub(self, other, context): if isinstance(other, (Color, Number)): return self._calc(other, operator.sub) return Literal.sub(self, other, context) def mul(self, other, context): if isinstance(other, (Color, Number)): return self._calc(other, operator.mul) return Literal.mul(self, other, context) def div(self, other, context): if isinstance(other, (Color, Number)): return self._calc(other, operator.sub) return Literal.div(self, other, context) def to_string(self, context): code = '#%02x%02x%02x' % self.value return self.from_name and _reverse_colors.get(code) or code def _calc(self, other, method): is_number = isinstance(other, Number) channels = [] for idx, val in enumerate(self.value): if is_number: other_val = int(other.value) else: other_val = other.value[idx] new_val = method(val, other_val) if new_val > 255: new_val = 255 elif new_val < 0: new_val = 0 channels.append(new_val) return Color(tuple(channels), lineno=self.lineno) class RGB(Expr): """ an expression that hopefully returns a Color object. """ def __init__(self, rgb, lineno=None): Expr.__init__(self, lineno) self.rgb = rgb def evaluate(self, context): args = [] for arg in self.rgb: arg = arg.evaluate(context) if isinstance(arg, Number): value = int(arg.value) elif isinstance(arg, Value) and arg.unit == '%': value = int(arg.value / 100.0 * 255) else: raise EvalException(self.lineno, 'colors defined using the ' 'rgb() literal only accept numbers and ' 'percentages.') if value < 0 or value > 255: raise EvalError(self.lineno, 'rgb components must be in ' 'the range 0 to 255.') args.append(value) return Color(args, lineno=self.lineno) class String(Literal): name = 'string' methods = { 'length': lambda x, c: Number(len(x.value)), 'upper': lambda x, c: String(x.value.upper()), 'lower': lambda x, c: String(x.value.lower()), 'strip': lambda x, c: String(x.value.strip()), 'split': lambda x, c, d=None: String(x.value.split(d)), 'eval': lambda x, c: Parser().parse_expr(x.lineno, x.value) .evaluate(c) } def mul(self, other, context): if isinstance(other, Number): return String(self.value * int(other.value), lineno=self.lineno) return Literal.mul(self, other, context, lineno=self.lineno) class URL(Literal): name = 'URL' methods = { 'length': lambda x, c: Number(len(self.value)) } def add(self, other, context): return URL(self.value + other.to_string(context), lineno=self.lineno) def mul(self, other, context): if isinstance(other, Number): return URL(self.value * int(other.value), lineno=self.lineno) return Literal.mul(self, other, context) def to_string(self, context): return 'url(%s)' % Literal.to_string(self, context) class Var(Expr): def __init__(self, name, lineno=None): self.name = name self.lineno = lineno def evaluate(self, context): if self.name not in context: raise EvalException(self.lineno, 'variable %s is not defined' % (self.name,)) val = context[self.name] context[self.name] = FailingVar(self, self.lineno) try: return val.evaluate(context) finally: context[self.name] = val class FailingVar(Expr): def __init__(self, var, lineno=None): Expr.__init__(self, lineno or var.lineno) self.var = var def evaluate(self, context): raise EvalException(self.lineno, 'Circular variable dependencies ' 'detected when resolving %s.' % (self.var.name,)) class List(Expr): name = 'list' methods = { 'length': lambda x, c: Number(len(x.items)), 'join': lambda x, c, d=String(' '): String(d.value.join( a.to_string(c) for a in x.items)) } def __init__(self, items, lineno=None): Expr.__init__(self, lineno) self.items = items def add(self, other): if isinstance(other, List): return List(self.items + other.items, lineno=self.lineno) return List(self.items + [other], lineno=self.lineno) def to_string(self, context): return ', '.join(x.to_string(context) for x in self.items) class Parser(object): """ Class with a bunch of methods that implement a tokenizer and parser. In fact this class has two parsers. One that splits up the code line by line and keeps track of indentions, and a second one for expressions in the value parts. """ def preparse(self, source): """ Do the line wise parsing and resolve indents. """ rule = (None, [], []) vars = {} indention_stack = [0] state_stack = ['root'] group_block_stack = [] rule_stack = [rule] root_rules = rule[1] new_state = None lineiter = LineIterator(source, emit_endmarker=True) def fail(msg): raise ParserError(lineno, msg) def parse_definition(): m = _def_re.search(line) if m is None: fail('invalid syntax for style definition') return lineiter.lineno, m.group(1), m.group(2) for lineno, line in lineiter: raw_line = line.rstrip().expandtabs() line = raw_line.lstrip() indention = len(raw_line) - len(line) # indenting if indention > indention_stack[-1]: if not new_state: fail('unexpected indent') state_stack.append(new_state) indention_stack.append(indention) new_state = None # dedenting elif indention < indention_stack[-1]: for level in indention_stack: if level == indention: while indention_stack[-1] != level: if state_stack[-1] == 'rule': rule = rule_stack.pop() elif state_stack[-1] == 'group_block': name, part_defs = group_block_stack.pop() for lineno, key, val in part_defs: rule[2].append((lineno, name + '-' + key, val)) indention_stack.pop() state_stack.pop() break else: fail('invalid dedent') # new state but no indention. bummer elif new_state: fail('expected definitions, found nothing') # end of data if line == '__END__': break # root and rules elif state_stack[-1] in ('rule', 'root'): # new rule blocks if line.endswith(':'): s_rule = line[:-1].rstrip() if not s_rule: fail('empty rule') new_state = 'rule' new_rule = (s_rule, [], []) rule[1].append(new_rule) rule_stack.append(rule) rule = new_rule # if we in a root block we don't consume group blocks # or style definitions but variable defs elif state_stack[-1] == 'root': if '=' in line: m = _var_def_re.search(line) if m is None: fail('invalid syntax') key = m.group(1) if key in vars: fail('variable "%s" defined twice' % key) vars[key] = (lineiter.lineno, m.group(2)) else: fail('Style definitions or group blocks are only ' 'allowed inside a rule or group block.') # definition group blocks elif line.endswith('->'): group_prefix = line[:-2].rstrip() if not group_prefix: fail('no group prefix defined') new_state = 'group_block' group_block_stack.append((group_prefix, [])) # otherwise parse a style definition. else: rule[2].append(parse_definition()) # group blocks elif state_stack[-1] == 'group_block': group_block_stack[-1][1].append(parse_definition()) # something unparseable happened else: fail('unexpected character %s' % line[0]) return root_rules, vars def parse(self, source): """ Create a flat structure and parse inline expressions. """ def handle_rule(rule, children, defs): def recurse(): if defs: result.append((get_selectors(), [ (k, self.parse_expr(lineno, v)) for lineno, k, v in defs ])) for child in children: handle_rule(*child) local_rules = [] reference_rules = [] for r in rule.split(','): r = r.strip() if '&' in r: reference_rules.append(r) else: local_rules.append(r) if local_rules: stack.append(local_rules) recurse() stack.pop() if reference_rules: if stack: parent_rules = stack.pop() push_back = True else: parent_rules = ['*'] push_back = False virtual_rules = [] for parent_rule in parent_rules: for tmpl in reference_rules: virtual_rules.append(tmpl.replace('&', parent_rule)) stack.append(virtual_rules) recurse() stack.pop() if push_back: stack.append(parent_rules) def get_selectors(): branches = [()] for level in stack: new_branches = [] for rule in level: for item in branches: new_branches.append(item + (rule,)) branches = new_branches return [' '.join(branch) for branch in branches] root_rules, vars = self.preparse(source) result = [] stack = [] for rule in root_rules: handle_rule(*rule) real_vars = {} for name, args in vars.items(): real_vars[name] = self.parse_expr(*args) return result, real_vars def parse_expr(self, lineno, s): def parse(): pos = 0 end = len(s) def process(token, group=0): return lambda m: (m.group(group), token) def process_string(m): value = m.group(0) try: if value[:1] == value[-1:] and value[0] in '"\'': value = value[1:-1].encode('utf-8') \ .decode('string-escape') \ .encode('utf-8') elif value == 'rgb': return None, 'rgb' elif value in _colors: return value, 'color' except UnicodeError: raise ParserError(lineno, 'invalid string escape') return value, 'string' rules = ((_operator_re, process('op')), (_call_re, process('call', 1)), (_value_re, lambda m: (m.groups(), 'value')), (_color_re, process('color')), (_number_re, process('number')), (_url_re, process('url', 1)), (_string_re, process_string), (_var_re, lambda m: (m.group(1) or m.group(2), 'var')), (_whitespace_re, None)) while pos < end: for rule, processor in rules: m = rule.match(s, pos) if m is not None: if processor is not None: yield processor(m) pos = m.end() break else: raise ParserError(lineno, 'Syntax error') s = s.rstrip(';') return self.expr(TokenStream(lineno, parse())) def expr(self, stream, ignore_comma=False): args = [self.concat(stream)] list_delim = [(';', 'op')] if not ignore_comma: list_delim.append((',', 'op')) while stream.current in list_delim: next(stream) args.append(self.concat(stream)) if len(args) == 1: return args[0] return List(args, lineno=stream.lineno) def concat(self, stream): args = [self.add(stream)] while stream.current[1] != 'eof' and \ stream.current not in ((',', 'op'), (';', 'op'), (')', 'op')): args.append(self.add(stream)) if len(args) == 1: node = args[0] else: node = ImplicitConcat(args, lineno=stream.lineno) return node def add(self, stream): left = self.sub(stream) while stream.current == ('+', 'op'): next(stream) left = Add(left, self.sub(stream), lineno=stream.lineno) return left def sub(self, stream): left = self.mul(stream) while stream.current == ('-', 'op'): next(stream) left = Sub(left, self.mul(stream), lineno=stream.lineno) return left def mul(self, stream): left = self.div(stream) while stream.current == ('*', 'op'): next(stream) left = Mul(left, self.div(stream), lineno=stream.lineno) return left def div(self, stream): left = self.mod(stream) while stream.current == ('/', 'op'): next(stream) left = Div(left, self.mod(stream), lineno=stream.lineno) return left def mod(self, stream): left = self.neg(stream) while stream.current == ('%', 'op'): next(stream) left = Mod(left, self.neg(stream), lineno=stream.lineno) return left def neg(self, stream): if stream.current == ('-', 'op'): next(stream) return Neg(self.primary(stream), lineno=stream.lineno) return self.primary(stream) def primary(self, stream): value, token = stream.current if token == 'number': next(stream) node = Number(value, lineno=stream.lineno) elif token == 'value': next(stream) node = Value(lineno=stream.lineno, *value) elif token == 'color': next(stream) node = Color(value, lineno=stream.lineno) elif token == 'rgb': next(stream) if stream.current == ('(', 'op'): next(stream) args = [] while len(args) < 3: if args: stream.expect(',', 'op') args.append(self.expr(stream, True)) stream.expect(')', 'op') return RGB(tuple(args), lineno=stream.lineno) else: node = String('rgb') elif token == 'string': next(stream) node = String(value, lineno=stream.lineno) elif token == 'url': next(stream) node = URL(value, lineno=stream.lineno) elif token == 'var': next(stream) node = Var(value, lineno=stream.lineno) elif token == 'op' and value == '(': next(stream) if stream.current == (')', 'op'): raise ParserError(stream.lineno, 'empty parentheses are ' 'not valid. If you want to use them as ' 'string you have to quote them.') node = self.expr(stream) stream.expect(')', 'op') else: if token == 'call': raise ParserError(stream.lineno, 'You cannot call standalone ' 'methods. If you wanted to use it as a ' 'string you have to quote it.') next(stream) node = String(value, lineno=stream.lineno) while stream.current[1] == 'call': node = self.call(stream, node) return node def call(self, stream, node): method, token = stream.current assert token == 'call' next(stream) args = [] while stream.current != (')', 'op'): if args: stream.expect(',', 'op') args.append(self.expr(stream)) stream.expect(')', 'op') return Call(node, method, args, lineno=stream.lineno) def convert(source, context=None): """Convert a CleverCSS file into a normal stylesheet.""" return Engine(source).to_css(context) def main(): """Entrypoint for the shell.""" import sys # help! if '--help' in sys.argv: print('usage: %s ... ' % sys.argv[0]) print(' if called with some filenames it will read each file, cut of') print(' the extension and append a ".css" extension and save. If ') print(' the target file has the same name as the source file it will') print(' abort, but if it overrides a file during this process it will') print(' continue. This is a desired functionality. To avoid that you') print(' must not give your source file a .css extension.') print() print(' if you call it without arguments it will read from stdin and') print(' write the converted css to stdout.') print() print(' called with the --eigen-test parameter it will evaluate the') print(' example from the module docstring.') print() print(' to get a list of known color names call it with --list-colors') # version elif '--version' in sys.argv: print('CleverCSS Version %s' % VERSION) print('Licensed under the BSD license.') print('(c) Copyright 2007 by Armin Ronacher and Georg Brandl.') # evaluate the example from the docstring. elif '--eigen-test' in sys.argv: print(convert('\n'.join(l[8:].rstrip() for l in re.compile(r'Example::\n(.*?)__END__(?ms)') .search(__doc__).group(1).splitlines()))) # color list elif '--list-colors' in sys.argv: print('%s known colors:' % len(_colors)) for color in sorted(_colors.items()): print(' %-30s%s' % color) # read from stdin and write to stdout elif len(sys.argv) == 1: try: print(convert(sys.stdin.read())) except (ParserError, EvalException) as e: sys.stderr.write('Error: %s\n' % e) sys.exit(1) # convert some files else: for fn in sys.argv[1:]: target = fn.rsplit('.', 1)[-1] + '.css' if fn == target: sys.stderr.write('Error: same name for source and target file' ' "%s".' % fn) sys.exit(2) src = file(fn) try: try: converted = convert(src.read()) except (ParserError, EvalException) as e: sys.stderr.write('Error in file %s: %s\n' % (fn, e)) sys.exit(1) dst = file(target, 'w') try: dst.write(converted) finally: dst.close() finally: src.close() if __name__ == '__main__': main()