## Built-in Functions ### red(color) Return the red component of the given `color`. red(#c00) // => 204 ### green(color) Return the green component of the given `color`. green(#0c0) // => 204 ### blue(color) Return the blue component of the given `color`. red(#00c) // => 204 ### alpha(color) Return the alpha component of the given `color`. alpha(#fff) // => 1 alpha(rgba(0,0,0,0.3)) // => 0.3 ### dark(color) Check if `color` is dark: dark(black) // => true dark(#005716) // => true dark(white) // => false ### light(color) Check if `color` is light: light(black) // => false light(white) // => true light(#00FF40) // => true ### hue(color) Return the hue of the given `color`. hue(hsla(50deg, 100%, 80%)) // => 50deg ### saturation(color) Return the saturation of the given `color`. hue(hsla(50deg, 100%, 80%)) // => 100% ### lightness(color) Return the lightness of the given `color`. hue(hsla(50deg, 100%, 80%)) // => 80% ### typeof(node) Return type of `node` as a string. type(12) // => 'unit' typeof(12) // => 'unit' typeof(#fff) // => 'rgba' type-of(#fff) // => 'rgba' Aliased as `type-of` and `type`. ### unit(unit[, type]) Return a string for the type of `unit` or an empty string, or assign the given `type` without unit conversion. unit(10) // => '' unit(15in) // => 'in' unit(15%, 'px') // => 15px unit(15%, px) // => 15px ### match(pattern, string) Test if `string` matches the given `pattern`. match('^foo(bar)?', foo) match('^foo(bar)?', foobar) // => true match('^foo(bar)?', 'foo') match('^foo(bar)?', 'foobar') // => true match('^foo(bar)?', 'bar') // => false ### abs(unit) abs(-5px) // => 5px abs(5px) // => 5px ### ceil(unit) ceil(5.5in) // => 6in ### floor(unit) floor(5.6px) // => 5px ### round(unit) round(5.5px) // => 6px round(5.4px) // => 5px ### min(a, b) min(1, 5) // => 1 ### max(a, b) max(1, 5) // => 5 ### even(unit) even(6px) // => true ### odd(unit) odd(5mm) // => true ### sum(nums) sum(1 2 3) // => 6 ### avg(nums) avg(1 2 3) // => 2 ### join(delim, vals...) Join the given `vals` with `delim`. join(' ', 1 2 3) // => "1 2 3" join(',', 1 2 3) // => "1,2,3" join(', ', foo bar baz) // => "foo, bar, baz" join(', ', foo, bar, baz) // => "foo, bar, baz" ### hsla(color | h[, s, l, a]) Convert the given `color` to an `HSLA` node, or h,s,l,a component values. hslaa(10deg, 50%, 30%, 0.5) // => HSLA hslaa(#ffcc00) // => HSLA ### hsla(color | h[, s, l]) Convert the given `color` to an `HSLA` node, or h,s,l component values. hsla(10, 50, 30) // => HSLA hsla(#ffcc00) // => HSLA ### rgba(color | r[, g, b, a]) Return `RGBA` from the r,g,b,a channels or provide a `color` to tweak the alpha. rgba(255,0,0,0.5) // => rgba(255,0,0,0.5) rgba(255,0,0,1) // => #ff0000 rgba(#ffcc00, 0.5) // rgba(255,204,0,0.5) ### rgb(color | r[, g, b]) Return a `RGBA` from the r,g,b channels or cast to an `RGBA` node. rgb(255,204,0) // => #ffcc00 rgb(#fff) // => #fff ### lighten(color, amount) Lighten the given `color` by `amount`. lighten(black, 50%) // => #808080 ### darken(color, amount) Darken the given `color` by `amount`. darken(white, 50%) // => #808080 ### lighten-by(color, amount) Lighten by `amount` of the current lightness value. lighten-by(black, 50%) // => #808080 lighten-by(lighten-by(black, 50%), 50%) // => #bfbfbf lighten-by(lighten-by(lighten-by(black, 50%), 50%), 50%) // => #fff essentially the same as: black + hsla(0,0,50%) black + hsla(0,0,75%) black + hsla(0,0,100%) ### darken-by(color, amount) Darken by `amount` of the current lightness value. darken-by(white, 50%) // => #808080 darken-by(darken-by(white, 50%), 50%) // => #404040 darken-by(darken-by(darken-by(white, 50%), 50%), 50%) // => #202020 ### desaturate(color, amount) Desaturate the given `color` by `amount`. desaturate(#f00, 40%) // => #c33 ### saturate(color, amount) Saturate the given `color` by `amount`. saturate(#c33, 40%) // => #f00 ### unquote(str | ident) Unquote the given `str` and returned as a `Literal` node. unquote("sans-serif") // => sans-serif unquote(sans-serif) // => sans-serif unquote('1px / 2px') // => 1px / 2px ### operate(op, left, right) Perform the given `op` on the `left` and `right` operands: op = '+' operate(op, 15, 5) // => 20 ### length([expr]) Parenthesized expressions may act as tuples, the `length()` function returns the length of such expressions. length((1 2 3 4)) // => 4 length((1 2)) // => 2 length((1)) // => 1 length(()) // => 0 length(1 2 3) // => 3 length(1) // => 1 length() // => 0 ### warn(msg) Warn with the given error `msg`, does not exit. warn("oh noes!") ### error(msg) Exits with the given error `msg`. add(a, b) unless a is a 'unit' and b is a 'unit' error('add() expects units') a + b ### last(expr) Return the _last_ value in the given `expr`: nums = 1 2 3 last(nums) last(1 2 3) // => 3 list = (one 1) (two 2) (three 3) last(list) // => (three 3) ### p(expr) Inspect the given `expr`: fonts = Arial, sans-serif p('test') p(123) p((1 2 3)) p(fonts) p(#fff) p(rgba(0,0,0,0.2)) add(a, b) a + b p(add) stdout: inspect: "test" inspect: 123 inspect: 1 2 3 inspect: Arial, sans-serif inspect: #fff inspect: rgba(0,0,0,0.2) inspect: add(a, b) ### opposite-position(positions) Return the opposites of the given `positions`. opposite-position(right) // => left opposite-position(top left) // => bottom right opposite-position('top' 'left') // => bottom right ### image-size(path) Returns the `width` and `height` of the image found at `path`. Lookups are performed in the same manner as `@import`, altered by the `paths` setting. width(img) return image-size(img)[0] height(img) return image-size(img)[1] image-size('tux.png') // => 405px 250px image-size('tux.png')[0] == width('tux.png') // => true ### Undefined Functions Undefined functions will output as literals, so for example we may call `rgba-stop(50%, #fff)` within our css, and it will output as you would expect. We can use this within helpers as well. In the example below we simply define the function `stop()` which returns the literal `rgba-stop()` call. stop(pos, rgba) rgba-stop(pos, rgba) stop(50%, orange) // => rgba-stop(50%, #ffa500)