CSS Function in mixin - grayscale

[Maxence]

Hello,
I'm trying to create a mixin for grayscaling an html element.

In CSS way, it should be :

filter: grayscale(50%);

My mixin :

@mixin grayscale_element($value) {
    -webkit-filter: grayscale($value);
    -moz-filter: grayscale($value);
    filter: grayscale($value);
}

My error :

Fatal error: Uncaught exception 'SassScriptFunctionException' with message 'SassNumber must be a SassColour
Source: -webkit-filter: grayscale($value)'

Problem is, in sass grayscale is already a function, and paramter should be a color.
Module: Sass::Script::Functions - Sass Documentation
http://sass-lang.com/documentation/Sass/Script/Functions.html#grayscale-instance_method

How can I use these filter in a mixin ?

[nick4fake]

duplicate of #107

[sense-design]

Hey guys, please try this

filter: unquote("grayscale(100%)")

[LukasMeine]

I have made a pull request to fix this. Hope it helps.