Update

sass.md

@@ -31,8 +31,8 @@ adjust-hue($color, 15deg)
 compliment($color)    /* like adjust-hue(_, 180deg) */
 invert($color)
 
-fade-in($color, .5)
+fade-in($color, .5)   /* aka opacify() */
-fade-out($color, .5)  /* halves the opacity */
+fade-out($color, .5)  /* aka transparentize() - halves the opacity */
 rgba($color, .5)      /* sets alpha to .5 */
 ```
 
@@ -48,23 +48,90 @@ alpha($color)         /* aka opacity() */
 ### Full adjustments
 
 ```scss
+/* Changes by fixed amounts */
 adjust-color($color, $blue: 5)
 adjust-color($color, $lightness: -30%)   /* like darken(_, 30%) */
 adjust-color($color, $alpha: -0.4)       /* like fade-out(_, .4) */
 adjust-color($color, $hue: 30deg)        /* like adjust-hue(_, 15deg) */
+
+/* Changes via percentage */
+scale-color($color, $lightness: 50%)
+
+/* Changes one property completely */
+change-color($color, $hue: 180deg)
+change-color($color, $blue: 250)
+
+/* Supported: $red $green $blue $hue $saturation $lightness $alpha */
 ```
 
 ## Other functions
 
-### Strings and units
+### Strings
 
 ```scss
 unquote('hello')
 quote(hello)
+
+to-upper-case(hello)
+to-lower-case(hello)
+
+str-length(hello world)
+str-slice(hello, 2, 5)      /* "ello" - it's 1-based, not 0-based */
+str-insert("abcd", "X", 1)  /* "Xabcd" */
+```
+
+### Units
+
+```scss
 unit(3em)        /* 'em' */
 unitless(100px)  /* false */
 ```
 
+### Numbers
+
+```scss
+floor(3.5)
+ceil(3.5)
+round(3.5)
+abs(3.5)
+
+min(1, 2, 3)
+max(1, 2, 3)
+
+percentage(.5)   /* 50% */
+random(3)        /* 0..3 */
+```
+
+### Misc
+
+```scss
+variable-exists(red)    /* checks for $red */
+mixin-exists(red-text)  /* checks for @mixin red-text */
+function-exists(redify)
+
+global-variable-exists(red)
+```
+
+```scss
+selector-append('.menu', 'li', 'a')   /* .menu li a */
+selector-nest('.menu', '&:hover li')  /* .menu:hover li */
+selector-extend(...)
+selector-parse(...)
+selector-replace(...)
+selector-unify(...)
+```
+
+## Feature checks
+
+```scss
+feature-exists(global-variable-shadowing)
+```
+
+* global-variable-shadowing
+* extend-selector-pseudoclass
+* units-level-3
+* at-error
+
 ## Loops
 
 ### For loops