diff --git a/functions.md b/functions.md new file mode 100644 index 0000000..d1157fb --- /dev/null +++ b/functions.md @@ -0,0 +1,43 @@ +# Functions + +Functions are first-class citizens in ginger. The simplest anonymous function +can be created like so: + +``` +(. fn [x] + (: + x 1)) +``` + +This function takes in a single number and returns that number plus one. It +could be assigned to a variable on the package using `def`, or by using the +shortcut `defn`. The following two statements are equivalent: + +``` + +(def incr + (. fn [x] + (: + x 1))) + +(. defn incr [x] + (: + x 1)) +``` + +## Variadic function + +Functions may take in any number of variables using the `...` syntax, similar to +how go does variadic functions. The variadic variable must be the last in the +function's argument list, and is used as a list inside of the function. A list +may also be used as the input for a variadic function, also using the `...` +syntax. + +The following is an example of both defining a variadic function and both ways +of using it. `+` is a variadic function in this example: + +``` +(. defn avg [...x] + (/ + (+ x...) + (len x))) + +(: fmt.Println (avg 1 2 3 4 5)) +```