ref: 23c8f3f9409d2826a94277464125872319156911
dir: /Function-Refs/README.md/
# Function References Limbo supports references to functions, similar to closures, but more similar to function pointers. The example in this section is a derivative of the function reference summary in the [Limbo Addendum](http://www.vitanuova.com/inferno/papers/addendum.pdf). ## Source ### funcrefs.b:18,34 The variable `fp` is a name whose type is a reference to a function with a given argument and return value scheme. A function which fulfills this scheme can be used to set the reference, in this case the `cmp()` function is referenced by `fp`. ### funcrefs.b:36,46 The `sort()` function takes a function reference as an argument, using it as a comparator. In this case `cmp()` and `rcmp()` are passed as a function reference argument. ### funcrefs.b:48,53 The `choose()` function returns a reference to a function, being called in this case to return a given comparator with the comparator being called in-line. ## Demo ; limbo funcrefs.b ; funcrefs Matched smiley! Did not match duck [ d b c a] [ a b c d] [ d c b a] quack ≥ quack ; ## Exercises - Change the value of `c` to 1, what happens? - Write a function which returns a function which returns a function.