6 List Operations
| (require qi/list) | package: qi-lib |
This module defines functional list operations analogous to those in racket/base and racket/list, except that these forms support flows in higher-order function positions and leverage the stream fusion / deforestation optimization to avoid constructing intermediate representations along the way to computing the result.
The forms in this module extend the syntax of the core Qi language. This extended syntax is given below:
| floe | = | (map floe) | ||
| | | (filter floe) | |||
| | | (filter-map floe) | |||
| | | (foldl floe expr) | |||
| | | (foldr floe expr) | |||
| | | (range expr) | |||
| | | (range expr expr) | |||
| | | (range expr expr expr) | |||
| | | (take expr) | |||
| | | car | |||
| | | cadr | |||
| | | caddr | |||
| | | cadddr | |||
| | | (list-ref expr) | |||
| | | length | |||
| | | empty? | |||
| | | null? |
The operations are categorized based on their role in the deforested pipeline.
6.1 Producers
Deforestable version of range from racket/list.
By default start is 0 and step is 1.
6.2 Transformers
syntax
(filter pred)
pred : (-> any/c any/c)
Deforestable version of filter from racket/base.
syntax
(map proc)
proc : (-> any/c any/c)
Deforestable version of map from racket/base. Note that, unlike the Racket version, this accepts only one argument. For the "zip"-like behavior with multiple list inputs, see △.
syntax
(filter-map proc)
proc : (-> any/c any/c)
Deforestable version of filter-map from racket/list.
syntax
(take pos)
pos : exact-nonnegative-integer?
Deforestable version of take from racket/list.
6.3 Consumers
syntax
(foldl proc init)
proc : (-> any/c any/c any/c any/c)
init : any/c
Deforestable version of foldl from racket/base.
syntax
(foldr proc init)
proc : (-> any/c any/c any/c any/c)
init : any/c
Deforestable version of foldr from racket/base.
syntax
Deforestable version of car from racket/base.
syntax
Deforestable version of cadr from racket/base.
syntax
Deforestable version of caddr from racket/base.
syntax
Deforestable version of cadddr from racket/base.
syntax
(list-ref pos)
pos : exact-nonnegative-integer?
Deforestable version of list-ref from racket/base.
syntax
Deforestable version of length from racket/base.
syntax
Deforestable version of empty? from racket/list.
syntax
Deforestable version of null? from racket/base.