新闻 Egison 3.5.1 发布，模式匹配编程语言 下载

Egison 是世界上首个实现了非线性模式匹配的编程语言，用于处理各种不自由的数据类型。如列表、多集合、集合、树和图。

示例代码：


;; Extract all twin primes from the infinite list of prime numbers with pattern-matching!
(define $twin-primes
(match-all primes (list integer)
[<join _ <cons $p <cons ,(+ p 2) _>>>
[p (+ p 2)]]))

;; Enumerate first 10 twin primes
(take 10 twin-primes)
;=>{[3 5] [5 7] [11 13] [17 19] [29 31] [41 43] [59 61] [71 73] [101 103] [107 109]}



Egison 3.5.1 发布，此版本更新内容如下：

移除 loop 表达式到模式外


(define $list
(lambda [$a]
(matcher
{[,$val []
{[$tgt (match [val tgt] [(list a) (list a)]
{[[<nil> <nil>] {[]}]
[[<cons $x $xs> <cons ,x ,xs>] {[]}]
[[_ _] {}]})]}]
[<nil> []
{[{} {[]}]
[_ {}]}]
[<cons $ $> [a (list a)]
{[{$x @$xs} {[x xs]}]
[_ {}]}]
[<snoc $ $> [a (list a)]
{[{@$xs $x} {[x xs]}]
[_ {}]}]
[<join $ $> [(list a) (list a)]
{[$tgt (match-all tgt (list a)
[(loop $i [1 $n] <cons $xa_i ...> $rs) [(foldr (lambda [$i $r] {xa_i @r}) {} (between 1 n))
rs]])]}]
[<nioj $ $> [(list a) (list a)]
{[$tgt (match-all tgt (list a)
[(loop $i [1 $n] <snoc $xa_i ...> $rs) [(foldr (lambda [$i $r] {xa_i @r}) {} (between 1 n))
rs]])]}]
[$ [something]
{[$tgt {tgt}]}]
})))
数组从 1 开始


(define $xa [| 1 2 3 4 5 |])
(array-size xa);=>5
xa_1;=>1
xa_5;=>5
xa_8;=>undefined
Egison 3.5.1 发布，模式匹配编程语言下载地址