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For next blog post con cdr car
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const cons = (x, y) => (m) => m(x, y) | |
const car = (z) => z((p, q) => p) | |
const cdr = (z) => z((p, q) => q) | |
const someLinkedList = cons(1, cons(2, cons(3 , null))) | |
// iterating | |
const each = (func, list) => { | |
if(list) { | |
element = car(list) | |
func(element) | |
each(func, cdr(list)) | |
} | |
} | |
// each(console.log, someLinkedList) | |
// let [head, ...tail] = [1,2,3,4,5] | |
const convertToLinkedList = (array) => { | |
if(!array.length) { | |
return null | |
} | |
const [head, ...tail] = array; | |
return cons(head, convertToLinkedList(tail)) | |
} | |
sampleLinked = convertToLinkedList([1,2,3,4,5]) | |
each(console.log, sampleLinked) | |
convertToArray = (linked, array=[]) => { | |
if(linked) { | |
const element = car(linked) | |
const rest = cdr(linked) | |
return convertToArray(rest, array.concat(element)) | |
} | |
return array; | |
} | |
convertToArray(sampleLinked) |
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cons = ->(x, y=nil) { | |
->(m){ m.(x, y) } | |
} | |
car = -> (z){ | |
z.(->(p,q=nil) {p}) | |
} | |
cdr = -> (z){ | |
z.(->(p,q=nil) {q}) | |
} |
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cons = ->(x, y=nil) { | |
->(m){ m.(x, y) } | |
} | |
car = -> (z){ | |
z.(->(p,q=nil) {p}) | |
} | |
cdr = -> (z){ | |
z.(->(p,q=nil) {q}) | |
} | |
convertToArray = ->(consz) { | |
if !consz.respond_to? :call | |
return [] | |
end | |
return [car.(consz)] + convertToArray.(cdr.(consz)) | |
} | |
covertToLinkedList = ->(array) { | |
if array.size == 0 | |
return nil | |
end | |
head, *tail = array | |
return cons.(head, covertToLinkedList.(tail)) | |
} | |
linkList = covertToLinkedList.([1,5,6,7,9]) | |
# cons(1, cons(2, cons(3, cons(4, null)))) | |
# convertToArray.(cons.(1, cons.(1, cons.(4)))) | |
# [car.(list)] + cdr.(list) | |
# head = ->(x) { | |
# head, *tail = x | |
# head | |
# } | |
# cons = ->(x, y) { | |
# [*y, x] | |
# } | |
reduceRight = ->(xs, acc, &f) { | |
id = ->(x) {x} | |
reduceResult = xs.reduce(id) {|accf, n| ->(z){ | |
accf.(f.(z,n)) | |
} } | |
reduceResult.(acc) | |
} #=> 151200 | |
reduceRight.([1,2,4], []) {|n, x| n.push(x) | |
n | |
} | |
map = ->(x, &f) { | |
x.reduce([]) {|acc, n| cons.(f.(n), acc) } | |
} #=> 151200 | |
convertToArray.(map.([1, 5, 7, 19]) { |n| n * n}) | |
class Array | |
def reduceRight(acc, &f) | |
id = ->(x) {x} | |
reduceResult = self.reduce(id) {|accf, n| ->(z){ | |
accf.(f.(z,n)) | |
} } | |
reduceResult.(acc) | |
end | |
end | |
# convertToArray.(map.([1, 5, 7, 19]) { |n| n * n}) | |
[1,2,4].reduceRight([]) {|n, x| n.push(x) | |
n | |
} |
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