function transduceExample() {
const { completing, transduce, wrap } = t;
const stringAppendFn = (acc: string, x: number) => acc + x;
const stringAppendTransformer = wrap(stringAppendFn);
const stringAppendThenLengthTransformer = completing(
stringAppendFn,
s => s.length,
);
const lengthsString1: string = transduce(
t.map((s: string) => s.length),
stringAppendFn,
"",
["a", "b"],
);
const lengthsString2: string = transduce(
t.map((s: string) => s.length),
stringAppendTransformer,
"",
["a", "b"],
);
const lengthsStringLength: number = transduce(
t.map((s: string) => s.length),
stringAppendThenLengthTransformer,
"",
["a", "b"],
);
}
function intoExample () {
var inc = function(n: number) { return n+1; };
var isEven = function(n: number) { return n % 2 == 0; };
var apush = function(arr: number[], x: number) { arr.push(x); return arr; };
var xf = t.comp(t.map(inc),t.filter(isEven));
t.into([], xf, [1,2,3,4]); // [2,4]
}
function advancedIntoExample() {
const array: number[] = into([], t.map((s: string) => s.length), [
"a",
"b",
]);
const string: string = into("", t.map((s: string) => s + s), ["a", "b"]);
const object1: { [key: string]: number } = into(
{},
t.map((s: string) => [s, s.length] as [string, number]),
["a", "b"],
);
const object2: { [key: string]: boolean } = into(
{},
t.map((kv: [string, number]) => [kv[0], true] as [string, boolean]),
{ a: 1, b: 2 }
);
}
function catExample () {
var reverse = function(arr: number[]) {
var arr: number[] = Array.prototype.slice.call(arr, 0);
arr.reverse();
return arr;
};
var xf = t.comp(t.map(reverse), t.cat);
t.into([], xf, [[3,2,1],[6,5,4]]); // [1,2,3,4,5,6]
}
it('transduces Stack without initial values', () => {
let s = Stack.of(1, 2, 3, 4);
let xform = t.comp(
t.filter(x => x % 2 === 0),
t.map(x => x + 1),
);
let s2 = t.transduce(xform, Stack(), s);
expect(s.toArray()).toEqual([1, 2, 3, 4]);
expect(s2.toArray()).toEqual([5, 3]);
});
it('transduces Set without initial values', () => {
let s1 = Set.of(1, 2, 3, 4);
let xform = t.comp(
t.filter(x => x % 2 === 0),
t.map(x => x + 1),
);
let s2 = t.transduce(xform, Set(), s1);
expect(s1.toArray()).toEqual([1, 2, 3, 4]);
expect(s2.toArray()).toEqual([3, 5]);
});
it('transduces Map without initial values', () => {
let m1 = Map({a: 1, b: 2, c: 3, d: 4});
let xform = t.comp(
t.filter(([k, v]) => v % 2 === 0),
t.map(([k, v]) => [k, v * 2]),
);
let m2 = t.transduce(xform, Map(), m1);
expect(m1.toObject()).toEqual({a: 1, b: 2, c: 3, d: 4});
expect(m2.toObject()).toEqual({b: 4, d: 8});
});
it('transduces List without initial values', () => {
let v = List.of(1, 2, 3, 4);
let xform = t.comp(
t.filter(x => x % 2 === 0),
t.map(x => x + 1),
);
let r = t.transduce(xform, List(), v);
expect(v.toArray()).toEqual([1, 2, 3, 4]);
expect(r.toArray()).toEqual([3, 5]);
});
it('transduces Stack with initial values', () => {
const v1 = Stack.of(1, 2, 3);
const v2 = Stack.of(4, 5, 6, 7);
const xform = t.comp(
t.filter(x => x % 2 === 0),
t.map(x => x + 1),
);
const r = t.transduce(xform, Stack(), v1, v2);
expect(v1.toArray()).toEqual([1, 2, 3]);
expect(v2.toArray()).toEqual([4, 5, 6, 7]);
expect(r.toArray()).toEqual([7, 5, 1, 2, 3]);
});
it('transduces Set with initial values', () => {
let s1 = Set.of(1, 2, 3, 4);
let s2 = Set.of(2, 3, 4, 5, 6);
let xform = t.comp(
t.filter(x => x % 2 === 0),
t.map(x => x + 1),
);
let s3 = t.transduce(xform, Set(), s1, s2);
expect(s1.toArray()).toEqual([1, 2, 3, 4]);
expect(s2.toArray()).toEqual([2, 3, 4, 5, 6]);
expect(s3.toArray()).toEqual([1, 2, 3, 4, 5, 7]);
});
