/
rillet.js
executable file
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/
rillet.js
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class NillValue {
constructor() { }
} // class NillValue
const Nill = new NillValue();
function* filter(iterable, predicate) {
for (const a of iterable)
if (predicate(a))
yield a;
} // filter
function* map(iterable, fn) {
for (const a of iterable)
yield fn(a);
} // map
function* flatMap(iterable, fn) {
for (const a of iterable) {
const v = fn(a)
if (non_string_iterable(v))
yield* v;
else
yield v;
}
} // flatMap
function* take(iterable, count) {
for (const a of iterable) {
if (count == 0)
break;
--count;
yield a;
} // for ...
} // take
function* takeWhile(iterable, predicate) {
for (const a of iterable) {
if (!predicate(a))
break;
yield a;
} // for ...
} // takeWhile
function* drop(iterable, count) {
const iter = iterable[Symbol.iterator]();
for (let i = 0; i != count; ++i)
iter.next();
yield* iter;
} // drop
function* dropWhile(iterable, predicate) {
const iter = iterable[Symbol.iterator]();
for (const a of iter)
if (!predicate(a)) {
yield a;
break;
} // if ...
yield* iter;
} // dropWhile
function non_string_iterable(item) {
return (item && item[Symbol.iterator] && typeof item != "string");
} // non_string_iterable
function* concat(...items) {
for (const item of items) {
for (const a of MangoRange.from(item)) {
// embedded iterable - flatten
if (non_string_iterable(a))
yield* concat(...a)
else
yield a;
} // for ...
} /// for ...
} // concat
function* flat(iterable, depth) {
for (const item of iterable)
if (non_string_iterable(item) && depth > 1)
yield* flat(item, depth-1);
else
yield item;
} // flat
function* flatten(iterable) {
for (const item of iterable)
if (non_string_iterable(item))
yield* flatten(item);
else
yield item;
} // flatten
function* uniq(iterable, fn) {
const seen = new Set();
for (const item of iterable) {
const projection = fn(item);
if (seen.has(projection))
continue;
seen.add(projection);
yield item;
} // for ...
} // uniq
function* compact(iterable) {
for (const item of iterable)
if (!!item)
yield item;
} // compact
function* cycle(iterable) {
if (Array.isArray(iterable)) {
if (iterable.length == 0)
return;
while (true)
yield* iterable;
} // if ...
const buffer = [];
for (const i of iterable) {
buffer.push(i);
yield i;
} // for ...
yield* cycle(buffer);
} // cycle
function* zipper(iterators) {
while(true) {
const values = [];
for (const iter of iterators) {
const {done, value} = iter.next();
if (done)
return;
values.push(value);
} // for ...
yield values;
} // while
} // zipper
function* numbers(start, step) {
for (let i = start; ; i += step)
yield i;
} // numbers
function first(iterable, fn) {
const {done, value} = iterable[Symbol.iterator]().next();
if (done)
return fn();
return value;
} // first
function last(iterable, fn) {
const iter = iterable[Symbol.iterator]();
let {done, value} = iter.next();
if (done)
return fn();
while(true) {
let {done, value: nextvalue} = iter.next();
if (done)
return value;
value = nextvalue;
} // while
} // last
function reduce(iterable, fn, seed) {
if ((seed === undefined) || (seed === Nill)) {
[seed, iterable] = advance(iterable, seed);
if (seed === Nill)
return undefined;
} // if ...
let total = seed;
for (const v of iterable)
total = fn(total, v);
return total;
} // reduce
function advance(iterable, seed) {
const iterator = iterable[Symbol.iterator]();
const head = iterator.next();
if (head.done)
return seed !== Nill ? exhausted() : [Nill];
return [head.value, new MangoRange(iterator)];
} // advance
function none(iterable, predicate) {
return test(iterable, predicate, false, true);
} // none
function every(iterable, predicate) {
return none(iterable, i => !predicate(i));
} // every
function some(iterable, predicate) {
return test(iterable, predicate, true, false);
} // some
function test(iterable, predicate, early, all) {
for (const item of iterable)
if (predicate(item))
return early;
return all;
} // test
function join(iterable, separator = ',') {
const iterator = iterable[Symbol.iterator]();
let head = iterator.next();
if (head.done)
return "";
let s = head.value.toString();
head = iterator.next();
while(!head.done) {
s += separator;
s += head.value.toString();
head = iterator.next();
} // while
return s;
} // join
function exhausted() {
throw "Sequence is exhausted";
} // exhausted
function identity(a) { return a; }
////////////////////////////
class MangoRange {
static empty() {
return new MangoRange([]);
} // empty
static of(...params) {
if (params.length === 0)
return MangoRange.empty();
if (params.length === 1) {
return new MangoRange(params);
} // if ...
return MangoRange.from(params);
} // MangoRange
static from(iterable) {
if (iterable == null)
return MangoRange.empty();
if (Array.isArray(iterable)) {
if (iterable.length == 1)
return MangoRange.from(iterable[0]);
return new MangoRange(iterable);
} // if ...
if (iterable[Symbol.iterator])
return new MangoRange(iterable);
return new MangoRange([iterable]);
} // from
static zip(...iterables) {
if (iterables.length === 0)
return MangoRange.empty();
const iterators = [];
for (const iterable of iterables) {
if (!iterable)
return MangoRange.empty();
const iter = iterable[Symbol.iterator]();
if (!iter)
return MangoRange.empty();
iterators.push(iter);
} // for ...
return new MangoRange(zipper(iterators));
} // zip
static numbers(start = 0, step = 1) {
return new MangoRange(numbers(start, step));
} // numbers
///////////////////////////
constructor(iterable) {
this.iterable = iterable;
} // constructor
*[Symbol.iterator]() {
yield* this.iterable;
}
filter(predicate) { return new MangoRange(filter(this.iterable, predicate)); }
map(fn) { return new MangoRange(map(this.iterable, fn)); }
flatMap(fn) { return new MangoRange(flatMap(this.iterable, fn)); }
take(count) { return new MangoRange(take(this.iterable, count)); }
takeWhile(predicate) { return new MangoRange(takeWhile(this.iterable, predicate)); }
drop(count) { return new MangoRange(drop(this.iterable, count)); }
dropWhile(predicate) { return new MangoRange(dropWhile(this.iterable, predicate)); }
concat(...iterable2) { return new MangoRange(concat(this.iterable, iterable2)); }
flat(depth = 1) { return new MangoRange(flat(this.iterable, depth)); }
flatten() { return new MangoRange(flatten(this.iterable)); }
uniq(fn = identity) { return new MangoRange(uniq(this.iterable, fn)); }
compact() { return new MangoRange(compact(this.iterable)); }
cycle() { return new MangoRange(cycle(this.iterable)); }
count() { let count = 0; for (const a of this.iterable) ++count; return count; }
forEach(fn) { for (const a of this.iterable) fn(a); }
first() { return first(this.iterable, exhausted); }
firstOrDefault(defaultValue) { return first(this.iterable, () => defaultValue); }
last() { return last(this.iterable, exhausted); }
lastOrDefault(defaultValue) { return last(this.iterable, () => defaultValue); }
reduce(fn, seed) { return reduce(this.iterable, fn, seed); }
max(comparator = (a,b) => a > b) { return reduce(this.iterable, (a,b) => comparator(a,b) ? a : b, Nill); }
min(comparator = (a,b) => a < b) { return reduce(this.iterable, (a,b) => comparator(a,b) ? a : b, Nill); }
sum() { return reduce(this.iterable, (a,b) => Number(a)+Number(b), 0); }
none(predicate) { return none(this.iterable, predicate); }
every(predicate) { return every(this.iterable, predicate); }
some(predicate) { return some(this.iterable, predicate); }
join(separator) { return join(this.iterable, separator); }
toArray() { return Array.from(this.iterable); }
} // class MangoRange
module.exports = MangoRange;