hellerve/nothing
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

almost there

Browse Source
This commit is contained in:
Veit Heller
2018-06-01 13:56:08 +02:00
parent 2845a5e308
commit 33e378fcd1
2 changed files with 96 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
nothing-helper.js
View File

@@ -1,4 +1,53 @@
module.exports = { const nothing = require('./nothing.js');
to_int: (f) => f(n => n+1)(0),
to_boolean: (f) => f(true)(false), const charset = '0123456789BFiuz';
const from_int = (n) => {
let f = nothing.ZERO;
for (let _ = 0; _ < n; _++) f = nothing.INC(f);
return f;
};
const to_int = (f) => nothing.TIMES(f)(i => i+1)(0);
const from_bool = (b) => b ? nothing.TRUE : nothing.FALSE;
const to_bool = (f) => f(true)(false);
const to_array = (l) => {
let a = [];
while (!to_bool(nothing.IS_EMPTY(l))) {
a.push(nothing.FIRST(l));
l = nothing.REST(l);
}
return a;
};
const from_array = (a) => {
let l = nothing.EMPTY;
while (a.length) l = nothing.UNSHIFT(l)(a.pop());
return l;
};
const to_char = (c) => charset[to_int(c)];
const from_char = (c) => from_int(charset.indexOf(c));
const to_string = (s) => to_array(s).map(to_char).join('');
const from_string = (s) => from_array(s.split('').map(from_char));
const representation_of = (v) => {
if (typeof v == "number") return from_int(v);
if (typeof v == "boolean") return from_bool(v);
if (typeof v == "string") return from_string(v);
if (Array.isArray(v)) return from_array(v.map(representation_of));
throw Error(`Oops, I don’t know how represent this: ${v}`);
};
const zip = (a, b) => a.map((e, i) => [e, b[i]]);
const check_represent = function(r, v) {
if (typeof v == "number") return to_int(r) == v;
if (typeof v == "boolean") return to_bool(r) == v;
if (typeof v == "string") { console.log("checking ", to_array(r).map(to_int), " against ", v); return to_string(r) == v; }
if (Array.isArray(v)) {
let a = to_array(r);
return a.length == v.length && zip(a, v).every(([r, v]) => check_represent(r,v));
}
throw Error(`Oops, I don’t know how check this: ${v}`);
};
module.exports = {
to_string, to_array, representation_of, check_represent, to_int, to_char
}; };

70
nothing.js
View File

@@ -18,37 +18,55 @@ const NOT = b => IF(b)(FALSE)(TRUE);
const AND = a => b => IF(a)(IF(b)(TRUE)(FALSE))(FALSE); const AND = a => b => IF(a)(IF(b)(TRUE)(FALSE))(FALSE);
const OR = a => b => IF(a)(TRUE)(IF(b)(TRUE)(FALSE)); const OR = a => b => IF(a)(TRUE)(IF(b)(TRUE)(FALSE));
const IS_ZERO = n => n(x => FALSE)(TRUE); const IS_ZERO = n => n(x => FALSE)(TRUE);
const IS_LEQ = n => m => IS_ZERO(SUBTRACT(n)(m)); // we only have positive ints const IS_LEQ = n => m => IS_ZERO(SUB(n)(m)); // we only have positive ints
const IS_EQ = n => m => AND(IS_LEQ(n)(m))(IS_LEQ(m)(n)); // this is stupid const IS_EQ = n => m => AND(IS_LEQ(n)(m))(IS_LEQ(m)(n)); // this is stupid
// time to get recursive! // time to get recursive!
const Y = f => (x => f(x(x)))(x => f(x(x))); // lazy recursion const Y = f => (x => f(x(x)))(x => f(x(x))); // lazy recursion
const Z = f => (x => f(_ => x(x)(_)))(x => f(_ => x(x)(_))); // eager recursion const Z = f => (x => f(_ => x(x)(_)))(x => f(_ => x(x)(_))); // eager recursion
const FACT = Z(f => n => IF(IS_ZERO(n))(ONE)(_ => MULT(n)(f(DEC(n)))(_))); const FACT = Z(f => n => IF(IS_ZERO(n))(ONE)(_ => MULT(n)(f(DEC(n)))(_)));
const DIV = null; const DIV = Z(f => n => m => IF(IS_LEQ(m)(n))(_ => INC(f(SUB(n)(m))(m))(_))(ZERO));
const MOD = null; const MOD = Z(f => n => m => IF(IS_LEQ(m)(n))(_ => f(SUB(n)(m))(m)(_))(m));
const PAIR = null; const PAIR = x => y => f => f(x)(y);
const LEFT = null; const LEFT = p => p(x => y => x);
const RIGHT = null; const RIGHT = p => p (x => y => y);
const EMPTY = null; const EMPTY = PAIR(TRUE)(TRUE);
const UNSHIFT = null; const UNSHIFT = l => x => PAIR(FALSE)(PAIR(x)(l));
const IS_EMPTY = null; const IS_EMPTY = LEFT;
const FIRST = null; const FIRST = l => LEFT(RIGHT(l));
const REST = null; const REST = l => RIGHT(RIGHT(l));
const INJECT = null; const INJECT = Z(f => l => x => g => IF(IS_EMPTY(l))(x)(_ => f(REST(l))(g(x)(FIRST(l)))(g)(_)));
const FOLD = null; const FOLD = Z(f => l => x => g => IF(IS_EMPTY(l))(x)(_ => g(f(REST(l))(x)(g))(FIRST(l))(_)));
const MAP = null; const MAP = k => f => FOLD(k)(EMPTY)(l => x => UNSHIFT(l)(f(x)));
const RANGE = null; const RANGE = Z(f => n => m => IF(IS_LEQ(n)(m))(_ => UNSHIFT(f(INC(n))(m))(n)(_))(EMPTY));
const SUM = null; const SUM = l => INJECT(l)(ZERO)(ADD);
const PROD = null; const PROD = l => INJECT(l)(ONE)(MULT);
const CONCAT = null; const CONCAT = k => l => FOLD(k)(l)(UNSHIFT);
const PUSH = null; const PUSH = l => x => CONCAT(l)(UNSHIFT(EMPTY)(x));
const REVERSE = null; const REVERSE = l => FOLD(l)(EMPTY)(PUSH);
const INC_ALL = null; const INC_ALL = l => MAP(l)(INC);
const DOUBLE_ALL = null; const DOUBLE_ALL = l => MAP(l)(MULT(TWO));
const TO_DIGITS = null; const TEN = INC(MULT(THREE)(THREE));
const TO_STRING = null; const RADIX = TEN;
const FIZZBUZZ = null; const FOUR = INC(THREE);
const FIVE = INC(INC(THREE));
const FIFTEEN = MULT(THREE)(FIVE);
const FIZZ = MAP(UNSHIFT(UNSHIFT(UNSHIFT(UNSHIFT(EMPTY)(FOUR))(FOUR))(TWO))(ONE))(ADD(RADIX));
const BUZZ = MAP(UNSHIFT(UNSHIFT(UNSHIFT(UNSHIFT(EMPTY)(FOUR))(FOUR))(THREE))(ZERO))(ADD(RADIX));
const FIZZBUZZ = n => MAP(RANGE(ONE)(n))(m =>
IF(IS_ZERO(MOD(m)(FIFTEEN)))(
CONCAT(FIZZ)(BUZZ)
)(IF(IS_ZERO(MOD(m)(THREE)))(
FIZZ
)(IF(IS_ZERO(MOD(m)(FIVE)))(
BUZZ
)(
m
)))
);
module.exports = { module.exports = {
ZERO, ONE, TWO, THREE, TIMES, INC, ADD, MULT, POWER, DEC, SUB, TRUE, ZERO, ONE, TWO, THREE, TIMES, INC, ADD, MULT, POWER, DEC, SUB, TRUE,
FALSE, IF, NOT, AND, OR, IS_ZERO, IS_LEQ, IS_EQ, IS_LEQ, Y, Z, FACT FALSE, IF, NOT, AND, OR, IS_ZERO, IS_LEQ, IS_EQ, IS_LEQ, Y, Z, FACT,
DIV, MOD, PAIR, LEFT, RIGHT, EMPTY, UNSHIFT, IS_EMPTY, FIRST, REST, INJECT,
FOLD, MAP, RANGE, SUM, PROD, CONCAT, PUSH, REVERSE, INC_ALL, DOUBLE_ALL,
TEN, RADIX, FOUR, FIVE, FIFTEEN, FIZZ, BUZZ, FIZZBUZZ
}; };