rpncalc-v4/builtin.mjs

77 lines
1.9 KiB
JavaScript

import {addDefn, addRPNASTDefn} from './eval.mjs';
import {parseExprs} from './parse.mjs';
import {tokenize} from './token.mjs';
const addRPNDefn = (name, def) => {
let toks = tokenize(def);
if (!toks) {
throw 'could not load builtin'
}
let ast = parseExprs(toks);
if (!ast.parsed) {
throw 'could not load builtin'
}
addRPNASTDefn(name, ast.parsed[0]);
}
const add = (_, args) => {
return [{type:"int", val:args[0] + args[1]}];
}
const sub = (_, args) => {
return [{type:"int", val:args[1] - args[0]}];
}
const div = (_, args) => {
return [{type:"int", val:args[1] / args[0]}];
}
const mult = (_, args) => {
return [{type:"int", val:args[0] * args[1]}];
}
const pow = (_, args) => {
return [{type:"int", val:Math.pow(args[1], args[0])}];
}
const root = (_, args) => {
return [{type:"int", val:Math.sqrt(args[0])}];
}
const type = (_, args) => {
return [{type:"string", val:args[0].type}];
}
const pair = (_, args) => {
return [{type:"pair", val:{fst:args[0], snd:args[1]}}];
}
const fst = (_, args) => [args[0].fst];
const snd = (_, args) => [args[0].snd];
const eq = (_, args) => {
if (args[0].type === args[1].type && args[0].val === args[1].val) {
return [{type:"ident", val:"true"}];
} else {
return [{type:"ident", val:"false"}];
}
}
addDefn("+", ["int", "int"], add);
addDefn("-", ["int", "int"], sub);
addDefn("/", ["int", "int"], div);
addDefn("*", ["int", "int"], mult);
addDefn("^", ["int", "int"], pow);
addDefn("sqrt", ["int"], root);
addDefn("==", 2, eq);
addDefn("typeof", 1, type);
addDefn("pair", 2, pair);
addDefn("fst", ["pair"], fst);
addDefn("snd", ["pair"], snd);
addRPNDefn("true", "(a b -> a)");
addRPNDefn("false", "(a b -> b)");
addRPNDefn("stop", "(-> \"stop)");
addRPNDefn("id", "(a -> a)");
addRPNDefn("inv", "(x -> 1 x /)");
addRPNDefn("fold", "(fn acc x -> '(-> x acc fn 'fn fold) '(-> acc) 'x \"stop ==)");