@thi.ng/units/cli.js

Extensible SI unit creation, conversions, quantities & calculations, CLI calculator (incl. Lisp-like DSL and ~170 predefined units & constants)

import { cliApp, THING_HEADER } from "@thi.ng/args";
import { compareByKey } from "@thi.ng/compare/keys";
import { defFormat } from "@thi.ng/strings/format";
import { padRight } from "@thi.ng/strings/pad-right";
import { $eval } from "./dsl.js";
import { ALIASES, UNITS } from "./unit.js";
import "./units/index.js";
cliApp({
  name: "units",
  start: 3,
  opts: {},
  commands: {
    list: {
      desc: "List known units (optionally filtered by given pattern)",
      opts: {},
      inputs: [0, 1],
      fn: async ({ inputs }) => {
        const re = inputs.length ? new RegExp(inputs[0]) : null;
        const fmt = defFormat([
          padRight(10),
          padRight(32),
          (x) => x
        ]);
        console.log(
          fmt("symbol", "aliases", "name"),
          "\n" + "-".repeat(72)
        );
        for (let [sym, aliases] of Object.entries(ALIASES).sort(
          compareByKey(0)
        )) {
          if (re && !(re.test(UNITS[sym].name) || [...aliases, sym].some((x) => re.test(x))))
            continue;
          console.log(fmt(sym, aliases.join(", "), UNITS[sym].name));
        }
      }
    },
    convert: {
      desc: "Unit conversion (x srcunit destunit)",
      opts: {},
      inputs: 3,
      fn: async ({ inputs }) => {
        console.log($eval(`(${inputs[2]} ${inputs[0]}${inputs[1]})`));
      }
    },
    calc: {
      desc: "Unit calculator (S-expression)",
      opts: {},
      inputs: 1,
      fn: async ({ inputs }) => {
        console.log($eval(inputs[0]));
      }
    }
  },
  ctx: async (ctx) => ctx,
  usage: {
    prefix: THING_HEADER(
      "@thi.ng/units",
      "1.4.0",
      "Unit converter & calculator"
    ) + "\n"
  }
});