@smartput/mass

Milligram to ton, with the imperial pounds and ounces.

Metric and avoirdupois in one table, canonical in grams.

Three doors, one table. The kind descriptor is for the engine, /validate is free functions over JS numbers, /class is an immutable value class — and all three read the same UnitTable, so a unit added once is added everywhere. See Validating without the engine.

Setup

npm add @smartput/mass

Example

import { parseMass, asMass, formatMass } from "@smartput/mass/validate";
import { Mass } from "@smartput/mass/class";

parseMass("500 g")                         // {"ok":true,"value":500,"unit":"g","raw":"500"}
asMass("500 g", "mg")                      // {"ok":true,"value":500000,"unit":"mg","raw":"500000"}
formatMass(parseMass("500 g"))             // "500g"
String(Mass.parse("500 g"))                // "500g"

// …and the same table through the engine:
engine.evaluate("1 kg + 500 g").formatted  // "1.5 kilograms"
engine.evaluate("3 lbs").formatted         // "3 pounds"
engine.evaluate("2 t in kg").formatted     // "2,000 kilograms"

parse and as never throw — they answer { ok: true, … } or { ok: false, code, input }. The value class throws on bad input and Mass.tryParse does not. All three read the one UnitTable below.

Entry points

| Import | Contents | | --- | --- | | @smartput/mass | The package root. | | @smartput/mass/units | The UnitTable: ratios and aliases, with no engine and no Decimal. | | @smartput/mass/validate | Free functions over JS numbers. Ok \| Err, never a throw. | | @smartput/mass/class | The immutable value class. | | @smartput/mass/locale/<id> | One language's words for this kind. 17 ship: en, de, fr, es, pt, it, nl, zh, ja, ar, ru, pl, tr, hi, ko, id, uk. |

Units

Read from the table itself, not typed out — a unit added to the source appears here on the next bun run docs:packages. Ratios are decimal strings, which is what lets the engine widen them to Decimal without a float in between.

MASS_UNITS

| Unit | Ratio to g | Aliases | | --- | --- | --- | | g | 1 | g gram grams | | mg | 0.001 | mg milligram milligrams | | kg | 1000 | kg kilo kilos kilogram | | t | 1000000 | t tonne tonnes | | oz | 28.349523125 | oz ounce ounces | | lb | 453.59237 | lb lbs pound pounds |

Runtime exports

Type-only exports are erased and do not appear here.

MASS_UNITS · mass

Dependencies

• @smartput/kind
• @smartput/shared

What it costs

Ceilings, not measurements. bun run check-size bundles each entry with bun build --minify and fails if a row crosses its ceiling or drops more than 30 % below it — a budget that is only an upper bound reports a vanished graph as a triumph.

| Import | Minified | Gzipped | | --- | --- | --- | | mass/validate parseMass only | ≤ 1.4 kB | ≤ 750 B |

Generated by scripts/gen-readmes.ts — run bun run docs:readmes. Every output above was produced by running the line beside it. The full page, with live demos, is docs/packages/mass.md.