Packages / toml · source

toml

A practical TOML config reader written entirely in Lumen.

V1 is intentionally focused on common read-only config use cases. It does not read files, mutate process state, or attempt the whole TOML 1.0 surface.

Use

import { getString, getInt, getBool, getArray, stringify } from "https://lumen-lang.org/package/std-contrib/toml/toml.ts";

let src = "[package]\nname = \"demo\"\nversion = 1\n";

let name = getString(src, "package.name", "");
let version = getInt(src, "package.version", 0);

let out = stringify(["package.name=demo", "package.version=1"]);

API

API	Meaning
parse(src: string): string[]	Parse into normalized path=value entries
keys(src: string): string[]	Return normalized keys in document order
has(src: string, key: string): bool	Return whether key exists
get(src, key, fallback): string	Return the last raw value for key
getString(src, key, fallback): string	Return a string value
getInt(src, key, fallback): int	Return an integer value
getBool(src, key, fallback): bool	Return a boolean value
getArray(src, key): string[]	Return simple array items as strings
stringify(entries: string[]): string	Serialize normalized path=value entries

The npm TOML ecosystem usually exposes parse and stringify over JavaScript objects. Lumen does not yet have the same dynamic object shape, so this package uses normalized path=value entries as the stable interchange format for now.

Supported V1 syntax

• comments beginning with # outside quotes
• bare keys and dotted keys
• tables like [package]
• nested tables like [database.primary]
• strings with "basic" and 'literal' quotes
• integers, including _ separators and negative values
• booleans: true, false
• simple arrays: ["a", "b"], [1, 2]
• duplicate keys, with get* returning the last value
• serialization from normalized entries with strings, ints, bools, and arrays

Out of scope for V1

• arrays of tables
• inline tables
• date/time values
• floats
• multiline strings
• quoted keys
• strict diagnostics for every malformed line
• full object-style serialization

Test:

lumen test packages/toml/toml.ts