suaveplan/packages/localization/i18n/i18n-shared/src/constants/interpolation-defaults.md

DEFAULT_INTERPOLATION — interpolation engine defaults

Purpose

DEFAULT_INTERPOLATION is the canonical default configuration for the ICU interpolation engine that ships with @suaveplan/i18n-icu-parser (Wave 2 of the modular split). Centralising the defaults here lets every leaf package — the parser, the catalog, the slim core, even custom plugins — agree on the same delimiter pair and nesting limit without re-declaring the literals. Consumers that want to override the defaults can spread them at construction time ({ ...DEFAULT_INTERPOLATION, prefix: "${" }); the immutable shape ensures no consumer can accidentally mutate the defaults at module init.

Features

• Mustache-compatible delimiters ({{ / }}) — drop-in for catalogs authored against any popular i18n format
• maxDepth: 10 ceiling — short-circuits pathological recursion
• as const shape — string literals narrow at the type level for branded types
• Frozen at module-init via as const — no consumer can mutate

Usage: Basic Example

import { DEFAULT_INTERPOLATION } from "@suaveplan/i18n-shared";

const prefix = DEFAULT_INTERPOLATION.prefix;   // "{{"
const suffix = DEFAULT_INTERPOLATION.suffix;   // "}}"
const maxDepth = DEFAULT_INTERPOLATION.maxDepth; // 10

Usage: Advanced Example

import { DEFAULT_INTERPOLATION } from "@suaveplan/i18n-shared/constants/interpolation-defaults";

// Override the prefix / suffix while keeping the depth limit
const customDelimiters = {
    ...DEFAULT_INTERPOLATION,
    prefix: "${",
    suffix: "}",
} as const;

// Pass the custom shape to the interpolation engine (parser package
// will accept this shape verbatim)
const interpolation = customDelimiters; // type-narrowed

API Reference

DEFAULT_INTERPOLATION

Frozen object literal with these fields:

Field	Type	Value
prefix	"{{"	Opening placeholder delimiter
suffix	"}}"	Closing placeholder delimiter
maxDepth	10	Maximum nested-resolution depth

Throws: nothing — read-only constant.

Implementation Notes

• The choice of {{ / }} matches Mustache, Handlebars, and i18next out of the box. Catalogs authored against any of those tools load without rewriting placeholders.
• The maxDepth of 10 is empirical — pathological self-referencing catalogs ({"a": "{{a}}"}) are detected within 10 expansions while well-formed nested-key cases (rare beyond depth 3) still complete normally.
• The shape is as const (NOT a Zod schema) because every consumer of this constant treats it as the authoritative literal — there is no boundary parsing required at this layer.