Add interpolator

Author: Adam Jenkins

Diff for: src/interpolate.js

@@ -0,0 +1,13 @@
+export const defaultInterpolation = /\{\{\s*(.+?)\s*\}\}/g
+
+export const needsInterpolation = (rule,regexp) => regexp.test(rule.toJSON(true));
+
+export const interpolateDeep = (o, params, regexp, resolver) => {
+  if (!o || typeof o === 'number' || typeof o === 'boolean') return o;
+
+  if (typeof o === 'string') return o.replace(regexp, (_, matched) => resolver(params,matched))
+
+  if (Array.isArray(o)) return o.map(t => interpolateDeep(t, params, regexp, resolver));
+
+  return Object.entries(o).reduce((acc, [k, v]) => ({...acc,[k]: interpolateDeep(v, params, regexp, resolver)}),{});
+};