feat(mf2): Rename :math as :offset, make it default

Author: XM5jDcsHTyGJtQqlCi

mf2/messageformat/src/functions/index.ts

@@ -25,7 +25,7 @@ export type { MessageString } from './string.ts';
 
 import { currency } from './currency.ts';
 import { date, datetime, time } from './datetime.ts';
-import { math } from './math.ts';
+import { offset } from './offset.ts';
 import { integer, number } from './number.ts';
 import { string } from './string.ts';
 import { unit } from './unit.ts';
@@ -53,6 +53,15 @@ export let DefaultFunctions = {
    */
   number,
 
+  /**
+   * Supports formatting and selection as defined in LDML 48 for the
+   * {@link https://www.unicode.org/reports/tr35/tr35-76/tr35-messageFormat.html#the-offset-function | :offset function}.
+   *
+   * The `operand` must be a number, BigInt, or string representing a JSON number,
+   * or an object wrapping such a value, with a `valueOf()` accessor and an optional `options` object.
+   */
+  offset,
+
   /**
    * Supports formatting and selection as defined in LDML 47 for the
    * {@link https://www.unicode.org/reports/tr35/tr35-75/tr35-messageFormat.html#the-string-function | :string function}.
@@ -111,15 +120,6 @@ export let DraftFunctions = {
    */
   datetime,
 
-  /**
-   * Supports formatting and selection as defined in LDML 47 for the
-   * {@link https://www.unicode.org/reports/tr35/tr35-75/tr35-messageFormat.html#the-math-function | :math function}.
-   *
-   * The `operand` must be a number, BigInt, or string representing a JSON number,
-   * or an object wrapping such a value, with a `valueOf()` accessor and an optional `options` object.
-   */
-  math,
-
   /**
    * Supports formatting as defined in LDML 47 for the
    * {@link https://www.unicode.org/reports/tr35/tr35-75/tr35-messageFormat.html#the-time-function | :time function}.

mf2/messageformat/src/functions/number.ts

@@ -8,9 +8,12 @@ import type { DefaultFunctions, DraftFunctions } from './index.ts';
 import { asPositiveInteger, asString } from './utils.ts';
 
 /**
- * The resolved value of a {@link DraftFunctions.currency | :currency},
- * {@link DefaultFunctions.integer | :integer}, {@link DraftFunctions.math | :math},
- * {@link DefaultFunctions.number | :number}, or {@link DraftFunctions.unit | :unit} expression.
+ * The resolved value of a
+ * {@link DraftFunctions.currency | :currency},
+ * {@link DefaultFunctions.integer | :integer},
+ * {@link DefaultFunctions.number | :number},
+ * {@link DefaultFunctions.offset | :offset},
+ * or {@link DraftFunctions.unit | :unit} expression.
  */
 export interface MessageNumber extends MessageValue<'number'> {
   readonly type: 'number';

mf2/messageformat/src/functions/math.ts renamed to mf2/messageformat/src/functions/offset.ts

@@ -4,11 +4,11 @@ import { MessageNumber, number, readNumericOperand } from './number.ts';
 import { asPositiveInteger } from './utils.ts';
 
 /**
- * `math` accepts a numeric value as input and adds or subtracts an integer value from it
+ * `offset` accepts a numeric value as input and adds or subtracts an integer value from it
  *
  * @beta
  */
-export function math(
+export function offset(
   ctx: MessageFunctionContext,
   exprOpt: Record<string | symbol, unknown>,
   operand?: unknown
@@ -26,7 +26,7 @@ export function math(
   }
   if (add < 0 === sub < 0) {
     const msg =
-      'Exactly one of "add" or "subtract" is required as a :math option';
+      'Exactly one of "add" or "subtract" is required as an :offset option';
     throw new MessageFunctionError('bad-option', msg, source);
   }
   const delta = add < 0 ? -sub : add;