Answer the result of partially formatting the specified template using format variable bindings contained in the given map. If a format variable does not have a corresponding binding in the map, then re-emit it into the (partially) formatted result.

A template intermixes raw character data with format variable interpolation sites. An interpolation site begins with either the ¢‘ or ¢“ metacharacter and ends with the corresponding close metacharacter, either ¢’ or ¢”, respectively. An interpolation site may contain any character except the expected close metacharacter. The contents are understood to name a variable that may appear as a key within the specified map; the associated value is this variable's value. If an interpolation site uses ¢“ (and ¢”), then the value will be converted to a string via `“_”` when it is copied into the result. If an interpolation site uses ¢‘ (and ¢’), then the value must be a string and will be copied directly into the result. To escape a metacharacter, precede it immediately by ¢`.

For example:

Assert: partially format ‘greeting’, ‘recipient’! with { greeting →"Hello" = Hello, ‘recipient’! ; Assert: partially format (partially format ‘greeting’, ‘recipient’! with { greeting →"Hello"}) with { recipient →"world"} = Hello, world! ;}