lib.types.coercedTo

The following is the current implementation of this function.

coercedTo = coercedType: coerceFunc: finalType:
      assert lib.assertMsg (coercedType.getSubModules == null)
        "coercedTo: coercedType must not have submodules (it’s a ${
          coercedType.description})";
      mkOptionType rec {
        name = "coercedTo";
        description = "${optionDescriptionPhrase (class: class == "noun") finalType} or ${optionDescriptionPhrase (class: class == "noun") coercedType} convertible to it";
        check = x: (coercedType.check x && finalType.check (coerceFunc x)) || finalType.check x;
        merge = loc: defs:
          let
            coerceVal = val:
              if coercedType.check val then coerceFunc val
              else val;
          in finalType.merge loc (map (def: def // { value = coerceVal def.value; }) defs);
        emptyValue = finalType.emptyValue;
        getSubOptions = finalType.getSubOptions;
        getSubModules = finalType.getSubModules;
        substSubModules = m: coercedTo coercedType coerceFunc (finalType.substSubModules m);
        typeMerge = t: null;
        functor = (defaultFunctor name) // { wrapped = finalType; };
        nestedTypes.coercedType = coercedType;
        nestedTypes.finalType = finalType;
      };