private NameAllocator nameAllocator(List<DataConstructor> constructors) {
NameAllocator nameAllocator = new NameAllocator();
constructors
.stream()
.forEach(
dc ->
nameAllocator.newName(
MapperDerivator.mapperFieldName(dc),
MapperDerivator.mapperFieldName(dc) + " arg"));
nameAllocator.newName("cata", "cata");
nameAllocator.newName(
Utils.uncapitalize(adt.typeConstructor().declaredType().asElement().getSimpleName()),
"adt var");
return nameAllocator;
}
private DeriveResult<DerivedCodeSpec> functionDispatchImpl(List<DataConstructor> constructors) {
NameAllocator nameAllocator = nameAllocator(constructors);
TypeElement f = FlavourImpl.findF(context.flavour(), utils.elements());
TypeName returnType =
TypeName.get(
utils
.types()
.getDeclaredType(
f,
adt.typeConstructor().declaredType(),
adt.matchMethod().returnTypeVariable()));
TypeSpec wrapper =
TypeSpec.anonymousClassBuilder("")
.addField(
FieldSpec.builder(returnType, nameAllocator.get("cata"))
.initializer(
CodeBlock.builder()
.addStatement(
"$L -> $L.$L($L)",
nameAllocator.get("adt var"),
nameAllocator.get("adt var"),
adt.matchMethod().element().getSimpleName(),
Utils.joinStringsAsArguments(
constructors
.stream()
.map(
constructor ->
constructor
.arguments()
.stream()
.map(DataArguments::getType)
.noneMatch(
tm ->
utils
.types()
.isSameType(
tm,
adt.typeConstructor()
.declaredType()))
? constructor.name()
: CodeBlock.builder()
.add(
"($L) -> $L.$L($L)",
Utils.asLambdaParametersString(
constructor.arguments(),
constructor.typeRestrictions()),
constructor.name(),
MapperDerivator.mapperApplyMethod(
utils, context, constructor),
Utils.joinStringsAsArguments(
Stream.concat(
constructor
.arguments()
.stream()
.map(
argument ->
utils
.types()
.isSameType(
argument
.type(),
adt.typeConstructor()
.declaredType())
? "() -> this."
+ nameAllocator
.get(
"cata")
+ "."
+ FlavourImpl
.functionApplyMethod(
utils,
context)
+ "("
+ argument
.fieldName()
+ ")"
: argument
.fieldName()),
constructor
.typeRestrictions()
.stream()
.map(
TypeRestriction
::idFunction)
.map(
DataArgument
::fieldName))))
.build()
.toString())))
.build())
.build())
.build();
MethodSpec cataMethod =
MethodSpec.methodBuilder("cata")
.addModifiers(Modifier.PUBLIC, Modifier.STATIC)
.addTypeVariables(
Stream.concat(
adt.typeConstructor().typeVariables().stream(),
Stream.of(adt.matchMethod().returnTypeVariable()))
.map(TypeVariableName::get)
.collect(Collectors.toList()))
.returns(returnType)
.addParameters(
constructors
.stream()
.map(
dc ->
ParameterSpec.builder(
cataMapperTypeName(dc), MapperDerivator.mapperFieldName(dc))
.build())
.collect(toList()))
.addStatement("return $L.$L", wrapper, nameAllocator.get("cata"))
.build();
return result(methodSpec(cataMethod));
}