IdPath

IdPath<A> wraps Id<A>, the identity monad. It always contains a value and never fails. This sounds useless until you need it.

Creation

IdPath<String> id = Path.id("hello");
IdPath<User> fromId = Path.idPath(idUser);

Core Operations

IdPath<String> name = Path.id("Alice");

IdPath<Integer> length = name.map(String::length);  // Id(5)
IdPath<String> upper = name.via(s -> Path.id(s.toUpperCase()));
IdPath<String> combined = name.zipWith(Path.id(25), (n, a) -> n + " is " + a);

Extraction

IdPath<String> path = Path.id("hello");
String value = path.run().value();  // "hello"
String value = path.get();          // "hello"

When to Use

IdPath is right when:

• You're writing generic code that works over any Path type
• Testing monadic code with known, predictable values
• You need a "no-op" Path that always succeeds
• Satisfying a type parameter that demands a Path

IdPath is wrong when:

• Failure is possible → you need one of the other types

// Works with any Path type
<P extends Path<P, A>, A> P process(P path) {
    return path.map(this::transform);
}

// Test with IdPath (no failures to worry about)
IdPath<String> testPath = Path.id("test");
IdPath<String> result = process(testPath);

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