map access or block behavior is inconsistent with the rest of the language

[juan-db]

Describe the bug

Please see the code snippets with commentary below.

Reproduction Steps

Try to compile the following code:

fn get_value(m map[string]int, key string) ?int {
	return m[key] or { none }
}

Expected Behavior

The program to compile successfully. This would be consistent with how or blocks behave in other contexts, e.g.:

fn even_or_none(i int) ?int {
	return if i % 2 == 0 { i } else { none }
}

fn useless_fn(i int) ?int {
	return even_or_none(i) or { none }
}

Current Behavior

The compiler gives an error.

map.v:2:21: error: `or` block must provide a value of type `int`, not `none`
    1 | fn get_value(m map[string]int, key string) ?int {
    2 |     return m[key] or { none }
      |                        ~~~~
    3 | }

Possible Solution

No response

Additional Information/Context

One of the users on Discord pointed out, I can use or { return none } instead of just or { none } and it'll work fine, but the second return seems redundant.

fn get_value(m map[string]int, key string) ?int {
	return m[key] or { return none }
}

V version

V 0.4.3 e19b2dd

Environment details (OS name and version, etc.)

V full version: V 0.4.3 5b96d8d.e19b2dd
OS: macos, macOS, 14.2.1, 23C71
Processor: 11 cpus, 64bit, little endian, Apple M3 Pro

vexe mtime: 2024-01-05 00:03:27

vroot: OK
VMODULES: OK
VTMP: OK

Git version: git version 2.39.3 (Apple Git-145)
Git vroot status: weekly.2024.01.test2-1-ge19b2dd4
.git/config present: true

CC version: Apple clang version 15.0.0 (clang-1500.1.0.2.5)
thirdparty/tcc status: thirdparty-macos-arm64 a668e5a0

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[shove70]

No, it's not about V.

fn get_value(m map[string]int, key string) ?int {
	return m[key] or { none }  // The or block here is map specific and is where we handle when the key doesn't exist
	                           // The priority of this or block is to the map, not to the previous return
}

fn even_or_none(i int) ?int {
	return if i % 2 == 0 { i } else { none }
}

fn useless_fn(i int) ?int {
	return even_or_none(i) or { none } // The or block here is the option that handles the return value of fn even_or_none()
}

They're not the same

[shove70]

fn get_value(m map[string]int, key string) ?int {
	return m[key] or { return none }
}

So it works

[juan-db]

Result behaves the same as Option.

fn even_or_error(i int) !int {
	return if i % 2 == 0 { i } else { error('${i}') }
}

fn useless_fn(i int) ?int {
	return even_or_error(i) or { none }
}

I can't think of another example that uses or syntax. So why should map behave differently from Result and Option?