V2002 arity_mismatch
A function was called with the wrong number of arguments, or a pattern has the wrong number of fields.
An error from the type phase. sakura explain V2002 prints this explanation offline.
A function was called with the wrong number of arguments, or a pattern has the wrong number of
fields. The diagnostic's expected and actual carry both counts; arguments are positional, with
no defaults (pass a record when a call needs options).
Wrong:
fn double(x: Int) -> Int { x * 2 }
fn four() -> Int { double(2, 2) }Fixed:
fn four() -> Int { double(2) }Wrong program
compiler/tests/ui/V2002_arity_mismatch.sakura, which the compiler's ui suite runs through sakura check:
fn double(x: Int) -> Int { x * 2 }
fn four() -> Int { double(2, 2) }sakura check --json reports this record (pretty-printed; $DIR is the fixture's directory):
{
"schema_version": "1.0",
"kind": "diagnostic",
"id": "d:61ad7e6f1b4ce063",
"code": "V2002",
"severity": "error",
"phase": "type",
"message": "this call passes 2 arguments to a function of type `fn(Int) -> Int`, which takes 1",
"snapshot": "sha256:$SNAPSHOT",
"symbol_id": "main::V2002_arity_mismatch::four",
"spans": [
{
"uri": "file://$DIR/V2002_arity_mismatch.sakura",
"content_hash": "sha256:c871525ab5c724ef81dd0f38e0dad00386ca60537d36d8e833a2e8bfe7e61031",
"start_byte": 89,
"end_byte": 101,
"role": "primary"
}
],
"related_ids": [],
"expected": null,
"actual": null,
"obligation": null,
"counterexample": null,
"explanation_uri": "sakura://explain/V2002",
"fixes": []
}More fixtures for this code: compiler/tests/ui/V2002_row_argument_count.sakura.
Fixed program
compiler/tests/ui/V2002_arity_mismatch.fixed.sakura, which sakura check accepts with no diagnostics:
fn double(x: Int) -> Int { x * 2 }
fn four() -> Int { double(2) }