E0049: unknown_handler_property

E0049 unknown_handler_property — an unknown handler annotation.

A compile-time error of soma check, the checker of the Soma programming language (soma explain E0049).

The rule

A handler annotation in brackets after the parameter list must be one of [native], [task], [deterministic] or [record]. A misspelt annotation such as [nativ] is refused rather than ignored, because the handler would otherwise silently run without it. Fix the spelling; the message suggests the closest known annotation.

A program that triggers it

cell Loans {
    face {
        signal monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) -> Int
    }
    on monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) [nativ] {
        let total = 0
        for m in range(0, months) {
            total = total + idiv(balance_cents * rate_bps, 120000)
        }
        return total
    }
}

What soma check prints:

$ soma check wrong.cell
error: unknown handler annotation [nativ] on `monthly_interest` — did you mean [native]? (known: [native], [task], [deterministic], [record])
  --> wrong.cell:5:5
  |
5 |     on monthly_interest(balance_cents: Int, rate_bps: Int, month…
  |     ^
  = code: E0049
✗ 1 error(s), 0 warning(s).

The fix field of soma check --json: did you mean [native]? (known: [native], [task], [deterministic], [record])

The fix

On line 5, on monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) [nativ] { becomes on monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) [native] {.

--- wrong.cell
+++ right.cell
@@ -3,5 +3,5 @@
         signal monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) -> Int
     }
-    on monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) [nativ] {
+    on monthly_interest(balance_cents: Int, rate_bps: Int, months: Int) [native] {
         let total = 0
         for m in range(0, months) {

With the fix, soma check accepts the program:

$ soma check right.cell
✓ All checks passed.