015 fmt ln scoped param produce out

✓ Passing Passing: the compiler rejects this program as expected.

Code

import std/fmt
import std/io

// The other half of declared conferral: `data` binds scoped inside the
// callee, so producing it out through a PLAIN `-> string` output refuses —
// only a declared `-> string<*@scoped>` output may carry the class on.
tor launder { data: string<*@scoped> } -> string
launder = std/io:print.ln(data): _ -> data

std/fmt:ln("item {{ 1:d }}"): l |> launder(data: l.text): d |> std/io:print.ln(d)

input.k

Actual compiler output

error[KORU030]: 'data' is @scoped — it dies with this frame and may not be produced out. Consume it in place, or copy it out first (std/string:from-page + take / fmt.blk)
  --> tests/regression/600_STDLIB/620_FMT/620_015_fmt_ln_scoped_param_produce_out/input.k:8:1

Must fail at runtime:

Program must error when executed.

Error output must contain

may not be produced out

Flows

subflow ~launder click a branch to expand · @labels scroll to their anchor

print.ln (expr: data)

flow ~ln click a branch to expand · @labels scroll to their anchor

ln ("item {{ 1:d }}")

Test Configuration

MUST_ERROR

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