099 sequential for phases under capture

✗ Failing This test is currently failing.

Failed: backend-exec

Failure Output

error[KORU028]: terminal branch 'done' has more than one unguarded handler — a `|` continuation runs at most once; distinguish them with `when` guards or remove the duplicate
  --> tests/regression/320_CONTROL_FLOW/320_099_sequential_for_phases_under_capture/input.k:14:0

❌ Compiler coordination error: Incomplete branch coverage
   (set KORU_BACKEND_TRACE=1 for the backend return trace)

Code

// PIN (failing): two sequential for-loops chained by `| done |>` under a single
// capture `! as` mis-group — BOTH loops' `done` branches get attributed to the
// capture flow root, tripping KORU051 ("branch 'done' has 2 continuations").
// Surfaced by AoC day18 (Conway), whose phases (parse / step-compute / step-copy
// / count) are sequential loops over a shared capture-array.
//
// The green multi-phase days (14/17/24) all chain phases via capture-fold
// `| captured` terminals, never via bare `for … | done |> for …` under a
// capture — so this is either a parser done-grouping bug or an unsupported
// idiom. Either way it blocks the natural shared-mutable-array-across-phases
// shape. Expected output: 20 (two passes summing 1+2+3+4).
import std/io

capture { sum: 0[i64], g: [4]i64{ 1, 2, 3, 4 } }
! as acc |> for(0..4)
    ! each i |> captured { sum: acc.sum + acc.g[i] }
  | done |> for(0..4)
    ! each j |> captured { sum: acc.sum + acc.g[j] }
  | done |> _
| captured result |> std/io:print.ln("{{ result.sum:d }}")

input.k

Expected output

Flows

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

capture (source: sum: 0[i64], g: [4]i64{ 1, 2, 3, 4 })

Test Configuration

MUST_RUN

← 097 if nested step under return switch 101 loopvar in complex capture array write →