○
Planned This feature is planned but not yet implemented.
KORU100 false positive: string interpolation reference not counted as binding use inside for loop body (post-transform AST loses interpolation→binding association)
Code
// TEST: KORU100 false positive — binding used in string interpolation inside for loop
//
// BUG: The flow checker emits KORU100 (unused binding) for a binding that IS
// used inside {{ }} string interpolation, when the branch appears inside a
// std.control:for loop body.
//
// The same pattern compiles correctly at the top level of a flow (outside any
// for loop). The for transform rewrites the AST during the comptime pass, and
// the binding-use tracker appears to lose the interpolation→binding association
// in the post-transform AST.
//
// Discovered while building the @korulang/postgres library: the pattern
// | some name |> std.io:print.ln("row {{ i }}: {{ name:s }}")
// inside a for loop triggers KORU100 for 'name', despite it being used.
//
// Expected: Compiles successfully — 'val' IS used in {{ val:s }}
// Actual: error[KORU100]: unused binding 'val'
~import "$std/io"
~import "$std/control"
~import "$app/source"
~std.control:for(0..3)
| each _ |>
source:maybe_str()
| none |> std.io:print.ln("nothing")
| some val |> std.io:print.ln("got: {{ val:s }}")
| done |> _
pub fn main() void {}
Imported Files
// Helper module: an event that optionally returns a string.
// Used by 220_003 to trigger the for-loop binding-use bug.
~pub event maybe_str {}
| some []const u8
| none
~proc maybe_str {
return .{ .some = "hello" };
}