subflow defines semantics

// Test 240: subflows define branch semantics
//
// Branch names in Koru are inert identifiers. Their meaning — what
// "return", "break", "continue", "ok", "north", or any other name
// signifies — is defined by the SUBFLOWS that resolve them, not by
// the compiler. This is the structural advantage over languages that
// bake fixed semantics for certain names into their grammar.
//
// This test deliberately uses names that ARE keywords in other
// languages (return, break, continue), to verify that the parser
// carries no value judgment about them. If a "common mistakes from
// other languages" trap is re-introduced at parser.zig parseStep,
// this test fails. That is the point.

~import "$std/io"

// Lower-level event: arbitrary outcome names
~pub event step {}
| return
| break
| continue

~step = continue

// Outer event: its own outcome vocabulary
~pub event run {}
| stopped
| iterated

// Subflow: `run` is satisfied by `step`, with `step`'s outcomes
// mapped to `run`'s. The meaning of `return`, `break`, `continue`
// lives HERE — in user code, not in the compiler.
~run = step()
| return |> stopped
| break |> stopped
| continue |> iterated

~std.io:print.ln("Testing subflow-defined semantics:")
~run()
| stopped |> std.io:print.ln("  stopped")
| iterated |> std.io:print.ln("  iterated")