bare-fmt-warns.ilo

-- `fmt` is pure-functional sprintf: it builds a string and returns it.
-- A bare `fmt "..." v` as a non-tail statement is silently discarded on
-- every engine (tree, VM, Cranelift). Nothing reaches stdout — the
-- common mistake is treating `fmt` like Rust's `println!` / Python's print.
--
-- The verifier flags this with ILO-T032. This file pins the two idiomatic
-- shapes that fix it. We wrap each `prnt` in a single-iteration foreach
-- so the loop-tail auto-print suppression keeps stdout to exactly the
-- intended line and `tests/examples_engines.rs` can assert it precisely.

-- Idiom 1: print directly with `prnt fmt ...`
report-print v:n>t;@i [v]{prnt fmt "v={}" v}

-- Idiom 2: capture to a name, then print
report-bind v:n>t;line=fmt "v={}" v;@i [v]{prnt line}

-- Tail position is fine: `fmt` as the function's return value is
-- exactly the documented idiom (no warning, no discard).
say-x v:n>t;fmt "x={}" v

-- run: report-print 7
-- out: v=7
-- run: report-bind 9
-- out: v=9
-- run: say-x 42
-- out: x=42