Adds `examples/print_float_whole_smoke.ail` (single `(app print
2.0)`) and `crates/ail/tests/print_float_whole_e2e.rs`. The test
builds and runs the fixture through the public `ail build` CLI
and asserts stdout is `"2.0\n"`.
Currently FAILS with `left: "2\n"`, `right: "2.0\n"` — runtime
`ailang_float_to_str` uses libc `snprintf("%g", x)` which strips
trailing zeros, so a whole-valued Float prints as Int-shaped
text. The surface printer at
`crates/ailang-surface/src/print.rs::write_float_lit` (lines
624-637) already enforces the `.0`-fallback property; the runtime
drifts. This RED pins the desired symmetry.
The GREEN side will mirror the surface fallback in
`runtime/str.c::ailang_float_to_str` and update the
`floats_e2e.rs` golden (`"4\n42\n-1.5\n"` → `"4.0\n42.0\n-1.5\n"`)
plus the doc comments at `crates/ail/tests/e2e.rs` and in the
runtime/example files that documented the previous `%g`-without-
fallback contract.
The alternative (document `%g`-behaviour in design/ ledger §Float
semantics as a deliberate human-friendly contract) was rejected:
the language's stated ethos is machine-readability + round-trip
identity (CLAUDE.md §"AILang — a language for LLM authors"); the
surface printer is the reference, runtime drift from it is a
defect not a feature.
refs #7
Brummel
f19b0dd860