The mechanical half, ahead of the parser change that needs it. tools/unit-return.py
fills the empty slot with () and rewrites Unit as () wherever a type is spelled --
(Fn [i32] Unit), (Map i32 Unit), a return type written out.
Deciding whether a defn already had a return type is the whole difficulty, and
the script does it the way parse.ml did: is_type_form is transcribed rather than
improved, because being identical to the parser it replaces is what makes the
sweep meaning-preserving. It is re-runnable, so the lanes that branched before
this can have the same pass at merge:
python3 tools/unit-return.py .
python3 tools/unit-return.py --in-strings test/test_flan.ml test/test_acceptance.ml \
test/test_session.ml emacs/test-flan-dev.el emacs/test-flan-mode.el
python3 tools/unit-return.py --raw-ml lib/prelude.ml
python3 tools/unit-return.py --in-html web/index.html
-v logs every defn it saw and what it decided, which is how a sweep of 440 sites
gets reviewed at all. Embedded modes pool a file's type declarations across all
its fragments, because a snippet split across concatenation -- decls ^ "(defn f
[s [u8]] Cursor ...)" -- cannot see the names the other half declared; pooled
names count only in bare-symbol position, for the same reason the prelude's do.
A fragment that cuts off mid-form is skipped rather than guessed at. Five sites
in test_flan.ml still needed a hand, and they are in this commit.
Two things ride along because the sweep needs them: parse.ml reads a lone () as
the return type of a function with no body, which was not a shape the old
optional slot could produce; and the map refusals name () rather than Unit, since
that is now the spelling a caller wrote.
render.ml's output and emacs/flan-inspect.el's parser are the two ends of one
wire format, which is why the printer was left on the colon when the rest of
the corpus moved: shifting it alone would have broken inspection in the dev
loop without breaking a test that said so. They move together here.
The field list in the inspector is labelled with the dot too, which is the
spelling flan-inspect-step-expr already used to build `(.x b)' — the label and
the expression it stands for now read the same.
One case needed a guard the colon never did: `...' also begins with a dot and
is the renderer saying it stopped, not a field called `..'. A field name never
starts with a second dot, so one character of lookahead separates them.
The colon is not gone from the rendered grammar. An enum member is `:green' and
is a *value*, so the two are now told apart by the character alone, which is
the only thing that distinguishes them.
Also font lock, handed over with the same change: `:name' was the rule that
drew field labels, and with the colon belonging to keywords every label in the
corpus was left unfontified. `.name' is drawn as a constant, in both the places
it appears — the label in `{.x 1.0}' and the accessor in `(.x v)', which are
the same name.
The reported bug — the second and later bindings of a let one column too far —
was never one missing rule. `flan-indent-function' checked the head of the
enclosing form, and inside a binding vector the enclosing open is `[' and the
symbol after it is the first binding's name, so it fell through to Emacs's
`lisp-indent-function', which treats the vector as a call and aligns under the
first argument instead of the first binding.
Emacs Lisp is the wrong reference. It has no vectors-as-bindings, no maps and
no bracket variety, so every rule Flan needs has to be added by hand and the
binding vector is simply the first one hit. The indenter is rewritten from
clojure-mode's source instead: `clojure-mode' is neither an ancestor nor a
dependency — flan-mode still needs nothing beyond stock Emacs — it is the file
whose rules were read and written out again.
A bracket aligns under its first element, and that one rule fixes the binding
vector, `defn' parameter lists, `restart-case' and `handler-bind' clause
parameters and both spellings of a struct literal at once. `{:x 1}' and
`{.x 1}' indent identically because nothing here looks at the key, which is
what the colon-to-dot lane needs of it.
Where Flan diverges it is handled on purpose. `defn' is `:defn' rather than a
count because the return type between the parameters and the body is optional.
A clause — `(Name [params] body)' — is recognised by its shape, since its head
is a condition class or a restart name and can never be in a table; clojure-mode
reaches the same clauses by backtracking out to the enclosing form, which buys
generality this language has no other use for. Special arguments indent by one
body rather than Clojure's two, and a call whose head is alone on its line
indents its arguments by a body rather than aligning them under the head,
because that is how the whole corpus is written.
Checked by reindenting every .flan file in the tree: the only lines that move
are sand.flan's reported bug, raylib.flan's hand-wrapped parameter vectors —
which is the fix — and lone-`;' comment continuations, which stock
`lisp-indent-line' has always moved.
test-flan-mode.el is loaded from test-flan-cider.el rather than given a stanza
of its own, because emacs/*.el is already a dependency of that test.
Two failures in test-flan-cider.el that predate this: fixture frames lacked
`:fetched', so folding one open went looking for a daemon, and `layout' was
identified by being the last request when `flan-cnr-show' now makes three.
