simon/jolt
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Compile data readers that return code forms

Browse source 
A registered #tag data reader whose fn returns a FORM (borkdude/html's #html
expands to (->Html (str …))) was rewritten to a runtime call (reader-fn 'inner),
so the returned code became a runtime list value instead of being compiled —
(str #html [:div]) rendered the code, not "<div>". Clojure applies a data reader
at read time and substitutes its result as code.

loader.ss now applies the reader at load time: a code form (a list) is spliced in
to be compiled, a value (time-literals #time/date -> a Date) keeps the runtime
call, which also keeps a non-serializable constant out of an AOT build. The build
emit path never applied data readers at all (a #tag literal failed a `jolt build`
with "unsupported form"); emit-image.ss gets an ei-emit-form-hook the build sets
to the same rewrite, left as a no-op elsewhere so the seed mint (which doesn't
load loader.ss) is unaffected and the self-host byte-fixpoint holds.

Also make clojure.test report the actual values of a failing (is (= a b)) — it
printed only the form. Restricted to the common pure predicates so a macro head
still takes the plain path.

Fixture test/chez/datareader-app + a smoke check (interpreted) and a build-smoke
check (AOT). make test green, no corpus change.
This commit is contained in:
Yogthos 2026-07-01 10:57:55 -04:00
parent 1008e922d8
commit 908ad63caa
10 changed files with 88 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

22
host/chez/loader.ss
View file

@ -57,9 +57,25 @@
((and (pmap? x) (eq? (jolt-get x rdr-kw-jolt-type) rdr-kw-jolt-tagged))
(let ((rdr (data-reader-symbol (jolt-get x rdr-kw-tag)))
(inner (ldr-apply-readers (jolt-get x rdr-kw-form))))
(cond (rdr (jolt-list rdr (jolt-list (jolt-symbol #f "quote") inner)))
((eq? inner (jolt-get x rdr-kw-form)) x)
(else (rdr-make-tagged (jolt-get x rdr-kw-tag) inner)))))
(cond
(rdr
;; Clojure applies a data reader at read time and substitutes its result
;; as code. A reader that returns a FORM (a list — e.g. borkdude.html's
;; #html expands to (->Html (str …))) must be compiled, so splice it in.
;; A reader that returns a VALUE (time-literals #time/date -> a Date) is
;; left as a runtime call (reader-fn 'inner): the value rebuilds at
;; startup, which also keeps a non-serializable constant out of an AOT
;; build. Apply is guarded — a reader that can't run at load time (its
;; deps not ready) falls back to the runtime call too.
(let ((result (and (symbol-t? rdr) (not (jolt-nil? (symbol-t-ns rdr)))
(guard (e (#t #f))
(let ((fn (var-deref (symbol-t-ns rdr) (symbol-t-name rdr))))
(and (procedure? fn) (jolt-invoke fn inner)))))))
(if (cseq? result)
result
(jolt-list rdr (jolt-list (jolt-symbol #f "quote") inner)))))
((eq? inner (jolt-get x rdr-kw-form)) x)
(else (rdr-make-tagged (jolt-get x rdr-kw-tag) inner)))))
((rdr-set-form? x)
(let-values (((items changed) (ldr-conv-each (seq->list (jolt-get x rdr-kw-value)))))
(if changed (rdr-carry-meta x (rdr-make-set items)) x)))