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

Chez numeric tower: exact ints / Ratio / double for JVM parity (jolt-n6al)

Browse source 
jolt was all-flonum (one :number type, inherited from Janet whose only number
type is a double). The Chez runtime has a full numeric tower, so the zero-Janet
path now carries it = JVM Clojure semantics:

  (/ 1 2)      => 1/2      (exact Ratio, was 0.5)
  (integer? 3) => true   (integer? 3.0) => false   (float? 3.0) => true
  (ratio? (/ 1 2)) => true   (= 3 3.0) => false   (== 3 3.0) => true
  (+ 1 2) => 3 (exact)   (/ 1.0 2) => 0.5 (double)

jolt= was already exactness-aware (values.ss) and == is value-equality, so
=/== match the JVM split. The reader preserves exactness (integer literals exact,
a/b ratios exact rationals, decimals/exponents flonums); backend_scheme emit-const
renders exact ints/ratios and flonums faithfully; the value-position arithmetic,
count, int, compare, bit ops, parseLong, string .length/.indexOf, range,
timestamps, and array bytes return exact integers (= JVM int/long) instead of
coercing to flonum. double/parseDouble/clojure.math floor|ceil|signum stay double.

Only the zero-Janet path carries the tower (the Janet reader loses exactness into
a double before emit). The prelude/all-flonum path is unaffected for compiled code;
the runtime reader is shared, so a couple of all-flonum reader assertions become
value (==) assertions. ~16 numeric corpus cases now give the JVM tower value vs the
Janet-era :expected and are allowlisted as tower divergences (Chez == reference
JVM) pending the corpus flip to JVM (jolt-ecz0). No BigDecimal type (1M).

Re-minted. zero-janet 2682 (floor 2698->2682, the reclassified tower cases), 0 new
divergences; fixpoint 10/10, bootstrap 6/6, spine 35/35, cli 49/49; Janet gate 155
files 0 failed.
This commit is contained in:
Yogthos 2026-06-20 23:09:27 -04:00
parent eb1c3298a4
commit 467ad75ff7
20 changed files with 291 additions and 210 deletions
Download patch file Download diff file Expand all files Collapse all files

14
host/chez/post-prelude.ss
View file

@ -80,3 +80,17 @@
(def-var! "clojure.core" "line-seq"
(lambda (rdr)
(if (reader-jhost? rdr) (chez-line-seq rdr) (jolt-invoke overlay-line-seq rdr)))))
;; JVM-parity numeric tower (jolt-n6al): the overlay (20-coll.clj) carries an
;; all-flonum number-predicate web with no Ratio concept (ratio? -> false,
;; double? -> not-integer, float? -> double?, rational? -> int?), which
;; misclassifies exact rationals on the Chez tower (e.g. (double? 1/2) -> true).
;; Re-assert the native tower-correct versions (predicates.ss) so they win over
;; the overlay defs. int?/double? alias integer?/float?. == is value-equality.
(def-var! "clojure.core" "integer?" jolt-integer?)
(def-var! "clojure.core" "int?" jolt-integer?)
(def-var! "clojure.core" "float?" jolt-float?)
(def-var! "clojure.core" "double?" jolt-float?)
(def-var! "clojure.core" "ratio?" jolt-ratio?)
(def-var! "clojure.core" "rational?" jolt-rational?)
(def-var! "clojure.core" "decimal?" jolt-decimal?)
(def-var! "clojure.core" "==" jolt-num-equiv)