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

7
host/chez/collections.ss
View file

@ -252,10 +252,11 @@
((or (cseq? coll) (empty-list-t? coll)) (seq-nth coll i #t d))
(else d))))))
;; jolt models every number as a double, so a count is a flonum — else
;; (= 2 (count m)) is false (jolt= is exactness-aware: 2.0 vs exact 2).
;; a count is an exact integer (JVM parity: count returns a long). jolt= is
;; exactness-aware, so this must be exact to match an exact integer literal:
;; (= 2 (count m)) -> 2 vs exact 2 -> true.
(define (jolt-count coll)
(exact->inexact
(begin
(cond ((pvec? coll) (pvec-count coll))
((pmap? coll) (pmap-cnt coll))
((pset? coll) (pset-count coll))