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Conformance: String/format static + java.text.NumberFormat

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Part of the java.* host-class gap (jolt-1nnn). String/format delegates to the
core format engine; NumberFormat getInstance/getNumberInstance/getIntegerInstance
group the integer part and honor min/max fraction digits.
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Yogthos 2026-06-22 18:04:51 -04:00
parent c7bbdea11d
commit 5c9c5ed6e1
2 changed files with 51 additions and 1 deletions
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50
host/chez/host-static.ss
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@ -259,8 +259,56 @@
(cons "isWhitespace" (lambda (c) (char<=? (integer->char (char-code c)) #\space)))))
;; String/valueOf(Object): "null" for nil, else jolt's str semantics.
;; String/format(fmt args…) / (locale fmt args…) -> the clojure.core format engine.
(register-class-statics! "String"
(list (cons "valueOf" (lambda (x . _) (if (jolt-nil? x) "null" (jolt-str-render-one x))))))
(list (cons "valueOf" (lambda (x . _) (if (jolt-nil? x) "null" (jolt-str-render-one x))))
(cons "format" (lambda (a . rest)
(if (and (jhost? a) (string=? (jhost-tag a) "locale"))
(apply jolt-format (car rest) (cdr rest))
(apply jolt-format a rest))))))
;; ---- java.text.NumberFormat (jolt-1nnn) -------------------------------------
;; A grouping decimal formatter (selmer number-format / cuerdas). state:
;; #(grouping? min-frac max-frac). .format groups the integer part with commas.
(define (nf-make grouping? minf maxf) (make-jhost "numberformat" (vector grouping? minf maxf)))
(define (group-int-str s) ; "1234567" -> "1,234,567"
(let* ((neg (and (> (string-length s) 0) (char=? (string-ref s 0) #\-)))
(digs (if neg (substring s 1 (string-length s)) s))
(n (string-length digs)) (out '()))
(let loop ((i 0))
(when (< i n)
(when (and (> i 0) (= 0 (modulo (- n i) 3))) (set! out (cons #\, out)))
(set! out (cons (string-ref digs i) out)) (loop (+ i 1))))
(string-append (if neg "-" "") (list->string (reverse out)))))
(define (nf-format self x)
(let* ((grouping? (vector-ref (jhost-state self) 0))
(minf (vector-ref (jhost-state self) 1)) (maxf (vector-ref (jhost-state self) 2))
(neg (< x 0)) (ax (abs (exact->inexact x)))
(scale (expt 10 maxf))
(scaled (exact (round (* ax scale))))
(ipart (quotient scaled scale)) (fpart (remainder scaled scale))
(istr (number->string ipart))
(fstr0 (if (> maxf 0) (let ((s (number->string fpart)))
(string-append (make-string (max 0 (- maxf (string-length s))) #\0) s)) ""))
;; trim trailing zeros down to minf
(fstr (let loop ((s fstr0)) (if (and (> (string-length s) minf)
(char=? (string-ref s (- (string-length s) 1)) #\0))
(loop (substring s 0 (- (string-length s) 1))) s))))
(string-append (if neg "-" "") (if grouping? (group-int-str istr) istr)
(if (> (string-length fstr) 0) (string-append "." fstr) ""))))
(register-host-methods! "numberformat"
(list (cons "format" (lambda (self n) (nf-format self n)))
(cons "setMaximumFractionDigits" (lambda (self d) (vector-set! (jhost-state self) 2 (jnum->exact d)) jolt-nil))
(cons "setMinimumFractionDigits" (lambda (self d) (vector-set! (jhost-state self) 1 (jnum->exact d)) jolt-nil))
(cons "setGroupingUsed" (lambda (self b) (vector-set! (jhost-state self) 0 (jolt-truthy? b)) jolt-nil))))
(register-class-statics! "NumberFormat"
(list (cons "getInstance" (lambda _ (nf-make #t 0 3)))
(cons "getNumberInstance" (lambda _ (nf-make #t 0 3)))
(cons "getIntegerInstance" (lambda _ (nf-make #t 0 0)))))
(register-class-statics! "java.text.NumberFormat"
(list (cons "getInstance" (lambda _ (nf-make #t 0 3)))
(cons "getNumberInstance" (lambda _ (nf-make #t 0 3)))
(cons "getIntegerInstance" (lambda _ (nf-make #t 0 0)))))
(register-class-statics! "Class"
;; an array descriptor ("[C", "[I", …) is its own class token (so instance? and