added two aux libraries for parsing and formatting floating point
numbers.
This commit is contained in:
Abdulaziz Ghuloum
parent
b324709e86
commit
0cc2aae7dc
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@ -1,5 +1,7 @@
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libikarusdir=$(pkglibdir)/ikarus
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dist_libikarus_DATA=ikarus/foreign.ss ikarus/ipc.ss ikarus/include.ss
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dist_libikarus_DATA= ikarus/foreign.ss ikarus/ipc.ss \
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ikarus/include.ss \
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ikarus/flonum-parser.sls ikarus/flonum-formatter.sls
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libCocoadir=$(pkglibdir)/Cocoa
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dist_libCocoa_DATA=Cocoa/helpers.ss
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@ -162,7 +162,10 @@ top_build_prefix = @top_build_prefix@
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top_builddir = @top_builddir@
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top_srcdir = @top_srcdir@
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libikarusdir = $(pkglibdir)/ikarus
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dist_libikarus_DATA = ikarus/foreign.ss ikarus/ipc.ss ikarus/include.ss
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dist_libikarus_DATA = ikarus/foreign.ss ikarus/ipc.ss \
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ikarus/include.ss \
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ikarus/flonum-parser.sls ikarus/flonum-formatter.sls
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libCocoadir = $(pkglibdir)/Cocoa
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dist_libCocoa_DATA = Cocoa/helpers.ss
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dist_pkglib_DATA = match.ss gl.ss glut.ss \
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@ -0,0 +1,72 @@
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;;; Copyright (c) 2009 Abdulaziz Ghuloum
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;;;
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;;; Permission is hereby granted, free of charge, to any person obtaining a
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;;; copy of this software and associated documentation files (the "Software"),
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;;; to deal in the Software without restriction, including without limitation
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;;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
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;;; and/or sell copies of the Software, and to permit persons to whom the
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;;; Software is furnished to do so, subject to the following conditions:
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;;;
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;;; The above copyright notice and this permission notice shall be included in
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;;; all copies or substantial portions of the Software.
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;;;
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;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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;;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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;;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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;;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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;;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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;;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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;;; DEALINGS IN THE SOFTWARE.
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(library (ikarus flonum-formatter)
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(export ikarus-format-flonum)
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(import (rnrs))
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(define (ikarus-format-flonum pos? digits expt)
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(define fixnum->string number->string)
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(define (next x)
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(if (null? x)
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(values #\0 '())
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(values (car x) (cdr x))))
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(define (format-flonum-no-expt expt d0 d*)
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(cond
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[(= expt 1)
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(cons d0 (if (null? d*) '(#\. #\0) (cons #\. d*)))]
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[else
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(cons d0
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(let-values ([(d0 d*) (next d*)])
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(format-flonum-no-expt (- expt 1) d0 d*)))]))
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(define (format-flonum-no-expt/neg expt d*)
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(cond
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[(= expt 0) d*]
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[else (cons #\0 (format-flonum-no-expt/neg (+ expt 1) d*))]))
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(define (sign pos? ls)
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(if pos?
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(list->string ls)
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(list->string (cons #\- ls))))
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(let ([d0 (car digits)] [d* (cdr digits)])
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(cond
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[(null? d*)
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(if (char=? d0 #\0)
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(if pos? "0.0" "-0.0")
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(if (= expt 1)
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(if pos?
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(string d0 #\. #\0)
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(string #\- d0 #\. #\0))
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(if (= expt 0)
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(if pos?
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(string #\0 #\. d0)
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(string #\- #\0 #\. d0))
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(string-append
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(if pos? "" "-")
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(string d0) "e" (fixnum->string (- expt 1))))))]
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[(and (null? d*) (char=? d0 #\0)) (if pos? "0.0" "-0.0")]
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[(<= 1 expt 9)
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(sign pos? (format-flonum-no-expt expt d0 d*))]
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[(<= -3 expt 0)
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(sign pos? (cons* #\0 #\. (format-flonum-no-expt/neg expt digits)))]
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[else
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(string-append
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(if pos? "" "-")
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(string d0) "." (list->string d*)
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"e" (fixnum->string (- expt 1)))]))))
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@ -0,0 +1,167 @@
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;;; The code here is extracted from
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;;; ``Printing Floating-Point Numbers Quickly and Accurately''
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;;; http://www.cs.indiana.edu/~burger/FP-Printing-PLDI96.pdf
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;;; It is believed to be in the public domain.
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;;; The copyright below is for the R6RS implementation not part
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;;; of the original work.
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;;; Copyright (c) 2009 Abdulaziz Ghuloum
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;;;
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;;; Permission is hereby granted, free of charge, to any person obtaining a
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;;; copy of this software and associated documentation files (the "Software"),
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;;; to deal in the Software without restriction, including without limitation
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;;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
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;;; and/or sell copies of the Software, and to permit persons to whom the
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;;; Software is furnished to do so, subject to the following conditions:
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;;;
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;;; The above copyright notice and this permission notice shall be included in
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;;; all copies or substantial portions of the Software.
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;;;
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;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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;;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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;;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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;;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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;;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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;;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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;;; DEALINGS IN THE SOFTWARE.
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;;; (parse-flonum <fl>
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;;; (lambda (positive? digits:list-of-chars exponent:int)
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;;; ---)
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;;; (lambda (inf/nan:string)
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;;; ---))
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;;; calls one of the two procedures depending on whether the
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;;; number has a real value or not.
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(library (ikarus flonum-parser)
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(export parse-flonum)
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(import (rnrs))
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(define fxsll fxarithmetic-shift-left)
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(define fxsra fxarithmetic-shift-right)
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(define (flonum-bytes f k)
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(let ([bv (make-bytevector 8)])
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(bytevector-ieee-double-set! bv 0 f (endianness big))
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(k (bytevector-u8-ref bv 0)
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(bytevector-u8-ref bv 1)
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(bytevector-u8-ref bv 2)
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(bytevector-u8-ref bv 3)
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(bytevector-u8-ref bv 4)
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(bytevector-u8-ref bv 5)
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(bytevector-u8-ref bv 6)
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(bytevector-u8-ref bv 7))))
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(define (flonum-parts x)
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(flonum-bytes x
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(lambda (b0 b1 b2 b3 b4 b5 b6 b7)
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(values
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(zero? (fxand b0 128))
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(+ (fxsll (fxand b0 127) 4)
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(fxsra b1 4))
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(+ (+ b7 (fxsll b6 8) (fxsll b5 16))
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(* (+ b4
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(fxsll b3 8)
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(fxsll b2 16)
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(fxsll (fxand b1 #b1111) 24))
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(expt 2 24)))))))
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(define flonum->digits
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(lambda (f e min-e p b B)
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;;; flonum v = f * b^e
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;;; p = precision (p >= 1)
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(let ([round? (even? f)])
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(if (>= e 0)
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(if (not (= f (expt b (- p 1))))
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(let ([be (expt b e)])
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(scale (* f be 2) 2 be be 0 B round? f e))
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(let* ([be (expt b e)] [be1 (* be b)])
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(scale (* f be1 2) (* b 2) be1 be 0 B round? f e)))
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(if (or (= e min-e) (not (= f (expt b (- p 1)))))
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(scale (* f 2) (* (expt b (- e)) 2) 1 1 0 B round? f e)
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(scale (* f b 2) (* (expt b (- 1 e)) 2) b 1 0 B round? f e))))))
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(define (len n)
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(let f ([n n] [i 0])
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(cond
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[(zero? n) i]
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[else (f (div n 2) (+ i 1))])))
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(define scale
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(lambda (r s m+ m- k B round? f e)
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(let ([est (exact
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(ceiling
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(- (* (+ e (len f) -1) (invlog2of B))
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1e-10)))])
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(if (>= est 0)
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(fixup r (* s (exptt B est)) m+ m- est B round?)
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(let ([scale (exptt B (- est))])
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(fixup (* r scale) s (* m+ scale) (* m- scale) est B round?))))))
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(define fixup
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(lambda (r s m+ m- k B round?)
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(if ((if round? >= >) (+ r m+) s) ; too low?
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(values (+ k 1) (generate r s m+ m- B round?))
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(values k (generate (* r B) s (* m+ B) (* m- B) B round?)))))
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(define (chr x)
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(vector-ref '#(#\0 #\1 #\2 #\3 #\4 #\5 #\6 #\7 #\8 #\9) x))
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(define generate
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(lambda (r s m+ m- B round?)
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(let-values ([(q r) (div-and-mod r s)])
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(let ([tc1 ((if round? <= <) r m-)]
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[tc2 ((if round? >= >) (+ r m+) s)])
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(if (not tc1)
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(if (not tc2)
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(cons (chr q) (generate (* r B) s (* m+ B) (* m- B) B round?))
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(list (chr (+ q 1))))
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(if (not tc2)
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(list (chr q))
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(if (< (* r 2) s)
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(list (chr q))
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(list (chr (+ q 1))))))))))
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(define invlog2of
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(let ([table (make-vector 37)]
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[log2 (log 2)])
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(do ([B 2 (+ B 1)])
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((= B 37))
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(vector-set! table B (/ log2 (log B))))
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(lambda (B)
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(if (<= 2 B 36)
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(vector-ref table B)
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(/ log2 (log B))))))
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(define exptt
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(let ([table (make-vector 326)])
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(do ([k 0 (+ k 1)] [v 1 (* v 10)])
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((= k 326))
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(vector-set! table k v))
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(lambda (B k)
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(if (and (= B 10) (<= 0 k 325))
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(vector-ref table k)
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(expt B k)))))
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(define (convert-real-flonum pos? m e p k)
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(let-values ([(expt digits) (flonum->digits m e 10 p 2 10)])
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(k pos? digits expt)))
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(define (parse-flonum x k0 k1)
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(assert (flonum? x))
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(assert (procedure? k0))
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(assert (procedure? k1))
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(let-values ([(pos? be m) (flonum-parts x)])
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(cond
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[(<= 1 be 2046) ; normalized flonum
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(convert-real-flonum pos? (+ m (expt 2 52)) (- be 1075) 53 k0)]
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[(= be 0)
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(convert-real-flonum pos? m -1074 52 k0)]
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[(= be 2047)
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(k1 (if (= m 0) (if pos? "+inf.0" "-inf.0") "+nan.0"))]
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[else (error 'flonum->string "cannot happen")]))))
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@ -1 +1 @@
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1819
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1820
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