/usr/share/common-lisp/source/clsql/sql/decimals.lisp is in cl-sql 6.7.0-1.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 | ;;; DECIMALS
;;
;; A decimal number parser and formatting package for Common Lisp.
;;
;; Author: Teemu Likonen <tlikonen@iki.fi>
;;
;; License: Public domain
;;
;; This program is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
(defpackage #:decimals
(:use #:cl)
(:export #:round-half-away-from-zero
#:format-decimal-number
#:parse-decimal-number
#:decimal-parse-error
#:define-decimal-formatter))
(in-package #:decimals)
(defun round-half-away-from-zero (number &optional (divisor 1))
"Divide _number_ by _divisor_ and round the result to the nearest integer.
If the result is half-way between two integers round away from zero. Two
values are returned: quotient and remainder.
This is similar to `cl:round` function except that `cl:round` rounds to
an even integer when number is exactly between two integers. Examples:
(round-half-away-from-zero 3/2) => 2, -1/2
(round 3/2) => 2, -1/2
(round-half-away-from-zero 5/2) => 3, -1/2
(round 5/2) => 2, 1/2"
(if (zerop number)
(values 0 0)
(let ((quotient (if (plusp number)
(floor (+ (/ number divisor) 1/2))
(ceiling (- (/ number divisor) 1/2)))))
(values quotient (- number (* quotient divisor))))))
(defun divide-into-groups (string &key (separator #\Space) (from-end nil)
(group-digits 3))
(assert (and (integerp group-digits)
(plusp group-digits))
(group-digits)
"The GROUP-DIGITS argument must be a positive integer")
(setf separator (princ-to-string separator))
(if (zerop (length separator))
string
(flet ((make-groups (string separator)
(loop :with length := (length string)
:with result := (make-array length :element-type 'character
:fill-pointer 0 :adjustable t)
:for c :across string
:for i :upfrom 1
:do (vector-push-extend c result)
:if (and (zerop (rem i group-digits))
(< i length))
:do (loop :for c :across separator
:do (vector-push-extend c result))
:finally (return result))))
(if from-end
(nreverse (make-groups (reverse string) (reverse separator)))
(make-groups string separator)))))
(defun decimal-round-split (number &key
(round-magnitude 0)
(rounder #'round-half-away-from-zero)
(positive-sign #\+)
(negative-sign #\-)
(zero-sign nil))
(assert (integerp round-magnitude) (round-magnitude)
"ROUND-MAGNITUDE argument must be an integer.")
(when (floatp number)
(setf number (rational number)))
(let ((divisor (expt 10 round-magnitude)))
(setf number (* divisor (funcall rounder number divisor))))
(let ((sign (cond ((plusp number) (or positive-sign ""))
((minusp number) (or negative-sign ""))
(t (or zero-sign "")))))
(multiple-value-bind (integer fractional)
(truncate (abs number))
(let ((fractional-string
(with-output-to-string (out)
(loop :with next := fractional
:with remainder
:repeat (abs round-magnitude)
:until (zerop next)
:do
(setf (values next remainder) (truncate (* next 10)))
(princ next out)
(setf next remainder)))))
(list (princ-to-string sign)
(princ-to-string integer)
fractional-string)))))
(defun string-align (string width &key (side :left) (char #\Space))
(if (>= (length string) width)
string
(let ((result (make-string width :initial-element char)))
(ecase side
(:left (replace result string))
(:right (replace result string
:start1 (- width (length string))))))))
(defun format-decimal-number (number &key
(round-magnitude 0)
(rounder #'round-half-away-from-zero)
(decimal-separator #\.)
(integer-group-separator nil)
(integer-group-digits 3)
(integer-minimum-width 0)
(integer-pad-char #\Space)
(fractional-group-separator nil)
(fractional-group-digits 3)
(fractional-minimum-width 0)
(fractional-pad-char #\Space)
(show-trailing-zeros nil)
(positive-sign nil)
(negative-sign #\-)
(zero-sign nil))
"Apply specified decimal number formatting rules to _number_ and
return a formatted string.
The second return value is (almost) the same formatted string divided
into four strings. It's a list of four strings: sign, integer part,
decimal separator and fractional part. Formatting arguments
_integer-minimum-width_ and _fractional-minimum-width_ do not apply to
the second return value. Everything else does.
_Number_ must be of type `real`. This function uses `rational` types
internally. If the given _number_ is a `float` it is first turned into
`rational` by calling `cl:rational`.
Formatting rules are specified with keyword arguments, as described
below. The default value is in parentheses.
* `round-magnitude (0)`
This is the order of magnitude used for rounding. The value must be
an integer and it is interpreted as a power of 10.
* `show-trailing-zeros (nil)`
If the value is non-nil print all trailing zeros in fractional part.
Examples:
(format-decimal-number 1/5 :round-magnitude -3
:show-trailing-zeros nil)
=> \"0.2\"
(format-decimal-number 1/5 :round-magnitude -3
:show-trailing-zeros t)
=> \"0.200\"
* `rounder (#'round-half-away-from-zero)`
The value must be a function (or a symbol naming a function). It is
used to round the number to the specified round magnitude. The
function must work like `cl:truncate`, `cl:floor`, `cl:ceiling` and
`cl:round`, that is, take two arguments, a number and a divisor, and
return the quotient as the first value.
This package introduces another rounding function,
`round-half-away-from-zero`, which is used by default. See its
documentation for more information.
* `decimal-separator (#\\.)`
If the value is non-nil the `princ` output of the value will be
added between integer and fractional parts. Probably the most useful
types are `character` and `string`.
* `integer-group-separator (nil)`
* `fractional-group-separator (nil)`
If the value is non-nil the digits in integer or fractional parts
are put in groups. The `princ` output of the value will be added
between digit groups.
* `integer-group-digits (3)`
* `fractional-group-digits (3)`
The value is a positive integer defining the number of digits in
groups.
* `integer-minimum-width (0)`
* `fractional-minimum-width (0)`
Format integer or fractional part using minimum of this amount of
characters, possibly using some padding characters (see below).
_positive-sign_, _negative-sign_ or _zero-sign_ (see below) is
included when calculating the width of the integer part. Similarly
_decimal-separator_ is included when calculating the width of the
fractional part.
* `integer-pad-char (#\\Space)`
* `fractional-pad-char (#\\Space)`
The value is the padding character which is used to fill
_integer-minimum-width_ or _fractional-minimum-width_.
* `positive-sign (nil)`
* `negative-sign (#\\-)`
* `zero-sign (nil)`
If values are non-nil these are used as the leading sign for
positive, negative and zero numbers. The `princ` output of the value
is used."
(destructuring-bind (sign integer fractional)
(decimal-round-split number
:round-magnitude round-magnitude
:rounder rounder
:positive-sign positive-sign
:negative-sign negative-sign
:zero-sign zero-sign)
(setf decimal-separator (if decimal-separator
(princ-to-string decimal-separator)
"")
integer (divide-into-groups
integer
:separator (or integer-group-separator "")
:group-digits integer-group-digits
:from-end t)
fractional (divide-into-groups
(if (and show-trailing-zeros
(plusp (- (- (length fractional))
round-magnitude)))
(replace (make-string (abs round-magnitude)
:initial-element #\0)
fractional)
fractional)
:separator (or fractional-group-separator "")
:group-digits fractional-group-digits
:from-end nil))
(values
(concatenate
'string
(string-align (concatenate 'string sign integer)
integer-minimum-width
:side :right :char integer-pad-char)
(string-align (if (plusp (length fractional))
(concatenate 'string decimal-separator fractional)
"")
fractional-minimum-width
:side :left :char fractional-pad-char))
(list sign integer decimal-separator fractional))))
(defmacro define-decimal-formatter (name &body keyword-arguments)
"Define a decimal number formatter function to use with the `~/`
directive of `cl:format`. The valid format is this:
(define-decimal-formatter name
(:keyword form)
...)
_Name_ is the symbol that names the function. _Keyword_ must be a valid
keyword argument for the `format-decimal-number` function (see its
documentation for more information). _Form_ is evaluated and the value
is used with the _keyword_ argument. Macro's side effect is that global
function _name_ is defined. It can be used with the `~/` directive of
`cl:format` function.
Examples:
(define-decimal-formatter my-formatter
(:round-magnitude -6)
(:decimal-separator \",\")
(:integer-group-separator \" \")
(:integer-minimum-width 4)
(:fractional-group-separator \" \")
(:fractional-minimum-width 10)
(:show-trailing-zeros t))
=> MY-FORMATTER
(format nil \"~/my-formatter/\" 10/6)
=> \" 1,666 667 \"
(format nil \"~/my-formatter/\" 100/8)
=> \" 12,500 000 \"
The `~/` directive function call can optionally take up to three
arguments to override the defaults:
~round-magnitude,integer-minimum-width,fractional-minimum-width/FUNCTION/
For example:
(format nil \"~-2,3,4/my-formatter/\" 10/6)
=> \" 1,67 \""
(let ((key-arg (gensym)))
`(let ((,key-arg (list ,@(loop :for (keyword value) :in keyword-arguments
:do (assert (keywordp keyword) (keyword)
"Keyword required.")
:collect keyword :collect value))))
(defun ,name (stream number &optional colon-p at-sign-p
round-magnitude integer-minimum-width
fractional-minimum-width)
(declare (ignore colon-p at-sign-p))
(let ((args (copy-list ,key-arg)))
(when round-magnitude
(setf (getf args :round-magnitude)
round-magnitude))
(when integer-minimum-width
(setf (getf args :integer-minimum-width)
integer-minimum-width))
(when fractional-minimum-width
(setf (getf args :fractional-minimum-width)
fractional-minimum-width))
(princ (apply #'format-decimal-number number args) stream))))))
(defun number-string-to-integer (string)
(handler-case (parse-integer string)
(parse-error () nil)))
(defun number-string-to-fractional (string)
(when (every #'digit-char-p string)
(setf string (string-right-trim "0" string))
(handler-case (/ (parse-integer string)
(expt 10 (length string)))
(parse-error () nil))))
(define-condition decimal-parse-error (parse-error)
nil
(:report "Not a valid decimal number string.")
(:documentation
"Function `parse-decimal-number` signals this condition when it
couldn't parse a decimal number from string."))
(defun parse-decimal-number (string &key
(decimal-separator #\.)
(positive-sign #\+)
(negative-sign #\-)
(start 0) (end nil))
"Examine _string_ (or its substring from _start_ to _end_) for a
decimal number. Assume that the decimal number is exact and return it as
a rational number.
Rules for parsing: First all leading and trailing `#\\Space` characters
are stripped. The resulting string may start with a _positive-sign_ or a
_negative-sign_ character. The latter causes this function to assume a
negative number. The following characters in the string must include one
or more digit characters and it may include one _decimal-separator_
character which separates integer and fractional parts. All other
characters are illegal. If these rules are not met a
`decimal-parse-error` condition is signaled.
Examples:
(parse-decimal-number \"0.2\") => 1/5
(parse-decimal-number \".2\") => 1/5
(parse-decimal-number \"+3.\") => 3
(parse-decimal-number \" -7 \") => -7
(parse-decimal-number \"−12,345\"
:decimal-separator #\\,
:negative-sign #\\−)
=> -2469/200"
(setf string (string-trim " " (subseq string start end)))
(if (not (plusp (length string)))
(error 'decimal-parse-error)
(let ((sign 1))
(cond ((char= (aref string 0) negative-sign)
(setf sign -1
string (subseq string 1)))
((char= (aref string 0) positive-sign)
(setf string (subseq string 1))))
(if (and (every (lambda (item)
(or (digit-char-p item)
(char= item decimal-separator)))
string)
(some #'digit-char-p string)
(<= 0 (count decimal-separator string) 1))
(let ((pos (position decimal-separator string)))
(* sign
(+ (or (number-string-to-integer (subseq string 0 pos))
0)
(if pos
(or (number-string-to-fractional
(subseq string (1+ pos)))
0)
0))))
(error 'decimal-parse-error)))))
|