From f67f8d68b33a5d0b2ae2409a81c30d852a475ebe Mon Sep 17 00:00:00 2001 From: Masaya Tojo Date: Fri, 9 Aug 2024 02:28:45 +0900 Subject: Add `unsafe?` option for image creation procedures - Add (private bitwise) module and use it - Add (private checker) module and use it - Add (private double-byte) module and use it --- pnm/private/checker.scm | 65 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 pnm/private/checker.scm (limited to 'pnm/private/checker.scm') diff --git a/pnm/private/checker.scm b/pnm/private/checker.scm new file mode 100644 index 0000000..e212948 --- /dev/null +++ b/pnm/private/checker.scm @@ -0,0 +1,65 @@ +;;; R7RS-PNM --- Library for reading and writing PNM (Portable Any Map) files for R7RS +;;; Copyright © 2024 Masaya Tojo +;;; +;;; This file is part of R7RS-PNM. +;;; +;;; R7RS-PNM is free software: you can redistribute it and/or modify it +;;; under the terms of the GNU Lesser General Public License as published +;;; by the Free Software Foundation, either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; R7RS-PNM 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. See the +;;; GNU Lesser General Public License for more details. +;;; +;;; You should have received a copy of the GNU Lesser General Public License +;;; along with R7RS-PNM. If not, see . + +(define-library (pnm private checker) + (export make-xy-checker + make-value-checker + make-boolean-value-checker) + (import (scheme base) + (scheme case-lambda) + (pnm image)) + (begin + (define (make-xy-checker width height) + (lambda (x y) + (when (or (not (exact-integer? x)) + (< x 0) + (<= width x)) + (error (string-append "`x` must be an integer such that 0 <= `x` < " + (number->string width)) + x)) + (when (and (not (exact-integer? y)) + (< y 0) + (<= height y)) + (error (string-append "`y` must be an integer such that 0 <= `y` < " + (number->string width)) + y)))) + + (define (make-value-checker maxval sym) + (define message + (string-append "`" (symbol->string sym) "`" + " must be an integer such that 0 < " + "`" (symbol->string sym) "`" + " < " + (number->string maxval))) + (lambda (v) + (when (or (not (exact-integer? v)) + (< v 0) + (< maxval v)) + (error message v)))) + + (define (make-boolean-value-checker) + (lambda (v) + (when (not (boolean? v)) + (error "`v` must be a boolean value" v)))) + + (define (split-value v) + (values (modulo (quotient v 256) 256) + (modulo v 256))) + + (define (combine-values l r) + (+ (* 256 l) r)))) -- cgit v1.2.3