78 lines
3.7 KiB
C
78 lines
3.7 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/alg/alg.h"
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#include "libc/fmt/bing.h"
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#include "libc/log/log.h"
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#include "libc/str/str.h"
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#define ALTCOUNT 21
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static const struct Cp437Multimappings {
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unsigned char b[ALTCOUNT];
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char16_t c[ALTCOUNT];
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} kCp437iMultimappings = {
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#define ALT(I, C, B) .c[I] = C, .b[I] = B
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ALT(0, u'\n', '\n'),
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ALT(1, u'\r', '\r'),
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ALT(2, u'?', '?'), /* TRIGRAPH */
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ALT(3, u'\'', '\''), /* CHARACTER LITERAL */
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ALT(4, u'\"', '\"'), /* STRING LITERAL */
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ALT(5, u'\\', '\\'), /* ESCAPE LITERAL */
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ALT(6, u'∅', '\0'), /* EMPTY SET */
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ALT(7, u'␀', '\0'), /* SYMBOL FOR NULL [sic] */
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ALT(7, 0x20A7, 0x9E), /* PESETA SIGN */
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ALT(8, u'Π' /* 03A0: GREEK CAPITAL LETTER PI */, 0xE3),
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ALT(9, u'∏' /* 220F: N-ARY PRODUCT */, 0xE3),
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ALT(10, u'∑' /* 2211: N-ARY SUMMATION */, 0xE4),
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ALT(11, u'µ' /* 03BC: MICRO SIGN */, 0xE6),
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ALT(12, u'Ω' /* 2126: OHM SIGN */, 0xEA),
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ALT(13, u'∂' /* 2202: PARTIAL DIFFERENTIAL */, 0xEB),
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ALT(14, u'ε' /* 03D5: PHI SMALL (CLOSED FORM) */, 0xED),
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ALT(15, u'ϕ' /* 03D5: PHI SMALL (CLOSED FORM) */, 0xED),
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ALT(16, u'∈' /* 2208: ELEMENT-OF SIGN */, 0xED),
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ALT(17, u'∊' /* 220A: SMALL ELEMENT OF */, 0xEE),
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ALT(18, u'∈' /* 03B5: ELEMENT-OF SIGN */, 0xEE),
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ALT(19, u'β' /* 03B2: GREEK SMALL BETA */, 0xE1),
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ALT(20, u'ſ' /* 017F: LATIN SMALL LETTER LONG S */, 0xF4),
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#undef ALT
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};
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/**
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* Turns CP437 unicode glyph into its binary representation.
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*
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* @param c is a unicode character
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* @return byte representation, or -1 if ch wasn't ibm cp437
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* @see bing()
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*/
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int unbing(int c) {
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int i;
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for (i = 0; i < 256; ++i) {
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if (c == kCp437[i]) {
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return i;
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}
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}
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for (i = 0; i < ALTCOUNT; ++i) {
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if (c == kCp437iMultimappings.c[i]) {
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return kCp437iMultimappings.b[i];
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}
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}
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return -1;
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}
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