mirror of
https://github.com/jart/cosmopolitan.git
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55 lines
2.6 KiB
C
55 lines
2.6 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 2022 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "tool/lambda/lib/blc.h"
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/**
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* Parses binary lambda calculus closed expression from stream.
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*/
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struct Parse Parse(int ignored, FILE* f) {
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int t, start;
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char bit, need;
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struct Parse p;
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for (need = 0, start = end;;) {
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if (end + 2 > TERMS) Error(5, "OUT OF TERMS");
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if ((bit = GetBit(f)) == -1) {
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if (!need) break;
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fflush(stdout);
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fputs("---\n", stderr);
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Print(start, 0, 0, stderr);
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Error(9, "UNFINISHED EXPRESSION");
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} else if (bit) {
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for (t = 0; NeedBit(f);) ++t;
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mem[end++] = VAR;
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mem[end++] = t;
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break;
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} else if (NeedBit(f)) {
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t = end;
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end += 2;
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mem[t] = APP;
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p = Parse(0, f);
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mem[t + 1] = p.n;
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need = 1;
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} else {
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mem[end++] = ABS;
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}
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}
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p.i = start;
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p.n = end - start;
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return p;
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}
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