From b517b450316ffd1b6ee9cb0c25085ff3b1d4b75b Mon Sep 17 00:00:00 2001 From: Marvin Borner Date: Sun, 8 Sep 2024 02:59:29 +0200 Subject: Some implementations --- src/impl/blc.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) (limited to 'src/impl/blc.c') diff --git a/src/impl/blc.c b/src/impl/blc.c index e69de29..893b856 100644 --- a/src/impl/blc.c +++ b/src/impl/blc.c @@ -0,0 +1,65 @@ +// Copyright (c) 2024, Marvin Borner +// SPDX-License-Identifier: MIT + +#include +#include + +static void encode(Term *term, FILE *fp) +{ + switch (term->type) { + case ABS: + fprintf(fp, "00"); + encode(term->u.abs.body, fp); + break; + case APP: + fprintf(fp, "01"); + encode(term->u.app.lhs, fp); + encode(term->u.app.rhs, fp); + break; + case IDX: + for (size_t i = 0; i <= term->u.index; i++) + fprintf(fp, "1"); + fprintf(fp, "0"); + break; + default: + fatal("invalid type %d\n", term->type); + } +} + +static Term *decode(FILE *fp) +{ + Term *res = 0; + + char a = getc(fp); + + if (a == '0') { + char b = getc(fp); + if (b == '0') { + res = term_new(ABS); + res->u.abs.body = decode(fp); + } else if (b == '1') { + res = term_new(APP); + res->u.app.lhs = decode(fp); + res->u.app.rhs = decode(fp); + } + } else if (a == '1') { + res = term_new(IDX); + res->u.index = 0; + while (getc(fp) == '1') + res->u.index++; + } + + if (!res) + fatal("invalid parsing state!\n"); + + return res; +} + +Impl impl_blc(void) +{ + return (Impl){ + .name = "blc", + .encode = encode, + .decode = decode, + }; +} -- cgit v1.2.3