Bootstrapping

1 files changed, 117 insertions, 0 deletions

diff --git a/src/build.c b/src/build.c
new file mode 100644
index 0000000..510afe0
--- /dev/null
+++ b/src/build.c
@@ -0,0 +1,117 @@
+// Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <build.h>
+#include <free.h>
+#include <parse.h>
+
+static void write_bit(char val, FILE *file, char *byte, int *bit)
+{
+	if (*bit > 7) { // flush byte
+		fwrite(byte, 1, 1, file);
+		*byte = 0;
+		*bit = 0;
+	}
+
+	if (val)
+		*byte |= 1UL << (7 - *bit);
+	(*bit)++;
+}
+
+static void rec_write_bblc(struct term *term, FILE *file, char *byte, int *bit)
+{
+	switch (term->type) {
+	case ABS:
+		write_bit(0, file, byte, bit);
+		write_bit(0, file, byte, bit);
+		rec_write_bblc(term->u.abs.term, file, byte, bit);
+		break;
+	case APP:
+		write_bit(0, file, byte, bit);
+		write_bit(1, file, byte, bit);
+		rec_write_bblc(term->u.app.lhs, file, byte, bit);
+		rec_write_bblc(term->u.app.rhs, file, byte, bit);
+		break;
+	case VAR:
+		for (int i = 0; i <= term->u.var.index; i++)
+			write_bit(1, file, byte, bit);
+		write_bit(0, file, byte, bit);
+		break;
+	default:
+		fprintf(stderr, "Invalid type %d\n", term->type);
+	}
+}
+
+// writes bit-encoded blc into file
+static void write_bblc(struct term *term, FILE *file)
+{
+	char byte = 0;
+	int bit = 0;
+	rec_write_bblc(term, file, &byte, &bit);
+
+	if (bit) // flush final
+		fwrite(&byte, 1, 1, file);
+}
+
+void write_bloc(struct term *term, const char *path)
+{
+	(void)term; // TODO
+
+	// example data
+	short length = 2;
+	struct term *M = parse_blc("0000000001100111100111100111100111011110");
+	struct term *N = parse_blc("00000000011001111001111001100111011110");
+
+	FILE *file = fopen(path, "wb");
+	fwrite(BLOC_IDENTIFIER, BLOC_IDENTIFIER_LENGTH, 1, file);
+	fwrite(&length, 2, 1, file);
+
+	write_bblc(M, file);
+	write_bblc(N, file);
+
+	// TODO
+	short table_index = 0;
+	char byte = 0;
+	int bit = 0;
+	write_bit(0, file, &byte, &bit);
+	write_bit(0, file, &byte, &bit);
+	write_bit(0, file, &byte, &bit);
+	write_bit(1, file, &byte, &bit);
+	write_bit(0, file, &byte, &bit);
+	write_bit(1, file, &byte, &bit);
+	write_bit(0, file, &byte, &bit);
+	write_bit(1, file, &byte, &bit);
+	write_bit(1, file, &byte, &bit);
+
+	for (int i = 0; i < 16; i++)
+		write_bit(0, file, &byte, &bit);
+
+	write_bit(0, file, &byte, &bit);
+	write_bit(0, file, &byte, &bit);
+	write_bit(1, file, &byte, &bit);
+
+	for (int i = 0; i < 16; i++)
+		write_bit(0, file, &byte, &bit);
+
+	write_bit(1, file, &byte, &bit);
+
+	for (int i = 0; i < 16; i++)
+		write_bit(0, file, &byte, &bit);
+
+	write_bit(1, file, &byte, &bit);
+
+	for (int i = 0; i < 16; i++)
+		write_bit(0, file, &byte, &bit);
+
+	if (bit) // flush final
+		fwrite(&byte, 1, 1, file);
+
+	fclose(file);
+
+	free_term(M);
+	free_term(N);
+}