1 files changed, 49 insertions, 0 deletions
diff --git a/src/targets/unblc.c b/src/targets/unblc.c
new file mode 100644
index 0000000..46d63a5
--- /dev/null
+++ b/src/targets/unblc.c
@@ -0,0 +1,49 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <target.h>
+#include <parse.h>
+#include <log.h>
+
+static void fprint_blc(struct term *term, struct bloc_parsed *bloc, FILE *file)
+{
+	switch (term->type) {
+	case ABS:
+		fprintf(file, "00");
+		fprint_blc(term->u.abs.term, bloc, file);
+		break;
+	case APP:
+		fprintf(file, "01");
+		fprint_blc(term->u.app.lhs, bloc, file);
+		fprint_blc(term->u.app.rhs, bloc, file);
+		break;
+	case VAR:
+		for (int i = 0; i <= term->u.var.index; i++)
+			fprintf(file, "1");
+		fprintf(file, "0");
+		break;
+	case REF:
+		if (term->u.ref.index + 1 >= bloc->length)
+			fatal("invalid ref index %ld\n", term->u.ref.index);
+		fprint_blc(bloc->entries[bloc->length - term->u.ref.index - 2],
+			   bloc, file);
+		break;
+	default:
+		fatal("invalid type %d\n", term->type);
+	}
+}
+
+static void write_blc(struct bloc_parsed *bloc, FILE *file)
+{
+	fprint_blc(bloc->entries[bloc->length - 1], bloc, file);
+	fprintf(file, "\n");
+}
+
+struct target_spec target_blc = {
+	.name = "blc",
+	.exec = write_blc,
+};