From b754e71ca502a5027ea3479eb3ea1a0ac28e5282 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Wed, 17 Jan 2024 00:59:12 +0100
Subject: Initial commit

---
 .gitignore           |   5 +++
 inc/log.h            |  11 ++++++
 inc/parse.h          |  20 ++++++++++
 inc/spec.h           |  20 ++++++++++
 inc/target.h         |  18 +++++++++
 inc/term.h           |  33 ++++++++++++++++
 license              |  21 ++++++++++
 makefile             |  54 +++++++++++++++++++++++++
 options.ggo          |   8 ++++
 readme.md            |  24 ++++++++++++
 src/.gitignore       |   1 +
 src/log.c            |  40 +++++++++++++++++++
 src/main.c           | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/parse.c          |  94 ++++++++++++++++++++++++++++++++++++++++++++
 src/target.c         |  32 +++++++++++++++
 src/targets/unbblc.c |  72 ++++++++++++++++++++++++++++++++++
 src/targets/unblc.c  |  49 +++++++++++++++++++++++
 src/term.c           |  41 +++++++++++++++++++
 18 files changed, 652 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 inc/log.h
 create mode 100644 inc/parse.h
 create mode 100644 inc/spec.h
 create mode 100644 inc/target.h
 create mode 100644 inc/term.h
 create mode 100644 license
 create mode 100644 makefile
 create mode 100644 options.ggo
 create mode 100644 readme.md
 create mode 100644 src/.gitignore
 create mode 100644 src/log.c
 create mode 100644 src/main.c
 create mode 100644 src/parse.c
 create mode 100644 src/target.c
 create mode 100644 src/targets/unbblc.c
 create mode 100644 src/targets/unblc.c
 create mode 100644 src/term.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c50f973
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+.cache/
+build/
+
+compile_commands.json
+tags
diff --git a/inc/log.h b/inc/log.h
new file mode 100644
index 0000000..fcae172
--- /dev/null
+++ b/inc/log.h
@@ -0,0 +1,11 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#ifndef BLOCADE_LOG_H
+#define BLOCADE_LOG_H
+
+void debug(const char *format, ...);
+void debug_enable(int enable);
+void fatal(const char *format, ...) __attribute__((noreturn));
+
+#endif
diff --git a/inc/parse.h b/inc/parse.h
new file mode 100644
index 0000000..2368199
--- /dev/null
+++ b/inc/parse.h
@@ -0,0 +1,20 @@
+// Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#ifndef BLOC_PARSE_H
+#define BLOC_PARSE_H
+
+#include <stddef.h>
+
+#include <term.h>
+#include <spec.h>
+
+struct bloc_parsed {
+	size_t length;
+	struct term **entries;
+};
+
+struct bloc_parsed *parse_bloc(const void *bloc);
+void free_bloc(struct bloc_parsed *bloc);
+
+#endif
diff --git a/inc/spec.h b/inc/spec.h
new file mode 100644
index 0000000..3d8300c
--- /dev/null
+++ b/inc/spec.h
@@ -0,0 +1,20 @@
+// Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#ifndef BLOC_SPEC_H
+#define BLOC_SPEC_H
+
+#define BLOC_IDENTIFIER "BLoC"
+#define BLOC_IDENTIFIER_LENGTH 4
+
+struct bloc_header {
+	char identifier[BLOC_IDENTIFIER_LENGTH];
+	short length;
+	void *entries;
+} __attribute__((packed));
+
+struct bloc_entry {
+	void *expression;
+} __attribute__((packed));
+
+#endif
diff --git a/inc/target.h b/inc/target.h
new file mode 100644
index 0000000..9196637
--- /dev/null
+++ b/inc/target.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#ifndef BLOCADE_TARGET_H
+#define BLOCADE_TARGET_H
+
+#include <stdio.h>
+
+#include <parse.h>
+
+struct target_spec {
+	const char *name;
+	void (*exec)(struct bloc_parsed *bloc, FILE *file);
+};
+
+void exec_target(char *name, struct bloc_parsed *bloc, FILE *file);
+
+#endif
diff --git a/inc/term.h b/inc/term.h
new file mode 100644
index 0000000..9823fc1
--- /dev/null
+++ b/inc/term.h
@@ -0,0 +1,33 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#ifndef BLOCADE_TERM_H
+#define BLOCADE_TERM_H
+
+#include <stddef.h>
+
+typedef enum { INV, ABS, APP, VAR, REF } term_type;
+
+struct term {
+	term_type type;
+	union {
+		struct {
+			struct term *term;
+		} abs;
+		struct {
+			struct term *lhs;
+			struct term *rhs;
+		} app;
+		struct {
+			int index;
+		} var;
+		struct {
+			size_t index;
+		} ref;
+	} u;
+};
+
+struct term *new_term(term_type type);
+void free_term(struct term *term);
+
+#endif
diff --git a/license b/license
new file mode 100644
index 0000000..4250710
--- /dev/null
+++ b/license
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Marvin Borner
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..1938be4
--- /dev/null
+++ b/makefile
@@ -0,0 +1,54 @@
+# Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
+# SPDX-License-Identifier: MIT
+
+CC = gcc
+TG = ctags
+
+BUILD = ${CURDIR}/build
+SRC = ${CURDIR}/src
+INC = ${CURDIR}/inc
+SRCS = $(wildcard $(SRC)/*.c) $(wildcard $(SRC)/*/*.c)
+OBJS = $(patsubst $(SRC)/%.c, $(BUILD)/%.o, $(SRCS))
+
+CFLAGS_DEBUG = -fsanitize=leak,undefined,address -g -O0
+CFLAGS_WARNINGS = -Wall -Wextra -Wshadow -Wpointer-arith -Wwrite-strings -Wredundant-decls -Wnested-externs -Wmissing-declarations -Wstrict-prototypes -Wmissing-prototypes -Wcast-qual -Wswitch-default -Wswitch-enum -Wunreachable-code -Wundef -Wold-style-definition -pedantic -Wno-switch-enum
+CFLAGS = $(CFLAGS_WARNINGS) -std=c99 -Ofast -I$(INC)
+
+ifdef DEBUG # TODO: Somehow clean automagically
+CFLAGS += $(CFLAGS_DEBUG)
+endif
+
+ifeq ($(PREFIX),)
+    PREFIX := /usr/local
+endif
+
+all: genopts compile
+
+full: all sync
+
+genopts:
+	@gengetopt -i ${CURDIR}/options.ggo -G --output-dir=$(SRC)
+
+compile: $(BUILD) $(OBJS) $(BUILD)/blocade
+
+clean:
+	@rm -rf $(BUILD)/*
+
+install:
+	@install -m 755 $(BUILD)/blocade $(DESTDIR)$(PREFIX)/bin/
+
+sync: # Ugly hack
+	@$(MAKE) $(BUILD)/blocade --always-make --dry-run | grep -wE 'gcc|g\+\+' | grep -w '\-c' | jq -nR '[inputs|{directory:".", command:., file: match(" [^ ]+$$").string[1:]}]' >compile_commands.json
+	@$(TG) -R --exclude=.git --exclude=build .
+
+$(BUILD)/%.o: $(SRC)/%.c
+	@mkdir -p $(@D)
+	@$(CC) -c -o $@ $(CFLAGS) $<
+
+$(BUILD)/blocade: $(OBJS)
+	@$(CC) -o $@ $(CFLAGS) $^
+
+.PHONY: all compile clean sync
+
+$(BUILD):
+	@mkdir -p $@
diff --git a/options.ggo b/options.ggo
new file mode 100644
index 0000000..8488bfd
--- /dev/null
+++ b/options.ggo
@@ -0,0 +1,8 @@
+package "BLoCade"
+version "1.0"
+purpose "Tool for converting BLoC to various targets"
+
+option "input" i "input file" string required
+option "output" o "output file" string optional
+option "verbose" v "enable debug logging output" flag off
+option "target" t "choose compilation target" string required
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..a5a85fb
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,24 @@
+# BLoCade
+
+[BLoC](https://github.com/marvinborner/bloc) is an optimized file format
+for binary lambda calculus (BLC).
+
+BLoCade is the BLoC-aid and turns BLoC files back into executable files
+(targets). This is useful for [bruijn](https://bruijn.marvinborner.de),
+benchmarking, or general term optimization.
+
+## Targets
+
+-   BLC (sharing by abstraction): Terms having BLoC entry indices get
+    abstracted and applied to the respective term. The indices get
+    converted to De Bruijn indices. Flag `bblc` (bits) and `blc` (ASCII
+    0/1).
+-   BLC (unshared): Every BLoC entry gets reinserted into the original
+    term. Do not use this if you want efficiency or small files. Flag
+    `unbblc` (bits) and `unblc` (ASCII 0/1).
+-   [Effekt](https://effekt-lang.org): Because, why not? Flag `effekt`.
+-   Planned: Scala, HVM, C, LLVM, JS, Haskell
+
+## Benchmarks
+
+To be evaluated.
diff --git a/src/.gitignore b/src/.gitignore
new file mode 100644
index 0000000..888d678
--- /dev/null
+++ b/src/.gitignore
@@ -0,0 +1 @@
+cmdline.*
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..e452610
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,40 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+#include <log.h>
+
+static int debug_enabled = 0;
+
+void debug(const char *format, ...)
+{
+	if (!debug_enabled)
+		return;
+
+	fprintf(stderr, "[DEBUG] ");
+
+	va_list ap;
+	va_start(ap, format);
+	vfprintf(stderr, format, ap);
+	va_end(ap);
+}
+
+void debug_enable(int enable)
+{
+	debug_enabled = enable;
+}
+
+void fatal(const char *format, ...)
+{
+	fprintf(stderr, "[FATAL] ");
+
+	va_list ap;
+	va_start(ap, format);
+	vfprintf(stderr, format, ap);
+	va_end(ap);
+
+	abort();
+}
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..05e85af
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,109 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <target.h>
+#include <term.h>
+#include <log.h>
+#include <parse.h>
+
+// automatically generated using gengetopt
+#include "cmdline.h"
+
+#define BUF_SIZE 1024
+static char *read_stdin(void)
+{
+	debug("reading from stdin\n");
+	char buffer[BUF_SIZE];
+	size_t size = 1;
+	char *string = malloc(sizeof(char) * BUF_SIZE);
+	if (!string)
+		fatal("out of memory!\n");
+	string[0] = '\0';
+	while (fgets(buffer, BUF_SIZE, stdin)) {
+		char *old = string;
+		size += strlen(buffer);
+		string = realloc(string, size);
+		if (!string) {
+			free(old);
+			return 0;
+		}
+		strcat(string, buffer);
+	}
+
+	if (ferror(stdin)) {
+		free(string);
+		fatal("can't read from stdin\n");
+	}
+	return string;
+}
+
+static char *read_file(FILE *f)
+{
+	fseek(f, 0, SEEK_END);
+	long fsize = ftell(f);
+	fseek(f, 0, SEEK_SET);
+
+	char *string = malloc(fsize + 1);
+	if (!string)
+		fatal("out of memory!\n");
+	int ret = fread(string, fsize, 1, f);
+
+	if (ret != 1) {
+		free(string);
+		fatal("can't read file: %s\n", strerror(errno));
+	}
+
+	string[fsize] = 0;
+	return string;
+}
+
+static char *read_path(const char *path)
+{
+	debug("reading from %s\n", path);
+	FILE *f = fopen(path, "rb");
+	if (!f)
+		fatal("can't open file %s: %s\n", path, strerror(errno));
+	char *string = read_file(f);
+	fclose(f);
+	return string;
+}
+
+int main(int argc, char **argv)
+{
+	struct gengetopt_args_info args;
+	if (cmdline_parser(argc, argv, &args))
+		exit(1);
+
+	debug_enable(args.verbose_flag);
+
+	char *input;
+	if (args.input_arg[0] == '-') {
+		input = read_stdin();
+	} else {
+		input = read_path(args.input_arg);
+	}
+
+	if (!input)
+		return 1;
+
+	if (args.target_arg) {
+		struct bloc_parsed *bloc = parse_bloc(input);
+
+		FILE *file =
+			args.output_arg ? fopen(args.output_arg, "wb") : stdout;
+		exec_target(args.target_arg, bloc, file);
+		fclose(file);
+
+		free(input);
+		free_bloc(bloc);
+		return 0;
+	}
+
+	fatal("invalid options: use --help for information\n");
+	return 1;
+}
diff --git a/src/parse.c b/src/parse.c
new file mode 100644
index 0000000..84cfcfd
--- /dev/null
+++ b/src/parse.c
@@ -0,0 +1,94 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <term.h>
+#include <spec.h>
+#include <parse.h>
+#include <log.h>
+
+#define BIT_AT(i) ((term[(i) / 8] & (1 << (7 - ((i) % 8)))) >> (7 - ((i) % 8)))
+
+// parses bloc's bit-encoded blc
+// 010M -> abstraction of M
+// 00MN -> application of M and N
+// 1X0 -> bruijn index, amount of 1s in X
+// 011I -> 2B index to entry
+static struct term *parse_bloc_bblc(const char *term, size_t *bit)
+{
+	struct term *res = 0;
+	if (!BIT_AT(*bit) && BIT_AT(*bit + 1) && !BIT_AT(*bit + 2)) {
+		(*bit) += 3;
+		res = new_term(ABS);
+		res->u.abs.term = parse_bloc_bblc(term, bit);
+	} else if (!BIT_AT(*bit) && !BIT_AT(*bit + 1)) {
+		(*bit) += 2;
+		res = new_term(APP);
+		res->u.app.lhs = parse_bloc_bblc(term, bit);
+		res->u.app.rhs = parse_bloc_bblc(term, bit);
+	} else if (BIT_AT(*bit)) {
+		const size_t cur = *bit;
+		while (BIT_AT(*bit))
+			(*bit)++;
+		res = new_term(VAR);
+		res->u.var.index = *bit - cur - 1;
+		(*bit)++;
+	} else if (!BIT_AT(*bit) && BIT_AT(*bit + 1) && BIT_AT(*bit + 2)) {
+		(*bit) += 3;
+
+		// selected bit pattern, see readme
+		int sel = (2 << (BIT_AT(*bit) * 2 + BIT_AT(*bit + 1) + 2));
+		(*bit) += 2;
+
+		res = new_term(REF);
+		size_t index = 0;
+		for (int i = 0; i < sel; i++) {
+			index |= BIT_AT(*bit) << i;
+			(*bit) += 1;
+		}
+		res->u.ref.index = index;
+	} else {
+		(*bit)++;
+		res = parse_bloc_bblc(term, bit);
+	}
+	return res;
+}
+
+struct bloc_parsed *parse_bloc(const void *bloc)
+{
+	const struct bloc_header *header = bloc;
+	if (memcmp(header->identifier, BLOC_IDENTIFIER,
+		   (size_t)BLOC_IDENTIFIER_LENGTH)) {
+		fatal("invalid BLoC identifier!\n");
+		return 0;
+	}
+
+	struct bloc_parsed *parsed = malloc(sizeof(*parsed));
+	parsed->length = header->length;
+	parsed->entries = malloc(header->length * sizeof(struct term *));
+
+	const struct bloc_entry *current = (const void *)&header->entries;
+	for (size_t i = 0; i < parsed->length; i++) {
+		size_t len = 0;
+		parsed->entries[i] =
+			parse_bloc_bblc((const char *)current, &len);
+		current =
+			(const struct bloc_entry *)(((const char *)current) +
+						    (len / 8) + (len % 8 != 0));
+	}
+
+	return parsed;
+}
+
+void free_bloc(struct bloc_parsed *bloc)
+{
+	for (size_t i = 0; i < bloc->length; i++) {
+		free_term(bloc->entries[i]);
+	}
+
+	free(bloc->entries);
+	free(bloc);
+}
diff --git a/src/target.c b/src/target.c
new file mode 100644
index 0000000..7a96f1e
--- /dev/null
+++ b/src/target.c
@@ -0,0 +1,32 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <string.h>
+
+#include <log.h>
+#include <target.h>
+
+extern struct target_spec target_unblc;
+extern struct target_spec target_unbblc;
+
+static struct target_spec *targets[] = {
+	&target_unblc,
+	&target_unbblc,
+};
+
+void exec_target(char *name, struct bloc_parsed *bloc, FILE *file)
+{
+	int count = sizeof(targets) / sizeof(struct target_spec *);
+	for (int i = 0; i < count; i++) {
+		if (!strcmp(targets[i]->name, name)) {
+			targets[i]->exec(bloc, file);
+			return;
+		}
+	}
+
+	printf("available targets:\n");
+	for (int i = 0; i < count; i++)
+		printf("  %s\n", targets[i]->name);
+
+	fatal("unknown target %s\n", name);
+}
diff --git a/src/targets/unbblc.c b/src/targets/unbblc.c
new file mode 100644
index 0000000..57bc1cf
--- /dev/null
+++ b/src/targets/unbblc.c
@@ -0,0 +1,72 @@
+// 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 write_bit(char val, FILE *file, char *byte, int *bit)
+{
+	if (*bit > 7) { // flush byte
+		fwrite(byte, 1, 1, file);
+		*byte = 0;
+		*bit = 0;
+	}
+
+	// TODO: which endianness should be default?
+	if (val)
+		*byte |= 1UL << *bit;
+	/* *byte |= 1UL << (7 - *bit); */
+	(*bit)++;
+}
+
+static void fprint_unbblc(struct term *term, struct bloc_parsed *bloc,
+			  FILE *file, char *byte, int *bit)
+{
+	switch (term->type) {
+	case ABS:
+		write_bit(0, file, byte, bit);
+		write_bit(0, file, byte, bit);
+		fprint_unbblc(term->u.abs.term, bloc, file, byte, bit);
+		break;
+	case APP:
+		write_bit(0, file, byte, bit);
+		write_bit(1, file, byte, bit);
+		fprint_unbblc(term->u.app.lhs, bloc, file, byte, bit);
+		fprint_unbblc(term->u.app.rhs, bloc, 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;
+	case REF:
+		if (term->u.ref.index + 1 >= bloc->length)
+			fatal("invalid ref index %ld\n", term->u.ref.index);
+		fprint_unbblc(
+			bloc->entries[bloc->length - term->u.ref.index - 2],
+			bloc, file, byte, bit);
+		break;
+	default:
+		fatal("invalid type %d\n", term->type);
+	}
+}
+
+static void write_unbblc(struct bloc_parsed *bloc, FILE *file)
+{
+	char byte = 0;
+	int bit = 0;
+	fprint_unbblc(bloc->entries[bloc->length - 1], bloc, file, &byte, &bit);
+
+	if (bit)
+		fwrite(&byte, 1, 1, file);
+}
+
+struct target_spec target_unbblc = {
+	.name = "unbblc",
+	.exec = write_unbblc,
+};
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,
+};
diff --git a/src/term.c b/src/term.c
new file mode 100644
index 0000000..f93a50c
--- /dev/null
+++ b/src/term.c
@@ -0,0 +1,41 @@
+// Copyright (c) 2024, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <term.h>
+#include <log.h>
+
+struct term *new_term(term_type type)
+{
+	struct term *term = malloc(sizeof(*term));
+	if (!term)
+		fatal("out of memory!\n");
+	term->type = type;
+	return term;
+}
+
+void free_term(struct term *term)
+{
+	switch (term->type) {
+	case ABS:
+		free_term(term->u.abs.term);
+		free(term);
+		break;
+	case APP:
+		free_term(term->u.app.lhs);
+		free_term(term->u.app.rhs);
+		free(term);
+		break;
+	case VAR:
+		free(term);
+		break;
+	case REF:
+		free(term);
+		break;
+	default:
+		fatal("invalid type %d\n", term->type);
+	}
+}
-- 
cgit v1.2.3