commit cd252f59086a8e01ba0acbef5a4471abfad68c2c
Author: ~keith <keith@keithhacks.cyou>
Date:   Wed Sep 22 09:54:29 2021 -0400

    oopsie i forgot to commit :zany:

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2ee39f0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+*.o
+/keithlisp
+.ccls-cache
+.directory
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..7a604a6
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,20 @@
+
+CFLAGS=-I. -Wall -g
+LFLAGS=-lm
+
+OBJ_DIR=obj
+
+SRCS = main.c dbg_malloc.c lisp_string.c parse.c native_funs.c
+OBJS = $(SRCS:%.c=$(OBJ_DIR)/%.o)
+
+keithlisp: $(OBJS)
+	gcc $(LFLAGS) -o $@ $^ $(CFLAGS)
+
+$(OBJ_DIR)/%.o: %.c
+	gcc -c -o $@ $^ $(CFLAGS)
+$(OBJ_DIR):
+	mkdir $(OBJ_DIR)
+
+.PHONY = clean
+clean:
+	rm $(OBJ_DIR)/*
diff --git a/crc_table.h b/crc_table.h
new file mode 100644
index 0000000..32cc07f
--- /dev/null
+++ b/crc_table.h
@@ -0,0 +1,66 @@
+static const unsigned int crc32_table[] = {
+0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
+0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
+0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
+0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
+0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
+0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
+0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
+0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
+0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
+0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
+0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
+0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
+0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
+0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
+0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
+0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
+0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
+0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
+0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
+0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
+0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
+0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
+0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
+0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
+0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
+0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
+0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
+0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
+0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
+0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
+0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
+0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
+0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
+0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
+0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
+0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
+0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
+0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
+0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
+0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
+0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
+0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
+0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
+0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
+0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
+0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
+0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
+0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
+0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
+0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
+0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
+0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
+0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
+0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
+0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
+0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
+0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
+0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
+0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
+0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
+0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
+0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
+0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
+0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
+};
diff --git a/dbg_malloc.c b/dbg_malloc.c
new file mode 100644
index 0000000..c012c7b
--- /dev/null
+++ b/dbg_malloc.c
@@ -0,0 +1,28 @@
+#include "dbg_malloc.h"
+
+size_t dbg_malloc_mem_usage = 0;
+size_t dbg_malloc_peak_usage = 0;
+
+#include <malloc.h>
+void* dbg_malloc(size_t size) {
+	void* ptr = malloc(size);
+	dbg_malloc_mem_usage += malloc_usable_size(ptr);
+	if (dbg_malloc_mem_usage > dbg_malloc_peak_usage)
+		dbg_malloc_peak_usage = dbg_malloc_mem_usage;
+	#ifdef DBG_MALLOC_PRINT
+	fprintf(stderr, "  malloc(%3li) -> %4liB used\n", size, dbg_malloc_mem_usage);
+	#endif
+	return ptr;
+}
+void dbg_free(void* ptr) {
+	dbg_malloc_mem_usage -= malloc_usable_size(ptr);
+	free(ptr);
+	#ifdef DBG_MALLOC_PRINT
+	fprintf(stderr, "    free()    -> %4liB used\n", dbg_malloc_mem_usage);
+	#endif
+}
+size_t dbg_reset_peak() {
+	size_t old_peak = dbg_malloc_peak_usage;
+	dbg_malloc_peak_usage = dbg_malloc_mem_usage;
+	return old_peak;
+}
diff --git a/dbg_malloc.h b/dbg_malloc.h
new file mode 100644
index 0000000..4dc49fb
--- /dev/null
+++ b/dbg_malloc.h
@@ -0,0 +1,15 @@
+#ifndef _DBG_MALLOC_H
+#define _DBG_MALLOC_H
+
+#include <stddef.h>
+
+//#define DBG_MALLOC_PRINT
+
+extern size_t dbg_malloc_mem_usage;
+extern size_t dbg_malloc_peak_usage;
+
+void* dbg_malloc(size_t size);
+void dbg_free(void* ptr);
+size_t dbg_reset_peak();
+
+#endif
diff --git a/lisp_string.c b/lisp_string.c
new file mode 100644
index 0000000..7bc24a1
--- /dev/null
+++ b/lisp_string.c
@@ -0,0 +1,46 @@
+#include "lisp_string.h"
+
+lisp_string* lisp_string_create(char* str) {
+	int len = strlen(str);
+	lisp_string* lstr = dbg_malloc(len + sizeof(int));
+	*((int*) lstr) = len;
+	strcpy(lstr + sizeof(int), str);
+	return lstr;
+}
+lisp_string* lisp_string_create_raw(char* buf, int len) {
+	lisp_string* lstr = dbg_malloc(len + sizeof(int));
+	*((int*) lstr) = len;
+	memcpy(lstr + sizeof(int), buf, len);
+	return lstr;
+}
+lisp_string* lisp_string_alloc(int len) {
+	lisp_string* lstr = dbg_malloc(len + sizeof(int));
+	*((int*) lstr) = len;
+	return lstr;
+}
+lisp_string* lisp_string_copy(lisp_string* lstr) {
+	return lisp_string_create_raw(lisp_string_data(lstr), lisp_string_len(lstr));
+}
+
+int lisp_string_cmp(lisp_string* a_lstr, lisp_string* b_lstr) {
+	if (a_lstr == NULL || b_lstr == NULL)
+		return (a_lstr > b_lstr) - (a_lstr < b_lstr);
+
+	int len_a = lisp_string_len(a_lstr);
+	int len_b = lisp_string_len(b_lstr);
+	char* data_a = lisp_string_data(a_lstr);
+	char* data_b = lisp_string_data(b_lstr);
+	if (len_a > 0 && len_b > 0) {
+		int cmp = memcmp(data_a, data_b, len_a > len_b ? len_b : len_a);
+		if (cmp != 0)
+			return cmp;
+	}
+	return (len_a > len_b) - (len_a < len_b);
+}
+
+void lisp_string_print(lisp_string* lstr) {
+	char* buf = lisp_string_data(lstr);
+	int len = lisp_string_len(lstr);
+	while (len--)
+		putchar(*(buf++));
+}
diff --git a/lisp_string.h b/lisp_string.h
new file mode 100644
index 0000000..fb193f9
--- /dev/null
+++ b/lisp_string.h
@@ -0,0 +1,23 @@
+#ifndef _LISP_STRING_H
+#define _LISP_STRING_H
+
+#include <string.h>
+#include <stdio.h>
+
+#include "dbg_malloc.h"
+#include "lisp_types.h"
+
+__attribute__((always_inline)) static inline int lisp_string_len(lisp_string* lstr) {
+	return *((int*) lstr);
+}
+__attribute__((always_inline)) static inline char* lisp_string_data(lisp_string* lstr) {
+	return lstr + sizeof(int);
+}
+char* lisp_string_create(char* str);
+char* lisp_string_create_raw(char* buf, int len);
+char* lisp_string_alloc(int len);
+char* lisp_string_copy(lisp_string* lstr);
+int lisp_string_cmp(lisp_string* a_lstr, lisp_string* b_lstr);
+void lisp_string_print(lisp_string* lstr);
+
+#endif
diff --git a/lisp_types.h b/lisp_types.h
new file mode 100644
index 0000000..498d303
--- /dev/null
+++ b/lisp_types.h
@@ -0,0 +1,34 @@
+#ifndef _LISP_TYPES_H
+#define _LISP_TYPES_H
+
+#define LISP_T_CONS   0
+#define LISP_T_ATOM   1
+#define LISP_T_INT    2
+#define LISP_T_FLOAT  3
+#define LISP_T_STRING 4
+#define LISP_T_FUNPTR 5
+
+typedef struct lisp_value lisp_value;
+typedef struct lisp_cons lisp_cons;
+typedef int lisp_atom;
+typedef char lisp_string;
+typedef void (*lisp_native_fun)(lisp_cons*, lisp_value*);
+
+struct lisp_value {
+	union {
+		lisp_cons* cons;
+		lisp_atom atom;
+		long _int;
+		float _float;
+		lisp_string* string;
+		lisp_native_fun funptr;
+	} value;
+	char type;
+} __attribute__((packed));
+
+struct lisp_cons {
+	lisp_value car;
+	lisp_value cdr;
+} __attribute__((packed));
+
+#endif
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..3dde255
--- /dev/null
+++ b/main.c
@@ -0,0 +1,382 @@
+#include "main.h"
+
+lisp_cons* syms_alist;
+lisp_cons* funs_alist;
+lisp_cons* atoms_alist;
+
+bool lisp_is_nil(lisp_value value) {
+	return (value.type == LISP_T_CONS) && (value.value.cons == NULL);
+}
+bool lisp_is_equal(lisp_value a, lisp_value b) {
+	if (a.type != b.type)
+		return false;
+	switch (a.type) {
+		case LISP_T_CONS:
+			return a.value.cons == b.value.cons;
+		case LISP_T_ATOM:
+			return a.value.atom == b.value.atom;
+		case LISP_T_INT:
+			return a.value._int == b.value._int;
+		case LISP_T_FLOAT:
+			return a.value._float == b.value._float;
+		case LISP_T_STRING:
+			return lisp_string_cmp(a.value.string, b.value.string) == 0;
+		default:
+			return false;
+	}
+}
+
+void lisp_cons_join(lisp_cons* head, lisp_cons* tail) {
+	while ((head->cdr.type == LISP_T_CONS) && !lisp_is_nil(head->cdr)) {
+		head = head->cdr.value.cons;
+	}
+	head->cdr.type = LISP_T_CONS;
+	head->cdr.value.cons = tail;
+}
+
+lisp_atom atom_t;
+lisp_atom atom_quote;
+
+#include "crc_table.h"
+lisp_atom lisp_atomize(lisp_string* atom_lstr) {
+	char* buf = lisp_string_data(atom_lstr);
+	int len = lisp_string_len(atom_lstr);
+	lisp_atom atom = 0xFFFFFFFF;
+	while (len--) {
+		atom = (atom << 8) ^ crc32_table[((atom >> 24) ^ *buf) & 255];
+		buf++;
+	}
+#ifdef LISP_USE_ATOMS_ALIST
+	lisp_value key;
+	key.type = LISP_T_ATOM;
+	key.value.atom = atom;
+	if (lisp_alist_getptr(atoms_alist, key) == NULL) {
+		lisp_cons* pair = dbg_malloc(sizeof(lisp_cons));
+		pair->car.type = LISP_T_ATOM;
+		pair->car.value.atom = atom;
+		pair->cdr.type = LISP_T_STRING;
+		pair->cdr.value.string = lisp_string_copy(atom_lstr);
+		lisp_cons* new_alist = dbg_malloc(sizeof(lisp_cons));
+		new_alist->car.type = LISP_T_CONS;
+		new_alist->car.value.cons = pair;
+		new_alist->cdr.type = LISP_T_CONS;
+		new_alist->cdr.value.cons = atoms_alist;
+		atoms_alist = new_alist;
+	}
+#endif
+	return atom;
+}
+lisp_atom lisp_atom_init(lisp_string* atom_lstr) {
+	lisp_atom atom = lisp_atomize(atom_lstr);
+	dbg_free(atom_lstr);
+	return atom;
+}
+
+lisp_cons** lisp_alist_getptr(lisp_cons* alist, lisp_value key) {
+	while (alist != NULL) {
+		if (alist->car.type != LISP_T_CONS || alist->car.value.cons == NULL)
+			goto next;
+		lisp_cons* pair = alist->car.value.cons;
+		if (lisp_is_equal(pair->car, key))
+			return &alist->car.value.cons;
+	next:
+		if (alist->cdr.type == LISP_T_CONS)
+			alist = alist->cdr.value.cons;
+		else
+			alist = NULL;
+	}
+	return NULL;
+}
+lisp_cons* lisp_alist_get(lisp_cons* alist, lisp_value key) {
+	lisp_cons** pairptr = lisp_alist_getptr(alist, key);
+	if (pairptr == NULL)
+		return NULL;
+	return *pairptr;
+}
+lisp_cons* lisp_alist_put(lisp_cons** alist, lisp_cons* pair) {
+	lisp_cons** pairptr = lisp_alist_getptr(*alist, pair->car);
+	if (pairptr != NULL) {
+		lisp_cons* old_pair = *pairptr;
+		*pairptr = pair;
+		return old_pair;
+	}
+	lisp_cons* new_alist = dbg_malloc(sizeof(lisp_cons));
+	new_alist->car.type = LISP_T_CONS;
+	new_alist->car.value.cons = pair;
+	new_alist->cdr.type = LISP_T_CONS;
+	new_alist->cdr.value.cons = *alist;
+	*alist = new_alist;
+	return NULL;
+}
+lisp_cons* lisp_alist_del(lisp_cons** alist, lisp_value key) {
+	lisp_cons* alist_cur = *alist;
+	lisp_cons* alist_prev = NULL;
+	while (alist_cur != NULL) {
+		if (alist_cur->car.type != LISP_T_CONS || alist_cur->car.value.cons == NULL)
+			goto next;
+		lisp_cons* pair = alist_cur->car.value.cons;
+		if (lisp_is_equal(pair->car, key)) {
+			// remove current element from list
+			if (alist_prev != NULL)
+				alist_prev->cdr = alist_cur->cdr;
+			else if (alist_cur->cdr.type == LISP_T_CONS)
+				*alist = alist_cur->cdr.value.cons;
+			return pair;
+		}
+	next:
+		alist_prev = alist_cur;
+		if (alist_cur->cdr.type == LISP_T_CONS)
+			alist_cur = alist_cur->cdr.value.cons;
+		else
+			alist_cur = NULL;
+	}
+	return NULL;
+}
+
+void test_print_value(lisp_value value) {
+	if (lisp_is_nil(value))
+		printf("nil");
+	else if (value.type == LISP_T_CONS)
+		test_print_cons(value.value.cons);
+	else if (value.type == LISP_T_ATOM) {
+#ifdef LISP_USE_ATOMS_ALIST
+		lisp_cons* pair = lisp_alist_get(atoms_alist, value);
+		if (pair != NULL)
+			lisp_string_print(pair->cdr.value.string);
+		else
+#endif
+		printf("<atom %08x>", value.value.atom);
+	} else if (value.type == LISP_T_INT)
+		printf("%li", value.value._int);
+	else if (value.type == LISP_T_FLOAT)
+		printf("%g", value.value._float);
+	else if (value.type == LISP_T_STRING) {
+		putchar('\"');
+		lisp_string_print(value.value.string);
+		putchar('\"');
+	} else if (value.type == LISP_T_FUNPTR)
+		printf("<native-fun %p>", value.value.funptr);
+}
+void test_print_cons(lisp_cons* cons) {
+	printf("(");
+	while (cons != NULL) {
+		test_print_value(cons->car);
+		if (cons->cdr.type == LISP_T_CONS) {
+			cons = cons->cdr.value.cons;
+			if (cons != NULL)
+				printf(" ");
+		} else {
+			printf(" . ");
+			test_print_value(cons->cdr);
+			cons = NULL;
+		}
+	}
+	printf(")");
+}
+
+void recursive_free(lisp_cons* cons) {
+	while (cons != NULL) {
+		if (cons->car.type == LISP_T_STRING)
+			dbg_free(cons->car.value.string);
+		else if (cons->car.type == LISP_T_CONS)
+			recursive_free(cons->car.value.cons);
+		if (cons->cdr.type == LISP_T_STRING)
+			dbg_free(cons->cdr.value.string);
+		lisp_cons* next_cons = NULL;
+		if (cons->cdr.type == LISP_T_CONS)
+			next_cons = cons->cdr.value.cons;
+		dbg_free(cons);
+		cons = next_cons;
+	}
+}
+
+bool fetch_tokens(lisp_cons** tokens) {
+	char buf[64];
+	//test_print_cons(*tokens);
+	//printf("> ");
+	if (!fgets(buf, 64, stdin))
+		return false;
+	lisp_tokenize(buf, strlen(buf), tokens);
+	return true;
+}
+
+lisp_atom lisp_defun_native(lisp_string* lstr, lisp_native_fun funptr) {
+	lisp_atom atom = lisp_atom_init(lstr);
+	lisp_cons* cons = dbg_malloc(sizeof(lisp_cons));
+	cons->car.type = LISP_T_ATOM;
+	cons->car.value.atom = atom;
+	cons->cdr.type = LISP_T_FUNPTR;
+	cons->cdr.value.funptr = funptr;
+	lisp_alist_put(&funs_alist, cons);
+	return atom;
+}
+
+void lisp_evaluate_value(lisp_value input, lisp_value* result) {
+	if (input.type == LISP_T_ATOM) {
+		if (input.value.atom == atom_t) {
+			*result = input;
+			return;
+		}
+		lisp_cons* sym_pair = lisp_alist_get(syms_alist, input);
+		if (sym_pair != NULL)
+			*result = sym_pair->cdr;
+		else {
+			result->type = LISP_T_CONS;
+			result->value.cons = NULL;
+		}
+	} else if (input.type == LISP_T_CONS && !lisp_is_nil(input))
+		lisp_evaluate(input.value.cons, result);
+	else
+		*result = input;
+}
+void lisp_evaluate(lisp_cons* cons, lisp_value* value) {
+	if (cons->car.value.atom == atom_quote) {
+		*value = cons->cdr.value.cons->car;
+		return;
+	}
+	if (cons->car.value.atom == atom_cond) {
+		lisp_macro_cond(cons->cdr.value.cons, value);
+		return;
+	}
+	lisp_cons* fun_cons = lisp_alist_get(funs_alist, cons->car);
+	if (fun_cons == NULL) {
+		fprintf(stderr, "EVAL ERROR! (no such fun)\n");
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	lisp_cons* args = NULL;
+	lisp_cons* args_tail = NULL;
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		lisp_cons* arg_cons = dbg_malloc(sizeof(lisp_cons));
+		arg_cons->cdr.type = LISP_T_CONS;
+		arg_cons->cdr.value.cons = NULL;
+		lisp_evaluate_value(cons->car, &arg_cons->car);
+		cons = cons->cdr.value.cons;
+		if (args == NULL)
+			args = arg_cons;
+		if (args_tail == NULL)
+			args_tail = args;
+		else {
+			args_tail->cdr.value.cons = arg_cons;
+			args_tail = arg_cons;
+		}
+	}
+	if (fun_cons->cdr.type == LISP_T_FUNPTR) {
+		// native-fun
+		(*fun_cons->cdr.value.funptr)(args, value);
+		while (args != NULL) {
+			args_tail = args->cdr.value.cons;
+			dbg_free(args);
+			args = args_tail;
+		}
+	} else {
+		fprintf(stderr, "EVAL ERROR! (not a native-fun)\n");
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+}
+lisp_atom atom_cond;
+void lisp_macro_cond(lisp_cons* cons, lisp_value* value) {
+	while (cons != NULL) {
+		lisp_cons* fork = cons->car.value.cons;
+		lisp_evaluate_value(fork->car, value);
+		if (!lisp_is_nil(*value)) {
+			fork = fork->cdr.value.cons;
+			while (fork != NULL) {
+				lisp_evaluate_value(fork->car, value);
+				fork = fork->cdr.value.cons;
+			}
+			return;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	value->type = LISP_T_CONS;
+	value->value.cons = NULL;
+}
+
+void lisp_set(lisp_cons* cons, lisp_value* value) {
+	lisp_cons* pair = dbg_malloc(sizeof(lisp_cons));
+	pair->car = cons->car;
+	pair->cdr = cons->cdr.value.cons->car;
+	lisp_alist_put(&syms_alist, pair);
+	*value = pair->cdr;
+}
+
+void lisp_fun(lisp_cons* cons, lisp_value* value) {
+	lisp_cons* pair = lisp_alist_get(funs_alist, cons->car);
+	*value = pair->cdr;
+}
+
+lisp_atom atom_cons;
+lisp_atom atom_atom;
+lisp_atom atom_int;
+lisp_atom atom_float;
+lisp_atom atom_string;
+lisp_atom atom_native_fun;
+
+int main() {
+	printf("sizeof(lisp_atom)   = %lu\n", sizeof(lisp_atom));
+	printf("sizeof(lisp_value)  = %lu\n", sizeof(lisp_value));
+	printf("sizeof(lisp_cons)   = %lu\n", sizeof(lisp_cons));
+
+	atom_t = lisp_atom_init(lisp_string_create("t"));
+	atom_quote = lisp_atom_init(lisp_string_create("quote"));
+
+	atom_cond = lisp_atom_init(lisp_string_create("cond"));
+
+	atom_cons = lisp_atom_init(lisp_string_create("cons"));
+	atom_atom = lisp_atom_init(lisp_string_create("atom"));
+	atom_int = lisp_atom_init(lisp_string_create("int"));
+	atom_float = lisp_atom_init(lisp_string_create("float"));
+	atom_string = lisp_atom_init(lisp_string_create("string"));
+	atom_native_fun = lisp_atom_init(lisp_string_create("native-fun"));
+
+	init_native_funs();
+	lisp_defun_native(lisp_string_create("set"), &lisp_set);
+	lisp_defun_native(lisp_string_create("fun"), &lisp_fun);
+
+	printf("Init: %4liB used\n", dbg_malloc_mem_usage);
+
+	while (true) {
+		lisp_cons* tokens = NULL;
+		lisp_value value;
+		printf("> ");
+		lisp_tokenize_init();
+		if (lisp_parse_recursive(&tokens, &fetch_tokens, &value)) {
+			//test_print_value(value);
+			//printf("\n");
+			lisp_value result;
+			lisp_evaluate_value(value, &result);
+			test_print_value(result);
+			printf("\n");
+			printf("Freeing sexpr...\n");
+			if (value.type == LISP_T_CONS)
+				recursive_free(value.value.cons);
+			else if (value.type == LISP_T_STRING)
+				dbg_free(value.value.string);
+			printf("Freeing tokens...\n");
+			recursive_free(tokens);
+
+			if (lisp_is_nil(value))
+				break;
+		} else {
+			printf("PARSE ERROR!\n");
+			test_print_cons(tokens);
+			printf("\n");
+		}
+	}
+
+	printf("Freeing syms-alist...\n");
+	recursive_free(syms_alist);
+	printf("Freeing funs-alist...\n");
+	recursive_free(funs_alist);
+	printf("Freeing atoms-alist...\n");
+	recursive_free(atoms_alist);
+	printf("Done: %4liB used (should be 0)\n", dbg_malloc_mem_usage);
+	printf("Peak: %4liB used\n", dbg_malloc_peak_usage);
+
+	return 0;
+}
diff --git a/main.h b/main.h
new file mode 100644
index 0000000..f514525
--- /dev/null
+++ b/main.h
@@ -0,0 +1,63 @@
+#ifndef _MAIN_H
+#define _MAIN_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <math.h>
+
+#include "dbg_malloc.h"
+#include "lisp_types.h"
+#include "lisp_string.h"
+#include "parse.h"
+#include "native_funs.h"
+
+/* LISP_USE_ATOMS_ALIST:
+ * If enabled, atom names will be stored in atoms_alist.
+ * This assists debugging and reflection, but makes atom evaluation
+ * slower and uses more memory. */
+#define LISP_USE_ATOMS_ALIST
+
+extern lisp_cons* syms_alist;
+extern lisp_cons* funs_alist;
+extern lisp_cons* atoms_alist;
+
+bool lisp_is_nil(lisp_value value);
+bool lisp_is_equal(lisp_value a, lisp_value b);
+
+void lisp_cons_join(lisp_cons* head, lisp_cons* tail);
+__attribute__((always_inline)) static inline lisp_cons* lisp_cons_pop(lisp_cons** head) {
+	lisp_cons* old_head = *head;
+	*head = old_head->cdr.value.cons;
+	return old_head;
+}
+
+extern lisp_atom atom_t;
+extern lisp_atom atom_quote;
+
+extern lisp_atom atom_cons;
+extern lisp_atom atom_atom;
+extern lisp_atom atom_int;
+extern lisp_atom atom_float;
+extern lisp_atom atom_string;
+extern lisp_atom atom_native_fun;
+
+lisp_atom lisp_atomize(lisp_string* atom_lstr);
+
+lisp_cons** lisp_alist_getptr(lisp_cons* alist, lisp_value key);
+lisp_cons* lisp_alist_get(lisp_cons* alist, lisp_value key);
+lisp_cons* lisp_alist_put(lisp_cons** alist, lisp_cons* pair);
+lisp_cons* lisp_alist_del(lisp_cons** alist, lisp_value key);
+
+void test_print_cons(lisp_cons* cons);
+void test_print_value(lisp_value value);
+
+lisp_atom lisp_defun_native(lisp_string* lstr, lisp_native_fun funptr);
+
+void lisp_evaluate_value(lisp_value input, lisp_value* result);
+void lisp_evaluate(lisp_cons* cons, lisp_value* value);
+extern lisp_atom atom_cond;
+void lisp_macro_cond(lisp_cons* cons, lisp_value* value);
+
+#endif
diff --git a/native_funs.c b/native_funs.c
new file mode 100644
index 0000000..e6dfaa5
--- /dev/null
+++ b/native_funs.c
@@ -0,0 +1,420 @@
+#include "native_funs.h"
+
+void lisp_add(lisp_cons* cons, lisp_value* value) {
+	long _int = 0;
+	float _float = 0.0f;
+	bool is_float = false;
+	while (cons != NULL) {
+		if (!is_float) {
+			if (cons->car.type == LISP_T_INT)
+				_int += cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT) {
+				_float = (float) _int;
+				is_float = true;
+				_float += cons->car.value._float;
+			}
+		} else {
+			if (cons->car.type == LISP_T_INT)
+				_float += cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT)
+				_float += cons->car.value._float;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	if (is_float) {
+		value->type = LISP_T_FLOAT;
+		value->value._float = _float;
+	} else {
+		value->type = LISP_T_INT;
+		value->value._int = _int;
+	}
+}
+void lisp_sub(lisp_cons* cons, lisp_value* value) {
+	long _int = 0;
+	float _float = 0.0f;
+	bool is_float = false;
+
+	if (cons->car.type == LISP_T_FLOAT) {
+		_float = cons->car.value._float;
+		is_float = true;
+	} else if (cons->car.type == LISP_T_INT) {
+		_int = cons->car.value._int;
+	} else {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+
+	if (cons->cdr.value.cons == NULL) {
+		if (is_float) {
+			value->type = LISP_T_FLOAT;
+			value->value._float = -_float;
+		} else {
+			value->type = LISP_T_INT;
+			value->value._int = -_int;
+		}
+		return;
+	} else
+		cons = cons->cdr.value.cons;
+
+	while (cons != NULL) {
+		if (!is_float) {
+			if (cons->car.type == LISP_T_INT)
+				_int -= cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT) {
+				_float = (float) _int;
+				is_float = true;
+				_float -= cons->car.value._float;
+			}
+		} else {
+			if (cons->car.type == LISP_T_INT)
+				_float -= cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT)
+				_float -= cons->car.value._float;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	if (is_float) {
+		value->type = LISP_T_FLOAT;
+		value->value._float = _float;
+	} else {
+		value->type = LISP_T_INT;
+		value->value._int = _int;
+	}
+}
+void lisp_mul(lisp_cons* cons, lisp_value* value) {
+	long _int = 1;
+	float _float = 1;
+	bool is_float = false;
+	while (cons != NULL) {
+		if (!is_float) {
+			if (cons->car.type == LISP_T_INT)
+				_int *= cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT) {
+				_float = (float) _int;
+				is_float = true;
+				_float *= cons->car.value._float;
+			}
+		} else {
+			if (cons->car.type == LISP_T_INT)
+				_float *= cons->car.value._int;
+			else if (cons->car.type == LISP_T_FLOAT)
+				_float *= cons->car.value._float;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	if (is_float) {
+		value->type = LISP_T_FLOAT;
+		value->value._float = _float;
+	} else {
+		value->type = LISP_T_INT;
+		value->value._int = _int;
+	}
+}
+void lisp_div(lisp_cons* cons, lisp_value* value) {
+	float _float = 0;
+
+	if (cons->car.type == LISP_T_FLOAT)
+		_float = cons->car.value._float;
+	else if (cons->car.type == LISP_T_INT)
+		_float = cons->car.value._int;
+	else {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		if (cons->car.type == LISP_T_INT)
+			_float /= cons->car.value._int;
+		else if (cons->car.type == LISP_T_FLOAT)
+			_float /= cons->car.value._float;
+		cons = cons->cdr.value.cons;
+	}
+	value->type = LISP_T_FLOAT;
+	value->value._float = _float;
+}
+void lisp_intdiv(lisp_cons* cons, lisp_value* value) {
+	long _int = 0;
+
+	if (cons->car.type == LISP_T_FLOAT)
+		_int = cons->car.value._float;
+	else if (cons->car.type == LISP_T_INT)
+		_int = cons->car.value._int;
+	else {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		if (cons->car.type == LISP_T_INT)
+			_int /= cons->car.value._int;
+		else if (cons->car.type == LISP_T_FLOAT)
+			_int /= cons->car.value._float;
+		cons = cons->cdr.value.cons;
+	}
+	value->type = LISP_T_INT;
+	value->value._int = _int;
+}
+
+void lisp_not(lisp_cons* cons, lisp_value* value) {
+	if (lisp_is_nil(cons->car)) {
+		value->type = LISP_T_ATOM;
+		value->value.atom = atom_t;
+	} else {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+	}
+}
+void lisp_or(lisp_cons* cons, lisp_value* value) {
+	while (cons != NULL) {
+		if (!lisp_is_nil(cons->car)) {
+			*value = cons->car;
+			return;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	value->type = LISP_T_CONS;
+	value->value.cons = NULL;
+}
+void lisp_and(lisp_cons* cons, lisp_value* value) {
+	value->type = LISP_T_CONS;
+	value->value.cons = NULL;
+	while (cons != NULL) {
+		*value = cons->car;
+		if (lisp_is_nil(cons->car))
+			return;
+		cons = cons->cdr.value.cons;
+	}
+}
+
+void lisp_eq(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		if (!lisp_is_equal(cmp_value, cons->car)) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+void lisp_num_eq(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	if (cmp_value.type != LISP_T_INT && cmp_value.type != LISP_T_FLOAT) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		bool cmp = false;
+		if (cons->car.type == LISP_T_INT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int == cons->car.value._int);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float == cons->car.value._int);
+		} else if (cons->car.type == LISP_T_FLOAT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int == cons->car.value._float);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float == cons->car.value._float);
+		}
+		if (!cmp) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+void lisp_num_lt(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	if (cmp_value.type != LISP_T_INT && cmp_value.type != LISP_T_FLOAT) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		bool cmp = false;
+		if (cons->car.type == LISP_T_INT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int < cons->car.value._int);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float < cons->car.value._int);
+		} else if (cons->car.type == LISP_T_FLOAT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int < cons->car.value._float);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float < cons->car.value._float);
+		}
+		if (!cmp) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cmp_value = cons->car;
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+void lisp_num_gt(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	if (cmp_value.type != LISP_T_INT && cmp_value.type != LISP_T_FLOAT) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		bool cmp = false;
+		if (cons->car.type == LISP_T_INT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int > cons->car.value._int);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float > cons->car.value._int);
+		} else if (cons->car.type == LISP_T_FLOAT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int > cons->car.value._float);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float > cons->car.value._float);
+		}
+		if (!cmp) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cmp_value = cons->car;
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+void lisp_num_le(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	if (cmp_value.type != LISP_T_INT && cmp_value.type != LISP_T_FLOAT) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		bool cmp = false;
+		if (cons->car.type == LISP_T_INT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int <= cons->car.value._int);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float <= cons->car.value._int);
+		} else if (cons->car.type == LISP_T_FLOAT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int <= cons->car.value._float);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float <= cons->car.value._float);
+		}
+		if (!cmp) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cmp_value = cons->car;
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+void lisp_num_ge(lisp_cons* cons, lisp_value* value) {
+	lisp_value cmp_value = cons->car;
+	if (cmp_value.type != LISP_T_INT && cmp_value.type != LISP_T_FLOAT) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	cons = cons->cdr.value.cons;
+	while (cons != NULL) {
+		bool cmp = false;
+		if (cons->car.type == LISP_T_INT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int >= cons->car.value._int);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float >= cons->car.value._int);
+		} else if (cons->car.type == LISP_T_FLOAT) {
+			if (cmp_value.type == LISP_T_INT)
+				cmp = (cmp_value.value._int >= cons->car.value._float);
+			else if (cmp_value.type == LISP_T_FLOAT)
+				cmp = (cmp_value.value._float >= cons->car.value._float);
+		}
+		if (!cmp) {
+			value->type = LISP_T_CONS;
+			value->value.cons = NULL;
+			return;
+		}
+		cmp_value = cons->car;
+		cons = cons->cdr.value.cons;
+	}
+	*value = cmp_value;
+}
+
+void lisp_type_of(lisp_cons* cons, lisp_value* value) {
+	if (lisp_is_nil(cons->car)) {
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return;
+	}
+	value->type = LISP_T_ATOM;
+	switch (cons->car.type) {
+		case LISP_T_CONS:
+			value->value.atom = atom_cons;
+			break;
+		case LISP_T_ATOM:
+			value->value.atom = atom_atom;
+			break;
+		case LISP_T_INT:
+			value->value.atom = atom_int;
+			break;
+		case LISP_T_FLOAT:
+			value->value.atom = atom_float;
+			break;
+		case LISP_T_STRING:
+			value->value.atom = atom_string;
+			break;
+		case LISP_T_FUNPTR:
+			value->value.atom = atom_native_fun;
+			break;
+	}
+}
+
+void lisp_addr_of(lisp_cons* cons, lisp_value* value) {
+	value->type = LISP_T_INT;
+	value->value._int = (long) cons->car.value.cons;
+}
+
+void init_native_funs() {
+	// arithmetic
+	lisp_defun_native(lisp_string_create("+"), &lisp_add);
+	lisp_defun_native(lisp_string_create("-"), &lisp_sub);
+	lisp_defun_native(lisp_string_create("*"), &lisp_mul);
+	lisp_defun_native(lisp_string_create("/"), &lisp_div);
+	lisp_defun_native(lisp_string_create("int/"), &lisp_intdiv);
+
+	// boolean logic
+	lisp_defun_native(lisp_string_create("not"), &lisp_not);
+	lisp_defun_native(lisp_string_create("or"), &lisp_or);
+	lisp_defun_native(lisp_string_create("and"), &lisp_and);
+
+	// comparison
+	lisp_defun_native(lisp_string_create("eq"), &lisp_eq);
+	lisp_defun_native(lisp_string_create("="), &lisp_num_eq);
+	lisp_defun_native(lisp_string_create("<"), &lisp_num_lt);
+	lisp_defun_native(lisp_string_create(">"), &lisp_num_gt);
+	lisp_defun_native(lisp_string_create("<="), &lisp_num_le);
+	lisp_defun_native(lisp_string_create(">="), &lisp_num_ge);
+
+	// etc
+	lisp_defun_native(lisp_string_create("type-of"), &lisp_type_of);
+	lisp_defun_native(lisp_string_create("addr-of"), &lisp_addr_of);
+}
diff --git a/native_funs.h b/native_funs.h
new file mode 100644
index 0000000..a340391
--- /dev/null
+++ b/native_funs.h
@@ -0,0 +1,32 @@
+#ifndef _NATIVE_FUNS_H
+#define _NATIVE_FUNS_H
+
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "lisp_types.h"
+#include "lisp_string.h"
+#include "main.h"
+
+void lisp_add(lisp_cons* cons, lisp_value* value);
+void lisp_sub(lisp_cons* cons, lisp_value* value);
+void lisp_mul(lisp_cons* cons, lisp_value* value);
+void lisp_div(lisp_cons* cons, lisp_value* value);
+void lisp_intdiv(lisp_cons* cons, lisp_value* value);
+
+void lisp_not(lisp_cons* cons, lisp_value* value);
+void lisp_or(lisp_cons* cons, lisp_value* value);
+void lisp_and(lisp_cons* cons, lisp_value* value);
+
+void lisp_eq(lisp_cons* cons, lisp_value* value);
+void lisp_num_eq(lisp_cons* cons, lisp_value* value);
+void lisp_num_lt(lisp_cons* cons, lisp_value* value);
+void lisp_num_gt(lisp_cons* cons, lisp_value* value);
+void lisp_num_le(lisp_cons* cons, lisp_value* value);
+void lisp_num_ge(lisp_cons* cons, lisp_value* value);
+
+void lisp_type_of(lisp_cons* cons, lisp_value* value);
+void lisp_addr_of(lisp_cons* cons, lisp_value* value);
+
+void init_native_funs();
+#endif
diff --git a/parse.c b/parse.c
new file mode 100644
index 0000000..5c98c4b
--- /dev/null
+++ b/parse.c
@@ -0,0 +1,327 @@
+#include "parse.h"
+
+#define lisp_tokenize_len 64
+char lisp_tokenize_buf[lisp_tokenize_len];
+int lisp_tokenize_pos;
+bool lisp_tokenize_quote_mode;
+bool lisp_tokenize_esc_mode;
+void lisp_tokenize_init() {
+	lisp_tokenize_buf[0] = '\0';
+	lisp_tokenize_pos = 0;
+	lisp_tokenize_quote_mode = false;
+	lisp_tokenize_esc_mode = false;
+}
+void lisp_tokenize_next(lisp_cons** head) {
+	lisp_tokenize_buf[lisp_tokenize_pos] = '\0';
+	lisp_string* token_lstr = lisp_string_create(lisp_tokenize_buf);
+	lisp_tokenize_buf[0] = '\0';
+	lisp_tokenize_pos = 0;
+
+	lisp_cons* tail = dbg_malloc(sizeof(lisp_cons));
+	tail->car.type = LISP_T_STRING;
+	tail->car.value.string = token_lstr;
+	tail->cdr.type = LISP_T_CONS;
+	tail->cdr.value.cons = NULL;
+	if (*head != NULL)
+		lisp_cons_join(*head, tail);
+	else
+		*head = tail;
+}
+void lisp_tokenize(char* buf, int len, lisp_cons** head) {
+	for (int i = 0; i < len; i++) {
+		if (lisp_tokenize_pos >= lisp_tokenize_len-1) {
+			lisp_tokenize_pos = lisp_tokenize_len-1;
+			lisp_tokenize_next(head);
+		}
+		char c = buf[i];
+		if (lisp_tokenize_quote_mode) {
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+			if (c == '\\')
+				lisp_tokenize_esc_mode = true;
+			else if ((c == '"') & !lisp_tokenize_esc_mode) { // end of string
+				lisp_tokenize_next(head);
+				lisp_tokenize_quote_mode = false;
+			} else
+				lisp_tokenize_esc_mode = false;
+			continue;
+		}
+
+		if (lisp_tokenize_esc_mode) {
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+			lisp_tokenize_esc_mode = false;
+			continue;
+		}
+
+		if ((c == ' ') || (c == '\t') || (c == '\n') || (c == '\r') || (c == '\v') || (c == '\f')) {
+			if (lisp_tokenize_pos > 0) // whitespace, end of token
+				lisp_tokenize_next(head);
+		} else if (c == ')') {
+			// end current token
+			if (lisp_tokenize_pos > 0)
+				lisp_tokenize_next(head);
+			// ) is its own token
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+			lisp_tokenize_next(head);
+		} else if (c == '(') {
+			// ( is its own token
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+			lisp_tokenize_next(head);
+		} else if ((c == '"') && (lisp_tokenize_pos == 0)) {
+			// enable quotes mode
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+			lisp_tokenize_quote_mode = true;
+		} else if (c == '\\') {
+			lisp_tokenize_esc_mode = true;
+		} else {
+			lisp_tokenize_buf[lisp_tokenize_pos++] = c;
+		}
+	}
+}
+
+bool lisp_parse_number(lisp_string* token_lstr, lisp_value* value) {
+	int token_len = lisp_string_len(token_lstr);
+	char* token_data = lisp_string_data(token_lstr);
+
+	bool neg = false;
+	bool exp_neg = false;
+	bool exp_mode = false;
+	bool point = false;
+	bool valid = false;
+	long _int = 0;
+	float _float = 0.0f;
+	float weight = 0.1f;
+	int exp_i = 0;
+	int exp = 0;
+	for (int i = 0; i < token_len; i++) {
+		char c = token_data[i];
+		if (!exp_mode) {
+			if (c == '-' && i == 0) {
+				neg = true;
+			} else if (c >= '0' && c <= '9') {
+				valid = true;
+				if (!point)
+					_int = (_int * 10) + (c - '0');
+				else {
+					_float += ((c - '0') * weight);
+					weight /= 10.0f;
+				}
+			} else if (c == '.' && !point) {
+				point = true;
+				_float = (float) _int;
+			} else if (c == 'e' || c == 'E') {
+				valid = false;
+				exp_mode = true;
+				if (!point)
+					_float = (float) _int;
+				point = true;
+				exp_i = i+1;
+			} else {
+				valid = false;
+				break;
+			}
+		} else {
+			if (c == '-' && i == exp_i) {
+				exp_neg = true;
+			} else if (c >= '0' && c <= '9') {
+				valid = true;
+				exp = (exp * 10) + (c - '0');
+			} else {
+				valid = false;
+				break;
+			}
+		}
+	}
+	if (valid && !point) {
+		if (neg)
+			_int = -_int;
+		value->type = LISP_T_INT;
+		value->value._int = _int;
+		return true;
+	} else if (valid) {
+		if (neg)
+			_float = -_float;
+		if (exp_neg)
+			exp = -exp;
+		value->type = LISP_T_FLOAT;
+		value->value._float = _float;
+		if (exp_mode)
+			value->value._float *= powf(10, exp);
+		return true;
+	}
+	return false;
+}
+bool lisp_parse_string(lisp_string* token_lstr, lisp_value* value) {
+	int token_len = lisp_string_len(token_lstr);
+	char* token_data = lisp_string_data(token_lstr);
+
+	if (token_data[0] != '"')
+		return false;
+
+	lisp_string* lstr = lisp_string_alloc(lisp_string_len(token_lstr) - 2);
+	int lstr_len = 0;
+	char* lstr_data = lisp_string_data(lstr);
+
+	bool esc_mode = false;
+	char esc_hex_mode = 0;
+	char esc_hex = 0;
+	for (int i = 1; i < token_len-1; i++) {
+		char c = token_data[i];
+		if (esc_mode) {
+			esc_mode = false;
+			switch (c) {
+				case 'b':
+					lstr_data[lstr_len++] = '\b';
+					break;
+				case 'e':
+					lstr_data[lstr_len++] = '\e';
+					break;
+				case 'f':
+					lstr_data[lstr_len++] = '\f';
+					break;
+				case 'n':
+					lstr_data[lstr_len++] = '\n';
+					break;
+				case 'r':
+					lstr_data[lstr_len++] = '\r';
+					break;
+				case 't':
+					lstr_data[lstr_len++] = '\t';
+					break;
+				case 'v':
+					lstr_data[lstr_len++] = '\v';
+					break;
+				case 'x':
+					esc_hex_mode = 2;
+					esc_hex = 0;
+					break;
+				default:
+					lstr_data[lstr_len++] = c;
+					break;
+			}
+		} else if (esc_hex_mode > 0) {
+			esc_hex_mode--;
+			esc_hex <<= 4;
+			if (c <= '9')
+				esc_hex += (c - '0');
+			else if (c <= 'F')
+				esc_hex += (c - ('A'-10));
+			else
+				esc_hex += (c - ('a'-10));
+
+			if (esc_hex_mode == 0)
+				lstr_data[lstr_len++] = esc_hex;
+		} else {
+			if (c == '\\') {
+				esc_mode = true;
+			} else {
+				lstr_data[lstr_len++] = c;
+			}
+		}
+	}
+	*((int*) lstr) = lstr_len;
+	value->type = LISP_T_STRING;
+	value->value.string = lstr;
+	return true;
+}
+bool lisp_parse_scalar(lisp_string* token_lstr, lisp_value* value) {
+	char* buf = lisp_string_data(token_lstr);
+	if (buf[0] == '(' || buf[0] == ')' || buf[0] == '\'') // parentheses, quote
+		return false;
+	if (lisp_string_len(token_lstr) == 3 && buf[0] == 'n' && buf[1] == 'i' && buf[2] == 'l') { // nil
+		value->type = LISP_T_CONS;
+		value->value.cons = NULL;
+		return true;
+	}
+
+	if (lisp_parse_string(token_lstr, value))
+		return true;
+	if (lisp_parse_number(token_lstr, value))
+		return true;
+	lisp_atom atom = lisp_atomize(token_lstr);
+	value->type = LISP_T_ATOM;
+	value->value.atom = atom;
+	return true;
+}
+
+bool lisp_parse_recursive(lisp_cons** tokens, bool (*fetch_tokens)(lisp_cons**), lisp_value* value) {
+	while (*tokens == NULL) // fetch more tokens
+		if ((*fetch_tokens)(tokens) == false)
+			return false;
+	lisp_cons* cons = lisp_cons_pop(tokens);
+	lisp_string* token_lstr = cons->car.value.string;
+	char* buf = lisp_string_data(token_lstr);
+	if (buf[0] == '\'') {
+		lisp_string* new_lstr = lisp_string_create_raw(lisp_string_data(token_lstr)+1, lisp_string_len(token_lstr)-1);
+		dbg_free(token_lstr);
+		cons->car.value.string = new_lstr;
+		*tokens = cons;
+		lisp_cons* quote_cons = dbg_malloc(sizeof(lisp_cons));
+		quote_cons->car.type = LISP_T_ATOM;
+		quote_cons->car.value.atom = atom_quote;
+		quote_cons->cdr.type = LISP_T_CONS;
+		quote_cons->cdr.value.cons = dbg_malloc(sizeof(lisp_cons));
+		quote_cons->cdr.value.cons->cdr.type = LISP_T_CONS;
+		quote_cons->cdr.value.cons->cdr.value.cons = NULL;
+		if (!lisp_parse_recursive(tokens, fetch_tokens, &quote_cons->cdr.value.cons->car))
+			return false;
+		value->type = LISP_T_CONS;
+		value->value.cons = quote_cons;
+		return true;
+	}
+	if (buf[0] == '(') {
+		buf = NULL;
+		dbg_free(token_lstr);
+		lisp_cons* head = NULL;
+		lisp_cons* tail = NULL;
+		lisp_cons* new_cons = cons;
+		bool cdr_mode = false;
+		while (lisp_parse_recursive(tokens, fetch_tokens, &new_cons->car)) {
+			new_cons->cdr.type = LISP_T_CONS;
+			new_cons->cdr.value.cons = NULL;
+			if (head == NULL)
+				head = new_cons;
+			if (tail == NULL)
+				tail = head;
+			else {
+				if (cdr_mode) {
+					tail->cdr = new_cons->car;
+					dbg_free(new_cons);
+				} else {
+					tail->cdr.value.cons = new_cons;
+					tail = new_cons;
+				}
+			}
+			new_cons = dbg_malloc(sizeof(lisp_cons));
+
+			while (*tokens == NULL) // fetch more tokens
+				if ((*fetch_tokens)(tokens) == false)
+					return false;
+			token_lstr = (*tokens)->car.value.string;
+			if (lisp_string_len(token_lstr) == 1) {
+				if (lisp_string_data(token_lstr)[0] == ')') {
+					cons = lisp_cons_pop(tokens);
+					dbg_free(cons);
+					dbg_free(token_lstr);
+					break;
+				} else if (lisp_string_data(token_lstr)[0] == '.') {
+					cons = lisp_cons_pop(tokens);
+					dbg_free(cons);
+					dbg_free(token_lstr);
+					cdr_mode = true;
+				}
+			}
+		}
+		dbg_free(new_cons);
+		value->type = LISP_T_CONS;
+		value->value.cons = head;
+
+		return true;
+	}
+	if (lisp_parse_scalar(token_lstr, value)) {
+		dbg_free(cons);
+		dbg_free(token_lstr);
+		return true;
+	}
+	*tokens = cons;
+	return false;
+}
diff --git a/parse.h b/parse.h
new file mode 100644
index 0000000..0b63163
--- /dev/null
+++ b/parse.h
@@ -0,0 +1,20 @@
+#ifndef _PARSE_H
+#define _PARSE_H
+
+#include <stdbool.h>
+
+#include "lisp_types.h"
+#include "lisp_string.h"
+#include "main.h"
+
+void lisp_tokenize_init();
+void lisp_tokenize_next(lisp_cons** head);
+void lisp_tokenize(char* buf, int len, lisp_cons** head);
+
+bool lisp_parse_number(lisp_string* token_lstr, lisp_value* value);
+bool lisp_parse_string(lisp_string* token_lstr, lisp_value* value);
+bool lisp_parse_scalar(lisp_string* token_lstr, lisp_value* value);
+
+bool lisp_parse_recursive(lisp_cons** tokens, bool (*fetch_tokens)(lisp_cons**), lisp_value* value);
+
+#endif