commit 5b6bd50f45b4e19e68f086620f30fe78714de4ec Author: Alexander Rosenberg Date: Sat Jun 28 16:47:23 2025 +0900 Initial commit diff --git a/.dir-locals.el b/.dir-locals.el new file mode 100644 index 0000000..15bf7da --- /dev/null +++ b/.dir-locals.el @@ -0,0 +1,5 @@ +;;; Directory Local Variables -*- no-byte-compile: t -*- +;;; For more information see (info "(emacs) Directory Variables") + +((nil . ((my/project-run-command . "build/simple-lisp") + (compile-command . "make -C build")))) diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..4cfafda --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +/.cache/ +/build/ \ No newline at end of file diff --git a/CMakeLists.txt b/CMakeLists.txt new file mode 100644 index 0000000..84e27a9 --- /dev/null +++ b/CMakeLists.txt @@ -0,0 +1,10 @@ +cmake_minimum_required(VERSION 3.10) + +set(CMAKE_C_STANDARD 11) +set(CMAKE_EXPORT_COMPILE_COMMANDS TRUE) + +project(simple-lisp) + +add_compile_options(-Wall -fsanitize=address,leak,undefined) +add_link_options(-fsanitize=address,leak,undefined) +add_executable(simple-lisp src/main.c src/lisp.c src/read.c) diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..f288702 --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/README.md b/README.md new file mode 100644 index 0000000..9160c72 --- /dev/null +++ b/README.md @@ -0,0 +1 @@ +# Simple Lisp diff --git a/src/lisp.c b/src/lisp.c new file mode 100644 index 0000000..902e971 --- /dev/null +++ b/src/lisp.c @@ -0,0 +1,552 @@ +#include "lisp.h" + +#include +#include +#include +#include + +struct _TypeNameEntry LISP_TYPE_NAMES[N_LISP_TYPES] = { + [TYPE_NULL] = {"null", sizeof("null") - 1}, + [TYPE_STRING] = {"string", sizeof("string") - 1}, + [TYPE_SYMBOL] = {"symbol", sizeof("symbol") - 1}, + [TYPE_PAIR] = {"pair", sizeof("pair") - 1}, + [TYPE_INTEGER] = {"integer", sizeof("integer") - 1}, + [TYPE_FLOAT] = {"float", sizeof("float") - 1}, + [TYPE_VECTOR] = {"vector", sizeof("vector") - 1}, + [TYPE_FUNCTION] = {"function", sizeof("function") - 1}, + [TYPE_HASHTABLE] = {"hashtable", sizeof("hashtable") - 1}, +}; + +LispVal _Qnil = { + .type = TYPE_NULL, + .ref_count = -1, +}; + +DEF_STATIC_STRING(_Qunbound_name, "unbound"); +LispSymbol _Qunbound = { + .type = TYPE_SYMBOL, + .ref_count = -1, + .name = &_Qunbound_name, + .plist = Qnil, + .function = Qunbound, + .value = Qunbound, +}; + +DEF_STATIC_STRING(_Qt_name, "t"); +LispSymbol _Qt = { + .type = TYPE_SYMBOL, + .ref_count = -1, + .name = &_Qt_name, + .plist = Qnil, + .function = Qunbound, + .value = Qunbound, +}; + +DEF_STATIC_SYMBOL(quote, "'"); +DEF_STATIC_SYMBOL(backquote, "`"); +DEF_STATIC_SYMBOL(comma, ","); + +void _internal_lisp_delete_object(LispVal *val) { + switch (TYPEOF(val)) { + case TYPE_NULL: + case TYPE_INTEGER: + case TYPE_FLOAT: + lisp_free(val); + break; + case TYPE_STRING: { + LispString *str = (LispString *) val; + if (!str->is_static) { + lisp_free(str->data); + } + lisp_free(val); + } break; + case TYPE_SYMBOL: { + LispSymbol *sym = (LispSymbol *) val; + lisp_unref(sym->name); + lisp_unref(sym->plist); + lisp_unref(sym->function); + lisp_unref(sym->value); + lisp_free(val); + } break; + case TYPE_PAIR: + lisp_unref(((LispPair *) val)->head); + lisp_unref(((LispPair *) val)->tail); + lisp_free(val); + break; + case TYPE_VECTOR: { + LispVector *vec = (LispVector *) val; + for (size_t i = 0; i < vec->length; ++i) { + lisp_unref(vec->data[i]); + } + lisp_free(vec->data); + lisp_free(val); + } break; + case TYPE_FUNCTION: + // TODO handle + break; + case TYPE_HASHTABLE: { + LispHashtable *tbl = (LispHashtable *) val; + for (size_t i = 0; i < tbl->table_size; ++i) { + struct HashtableBucket *cur = tbl->data[i]; + while (cur) { + lisp_unref(cur->key); + lisp_unref(cur->value); + struct HashtableBucket *next = cur->next; + lisp_free(cur); + cur = next; + } + } + lisp_free(tbl->data); + lisp_unref(tbl->eq_fn); + lisp_unref(tbl->hash_fn); + lisp_free(val); + } break; + default: + abort(); + }; +} + +void *lisp_malloc(size_t size) { + return lisp_realloc(NULL, size); +} + +void *lisp_realloc(void *old_ptr, size_t size) { + if (!size) { + return NULL; + } + void *new_ptr = realloc(old_ptr, size); + if (!new_ptr) { + abort(); + } + return new_ptr; +} + +char *lisp_strdup(const char *str) { + size_t len = strlen(str); + char *new_str = lisp_malloc(len + 1); + memcpy(new_str, str, len + 1); + return new_str; +} + +LispVal *make_lisp_string(const char *data, size_t length, bool take, + bool is_static) { + LispString *self = lisp_malloc(sizeof(LispString)); + self->type = TYPE_STRING; + self->ref_count = 0; + if (take) { + self->data = (char *) data; + } else { + self->data = lisp_strdup(data); + } + self->length = length; + self->is_static = is_static; + return LISPVAL(self); +} + +LispVal *sprintf_lisp(const char *format, ...) { + va_list args; + va_start(args, format); + va_list args_measure; + va_copy(args_measure, args); + int size = vsnprintf(NULL, 0, format, args_measure) + 1; + va_end(args_measure); + char *buffer = lisp_malloc(size); + vsnprintf(buffer, size, format, args); + LispVal *obj = make_lisp_string(buffer, size, true, false); + va_end(args); + return obj; +} + +LispVal *make_lisp_symbol(LispVal *name) { + LispSymbol *self = lisp_malloc(sizeof(LispSymbol)); + self->type = TYPE_SYMBOL; + self->ref_count = 0; + self->name = (LispString *) lisp_ref(name); + self->plist = Qnil; + self->function = Qunbound; + self->value = Qunbound; + return LISPVAL(self); +} + +LispVal *make_lisp_pair(LispVal *head, LispVal *tail) { + LispPair *self = lisp_malloc(sizeof(LispPair)); + self->type = TYPE_PAIR; + self->ref_count = 0; + self->head = lisp_ref(head); + self->tail = lisp_ref(tail); + return LISPVAL(self); +} + +LispVal *make_lisp_integer(intmax_t value) { + LispInteger *self = lisp_malloc(sizeof(LispInteger)); + self->type = TYPE_INTEGER; + self->ref_count = 0; + self->value = value; + return LISPVAL(self); +} + +LispVal *make_lisp_float(long double value) { + LispFloat *self = lisp_malloc(sizeof(LispFloat)); + self->type = TYPE_FLOAT; + self->ref_count = 0; + self->value = value; + return LISPVAL(self); +} + +LispVal *make_lisp_vector(LispVal **data, size_t length) { + LispVector *self = lisp_malloc(sizeof(LispVector)); + self->type = TYPE_VECTOR; + self->ref_count = 0; + self->data = data; + self->length = length; + return LISPVAL(self); +} + +LispVal *make_lisp_hashtable(LispVal *eq_fn, LispVal *hash_fn) { + LispHashtable *self = lisp_malloc(sizeof(LispHashtable)); + self->type = TYPE_HASHTABLE; + self->ref_count = 0; + self->table_size = LISP_HASHTABLE_INITIAL_SIZE; + self->data = + lisp_malloc(sizeof(struct HashtableBucket *) * self->table_size); + memset(self->data, 0, sizeof(struct HashtableBucket *) * self->table_size); + self->count = 0; + self->eq_fn = eq_fn; + self->hash_fn = hash_fn; + return LISPVAL(self); +} + +DEFUN(type_of, "type-of", (LispVal * obj)) { + if (obj->type < 0 || obj->type >= N_LISP_TYPES) { + return Qnil; + } + LispVal *name = + make_lisp_string((char *) LISP_TYPE_NAMES[obj->type].name, + LISP_TYPE_NAMES[obj->type].len, true, true); + lisp_ref(name); + LispVal *sym = Fintern(name); + UNREF_INPLACE(name); + return sym; +} + +DEFUN(pair, "pair", (LispVal * head, LispVal *tail)) { + return make_lisp_pair(head, tail); +} + +DEFUN(hash_string, "hash-string", (LispVal * obj)) { + CHECK_TYPE(TYPE_STRING, obj); + const char *str = ((LispString *) obj)->data; + uint64_t hash = 5381; + int c; + while ((c = *(str++))) { + hash = ((hash << 5) + hash) + c; + } + return make_lisp_integer(hash); +} + +DEFUN(strings_equal, "strings-equal", (LispVal * obj1, LispVal *obj2)) { + CHECK_TYPE(TYPE_STRING, obj1); + CHECK_TYPE(TYPE_STRING, obj2); + LispString *str1 = (LispString *) obj1; + LispString *str2 = (LispString *) obj2; + if (str1->length != str2->length) { + return Qnil; + } + return LISP_BOOL(memcmp(str1->data, str2->data, str1->length) == 0); +} + +bool strings_equal_nocase(const char *s1, const char *s2, size_t n) { + for (size_t i = 0; i < n; ++i) { + if (!s1[i] || !s2[i]) { + return !s1[i] && !s2[i]; + } else if (tolower(s1[i]) != tolower(s2[i])) { + return false; + } + } + return true; +} + +DEFUN(id, "id", (LispVal * obj)) { + return make_lisp_integer((int64_t) obj); +} + +DEFUN(eq, "eq", (LispVal * obj1, LispVal *obj2)) { + return LISP_BOOL(obj1 == obj2); +} + +static bool hash_table_eq(LispHashtable *self, LispVal *v1, LispVal *v2) { + if (NILP(self->eq_fn)) { + return v1 == v2; + } else if (self->eq_fn == Qstrings_equal) { + return !NILP(Fstrings_equal(v1, v2)); + } else { + // TODO call the function + return false; + } +} + +static uint64_t hash_table_hash(LispHashtable *self, LispVal *key) { + if (NILP(self->hash_fn)) { + return (uint64_t) key; + } else if (self->hash_fn == Qhash_string) { + // Make obarray lookups faster + LispVal *hash_obj = Fhash_string(key); + uint64_t hash = ((LispInteger *) hash_obj)->value; + UNREF_INPLACE(hash_obj); + return hash; + } else { + // TODO call the hash function + return 0; + } +} + +static struct HashtableBucket * +find_hash_table_bucket(LispHashtable *self, LispVal *key, uint64_t hash) { + struct HashtableBucket *cur = self->data[hash % self->table_size]; + while (cur) { + if (hash_table_eq(self, key, cur->key)) { + return cur; + } + cur = cur->next; + } + return NULL; +} + +static void hash_table_rehash(LispHashtable *self, size_t new_size) { + struct HashtableBucket **new_data = + lisp_malloc(sizeof(struct HashtableBucket *) * new_size); + memset(new_data, 0, sizeof(struct HashtableBucket *) * new_size); + for (size_t i = 0; i < self->table_size; ++i) { + struct HashtableBucket *cur = self->data[i]; + while (cur) { + struct HashtableBucket *next = cur->next; + cur->next = new_data[cur->hash % new_size]; + new_data[cur->hash % new_size] = cur; + cur = next; + } + } + free(self->data); + self->data = new_data; + self->table_size = new_size; +} + +DEFUN(puthash, "puthash", (LispVal * table, LispVal *key, LispVal *value)) { + CHECK_TYPE(TYPE_HASHTABLE, table); + LispHashtable *self = (LispHashtable *) table; + uint64_t hash = hash_table_hash(self, key); + struct HashtableBucket *cur_bucket = + find_hash_table_bucket(self, key, hash); + if (cur_bucket) { + UNREF_INPLACE(cur_bucket->value); + cur_bucket->value = lisp_ref(value); + } else { + cur_bucket = lisp_malloc(sizeof(struct HashtableBucket)); + cur_bucket->next = self->data[hash % self->table_size]; + cur_bucket->hash = hash; + cur_bucket->key = lisp_ref(key); + cur_bucket->value = lisp_ref(value); + self->data[hash % self->table_size] = cur_bucket; + ++self->count; + if ((double) self->count / self->table_size + >= LISP_HASHTABLE_GROWTH_THRESHOLD) { + hash_table_rehash(self, + LISP_HASHTABLE_GROWTH_FACTOR * self->table_size); + } + } + return table; +} + +DEFUN(gethash, "gethash", (LispVal * table, LispVal *key, LispVal *def)) { + CHECK_TYPE(TYPE_HASHTABLE, table); + LispHashtable *self = (LispHashtable *) table; + uint64_t hash = hash_table_hash(self, key); + struct HashtableBucket *cur_bucket = + find_hash_table_bucket(self, key, hash); + if (cur_bucket) { + return cur_bucket->value; + } + return def; +} + +DEFUN(remhash, "remhash", (LispVal * table, LispVal *key)) { + CHECK_TYPE(TYPE_HASHTABLE, table); + LispHashtable *self = (LispHashtable *) table; + uint64_t hash = hash_table_hash(self, key); + struct HashtableBucket *cur_bucket = self->data[hash % self->table_size]; + if (cur_bucket && hash_table_eq(self, cur_bucket->key, key)) { + self->data[hash % self->table_size] = cur_bucket->next; + UNREF_INPLACE(cur_bucket->key); + UNREF_INPLACE(cur_bucket->value); + free(cur_bucket); + --self->count; + } else { + struct HashtableBucket *prev_bucket = cur_bucket; + cur_bucket = cur_bucket->next; + while (cur_bucket) { + if (hash_table_eq(self, cur_bucket->key, key)) { + prev_bucket->next = cur_bucket->next; + UNREF_INPLACE(cur_bucket->key); + UNREF_INPLACE(cur_bucket->value); + free(cur_bucket); + --self->count; + break; + } + } + } + if ((double) self->count / self->table_size + <= LISP_HASHTABLE_SHRINK_THRESHOLD + && self->table_size > LISP_HASHTABLE_INITIAL_SIZE) { + hash_table_rehash(self, + self->table_size / LISP_HASHTABLE_GROWTH_FACTOR); + } + return table; +} + +DEFUN(hash_table_count, "hash-table-count", (LispVal * table)) { + CHECK_TYPE(TYPE_HASHTABLE, table); + return make_lisp_integer(((LispHashtable *) table)->count); +} + +DEFUN(intern, "intern", (LispVal * name)) { + CHECK_TYPE(TYPE_STRING, name); + LispVal *cur = Fgethash(Vobarray, name, Qunbound); + if (cur != Qunbound) { + return cur; + } + LispVal *sym = make_lisp_symbol(name); + Fputhash(Vobarray, name, sym); + return sym; +} + +LispVal *intern(const char *name, size_t length, bool take) { + LispVal *name_obj = make_lisp_string((char *) name, length, take, false); + lisp_ref(name_obj); + LispVal *sym = Fintern(name_obj); + UNREF_INPLACE(name_obj); + return sym; +} + +DEFUN(sethead, "sethead", (LispVal * pair, LispVal *head)) { + CHECK_TYPE(TYPE_PAIR, pair); + UNREF_INPLACE(((LispPair *) pair)->head); + ((LispPair *) pair)->head = lisp_ref(head); + return Qnil; +} + +DEFUN(settail, "settail", (LispVal * pair, LispVal *tail)) { + CHECK_TYPE(TYPE_PAIR, pair); + UNREF_INPLACE(((LispPair *) pair)->tail); + ((LispPair *) pair)->tail = lisp_ref(tail); + return Qnil; +} + +DEFUN(throw, "throw", (LispVal * signal, LispVal *rest)) { + if (!SYMBOLP(signal)) { + printf("Attempt to throw non-symbol value!\n"); + } else { + LispSymbol *sym = (LispSymbol *) signal; + printf("Throw %*s! Data: ", (int) sym->name->length, sym->name->data); + debug_dump(stdout, rest, true); + } + return Qnil; +} + +DEF_STATIC_SYMBOL(type_error, "type-error"); +DEF_STATIC_SYMBOL(read_error, "read-error"); + +LispVal *Vobarray = Qnil; + +void lisp_init() { + Vobarray = lisp_ref(make_lisp_hashtable(Qstrings_equal, Qhash_string)); +} + +void lisp_shutdown() { + UNREF_INPLACE(Vobarray); +} + +static void debug_dump_real(FILE *stream, void *obj, bool first) { + switch (TYPEOF(obj)) { + case TYPE_NULL: + fprintf(stream, "nil"); + break; + case TYPE_STRING: { + LispString *str = (LispString *) obj; + // TODO actually quote + fputc('"', stream); + fwrite(str->data, 1, str->length, stream); + fputc('"', stream); + } break; + case TYPE_SYMBOL: { + LispSymbol *sym = (LispSymbol *) obj; + fwrite(sym->name->data, 1, sym->name->length, stream); + } break; + case TYPE_PAIR: { + LispPair *pair = (LispPair *) obj; + if (first) { + fputc('(', stream); + } else { + fputc(' ', stream); + } + debug_dump_real(stream, pair->head, true); + if (NILP(pair->tail)) { + fputc(')', stream); + } else if (PAIRP(pair->tail)) { + debug_dump_real(stream, pair->tail, false); + } else { + fprintf(stream, " . "); + debug_dump_real(stream, pair->tail, false); + fputc(')', stream); + } + } break; + case TYPE_INTEGER: + fprintf(stream, "%jd", ((LispInteger *) obj)->value); + break; + case TYPE_FLOAT: + fprintf(stream, "%Lf", ((LispFloat *) obj)->value); + break; + case TYPE_VECTOR: { + LispVector *vec = (LispVector *) obj; + fputc('[', stream); + for (size_t i = 0; i < vec->length; ++i) { + if (i) { + fputc(' ', stream); + } + debug_dump_real(stream, vec->data[i], true); + } + fputc(']', stream); + } break; + case TYPE_FUNCTION: + if (((LispFunction *) obj)->builtin) { + fprintf(stream, "", (uintmax_t) obj); + } else { + fprintf(stream, "", (uintmax_t) obj); + } + break; + case TYPE_HASHTABLE: { + LispHashtable *tbl = (LispHashtable *) obj; + fprintf(stream, "", + tbl->table_size, tbl->count, (uintmax_t) obj); + } break; + default: + fprintf(stream, "", + (uintmax_t) LISPVAL(obj)->type, (uintmax_t) obj); + break; + } +} + +void debug_dump(FILE *stream, void *obj, bool newline) { + debug_dump_real(stream, obj, true); + if (newline) { + fputc('\n', stream); + } +} + +void debug_print_hashtable(FILE *stream, LispVal *table) { + debug_dump(stream, table, true); + HASHTABLE_FOREACH(key, val, table, { + fprintf(stream, "- "); + debug_dump(stream, key, false); + fprintf(stream, " = "); + debug_dump(stream, val, true); + }); +} diff --git a/src/lisp.h b/src/lisp.h new file mode 100644 index 0000000..8e494e7 --- /dev/null +++ b/src/lisp.h @@ -0,0 +1,326 @@ +#ifndef INCLUDED_LISP_H +#define INCLUDED_LISP_H + +#include +#include +#include +#include +#include +#include + +#if __has_attribute(format) +# define PRINTF_FORMAT(first, second) \ + __attribute__((format(printf, first, second))) +#else +# define PRINTF_FORMAT(first, second) +#endif + +typedef enum { + TYPE_NULL = 0, + TYPE_STRING, + TYPE_SYMBOL, + TYPE_PAIR, + TYPE_INTEGER, + TYPE_FLOAT, + TYPE_VECTOR, + TYPE_FUNCTION, + TYPE_HASHTABLE, + N_LISP_TYPES, +} LispType; + +struct _TypeNameEntry { + const char *name; + size_t len; +}; +extern struct _TypeNameEntry LISP_TYPE_NAMES[N_LISP_TYPES]; +#define OBJ_TYPE_NAME(obj) (LISP_TYPE_NAMES[LISPVAL(obj)->type].name) + +#define LISP_OBJECT_HEADER \ + LispType type; \ + ptrdiff_t ref_count; + +typedef struct { + LISP_OBJECT_HEADER; +} LispVal; +#define LISPVAL(obj) ((LispVal *) (obj)) +#define STATICP(v) (LISPVAL(v)->ref_count < 0) +#define TYPEOF(v) (LISPVAL(v)->type) + +typedef struct { + LISP_OBJECT_HEADER; + + char *data; + size_t length; + bool is_static; +} LispString; + +typedef struct { + LISP_OBJECT_HEADER; + + LispString *name; + LispVal *plist; + LispVal *function; + LispVal *value; +} LispSymbol; + +typedef struct { + LISP_OBJECT_HEADER; + + LispVal *head; + LispVal *tail; +} LispPair; + +typedef struct { + LISP_OBJECT_HEADER; + + intmax_t value; +} LispInteger; + +typedef struct { + LISP_OBJECT_HEADER; + + long double value; +} LispFloat; + +typedef struct { + LISP_OBJECT_HEADER; + + LispVal **data; + size_t length; +} LispVector; + +typedef LispVal *(*lisp_builtin_t)(); + +typedef struct { + LISP_OBJECT_HEADER; + + LispVal *doc; + LispVal *args; + bool is_builtin; + union { + LispVal *body; + lisp_builtin_t builtin; + }; +} LispFunction; + +struct HashtableBucket { + struct HashtableBucket *next; + uint64_t hash; + LispVal *key; + LispVal *value; +}; + +#define LISP_HASHTABLE_INITIAL_SIZE 32 +#define LISP_HASHTABLE_GROWTH_FACTOR 2 +#define LISP_HASHTABLE_GROWTH_THRESHOLD 0.75f +#define LISP_HASHTABLE_SHRINK_THRESHOLD 0.25f + +typedef struct { + LISP_OBJECT_HEADER; + + struct HashtableBucket **data; + size_t table_size; + size_t count; + LispVal *eq_fn; + LispVal *hash_fn; +} LispHashtable; + +#define NILP(v) (TYPEOF(v) == TYPE_NULL) +#define STRINGP(v) (TYPEOF(v) == TYPE_STRING) +#define SYMBOLP(v) (TYPEOF(v) == TYPE_SYMBOL) +#define PAIRP(v) (TYPEOF(v) == TYPE_PAIR) +#define INTEGERP(v) (TYPEOF(v) == TYPE_INTEGER) +#define FLOATP(v) (TYPEOF(v) == TYPE_FLOAT) +#define VECTORP(v) (TYPEOF(v) == TYPE_VECTOR) +#define FUNCTIONP(v) (TYPEOF(v) == TYPE_FUNCTION) +#define HASHTABLEP(v) (TYPEOF(v) == TYPE_HASHTABLE) + +#define ATOM(v) (TYPEOF(v) != TYPE_PAIR) + +inline static bool LISTP(LispVal *v) { + return NILP(v) || PAIRP(v); +} + +inline static bool NUMBERP(LispVal *v) { + return INTEGERP(v) || FLOATP(v); +} + +extern LispVal _Qnil; +extern LispSymbol _Qunbound; +extern LispSymbol _Qt; + +#define Qnil (&_Qnil) +#define Qunbound (LISPVAL(&_Qunbound)) +#define Qt (LISPVAL(&_Qt)) + +extern LispVal *Qquote; +extern LispVal *Qbackquote; +extern LispVal *Qcomma; + +#define LISP_BOOL(v) ((v) ? Qt : Qnil) + +#define DEF_STATIC_STRING(name, value) \ + static LispString name = { \ + .type = TYPE_STRING, \ + .ref_count = -1, \ + .data = value, \ + .length = sizeof(value) - 1, \ + .is_static = true, \ + }; +#define DEF_STATIC_SYMBOL(c_name, lisp_name) \ + DEF_STATIC_STRING(_Q##c_name##_name, lisp_name); \ + static LispSymbol _Q##c_name = { \ + .type = TYPE_SYMBOL, \ + .ref_count = -1, \ + .name = &_Q##c_name##_name, \ + .plist = Qnil, \ + .function = Qunbound, \ + .value = Qunbound, \ + }; \ + LispVal *Q##c_name = LISPVAL(&_Q##c_name); + +void *lisp_malloc(size_t size); +void *lisp_realloc(void *old_ptr, size_t size); +#define lisp_free free +char *lisp_strdup(const char *str); + +inline static void *lisp_ref(void *val) { + if (!STATICP(val)) { + ++((LispVal *) val)->ref_count; + } + return val; +} + +inline static void *lisp_float_ref(void *val) { + if (LISPVAL(val)->ref_count > 0) { + --LISPVAL(val)->ref_count; + } + return val; +} + +void _internal_lisp_delete_object(LispVal *val); +inline static void *lisp_unref(void *val) { + if (STATICP(val)) { + return val; + } else if (LISPVAL(val)->ref_count > 1) { + --LISPVAL(val)->ref_count; + return val; + } else { + _internal_lisp_delete_object(val); + return Qnil; + } +} +#define UNREF_INPLACE(variable) \ + { \ + variable = lisp_unref(variable); \ + } + +LispVal *make_lisp_string(const char *data, size_t length, bool take, + bool is_static); +#define STATIC_STRING(s) (make_lisp_string((s), sizeof(s) - 1, true, true)) +LispVal *sprintf_lisp(const char *format, ...) PRINTF_FORMAT(1, 2); +LispVal *make_lisp_symbol(LispVal *name); +LispVal *make_lisp_pair(LispVal *head, LispVal *tail); +LispVal *make_lisp_integer(intmax_t value); +LispVal *make_lisp_float(long double value); +LispVal *make_lisp_vector(LispVal **data, size_t length); +// TODO make_lisp_function +LispVal *make_lisp_hashtable(LispVal *eq_fn, LispVal *hash_fn); + +#define DECLARE_FUNCTION(c_name, args) \ + extern LispVal *Q##c_name; \ + LispVal *F##c_name args; + +// The args and doc fields are filled when the function is registered +#define DEFUN(c_name, lisp_name, c_args) \ + DEF_STATIC_STRING(_Q##c_name##_name, lisp_name); \ + static LispFunction _Q##c_name##_function = { \ + .type = TYPE_FUNCTION, \ + .ref_count = -1, \ + .doc = Qnil, \ + .args = Qnil, \ + .is_builtin = true, \ + .builtin = &F##c_name, \ + }; \ + static LispSymbol _Q##c_name = { \ + .type = TYPE_SYMBOL, \ + .ref_count = -1, \ + .name = &_Q##c_name##_name, \ + .plist = Qnil, \ + .function = LISPVAL(&_Q##c_name##_function), \ + }; \ + LispVal *Q##c_name = (LispVal *) &_Q##c_name; \ + LispVal *F##c_name c_args + +DECLARE_FUNCTION(type_of, (LispVal * obj)); +DECLARE_FUNCTION(pair, (LispVal * head, LispVal *tail)); +DECLARE_FUNCTION(hash_string, (LispVal * obj)); +DECLARE_FUNCTION(strings_equal, (LispVal * obj1, LispVal *obj2)); +bool strings_equal_nocase(const char *s1, const char *s2, size_t n); +DECLARE_FUNCTION(id, (LispVal * obj)); +DECLARE_FUNCTION(eq, (LispVal * obj1, LispVal *obj2)); +DECLARE_FUNCTION(puthash, (LispVal * table, LispVal *key, LispVal *value)); +DECLARE_FUNCTION(gethash, (LispVal * table, LispVal *key, LispVal *def)); +DECLARE_FUNCTION(remhash, (LispVal * table, LispVal *key)); +DECLARE_FUNCTION(hash_table_count, (LispVal * table)); +#define HASHTABLE_FOREACH(key_var, val_var, table, body) \ + { \ + LispHashtable *__hashtable_foreach_table = (LispHashtable *) table; \ + for (size_t __hashtable_foreach_i = 0; \ + __hashtable_foreach_i < __hashtable_foreach_table->count; \ + ++__hashtable_foreach_i) { \ + struct HashtableBucket *__hashtable_foreach_cur = \ + __hashtable_foreach_table->data[__hashtable_foreach_i]; \ + while (__hashtable_foreach_cur) { \ + LispVal *key_var = __hashtable_foreach_cur->key; \ + LispVal *val_var = __hashtable_foreach_cur->value; \ + {body}; \ + __hashtable_foreach_cur = __hashtable_foreach_cur->next; \ + } \ + } \ + } +DECLARE_FUNCTION(intern, (LispVal * name)); +LispVal *intern(const char *name, size_t length, bool take); +#define INTERN_STATIC(name) (Fintern(STATIC_STRING(name))) + +DECLARE_FUNCTION(sethead, (LispVal * pair, LispVal *head)); +DECLARE_FUNCTION(settail, (LispVal * pair, LispVal *tail)); +static inline LispVal *make_list(int len, ...) { + LispVal *list = Qnil; + LispVal *end; + va_list args; + va_start(args, len); + while (len--) { + LispVal *elt = va_arg(args, LispVal *); + if (NILP(list)) { + list = Fpair(elt, Qnil); + end = list; + } else { + LispVal *new_end = Fpair(elt, Qnil); + Fsettail(end, new_end); + end = new_end; + } + } + va_end(args); + return list; +} + +DECLARE_FUNCTION(throw, (LispVal * signal, LispVal *rest)); + +extern LispVal *Qtype_error; +extern LispVal *Qread_error; + +#define CHECK_TYPE(type, val) \ + if (TYPEOF(val) != type) { \ + Fthrow(Qtype_error, Qnil); \ + return Qnil; \ + } + +extern LispVal *Vobarray; + +void lisp_init(void); +void lisp_shutdown(void); +void debug_dump(FILE *stream, void *obj, bool newline); +void debug_print_hashtable(FILE *stream, LispVal *table); + +#endif diff --git a/src/main.c b/src/main.c new file mode 100644 index 0000000..aafd1d7 --- /dev/null +++ b/src/main.c @@ -0,0 +1,18 @@ +#include "lisp.h" +#include "read.h" + +#include + +int main(int argc, const char **argv) { + lisp_init(); + char buffer[] = "1"; + LispVal *tv; + size_t count = read_from_buffer(buffer, sizeof(buffer) - 1, &tv); + lisp_ref(tv); + printf("Read %zu chars\n", count); + printf("Type: %s\n", OBJ_TYPE_NAME(tv)); + debug_dump(stdout, tv, true); + UNREF_INPLACE(tv); + lisp_shutdown(); + return 0; +} diff --git a/src/read.c b/src/read.c new file mode 100644 index 0000000..4872e29 --- /dev/null +++ b/src/read.c @@ -0,0 +1,404 @@ +#include "read.h" + +#include +#include +#include +#include + +struct ReadState { + const char *head; + size_t left; + size_t off; + size_t line; + size_t col; + + size_t backquote_level; +}; + +#define EOS -1 + +static int popc(struct ReadState *state) { + if (!state->left) { + return EOS; + } + ++state->off; + --state->left; + int c = *(state->head++); + if (c == '\n') { + ++state->line; + state->off = 0; + } else { + ++state->col; + } + return c; +} + +static int peekc(struct ReadState *state) { + if (!state->left) { + return EOS; + } + return *state->head; +} + +static inline void _internal_read_error(struct ReadState *state, size_t len, + LispVal *desc) { + // TODO format better + LispVal *args = make_list( + 4, make_lisp_integer(state->line), make_lisp_integer(state->col), + make_lisp_string(state->head, len, false, false), desc); + lisp_ref(args); + Fthrow(Qread_error, args); + UNREF_INPLACE(args); +} +#define READ_ERROR(state, len, ...) \ + _internal_read_error(state, len, sprintf_lisp(__VA_ARGS__)) +#define EOF_ERROR(state) READ_ERROR(state, 1, "unexpected end of file") + +#define SKIP_WHILE(cond, state) \ + while (cond) { \ + popc(state); \ + } +#define SKIP_WHITESPACE(state) SKIP_WHILE(isblank(peekc(state)), state) + +static bool is_symbol_end(int c) { + return c == EOS || isspace(c) || c == '(' || c == ')' || c == '[' + || c == ']'; +} + +static LispVal *read_internal(struct ReadState *state); + +static LispVal *read_list(struct ReadState *state) { + popc(state); // open ( + LispVal *list = Qnil; + LispVal *end = list; + SKIP_WHITESPACE(state); + int c; + while ((c = peekc(state)) != ')') { + if (c == EOS) { + EOF_ERROR(state); + UNREF_INPLACE(list); + return Qnil; + } + LispVal *elt = read_internal(state); + if (NILP(list)) { + list = Fpair(elt, Qnil); + end = list; + } else { + LispVal *new_end = Fpair(elt, Qnil); + Fsettail(end, new_end); + end = new_end; + } + SKIP_WHITESPACE(state); + } + popc(state); // close ) + return list; +} + +static LispVal *read_vector(struct ReadState *state) { + popc(state); // open [ + LispVal **values = NULL; + size_t values_len = 0; + SKIP_WHITESPACE(state); + int c; + while ((c = peekc(state)) != ']') { + if (c == EOS) { + EOF_ERROR(state); + for (size_t i = 0; i < values_len; ++i) { + lisp_unref(values[i]); + } + lisp_free(values); + return Qnil; + } + LispVal *elt = lisp_ref(read_internal(state)); + values = lisp_realloc(values, sizeof(LispVal *) * ++values_len); + values[values_len - 1] = elt; + SKIP_WHITESPACE(state); + } + popc(state); // close ] + return make_lisp_vector(values, values_len); +} + +static LispVal *read_string(struct ReadState *state) { + popc(state); // open " + bool backslash = false; + int c; + char *str = lisp_malloc(1); + size_t str_len = 0; + while (backslash || (c = peekc(state)) != '"') { + if (c == EOS) { + lisp_free(str); + EOF_ERROR(state); + return Qnil; + } + popc(state); + if (!backslash && c == '\\') { + backslash = true; + } else if (backslash && c == '\n') { + backslash = false; + } else { + str = lisp_realloc(str, ++str_len + 1); + int to_add = c; + if (backslash) { + switch (c) { + case 'n': + to_add = '\n'; + break; + case 't': + to_add = '\t'; + break; + case 'r': + to_add = '\r'; + break; + case '0': + to_add = '\0'; + break; + case '"': + to_add = '"'; + break; + default: + // TODO make this point at the correct thing + READ_ERROR(state, 1, "unknown escape sequence"); + lisp_free(str); + return Qnil; + } + } + backslash = false; + str[str_len - 1] = to_add; + } + } + str[str_len] = '\n'; + popc(state); // close " + return make_lisp_string(str, str_len, true, false); +} + +static LispVal *read_character(struct ReadState *state) { + static struct { + const char *name; + size_t len; + char value; + } LOOKUP_TABLE[] = { + {"null", 4, '\0'}, {"\\0", 2, '\0'}, {"newline", 7, '\n'}, + {"\\n", 2, '\n'}, {"tab", 3, '\t'}, {"\\t", 2, '\t'}, + }; +#define LOOKUP_TABLE_SIZE (sizeof(LOOKUP_TABLE) / sizeof(LOOKUP_TABLE[0])) + struct ReadState start_state = *state; + popc(state); // # + const char *start = state->head; + while (!is_symbol_end(peekc(state))) { + popc(state); + } + size_t len = state->head - start; + for (size_t i = 0; i < LOOKUP_TABLE_SIZE; ++i) { + if (len == LOOKUP_TABLE[i].len + && strings_equal_nocase(start, LOOKUP_TABLE[i].name, len)) { + return make_lisp_integer(LOOKUP_TABLE[i].value); + } + } + READ_ERROR(&start_state, len, "unknown character liternal: %*s", (int) len, + start); + return Qnil; +#undef LOOKUP_TABLE_SIZE +} + +#define INVALID_BASE -2 +#define ANY_BASE -1 + +static bool is_base_char(int base, int c) { + c = tolower(c); + if (base == ANY_BASE) { + base = 10; + } + switch (base) { + case 16: + if (c >= 'a' || c <= 'f') { + return true; + } + case 10: + case 8: + case 2: + return c >= '0' && c <= '0' + base - 1; + default: + return false; + } +} + +static int parse_base(size_t left, const char *c) { + if (left >= 2 && *c == '2' && *(c + 1) == '#') { + return 2; + } else if (left >= 2 && *c == '8' && *(c + 1) == '#') { + return 8; + } else if (left >= 3 && *c == '1' && *(c + 1) == '0' && *(c + 2) == '#') { + return 10; + } else if (left >= 3 && *c == '1' && *(c + 1) == '6' && *(c + 2) == '#') { + return 16; + } else { + return INVALID_BASE; + } +} + +static LispVal *read_symbol(struct ReadState *state) { + const char *start = state->head; + while (!is_symbol_end(peekc(state))) { + popc(state); + } + return intern(start, state->head - start, false); +} + +static LispVal *read_number_or_symbol(struct ReadState *state, int base) { + size_t size_t_len = ((sizeof(size_t) * 8) / 3) + 1; + char fmt_buf[3 + size_t_len + 1]; + struct ReadState start_state = *state; + bool has_decimal = false; + const char *number_start = state->head; + const char *exp_start = NULL; + int c; + while (!is_symbol_end(c = peekc(state))) { + popc(state); + if (c == '#') { + if (base != ANY_BASE) { + goto change_to_symbol; + } + base = parse_base(start_state.left, start_state.head); + if (base == INVALID_BASE) { + goto change_to_symbol; + } + number_start = state->head; + } else if (c == '.') { + if (base != ANY_BASE || has_decimal || exp_start) { + goto change_to_symbol; + } + has_decimal = true; + } else if ((c == '-' || c == '+')) { + if (state->head - 1 != number_start + && state->head - 1 != exp_start) { + goto change_to_symbol; + } + // fallthrough + } else if (!is_base_char(base, c)) { + if ((c == 'e' || c == 'E') && !exp_start && base == ANY_BASE) { + exp_start = state->head; + } else { + goto change_to_symbol; + } + } + } + size_t len = state->head - number_start; + // ceil(# bytes in size_t / 3) + // This works because log10(2^n) is O(n) for k=3 + if (has_decimal || exp_start) { + if (exp_start == state->head) { + goto change_to_symbol; + } + snprintf(fmt_buf, sizeof(fmt_buf), "%%%zuLf", len); + long double value; + sscanf(number_start, fmt_buf, &value); + return make_lisp_float(value); + // float + } else { + snprintf(fmt_buf, sizeof(fmt_buf), "%%%zujd", len); + intmax_t value; + sscanf(number_start, fmt_buf, &value); + return make_lisp_integer(value); + // int + } + abort(); +change_to_symbol: + *state = start_state; + return read_symbol(state); +} + +static LispVal *read_internal(struct ReadState *state) { + SKIP_WHILE(isspace(peekc(state)), state); + int c = peekc(state); + // comment + while (c == ';') { + SKIP_WHILE(peekc(state) != '\n', state); + SKIP_WHITESPACE(state); + c = peekc(state); + } + switch (c) { + // list + case EOS: + return NULL; + case ')': + READ_ERROR(state, 1, "unmatched \")\""); + return Qnil; + case ']': + READ_ERROR(state, 1, "unmatched \"]\""); + return Qnil; + case '(': + return read_list(state); + // string + case '"': + return read_string(state); + // vector + case '[': + return read_vector(state); + // quoted form + case '\'': { + popc(state); // ' + LispVal *tail = read_internal(state); + return Fpair(Qquote, Fpair(tail, Qnil)); + } + // backquote + case '`': { + popc(state); // ` + ++state->backquote_level; + LispVal *tail = read_internal(state); + --state->backquote_level; + return Fpair(Qbackquote, Fpair(tail, Qnil)); + } + // comma + case ',': + popc(state); // , + if (state->backquote_level) { + --state->backquote_level; + LispVal *tail = read_internal(state); + ++state->backquote_level; + return Fpair(Qcomma, Fpair(tail, Qnil)); + } else { + READ_ERROR(state, 1, "comma not inside backquote"); + return Qnil; + } + // character literal + case '#': + return read_character(state); + // number + case '+': + case '-': + case '.': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + case '0': + return read_number_or_symbol(state, ANY_BASE); + // symbol + default: + return read_symbol(state); + } +} + +size_t read_from_buffer(const char *text, size_t length, LispVal **out) { + struct ReadState state = { + .head = text, + .left = length, + .off = 0, + .line = 1, + .col = 0, + .backquote_level = 0, + }; + LispVal *res = read_internal(&state); + if (!res) { + EOF_ERROR(&state); + *out = Qnil; + } else { + *out = res; + } + return state.off; +} diff --git a/src/read.h b/src/read.h new file mode 100644 index 0000000..bbaaed4 --- /dev/null +++ b/src/read.h @@ -0,0 +1,15 @@ +#ifndef INCLUDED_READ_H +#define INCLUDED_READ_H + +#include "lisp.h" + +#include + +typedef enum { + SEVERITY_WARN, + SEVERITY_ERROR, +} ReadErrorSeverity; + +size_t read_from_buffer(const char *text, size_t length, LispVal **out); + +#endif