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#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "types.h"
#include "readline.h"
#include "reader.h"
#include "core.h"
// Declarations
MalVal *EVAL(MalVal *ast, Env *env);
// read
MalVal *READ(char prompt[], char *str) {
char *line;
MalVal *ast;
if (str) {
line = str;
} else {
line = _readline(prompt);
if (!line) {
_error("EOF");
return NULL;
}
}
ast = read_str(line);
if (!str) { free(line); }
return ast;
}
// eval
MalVal *eval_ast(MalVal *ast, Env *env) {
if (!ast || mal_error) return NULL;
if (ast->type == MAL_SYMBOL) {
//g_print("EVAL symbol: %s\n", ast->val.string);
return env_get(env, ast);
} else if ((ast->type == MAL_LIST) || (ast->type == MAL_VECTOR)) {
//g_print("EVAL sequential: %s\n", _pr_str(ast,1));
MalVal *el = _map2((MalVal *(*)(void*, void*))EVAL, ast, env);
if (!el || mal_error) return NULL;
el->type = ast->type;
return el;
} else if (ast->type == MAL_HASH_MAP) {
//g_print("EVAL hash_map: %s\n", _pr_str(ast,1));
GHashTableIter iter;
gpointer key, value;
MalVal *seq = malval_new_list(MAL_LIST,
g_array_sized_new(TRUE, TRUE, sizeof(MalVal*),
_count(ast)));
g_hash_table_iter_init (&iter, ast->val.hash_table);
while (g_hash_table_iter_next (&iter, &key, &value)) {
MalVal *kname = malval_new_string((char *)key);
g_array_append_val(seq->val.array, kname);
MalVal *new_val = EVAL((MalVal *)value, env);
g_array_append_val(seq->val.array, new_val);
}
return _hash_map(seq);
} else {
//g_print("EVAL scalar: %s\n", _pr_str(ast,1));
return ast;
}
}
MalVal *EVAL(MalVal *ast, Env *env) {
if (!ast || mal_error) return NULL;
//g_print("EVAL: %s\n", _pr_str(ast,1));
if (ast->type != MAL_LIST) {
return eval_ast(ast, env);
}
if (!ast || mal_error) return NULL;
// apply list
//g_print("EVAL apply list: %s\n", _pr_str(ast,1));
int i, len;
if (_count(ast) == 0) { return ast; }
MalVal *a0 = _nth(ast, 0);
if ((a0->type & MAL_SYMBOL) &&
strcmp("def!", a0->val.string) == 0) {
//g_print("eval apply def!\n");
MalVal *a1 = _nth(ast, 1),
*a2 = _nth(ast, 2);
MalVal *res = EVAL(a2, env);
if (mal_error) return NULL;
env_set(env, a1, res);
return res;
} else if ((a0->type & MAL_SYMBOL) &&
strcmp("let*", a0->val.string) == 0) {
//g_print("eval apply let*\n");
MalVal *a1 = _nth(ast, 1),
*a2 = _nth(ast, 2),
*key, *val;
assert_type(a1, MAL_LIST|MAL_VECTOR,
"let* bindings must be list or vector");
len = _count(a1);
assert((len % 2) == 0, "odd number of let* bindings forms");
Env *let_env = new_env(env, NULL, NULL);
for(i=0; i<len; i+=2) {
key = g_array_index(a1->val.array, MalVal*, i);
val = g_array_index(a1->val.array, MalVal*, i+1);
assert_type(key, MAL_SYMBOL, "let* bind to non-symbol");
env_set(let_env, key, EVAL(val, let_env));
}
return EVAL(a2, let_env);
} else if ((a0->type & MAL_SYMBOL) &&
strcmp("do", a0->val.string) == 0) {
//g_print("eval apply do\n");
MalVal *el = eval_ast(_rest(ast), env);
return _last(el);
} else if ((a0->type & MAL_SYMBOL) &&
strcmp("if", a0->val.string) == 0) {
//g_print("eval apply if\n");
MalVal *a1 = _nth(ast, 1);
MalVal *cond = EVAL(a1, env);
if (!cond || mal_error) return NULL;
if (cond->type & (MAL_FALSE|MAL_NIL)) {
// eval false slot form
if (ast->val.array->len > 3) {
return EVAL(_nth(ast, 3), env);
} else {
return &mal_nil;
}
} else {
// eval true slot form
MalVal *a2 = _nth(ast, 2);
return EVAL(a2, env);
}
} else if ((a0->type & MAL_SYMBOL) &&
strcmp("fn*", a0->val.string) == 0) {
//g_print("eval apply fn*\n");
MalVal *mf = malval_new(MAL_FUNCTION_MAL, NULL);
mf->val.func.evaluator = EVAL;
mf->val.func.args = _nth(ast, 1);
mf->val.func.body = _nth(ast, 2);
mf->val.func.env = env;
return mf;
} else {
//g_print("eval apply\n");
MalVal *el = eval_ast(ast, env);
if (!el || mal_error) { return NULL; }
MalVal *f = _first(el),
*args = _rest(el);
assert_type(f, MAL_FUNCTION_C|MAL_FUNCTION_MAL,
"cannot apply '%s'", _pr_str(f,1));
return _apply(f, args);
}
}
// print
char *PRINT(MalVal *exp) {
if (mal_error) {
fprintf(stderr, "Error: %s\n", mal_error->val.string);
malval_free(mal_error);
mal_error = NULL;
return NULL;
}
return _pr_str(exp,1);
}
// repl
// read and eval
MalVal *RE(Env *env, char *prompt, char *str) {
MalVal *ast, *exp;
ast = READ(prompt, str);
if (!ast || mal_error) return NULL;
exp = EVAL(ast, env);
if (ast != exp) {
malval_free(ast); // Free input structure
}
return exp;
}
// Setup the initial REPL environment
Env *repl_env;
void init_repl_env() {
repl_env = new_env(NULL, NULL, NULL);
// core.c: defined using C
int i;
for(i=0; i < (sizeof(core_ns) / sizeof(core_ns[0])); i++) {
env_set(repl_env,
malval_new_symbol(core_ns[i].name),
malval_new_function(core_ns[i].func, core_ns[i].arg_cnt));
}
// core.mal: defined using the language itself
RE(repl_env, "", "(def! not (fn* (a) (if a false true)))");
}
int main()
{
MalVal *exp;
char *output;
char prompt[100];
// Set the initial prompt and environment
snprintf(prompt, sizeof(prompt), "user> ");
init_repl_env();
// repl loop
for(;;) {
exp = RE(repl_env, prompt, NULL);
if (mal_error && strcmp("EOF", mal_error->val.string) == 0) {
return 0;
}
output = PRINT(exp);
if (output) {
g_print("%s\n", output);
free(output); // Free output string
}
//malval_free(exp); // Free evaluated expression
}
}
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