fix memory problem

10 files changed, 109 insertions, 18 deletions

diff --git a/README.md b/README.md
index 15a5257..f84dd0a 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,9 @@ some built-in functions to make the language usable, though
 I plan to add support for macros and other stuff. This
 is a functional programming language so functions are first-class.
 
+I wrote this programming language within just six days, and I wrote
+the bulk of it (~1400 LoC) within the first two days.
+
 ## TODO
 Each todo here represents one task that I have not done.
 Note that all the tasks that I finished are bigger than
diff --git a/doc/main.nxs b/doc/main.nxs
index d3aa986..cb6985d 100644
--- a/doc/main.nxs
+++ b/doc/main.nxs
@@ -1,8 +1,9 @@
 (include "fib.nxs")
 
 (bind factorial (lambda (n)
-	(if (= n 0) 1 (* n (factorial (print(- n 1)))))))
-(print(fib 7))
+	(if (= n 0) 1 (* n (factorial (- n 1))))))
+
+(print (fib 7))
 (print (+ (factorial 5) 10))
 
-(print(car (quote (+ (3 2) 4))))
+(print (quote (+ (3 2) 4)))
diff --git a/src/hash_table.c b/src/hash_table.c
index 6648bd1..29946b1 100644
--- a/src/hash_table.c
+++ b/src/hash_table.c
@@ -78,6 +78,15 @@ void sl_list_add(sl_list_t *l, char *key, ast_t *value) {
   }
 }
 
+void sl_list_modify(sl_list_t *l, char *key, ast_t *value) {
+  sl_node_t *cur = l->head;
+  while (cur != NULL) {
+    if (strcmp(cur->value->key, key) == 0)
+      cur->value->value = value;
+    cur = cur->next;
+  }
+}
+
 ast_t *sl_list_get(sl_list_t *l, char *key) {
   sl_node_t *cur = l->head;
   for (int i = 0; i < l->size; i++) {
@@ -123,6 +132,8 @@ hash_table_t *init_hash_table(int size) {
 
 void hash_table_add(hash_table_t *h, char *key, ast_t *value) {
   sl_list_t *l = h->buckets[hash(key, h->size)];
+  if (sl_list_exists(l, key))
+    sl_list_modify(l, key, value);
   sl_list_add(l, key, value);
 }
 
diff --git a/src/include/macros.h b/src/include/macros.h
index ee89597..bbf541e 100644
--- a/src/include/macros.h
+++ b/src/include/macros.h
@@ -82,4 +82,6 @@
 #define COLOR_RESET "\e[0m"
 
 void die(char *message);
+
+char *char_to_string(char c);
 #endif
diff --git a/src/lexer.c b/src/lexer.c
index e58197a..4e03a02 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -57,13 +57,6 @@ static bool is_valid_id_char(char c) {
   return true;
 }
 
-static char *char_to_string(char c) {
-  char *s = (char *)malloc(2 * sizeof(char));
-  s[0] = c;
-  s[1] = '\0';
-  return s;
-}
-
 token_t *lexer_collect_bool(lexer_t *lexer) {
   lexer_move(lexer);
   if (lexer->c == 't') {
@@ -158,7 +151,6 @@ start:
     return lexer_move_with(
         lexer, init_token(TOKEN_PERIOD, ".", lexer->row, lexer->col));
   else {
-    printf("returns null\n");
     return NULL;
   }
 }
diff --git a/src/macros.c b/src/macros.c
index 1effefe..1643168 100644
--- a/src/macros.c
+++ b/src/macros.c
@@ -8,3 +8,10 @@ void die(char *message) {
   fprintf(stderr, "%sFATAL ERROR: %s%s\n", RED, message, reset);
   exit(EXIT_FAILURE);
 }
+
+char *char_to_string(char c) {
+  char *s = malloc(2);
+  s[0] = c;
+  s[1] = '\0';
+  return s;
+}
diff --git a/src/main.c b/src/main.c
index c75ef85..ba710bf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -12,9 +12,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-// Read the file into allocated memory.
-// Return NULL on error.
-
 int main(int argc, char **argv) {
   /* DONE: TEST LEXER */
   /* lexer_t *lexer = init_lexer("'(fasd asdf)"); */
@@ -134,6 +131,8 @@ int main(int argc, char **argv) {
   if (strcmp(argv[1], "-v") == 0 || strcmp(argv[1], "--version") == 0) {
     printf("nxs, version 1.2 alpha\n");
     exit(0);
+  } else if (strcmp(argv[1], "-r") == 0 || strcmp(argv[1], "--repl") == 0) {
+    /* Start a REPL */
   }
 
   char *filename = argv[1];
@@ -145,13 +144,13 @@ int main(int argc, char **argv) {
     fseek(f, 0, SEEK_END);
     length = ftell(f);
     fseek(f, 0, SEEK_SET);
-    buffer = malloc(length);
+    buffer = malloc(length + 1);
     if (buffer) {
       fread(buffer, 1, length, f);
     }
     fclose(f);
   }
-
+  buffer[length] = '\0';
   if (buffer) {
     /* lexer_t *lexer = init_lexer(buffer); */
     /* token_t *t = lexer_collect_next(lexer); */
@@ -163,7 +162,7 @@ int main(int argc, char **argv) {
     lexer_t *lexer = init_lexer(buffer);
     parser_t *parser = init_parser(lexer);
     visitor_t *visitor = init_visitor(parser);
-    ast_t *root = eval(visitor);
+    eval(visitor);
     /* print_root(root); */
   }
 
diff --git a/src/parser.c b/src/parser.c
index 157bc4d..0f1ba69 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -30,6 +30,7 @@ parser_t *init_parser_copy_hash(lexer_t *lexer, hash_table_t *h) {
     p->tokens[size - 1] = t;
     if (t == NULL)
       break;
+    /* printf("%d: %s\n", t->type, t->value); */
   }
   p->size = size;
   return p;
@@ -185,7 +186,7 @@ ast_t *parse_include(parser_t *parser) {
     fseek(f, 0, SEEK_END);
     length = ftell(f);
     fseek(f, 0, SEEK_SET);
-    buffer = malloc(length);
+    buffer = malloc(length + 1);
     if (buffer) {
       fread(buffer, 1, length, f);
     }
@@ -194,6 +195,7 @@ ast_t *parse_include(parser_t *parser) {
     parser_error(parser);
   }
   if (buffer) {
+    buffer[length] = '\0';
     lexer_t *lexer = init_lexer(buffer);
     parser_t *p = init_parser_copy_hash(lexer, parser->symbol_table);
     ast_t *root = parse_all(p);
diff --git a/src/visitor.c b/src/visitor.c
index 6fd487a..65af934 100644
--- a/src/visitor.c
+++ b/src/visitor.c
@@ -449,6 +449,60 @@ ast_t *eval_list(visitor_t *v, ast_t *e) {
       print(arg1);
       printf("\n");
       return arg1;
+    } else if (strcmp(function->string_value, "read") == 0) {
+      if (cmp != 1)
+        eval_error(v, e);
+
+      ast_t *arg1 = eval_expr(v, args->car);
+      if (arg1->type == AST_STRING) {
+        char *buffer = 0;
+        long length;
+        FILE *f = fopen(arg1->string_value, "rb");
+
+        if (f) {
+          fseek(f, 0, SEEK_END);
+          length = ftell(f);
+          fseek(f, 0, SEEK_SET);
+          buffer = malloc(length);
+          if (buffer) {
+            fread(buffer, 1, length, f);
+          }
+          fclose(f);
+        } else {
+          eval_error(v, e);
+        }
+
+        if (buffer) {
+          return init_ast_string(buffer);
+        } else {
+          eval_error(v, e);
+        }
+      }
+    } else if (strcmp(function->string_value, "bound?") == 0) {
+      if (cmp != 1)
+        eval_error(v, e);
+
+      ast_t *arg1 = eval_expr(v, args->car);
+
+      if (arg1->type == AST_SYMBOL) {
+        if (hash_table_exists(v->p->symbol_table, arg1->string_value)) {
+          return init_ast_bool(true);
+        }
+        return init_ast_bool(false);
+      } else
+        eval_error(v, e);
+    } else if (strcmp(function->string_value, "at") == 0) {
+      if (cmp != 2)
+        eval_error(v, e);
+
+      ast_t *arg1 = eval_expr(v, args->car);
+      ast_t *arg2 = eval_expr(v, args->cdr->car);
+      if (arg1->type == AST_STRING && arg2->type == AST_INT &&
+          arg2->int_value < strlen(arg1->string_value)) {
+        return init_ast_string(
+            char_to_string(arg1->string_value[arg2->int_value]));
+      } else
+        eval_error(v, e);
     }
 
     return NULL;
diff --git a/stdlib/math.nxs b/stdlib/math.nxs
new file mode 100644
index 0000000..f913d82
--- /dev/null
+++ b/stdlib/math.nxs
@@ -0,0 +1,20 @@
+;; some bootstrapping needed in order to obtain more complicated functions;
+;; the power series requires a factorial and integer power function
+(bind powi (lambda (x y)
+	(if (= y 1)
+	x
+	(* x (pow x (- y 1)))
+)))
+(bind factorial (lambda (n)
+        (if (= n 0) 1 (* n (factorial (print(- n 1)))))))
+
+;; complicated functions
+(bind exp (lambda (x) x))
+
+(bind ln (lambda (x) x))
+
+(bind sin (lambda (x) x))
+
+(bind cos (lambda (x) x))
+
+(bind tan (lambda (x) (/ (sin x) (cos x))))