4 files changed, 57 insertions, 1 deletions

diff --git a/src/include/nxspp.h b/src/include/nxspp.h
index d60832f..d88ab57 100644
--- a/src/include/nxspp.h
+++ b/src/include/nxspp.h
@@ -1,4 +1,12 @@
 #ifndef NXSPP_H
 #define NXSPP_H
 
+typedef struct {
+  char *source;
+  char c;
+  int i;
+} npp_t;
+
+npp_t *init_npp(char *source);
+char *process_string(npp_t *p);
 #endif
diff --git a/src/nxspp.c b/src/nxspp.c
new file mode 100644
index 0000000..7888cbb
--- /dev/null
+++ b/src/nxspp.c
@@ -0,0 +1,24 @@
+#include "./include/nxspp.h"
+#include "./include/macros.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+npp_t *init_npp(char *source) {
+  npp_t *n = malloc(sizeof(npp_t));
+  if (n == NULL)
+    die("malloc on nxspp");
+  n->source = source;
+  n->i = 0;
+  n->c = source[n->i];
+  return n;
+}
+
+char *nxspp_collect_id(char *source, int i) {}
+
+void npp_move(npp_t *p) {
+  if (p->c != '\0') {
+    p->i++;
+    p->c = p->source[p->i];
+  }
+}
diff --git a/src/parser.c b/src/parser.c
index 6a77e87..0a2b213 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -133,6 +133,8 @@ void parse_bind(parser_t *parser) {
                                        hash table transfers to visitor JIT */
   if (expr == NULL)
     parser_error(parser);
+  if (expr->type == AST_ROOT)
+    parser_error(parser);
   hash_table_add(parser->symbol_table, name, expr);
   if (parser->tokens[parser->i]->type != TOKEN_RPAREN)
     parser_error(parser);
@@ -140,6 +142,8 @@ void parse_bind(parser_t *parser) {
   parser_move(parser);
 }
 
+ast_t *parse_include(parser_t *parser) { parser_eat(parser, TOKEN_STRING); }
+
 ast_t *parse_list(parser_t *parser) {
   ast_t *car;
   ast_t *head = init_ast_pair(NULL, NULL);
@@ -162,6 +166,8 @@ ast_t *parse_list(parser_t *parser) {
       car = parse_expr(parser);
       if (car == NULL)
         parser_error(parser);
+      if (car->type == AST_ROOT)
+        parser_error(parser);
     }
     cur->car = car;
     cur->cdr = init_ast_pair(NULL, NULL);
@@ -179,6 +185,8 @@ ast_t *parse_quote(parser_t *parser) {
   ast_t *expr = parse_expr(parser);
   if (expr == NULL)
     parser_error(parser);
+  if (expr->type == AST_ROOT)
+    parser_error(parser);
   ast_t *ret = init_ast_pair(
       car, init_ast_pair(
                expr, init_ast_pair(NULL, NULL))); /* Converts ' to `quote` */
diff --git a/src/visitor.c b/src/visitor.c
index 14ea404..25fb7cd 100644
--- a/src/visitor.c
+++ b/src/visitor.c
@@ -60,6 +60,10 @@ bool is_built_in(ast_t *e) {
       strcmp(cmp, "atof") == 0 || strcmp(cmp, "ftoa") == 0)
     return true;
 
+  /* I/O and other operating system stuff */
+  if (strcmp(cmp, "exit") == 0 || strcmp(cmp, "readin") == 0 ||
+      strcmp(cmp, "read") == 0)
+    return true;
   return false;
 }
 
@@ -422,10 +426,22 @@ ast_t *eval_list(visitor_t *v, ast_t *e) {
         char *ret = malloc((string_len1 + string_len2) * sizeof(char));
         strcat(ret, arg1->string_value);
         strcat(ret, arg2->string_value);
-        return ret;
+        return init_ast_string(ret);
+      } else
+        eval_error(v, e);
+    } else if (strcmp(function->string_value, "exit") == 0) {
+      if (cmp != 1)
+        eval_error(v, e);
+
+      ast_t *arg1 = eval_expr(v, args->car);
+
+      if (arg1->type == AST_INT) {
+        int code = arg1->int_value;
+        exit(code);
       } else
         eval_error(v, e);
     }
+    return NULL;
   }
 
   /* printf("debug 2\n"); */