Revert "remove file.c"

This reverts commit 4cf8f3d7f6.

file.c

@@ -0,0 +1,119 @@
+/**
+ * See Copyright Notice in picrin.h
+ */
+
+#include "picrin.h"
+#include "picrin/port.h"
+#include "picrin/error.h"
+
+static noreturn void
+file_error(pic_state *pic, const char *msg)
+{
+  pic_throw(pic, PIC_ERROR_FILE, msg, pic_nil_value());
+}
+
+static pic_value
+generic_open_file(pic_state *pic, const char *fname, char *mode, short flags)
+{
+  struct pic_port *port;
+  xFILE *file;
+
+  file = xfopen(fname, mode);
+  if (! file) {
+    file_error(pic, "could not open file");
+  }
+
+  port = (struct pic_port *)pic_obj_alloc(pic, sizeof(struct pic_port), PIC_TT_PORT);
+  port->file = file;
+  port->flags = flags;
+  port->status = PIC_PORT_OPEN;
+
+  return pic_obj_value(port);
+}
+
+pic_value
+pic_file_open_input_file(pic_state *pic)
+{
+  static const short flags = PIC_PORT_IN | PIC_PORT_TEXT;
+  char *fname;
+
+  pic_get_args(pic, "z", &fname);
+
+  return generic_open_file(pic, fname, "r", flags);
+}
+
+pic_value
+pic_file_open_input_binary_file(pic_state *pic)
+{
+  static const short flags = PIC_PORT_IN | PIC_PORT_BINARY;
+  char *fname;
+
+  pic_get_args(pic, "z", &fname);
+
+  return generic_open_file(pic, fname, "rb", flags);
+}
+
+pic_value
+pic_file_open_output_file(pic_state *pic)
+{
+  static const short flags = PIC_PORT_OUT | PIC_PORT_TEXT;
+  char *fname;
+
+  pic_get_args(pic, "z", &fname);
+
+  return generic_open_file(pic, fname, "w", flags);
+}
+
+pic_value
+pic_file_open_output_binary_file(pic_state *pic)
+{
+  static const short flags = PIC_PORT_OUT | PIC_PORT_BINARY;
+  char *fname;
+
+  pic_get_args(pic, "z", &fname);
+
+  return generic_open_file(pic, fname, "wb", flags);
+}
+
+pic_value
+pic_file_exists_p(pic_state *pic)
+{
+  char *fname;
+  FILE *fp;
+
+  pic_get_args(pic, "z", &fname);
+
+  fp = fopen(fname, "r");
+  if (fp) {
+    fclose(fp);
+    return pic_true_value();
+  } else {
+    return pic_false_value();
+  }
+}
+
+pic_value
+pic_file_delete(pic_state *pic)
+{
+  char *fname;
+
+  pic_get_args(pic, "z", &fname);
+
+  if (remove(fname) != 0) {
+    file_error(pic, "file cannot be deleted");
+  }
+  return pic_none_value();
+}
+
+void
+pic_init_file(pic_state *pic)
+{
+  pic_deflibrary (pic, "(scheme file)") {
+    pic_defun(pic, "open-input-file", pic_file_open_input_file);
+    pic_defun(pic, "open-input-binary-file", pic_file_open_input_binary_file);
+    pic_defun(pic, "open-output-file", pic_file_open_output_file);
+    pic_defun(pic, "open-output-binary-file", pic_file_open_output_binary_file);
+    pic_defun(pic, "file-exists?", pic_file_exists_p);
+    pic_defun(pic, "delete-file", pic_file_delete);
+  }
+}

init.c

@@ -12,6 +12,7 @@ void pic_init_bool(pic_state *);
 void pic_init_pair(pic_state *);
 void pic_init_port(pic_state *);
 void pic_init_number(pic_state *);
+void pic_init_file(pic_state *);
 void pic_init_proc(pic_state *);
 void pic_init_symbol(pic_state *);
 void pic_init_vector(pic_state *);
@@ -48,6 +49,7 @@ pic_init_core(pic_state *pic)
     pic_init_pair(pic); DONE;
     pic_init_port(pic); DONE;
     pic_init_number(pic); DONE;
+    pic_init_file(pic); DONE;
     pic_init_proc(pic); DONE;
     pic_init_symbol(pic); DONE;
     pic_init_vector(pic); DONE;