implement load procedure

src/init.c

@@ -23,6 +23,7 @@ void pic_init_error(pic_state *);
 void pic_init_str(pic_state *);
 void pic_init_macro(pic_state *);
 void pic_init_var(pic_state *);
+void pic_init_load(pic_state *);
 
 void
 pic_load_stdlib(pic_state *pic)
@@ -126,6 +127,7 @@ pic_init_core(pic_state *pic)
   pic_init_str(pic); DONE;
   pic_init_macro(pic); DONE;
   pic_init_var(pic); DONE;
+  pic_init_load(pic); DONE;
 
   pic_load_stdlib(pic); DONE;
 

src/load.c

@@ -0,0 +1,58 @@
+#include "picrin.h"
+#include "picrin/pair.h"
+
+pic_value
+pic_load(pic_state *pic, const char *fn)
+{
+  FILE *file;
+  int n, i, ai;
+  pic_value v, vs;
+  struct pic_proc *proc;
+
+  file = fopen(fn, "r");
+  if (file == NULL) {
+    pic_error(pic, "load: could not read file");
+  }
+
+  n = pic_parse_file(pic, file, &vs);
+  if (n < 0) {
+    pic_error(pic, "load: parse failure");
+  }
+
+  ai = pic_gc_arena_preserve(pic);
+  for (i = 0; i < n; ++i, vs = pic_cdr(pic, vs)) {
+    v = pic_car(pic, vs);
+
+    proc = pic_codegen(pic, v);
+    if (proc == NULL) {
+      pic_error(pic, "load: compilation failure");
+    }
+
+    v = pic_apply(pic, proc, pic_nil_value());
+    if (pic_undef_p(v)) {
+      pic_error(pic, "load: evaluation failure");
+    }
+
+    pic_gc_arena_restore(pic, ai);
+  }
+
+  return pic_none_value();
+}
+
+static pic_value
+pic_load_load(pic_state *pic)
+{
+  pic_value envid;
+  char *fn;
+  size_t len;
+
+  pic_get_args(pic, "s|o", &fn, &len, &envid);
+
+  return pic_load(pic, fn);
+}
+
+void
+pic_init_load(pic_state *pic)
+{
+  pic_defun(pic, "load", pic_load_load);
+}