add OP_LAMBDA (lambda object creation)

include/picrin.h

@@ -16,10 +16,10 @@ typedef struct {
   pic_value *sp;
   pic_value *stbase, *stend;
 
-  pic_value sDEFINE, sCONS;
   pic_callinfo *ci;
   pic_callinfo *cibase, *ciend;
 
+  pic_value sDEFINE, sLAMBDA, sCONS;
   pic_value sADD, sSUB, sMUL, sDIV;
   struct pic_env *global_env;
 

include/picrin/irep.h

@@ -8,6 +8,8 @@ enum pic_instruction {
   OP_GREF,
   OP_GSET,
   OP_CALL,
+  OP_RET,
+  OP_LAMBDA,
   OP_CONS,
   OP_ADD,
   OP_SUB,
@@ -28,6 +30,9 @@ struct pic_code {
 struct pic_irep {
   struct pic_code *code;
   size_t clen, ccapa;
+
+  struct pic_irep **proto;
+  size_t plen, pcapa;
 };
 
 #endif