replaced many `dynamic_cast` to `static_cast`

3 files changed, 27 insertions, 18 deletions

diff --git a/builtin.cpp b/builtin.cpp
index 75f470e..1ac0cf2 100644
--- a/builtin.cpp
+++ b/builtin.cpp
@@ -53,7 +53,8 @@ void SpecialOptIf::prepare(Cons *pc) {
 
 void SpecialOptIf::pre_call(ArgList *args, Cons *pc,
         Environment *envt) {
-    pc = dynamic_cast<Cons*>(pc->car); 
+    // static_cast because it's a call invocation
+    pc = static_cast<Cons*>(pc->car); 
     // Condition evaluated and the decision is made
     state = 1;
     if (args->cdr->car->is_true())
@@ -82,7 +83,7 @@ EvalObj *SpecialOptIf::post_call(ArgList *args, Cons *pc,
 
 Cons *SpecialOptIf::call(ArgList *args, Environment * &envt, 
                         Continuation * &cont, FrameObj ** &top_ptr) {
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
     if (state) 
     {
         *top_ptr++ = post_call(args, ret_addr, envt);
@@ -93,7 +94,8 @@ Cons *SpecialOptIf::call(ArgList *args, Environment * &envt,
         pre_call(args, ret_addr, envt);
         top_ptr += 2;
         // Undo pop and invoke again
-        return dynamic_cast<Cons*>(ret_addr->car)->next;
+        // static_cast because it's a call invocation
+        return static_cast<Cons*>(ret_addr->car)->next;
     }
 }
 
@@ -116,8 +118,8 @@ void SpecialOptLambda::prepare(Cons *pc) {
 
 Cons *SpecialOptLambda::call(ArgList *args, Environment * &envt, 
                             Continuation * &cont, FrameObj ** &top_ptr) {
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
-    Cons *pc = dynamic_cast<Cons*>(ret_addr->car);
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
+    Cons *pc = static_cast<Cons*>(ret_addr->car);
     SymbolList *para_list = dynamic_cast<SymbolList*>(pc->cdr->car);  // parameter list
     // Clear the flag to avoid side-effects (e.g. proc calling)
     FILL_MARKS(pc, false);
@@ -150,8 +152,8 @@ void SpecialOptDefine::prepare(Cons *pc) {
 
 Cons *SpecialOptDefine::call(ArgList *args, Environment * &envt, 
         Continuation * &cont, FrameObj ** &top_ptr) {
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
-    Cons *pc = dynamic_cast<Cons*>(ret_addr->car);
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
+    Cons *pc = static_cast<Cons*>(ret_addr->car);
     EvalObj *obj;
     SymObj *id;
     // TODO: check identifier
@@ -162,7 +164,8 @@ Cons *SpecialOptDefine::call(ArgList *args, Environment * &envt,
     }
     else
     {
-        Cons *plst = dynamic_cast<Cons*>(pc->cdr->car);
+        // static_cast because of is_simple_obj() is false
+        Cons *plst = static_cast<Cons*>(pc->cdr->car);
         id = dynamic_cast<SymObj*>(plst->car);
         ArgList *para_list = plst->cdr;
         // Clear the flag to avoid side-effects (e.g. proc calling)
@@ -192,8 +195,8 @@ void SpecialOptSet::prepare(Cons *pc) {
 
 Cons *SpecialOptSet::call(ArgList *args, Environment * &envt, 
                             Continuation * &cont, FrameObj ** &top_ptr) {
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
-    Cons *pc = dynamic_cast<Cons*>(ret_addr->car);
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
+    Cons *pc = static_cast<Cons*>(ret_addr->car);
     SymObj *id = dynamic_cast<SymObj*>(pc->cdr->car);
     bool flag = envt->add_binding(id, args->cdr->car, false);
     // TODO: throw an exc "unbound variable"
diff --git a/eval.cpp b/eval.cpp
index 44569c1..e536f8f 100644
--- a/eval.cpp
+++ b/eval.cpp
@@ -34,14 +34,16 @@ void push(Cons * &pc, FrameObj ** &top_ptr, Environment *envt) {
     if (pc->car->is_simple_obj())           // Not an opt invocation
     {
         *top_ptr = envt->get_obj(pc->car);  // Objectify the symbol
-        dynamic_cast<EvalObj*>(*top_ptr)->prepare(pc);
+        // static_cast because of is_simple_obj() is true
+        static_cast<EvalObj*>(*top_ptr)->prepare(pc);
         top_ptr++;
         pc = pc->next;                      // Move to the next instruction
     }
     else                                    // Operational Invocation
     {
         *top_ptr++ = new RetAddr(pc);       // Push the return address
-        pc = dynamic_cast<Cons*>(pc->car);  // Go deeper to enter the call
+        // static_cast because of is_simple_obj() is false
+        pc = static_cast<Cons*>(pc->car);  // Go deeper to enter the call
     }
 }
 
@@ -67,8 +69,9 @@ EvalObj *Evaluator::run_expr(Cons *prog) {
         {
             Cons *args = empty_list;
             while (!(*(--top_ptr))->is_ret_addr())
-                args = new Cons(dynamic_cast<EvalObj*>(*top_ptr), args);
-            RetAddr *ret_addr = dynamic_cast<RetAddr*>(*top_ptr);
+                args = new Cons(static_cast<EvalObj*>(*top_ptr), args);
+                //< static_cast because the while condition
+            RetAddr *ret_addr = static_cast<RetAddr*>(*top_ptr);
             if (!ret_addr->addr)
             {
                 Cons *nexp = cont->proc_body->cdr;
@@ -87,5 +90,6 @@ EvalObj *Evaluator::run_expr(Cons *prog) {
                 pc = dynamic_cast<OptObj*>(args->car)->call(args, envt, cont, top_ptr);
         }
     }
-    return dynamic_cast<EvalObj*>(*(eval_stack));
+    // static_cast because the previous while condition
+    return static_cast<EvalObj*>(*(eval_stack));
 }
diff --git a/model.cpp b/model.cpp
index 95f70c6..9ecd5f7 100644
--- a/model.cpp
+++ b/model.cpp
@@ -88,14 +88,16 @@ ProcObj::ProcObj(ASTList *_body,
 Cons *ProcObj::call(ArgList *args, Environment * &_envt,
                     Continuation * &cont, FrameObj ** &top_ptr) {
     // Create a new continuation
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
+    // static_cast see `call` invocation in eval.cpp
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
     Continuation *ncont = new Continuation(_envt, ret_addr, cont, body);
     cont = ncont;                   // Add to the cont chain
     _envt = new Environment(envt);   // Create local env and recall the closure
     // TODO: Compare the arguments to the parameters
+    // static_cast<SymObj*> because the para_list is already checked
     for (Cons *ptr = args->cdr, *ppar = para_list; 
             ptr != empty_list; ptr = ptr->cdr, ppar = ppar->cdr)
-        _envt->add_binding(dynamic_cast<SymObj*>(ppar->car), ptr->car);
+        _envt->add_binding(static_cast<SymObj*>(ppar->car), ptr->car);
     *top_ptr++ = new RetAddr(NULL);   // Mark the entrance of a cont
     return body;                    // Move pc to the proc entry point
 }
@@ -116,7 +118,7 @@ BuiltinProcObj::BuiltinProcObj(BuiltinProc f, string _name) :
 Cons *BuiltinProcObj::call(ArgList *args, Environment * &envt,
                                 Continuation * &cont, FrameObj ** &top_ptr) {
 
-    Cons *ret_addr = dynamic_cast<RetAddr*>(*top_ptr)->addr;
+    Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr;
     *top_ptr++ = handler(args->cdr);
     return ret_addr->next;          // Move to the next instruction
 }