Version 0.28 : Ternary operator

Rudimentary call stack on error
                   Added String Character functions
                   Added shift operators

TinyJS.cpp

@@ -88,14 +88,18 @@
                    Add built-in array functions
    Version 0.27 :  Added OZLB's TinyJS.setVariable (with some tweaks)
                    Added OZLB's Maths Functions
+   Version 0.28 :  Ternary operator
+                   Rudimentary call stack on error
+                   Added String Character functions
+                   Added shift operators
 
 
     NOTE: This doesn't support constructors for objects
+          Constructing an array with an initial length 'Array(5)' doesn't work
           Recursive loops of data such as a.foo = a; fail to be garbage collected
-          'length' cannot be set
+          length variable cannot be set
-          There is no ternary operator implemented yet
+          The postfix increment operator returns the current value, not the previous as it should.
-          The postfix increment operator returns the current value, not the
+          There is no prefix increment operator
-             previous as it should.
           Arrays are implemented as a linked list - hence a lookup time is O(n)
 
     TODO:
@@ -341,6 +345,7 @@ string CScriptLex::getTokenStr(int token) {
         case LEX_LSHIFTEQUAL : return "<<=";
         case LEX_GEQUAL : return ">=";
         case LEX_RSHIFT : return ">>";
+        case LEX_RSHIFTUNSIGNED : return ">>";
         case LEX_RSHIFTEQUAL : return ">>=";
         case LEX_PLUSEQUAL : return "+=";
         case LEX_MINUSEQUAL : return "-=";
@@ -545,9 +550,12 @@ void CScriptLex::getNextToken() {
         } else if (tk=='>' && currCh=='>') {
             tk = LEX_RSHIFT;
             getNextCh();
-            if (currCh=='=') { // <<=
+            if (currCh=='=') { // >>=
               tk = LEX_RSHIFTEQUAL;
               getNextCh();
+            } else if (currCh=='>') { // >>>
+              tk = LEX_RSHIFTUNSIGNED;
+              getNextCh();
             }
         }  else if (tk=='+' && currCh=='=') {
             tk = LEX_PLUSEQUAL;
@@ -602,9 +610,9 @@ string CScriptLex::getSubString(int lastPosition) {
 CScriptLex *CScriptLex::getSubLex(int lastPosition) {
     int lastCharIdx = tokenLastEnd+1;
     if (lastCharIdx < dataEnd)
-        return new CScriptLex( this, lastPosition, lastCharIdx);
+        return new CScriptLex(this, lastPosition, lastCharIdx);
     else
-        return new CScriptLex( this, lastPosition, dataEnd );
+        return new CScriptLex(this, lastPosition, dataEnd );
 }
 
 string CScriptLex::getPosition(int pos) {
@@ -1290,6 +1298,9 @@ void CTinyJS::execute(const string &code) {
     CScriptLex *oldLex = l;
     vector<CScriptVar*> oldScopes = scopes;
     l = new CScriptLex(code);
+#ifdef TINYJS_CALL_STACK
+    call_stack.clear();
+#endif
     scopes.clear();
     scopes.push_back(root);
     try {
@@ -1297,9 +1308,15 @@ void CTinyJS::execute(const string &code) {
         while (l->tk) statement(execute);
     } catch (CScriptException *e) {
         ostringstream msg;
-        msg << "Error " << e->text << " at " << l->getPosition();
+        msg << "Error " << e->text;
+#ifdef TINYJS_CALL_STACK
+        for (int i=(int)call_stack.size()-1;i>=0;i--)
+          msg << "\n" << i << ": " << call_stack.at(i);
+#endif
+        msg << " at " << l->getPosition();
         delete l;
         l = oldLex;
+
         throw new CScriptException(msg.str());
     }
     delete l;
@@ -1312,6 +1329,9 @@ CScriptVarLink CTinyJS::evaluateComplex(const string &code) {
     vector<CScriptVar*> oldScopes = scopes;
 
     l = new CScriptLex(code);
+#ifdef TINYJS_CALL_STACK
+    call_stack.clear();
+#endif
     scopes.clear();
     scopes.push_back(root);
     CScriptVarLink *v = 0;
@@ -1323,10 +1343,16 @@ CScriptVarLink CTinyJS::evaluateComplex(const string &code) {
           if (l->tk!=LEX_EOF) l->match(';');
         } while (l->tk!=LEX_EOF);
     } catch (CScriptException *e) {
-        ostringstream msg;
+      ostringstream msg;
-        msg << "Error " << e->text << " at " << l->getPosition();
+      msg << "Error " << e->text;
-        delete l;
+#ifdef TINYJS_CALL_STACK
-        l = oldLex;
+      for (int i=(int)call_stack.size()-1;i>=0;i--)
+        msg << "\n" << i << ": " << call_stack.at(i);
+#endif
+      msg << " at " << l->getPosition();
+      delete l;
+      l = oldLex;
+
         throw new CScriptException(msg.str());
     }
     delete l;
@@ -1475,6 +1501,9 @@ CScriptVarLink *CTinyJS::factor(bool &execute) {
                 // add the function's execute space to the symbol table so we can recurse
                 CScriptVarLink *returnVarLink = functionRoot->addChild(TINYJS_RETURN_VAR);
                 scopes.push_back(functionRoot);
+#ifdef TINYJS_CALL_STACK
+                call_stack.push_back(a->name + " from " + l->getPosition());
+#endif
 
                 if (a->var->isNative()) {
                     ASSERT(a->var->jsCallback);
@@ -1500,7 +1529,9 @@ CScriptVarLink *CTinyJS::factor(bool &execute) {
                     if (exception)
                       throw exception;
                 }
-
+#ifdef TINYJS_CALL_STACK
+                if (!call_stack.empty()) call_stack.pop_back();
+#endif
                 scopes.pop_back();
                 /* get the real return var before we remove it from our function */
                 returnVar = new CScriptVarLink(returnVarLink->var);
@@ -1548,7 +1579,7 @@ CScriptVarLink *CTinyJS::factor(bool &execute) {
                 l->match(LEX_ID);
             } else if (l->tk == '[') { // ------------------------------------- Array Access
                 l->match('[');
-                CScriptVarLink *index = expression(execute);
+                CScriptVarLink *index = base(execute);
                 l->match(']');
                 if (execute) {
                   CScriptVarLink *child = a->var->findChildOrCreate(index->var->getString());
@@ -1719,8 +1750,25 @@ CScriptVarLink *CTinyJS::expression(bool &execute) {
     return a;
 }
 
+CScriptVarLink *CTinyJS::shift(bool &execute) {
+  CScriptVarLink *a = expression(execute);
+  if (l->tk==LEX_LSHIFT || l->tk==LEX_RSHIFT || l->tk==LEX_RSHIFTUNSIGNED) {
+    int op = l->tk;
+    l->match(op);
+    CScriptVarLink *b = base(execute);
+    int shift = execute ? b->var->getInt() : 0;
+    CLEAN(b);
+    if (execute) {
+      if (op==LEX_LSHIFT) a->var->setInt(a->var->getInt() << shift);
+      if (op==LEX_RSHIFT) a->var->setInt(a->var->getInt() >> shift);
+      if (op==LEX_RSHIFTUNSIGNED) a->var->setInt(((unsigned int)a->var->getInt()) >> shift);
+    }
+  }
+  return a;
+}
+
 CScriptVarLink *CTinyJS::condition(bool &execute) {
-    CScriptVarLink *a = expression(execute);
+    CScriptVarLink *a = shift(execute);
     CScriptVarLink *b;
     while (l->tk==LEX_EQUAL || l->tk==LEX_NEQUAL ||
            l->tk==LEX_TYPEEQUAL || l->tk==LEX_NTYPEEQUAL ||
@@ -1728,7 +1776,7 @@ CScriptVarLink *CTinyJS::condition(bool &execute) {
            l->tk=='<' || l->tk=='>') {
         int op = l->tk;
         l->match(l->tk);
-        b = expression(execute);
+        b = shift(execute);
         if (execute) {
             CScriptVar *res = a->var->mathsOp(b->var, op);
             CREATE_LINK(a,res);
@@ -1775,8 +1823,36 @@ CScriptVarLink *CTinyJS::logic(bool &execute) {
     return a;
 }
 
+CScriptVarLink *CTinyJS::ternary(bool &execute) {
+  CScriptVarLink *lhs = logic(execute);
+  bool noexec = false;
+  if (l->tk=='?') {
+    l->match('?');
+    if (!execute) {
+      CLEAN(lhs);
+      CLEAN(base(noexec));
+      l->match(':');
+      CLEAN(base(noexec));
+    } else {
+      bool first = lhs->var->getBool();
+      CLEAN(lhs);
+      if (first) {
+        lhs = base(execute);
+        l->match(':');
+        CLEAN(base(noexec));
+      } else {
+        CLEAN(base(noexec));
+        l->match(':');
+        lhs = base(execute);
+      }
+    }
+  }
+
+  return lhs;
+}
+
 CScriptVarLink *CTinyJS::base(bool &execute) {
-    CScriptVarLink *lhs = logic(execute);
+    CScriptVarLink *lhs = ternary(execute);
     if (l->tk=='=' || l->tk==LEX_PLUSEQUAL || l->tk==LEX_MINUSEQUAL) {
         /* If we're assigning to this and we don't have a parent,
          * add it to the symbol table root as per JavaScript. */
@@ -1846,27 +1922,31 @@ void CTinyJS::statement(bool &execute) {
          * hand side. Maybe just have a flag called can_create_var that we
          * set and then we parse as if we're doing a normal equals.*/
         l->match(LEX_R_VAR);
-        CScriptVarLink *a = 0;
+        while (l->tk != ';') {
-        if (execute)
+          CScriptVarLink *a = 0;
-          a = scopes.back()->findChildOrCreate(l->tkStr);
+          if (execute)
-        l->match(LEX_ID);
+            a = scopes.back()->findChildOrCreate(l->tkStr);
-        // now do stuff defined with dots
+          l->match(LEX_ID);
-        while (l->tk == '.') {
+          // now do stuff defined with dots
-            l->match('.');
+          while (l->tk == '.') {
-            if (execute) {
+              l->match('.');
-                CScriptVarLink *lastA = a;
+              if (execute) {
-                a = lastA->var->findChildOrCreate(l->tkStr);
+                  CScriptVarLink *lastA = a;
-            }
+                  a = lastA->var->findChildOrCreate(l->tkStr);
-            l->match(LEX_ID);
+              }
-        }
+              l->match(LEX_ID);
-        // sort out initialiser
+          }
-        if (l->tk == '=') {
+          // sort out initialiser
-            l->match('=');
+          if (l->tk == '=') {
-            CScriptVarLink *var = base(execute);
+              l->match('=');
-            if (execute)
+              CScriptVarLink *var = base(execute);
-                a->replaceWith(var);
+              if (execute)
-            CLEAN(var);
+                  a->replaceWith(var);
-        }
+              CLEAN(var);
+          }
+          if (l->tk != ';')
+            l->match(',');
+        }       
         l->match(';');
     } else if (l->tk==LEX_R_IF) {
         l->match(LEX_R_IF);

TinyJS.h

@@ -26,6 +26,9 @@
 #ifndef TINYJS_H
 #define TINYJS_H
 
+// If defined, this keeps a note of all calls and where from in memory. This is slower, but good for debugging
+#define TINYJS_CALL_STACK
+
 #ifdef _WIN32
 #ifdef _DEBUG
 #define _CRTDBG_MAP_ALLOC
@@ -40,6 +43,7 @@
 #define TRACE printf
 #endif // TRACE
 
+
 const int TINYJS_LOOP_MAX_ITERATIONS = 8192;
 
 enum LEX_TYPES {
@@ -58,6 +62,7 @@ enum LEX_TYPES {
     LEX_LSHIFTEQUAL,
     LEX_GEQUAL,
     LEX_RSHIFT,
+    LEX_RSHIFTUNSIGNED,
     LEX_RSHIFTEQUAL,
     LEX_PLUSEQUAL,
     LEX_MINUSEQUAL,
@@ -319,6 +324,10 @@ public:
 private:
     CScriptLex *l;             /// current lexer
     std::vector<CScriptVar*> scopes; /// stack of scopes when parsing
+#ifdef TINYJS_CALL_STACK
+    std::vector<std::string> call_stack; /// Names of places called so we can show when erroring
+#endif
+
     CScriptVar *stringClass; /// Built in string class
     CScriptVar *objectClass; /// Built in object class
     CScriptVar *arrayClass; /// Built in array class
@@ -328,8 +337,10 @@ private:
     CScriptVarLink *unary(bool &execute);
     CScriptVarLink *term(bool &execute);
     CScriptVarLink *expression(bool &execute);
+    CScriptVarLink *shift(bool &execute);
     CScriptVarLink *condition(bool &execute);
     CScriptVarLink *logic(bool &execute);
+    CScriptVarLink *ternary(bool &execute);
     CScriptVarLink *base(bool &execute);
     void block(bool &execute);
     void statement(bool &execute);

TinyJS_Functions.cpp

@@ -93,6 +93,15 @@ void scStringCharAt(CScriptVar *c, void *) {
       c->getReturnVar()->setString("");
 }
 
+void scStringCharCodeAt(CScriptVar *c, void *) {
+    string str = c->getParameter("this")->getString();
+    int p = c->getParameter("pos")->getInt();
+    if (p>=0 && p<(int)str.length())
+      c->getReturnVar()->setInt(str.at(p));
+    else
+      c->getReturnVar()->setInt(0);
+}
+
 void scStringSplit(CScriptVar *c, void *) {
     string str = c->getParameter("this")->getString();
     string sep = c->getParameter("separator")->getString();
@@ -111,6 +120,13 @@ void scStringSplit(CScriptVar *c, void *) {
       result->setArrayIndex(length++, new CScriptVar(str));
 }
 
+void scStringFromCharCode(CScriptVar *c, void *) {
+    char str[2];
+    str[0] = c->getParameter("char")->getInt();
+    str[1] = 0;
+    c->getReturnVar()->setString(str);
+}
+
 void scIntegerParseInt(CScriptVar *c, void *) {
     string str = c->getParameter("str")->getString();
     int val = strtol(str.c_str(),0,0);
@@ -206,6 +222,8 @@ void registerFunctions(CTinyJS *tinyJS) {
     tinyJS->addNative("function String.indexOf(search)", scStringIndexOf, 0); // find the position of a string in a string, -1 if not
     tinyJS->addNative("function String.substring(lo,hi)", scStringSubstring, 0);
     tinyJS->addNative("function String.charAt(pos)", scStringCharAt, 0);
+    tinyJS->addNative("function String.charCodeAt(pos)", scStringCharCodeAt, 0);
+    tinyJS->addNative("function String.fromCharCode(char)", scStringFromCharCode, 0);
     tinyJS->addNative("function String.split(separator)", scStringSplit, 0);
     tinyJS->addNative("function Integer.parseInt(str)", scIntegerParseInt, 0); // string to int
     tinyJS->addNative("function Integer.valueOf(str)", scIntegerValueOf, 0); // value of a single character

tests/test033.js

@@ -0,0 +1,5 @@
+// test for shift
+var a = (2<<2);
+var b = (16>>3);
+var c = (-1 >>> 16);
+result = a==8 && b==2 && c == 0xFFFF;

tests/test034.js

@@ -0,0 +1,3 @@
+// test for ternary
+
+result = (true?3:4)==3 && (false?5:6)==6;