null argument to support print w/o newline|new EMIT fn for BASIC

assets/tbas/basic.js

@@ -123,12 +123,12 @@ function parseSigil(s) {
 function resolve(variable) {
     if (variable.type == "string" || variable.type == "number")
         return variable.value;
-    else if (variable.type == "literal") {
+    else if (variable.type == "literal")
         return basicInterpreterStatus.variables[parseSigil(variable.value).name].literal;
-    }
-    else {
+    else if (variable.type == "null")
+        return undefined;
+    else
         throw "InternalError: unknown variable with type "+variable.type+", with value "+variable.value
-    }
 }
 var basicInterpreterStatus = {};
 basicInterpreterStatus.gosubStack = [];
@@ -237,11 +237,33 @@ basicInterpreterStatus.builtin = {
 
     if (args.length == 0)
         println();
-    else
-        println(args.map(function(it) {
-            var it2 = resolve(it);
-            return ((!isNaN(it2)) ? " " : "") + it2; // BASIC always put a space before a number
-        }).join("\t"));
+    else {
+        if (args[args.length - 1].type == "null") {
+            print(args.slice(0, args.length - 1).map(function(it) {
+                var it2 = resolve(it);
+                return ((!isNaN(it2)) ? " " : "") + it2; // BASIC always put a space before a number
+            }).join("\t"));
+        }
+        else {
+            println(args.map(function(it) {
+                var it2 = resolve(it);
+                return ((!isNaN(it2)) ? " " : "") + it2; // BASIC always put a space before a number
+            }).join("\t"));
+        }
+    }
+},
+"EMIT" : function(lnum, args) {
+    if (args.length > 0) {
+        for (var llll = 0; llll < args.length; llll++) {
+            var lvalll = resolve(args[llll]);
+            if (isNaN(lvalll)) {
+                print(lvalll);
+            }
+            else {
+                con.addch(lvalll);
+            }
+        }
+    }
 },
 "POKE" : function(lnum, args) {
     if (args.length != 2) throw lang.syntaxfehler(lnum);
@@ -1040,7 +1062,7 @@ basicFunctions._executeSyntaxTree = function(lnum, syntaxTree, recDepth) {
     if (_debugExec) serial.println(recWedge+"@@ EXECUTE @@");
 
     if (syntaxTree === undefined)
-        throw "InternalError: tree is undefined";
+        return new SyntaxTreeReturnObj("null", undefined, lnum + 1);
     else if (syntaxTree.type == "function" || syntaxTree.type == "operator") {
         if (_debugExec) serial.println(recWedge+"function|operator");
         if (_debugExec) serial.println(recWedge+syntaxTree.toString());

src/net/torvald/tsvm/GraphicsJSR223Delegate.kt

@@ -71,6 +71,8 @@ class GraphicsJSR223Delegate(val vm: VM) {
     fun putSymbol(char: Byte) {
         getFirstGPU()?.let {
             val (cx, cy) = it.getCursorPos()
+
+
             it.putChar(cx, cy, char)
             it.setCursorPos(cx + 1, cy)
         }

src/net/torvald/tsvm/peripheral/GlassTty.kt

@@ -34,13 +34,7 @@ abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
     abstract fun putChar(x: Int, y: Int, text: Byte, foreColour: Byte = ttyFore.toByte(), backColour: Byte = ttyBack.toByte())
 
     fun writeOut(char: Byte) {
-        // deal with y-axis out-of-bounds
-        var (cx, cy) = getCursorPos()
-        if (cy >= TEXT_ROWS) {
-            scrollUp(cy - TEXT_ROWS + 1)
-            setCursorPos(cx, TEXT_ROWS - 1)
-            cy = TEXT_ROWS - 1
-        }
+        val (cx, cy) = getCursorPos()
 
         val printable = acceptChar(char) // this function processes the escape codes and CRLFs
 

src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt

@@ -69,11 +69,7 @@ class GraphicsAdapter(val vm: VM, val lcdMode: Boolean = false, lcdInvert: Boole
         set(value) { spriteAndTextArea.setShort(memTextCursorPosOffset, value.toShort()) }
 
     override fun getCursorPos() = rawCursorPos % TEXT_COLS to rawCursorPos / TEXT_COLS
-    /**
-     * Think of it as a real paper tty;
-     * setCursorPos must "wrap" the cursor properly when x-value goes out of screen bound.
-     * For y-value, only when y < 0, set y to zero and don't care about the y-value goes out of bound.
-     */
+
     override fun setCursorPos(x: Int, y: Int) {
         var newx = x
         var newy = y
@@ -89,6 +85,11 @@ class GraphicsAdapter(val vm: VM, val lcdMode: Boolean = false, lcdInvert: Boole
         if (newy < 0) {
             newy = 0 // DON'T SCROLL when cursor goes ABOVE the screen
         }
+        else if (newy >= TEXT_ROWS) {
+            scrollUp(newy - TEXT_ROWS + 1)
+            setCursorPos(newy, TEXT_ROWS - 1)
+            newy = TEXT_ROWS - 1
+        }
 
         rawCursorPos = toTtyTextOffset(newx, newy)
     }