Allow object as string

src/expression.jsx

@@ -994,6 +994,9 @@ class AsExpression extends UnaryExpression {
 				// ok
 				success = true;
 			}
+		} else if (this._type.equals(Type.stringType)) {
+			// ok: any-but-null => string
+			success = true;
 		} else if (exprType instanceof PrimitiveType) {
 			if (this._type instanceof PrimitiveType) {
 				// ok: primitive => primitive

src/jsemitter.jsx

@@ -1648,6 +1648,11 @@ class _AsExpressionEmitter extends _ExpressionEmitter {
 				new _AsNoConvertExpressionEmitter(this._emitter, new AsNoConvertExpression(this._expr.getToken(), this._expr.getExpr(), this._expr.getType())).emit(outerOpPrecedence);
 				return;
 			}
+			if (destType.equals(Type.stringType)) {
+				var prec = _AdditiveExpressionEmitter._operatorPrecedence;
+				this._emitWithParens(outerOpPrecedence, prec, prec, null, " + \"\"");
+				return;
+			}
 		}
 		if (srcType.resolveIfNullable().equals(Type.booleanType)) {
 			// from boolean

t/run/346.object-as-string.jsx

@@ -0,0 +1,18 @@
+/*EXPECTED
+foo
+null
+*/
+
+class _Main {
+  override function toString() : string {
+    return "foo";
+  }
+
+  static function main(args : string[]) : void {
+    var object = new _Main;
+    log object as string;
+    object = null;
+    log object as string;
+  }
+}
+// vim: set expandtab tabstop=2 shiftwidth=2 ft=jsx:

t/run/347.generic-as-string.jsx

@@ -0,0 +1,29 @@
+/*EXPECTED
+C: foo
+C: _Main
+C: null
+*/
+
+class C.<T> {
+  var value : T;
+  function constructor(value : T) {
+    this.value = value;
+  }
+
+  function debugLog() : void {
+    log "C: " + this.value as string;
+  }
+}
+
+class _Main {
+  override function toString() : string {
+    return "_Main";
+  }
+
+  static function main(args : string[]) : void {
+    new C.<string>("foo").debugLog();
+    new C.<_Main>(new _Main).debugLog();
+    new C.<_Main>(null).debugLog();
+  }
+}
+// vim: set expandtab tabstop=2 shiftwidth=2 ft=jsx: