support C# like as operator test the as operator

2007-08-20  Mathias Hasselmann  <mathias.hasselmann@gmx.de>

	* vala/valacastexpression.vala, gobject/valacodegenerator.vala,
	vala/parser.y, vala/scanner.l: support C# like as operator
	* tests/Makefile.am, tests/test-034.*: test the as operator

svn path=/trunk/; revision=489

ChangeLog

+2007-08-20  Mathias Hasselmann  <mathias.hasselmann@gmx.de>
+
+	* vala/valacastexpression.vala, gobject/valacodegenerator.vala,
+	vala/parser.y, vala/scanner.l: support C# like as operator
+	* tests/Makefile.am, tests/test-034.*: test the as operator 
+
 2007-08-20  Jürg Billeter  <j@bitron.ch>
 
 	* vala/valafield.vala: support cheader_filename attribute,

gobject/valacodegenerator.vala

@@ -2453,7 +2453,25 @@ public class Vala.CodeGenerator : CodeVisitor {
 	public override void visit_cast_expression (CastExpression! expr) {
 		if (expr.type_reference.data_type is Class || expr.type_reference.data_type is Interface) {
 			// GObject cast
-			expr.ccodenode = new InstanceCast ((CCodeExpression) expr.inner.ccodenode, expr.type_reference.data_type);
+			if (expr.is_silent_cast) {
+				var ccomma = new CCodeCommaExpression ();
+				var temp_decl = get_temp_variable_declarator (expr.inner.static_type);
+
+				temp_vars.add (temp_decl);
+
+				var ctemp = new CCodeIdentifier (temp_decl.name);
+				var cinit = new CCodeAssignment (ctemp, (CCodeExpression) expr.inner.ccodenode);
+				var ccheck = create_type_check (ctemp, expr.type_reference.data_type);
+				var ccast = new CCodeCastExpression (ctemp, expr.type_reference.get_cname ());
+				var cnull = new CCodeConstant ("NULL");
+
+				ccomma.append_expression (cinit);
+				ccomma.append_expression (new CCodeConditionalExpression (ccheck, ccast, cnull));
+	
+				expr.ccodenode = ccomma;
+			} else {
+				expr.ccodenode = new InstanceCast ((CCodeExpression) expr.inner.ccodenode, expr.type_reference.data_type);
+			}
 		} else {
 			expr.ccodenode = new CCodeCastExpression ((CCodeExpression) expr.inner.ccodenode, expr.type_reference.get_cname ());
 		}
@@ -2549,10 +2567,14 @@ public class Vala.CodeGenerator : CodeVisitor {
 		visit_expression (expr);
 	}
 
+	static CCodeFunctionCall create_type_check (CCodeNode! ccodenode, DataType! type) {
+		var ccheck = new CCodeFunctionCall (new CCodeIdentifier (type.get_upper_case_cname ("IS_")));
+		ccheck.add_argument ((CCodeExpression) ccodenode);
+		return ccheck;
+	}
+
 	public override void visit_type_check (TypeCheck! expr) {
-		var ccheck = new CCodeFunctionCall (new CCodeIdentifier (expr.type_reference.data_type.get_upper_case_cname ("IS_")));
-		ccheck.add_argument ((CCodeExpression) expr.expression.ccodenode);
-		expr.ccodenode = ccheck;
+		expr.ccodenode = create_type_check (expr.expression.ccodenode, expr.type_reference.data_type);
 	}
 
 	public override void visit_conditional_expression (ConditionalExpression! expr) {

tests/Makefile.am

@@ -66,6 +66,7 @@ TESTS = \
 	test-031.vala \
 	test-032.vala \
 	test-033.vala \
+	test-034.vala \
 	$(NULL)
 
 EXTRA_DIST = \
@@ -103,6 +104,7 @@ EXTRA_DIST = \
 	test-031.vala \
 	test-032.vala \
 	test-033.vala \
+	test-034.vala \
 	test-001.out \
 	test-002.out \
 	test-003.out \
@@ -136,6 +138,7 @@ EXTRA_DIST = \
 	test-031.out \
 	test-032.out \
 	test-033.out \
+	test-034.out \
 	\
 	testenchant.stamp \
 	testenchant.vala \

tests/test-034.out

+init: 1 1 1
+is A: 1 1 0
+is B: 0 1 0
+is C: 0 0 1
+as A: 1 1 0
+as B: 0 1 0
+as C: 0 0 1

tests/test-034.vala

+using GLib;
+
+class Maman.A {
+}
+
+class Maman.B : A {
+}
+
+class Maman.C {
+}
+
+class Maman.Bar {
+	static void main () {
+		var a = new A ();
+		var b = new B ();
+		var c = new C ();
+
+		stdout.printf ("init: %d %d %d\n", null != a, null != b, null != c);
+
+		stdout.printf ("is A: %d %d %d\n", a is A, b is A, c is A);
+		stdout.printf ("is B: %d %d %d\n", a is B, b is B, c is B);
+		stdout.printf ("is C: %d %d %d\n", a is C, b is C, c is C);
+
+		stdout.printf ("as A: %d %d %d\n", null != (a as A), null != (b as A), null != (c as A));
+		stdout.printf ("as B: %d %d %d\n", null != (a as B), null != (b as B), null != (c as B));
+		stdout.printf ("as C: %d %d %d\n", null != (a as C), null != (b as C), null != (c as C));
+	}
+}

vala/parser.y

@@ -149,6 +149,7 @@ static gboolean check_is_class (ValaSymbol *symbol, ValaSourceReference *src);
 %token PERCENT "%"
 
 %token ABSTRACT "abstract"
+%token AS "as"
 %token BASE "base"
 %token BREAK "break"
 %token CASE "case"
@@ -951,7 +952,7 @@ cast_expression
 	: OPEN_CAST_PARENS type CLOSE_PARENS unary_expression
 	  {
 		ValaSourceReference *src = src(@1);
-		$$ = VALA_EXPRESSION (vala_cast_expression_new ($4, $2, src));
+		$$ = VALA_EXPRESSION (vala_cast_expression_new ($4, $2, src, FALSE));
 		g_object_unref (src);
 		g_object_unref ($2);
 		g_object_unref ($4);
@@ -1090,6 +1091,14 @@ relational_expression
 		g_object_unref ($1);
 		g_object_unref ($3);
 	  }
+	| relational_expression AS type
+	  {
+		ValaSourceReference *src = src(@2);
+	  	$$ = VALA_EXPRESSION (vala_cast_expression_new ($1, $3, src, TRUE));
+		g_object_unref (src);
+		g_object_unref ($1);
+		g_object_unref ($3);
+	  }
 	;
 
 equality_expression

vala/scanner.l

@@ -128,6 +128,7 @@ literal				({integer_literal}|{real_literal}|{character_literal}|{string_literal
 "@"[[:alnum:]_]+	{ uploc; yylval->str = g_strdup (yytext + 1); return IDENTIFIER; }
 
 "abstract"	{ uploc; return ABSTRACT; }
+"as"		{ uploc; return AS; }
 "base"		{ uploc; return BASE; }
 "break"		{ uploc; return BREAK; }
 "case"		{ uploc; return CASE; }

vala/valacastexpression.vala

@@ -44,6 +44,11 @@ public class Vala.CastExpression : Expression {
 	 */
 	public TypeReference! type_reference { get; set construct; }
 
+	/**
+	 * Checked casts return NULL instead of raising an error.
+	 */
+	public bool is_silent_cast { get; set construct; }
+
 	private Expression! _inner;
 
 	/**
@@ -53,10 +58,7 @@ public class Vala.CastExpression : Expression {
 	 * @param type  target type
 	 * @return      newly created cast expression
 	 */
-	public CastExpression (Expression! _inner, TypeReference! type, SourceReference source) {
-		inner = _inner;
-		type_reference = type;
-		source_reference = source;
+	public CastExpression (construct Expression! inner, construct TypeReference! type_reference, construct SourceReference source_reference, construct bool is_silent_cast) {
 	}
 	
 	public override void accept (CodeVisitor! visitor) {