diff --git a/gsk/gskslnode.c b/gsk/gskslnode.c
index e53dd6b921..06a5e433d2 100644
--- a/gsk/gskslnode.c
+++ b/gsk/gskslnode.c
@@ -269,6 +269,117 @@ static const GskSlNodeClass GSK_SL_NODE_ASSIGNMENT = {
   gsk_sl_node_assignment_is_constant
 };
 
+/* BINARY */
+
+typedef enum {
+  GSK_SL_OPERATION_MUL,
+  GSK_SL_OPERATION_DIV,
+  GSK_SL_OPERATION_MOD,
+  GSK_SL_OPERATION_ADD,
+  GSK_SL_OPERATION_SUB,
+  GSK_SL_OPERATION_LSHIFT,
+  GSK_SL_OPERATION_RSHIFT,
+  GSK_SL_OPERATION_LESS,
+  GSK_SL_OPERATION_GREATER,
+  GSK_SL_OPERATION_LESS_EQUAL,
+  GSK_SL_OPERATION_GREATER_EQUAL,
+  GSK_SL_OPERATION_EQUAL,
+  GSK_SL_OPERATION_NOT_EQUAL,
+  GSK_SL_OPERATION_AND,
+  GSK_SL_OPERATION_XOR,
+  GSK_SL_OPERATION_OR,
+  GSK_SL_OPERATION_LOGICAL_AND,
+  GSK_SL_OPERATION_LOGICAL_XOR,
+  GSK_SL_OPERATION_LOGICAL_OR
+} GskSlOperation;
+
+typedef struct _GskSlNodeOperation GskSlNodeOperation;
+
+struct _GskSlNodeOperation {
+  GskSlNode parent;
+
+  GskSlOperation op;
+  GskSlNode *left;
+  GskSlNode *right;
+};
+
+static void
+gsk_sl_node_operation_free (GskSlNode *node)
+{
+  GskSlNodeOperation *operation = (GskSlNodeOperation *) node;
+
+  gsk_sl_node_unref (operation->left);
+  if (operation->right)
+    gsk_sl_node_unref (operation->right);
+
+  g_slice_free (GskSlNodeOperation, operation);
+}
+
+static void
+gsk_sl_node_operation_print (GskSlNode *node,
+                             GString   *string)
+{
+  const char *op_str[] = {
+    [GSK_SL_OPERATION_MUL] = " * ",
+    [GSK_SL_OPERATION_DIV] = " / ",
+    [GSK_SL_OPERATION_MOD] = " % ",
+    [GSK_SL_OPERATION_ADD] = " + ",
+    [GSK_SL_OPERATION_SUB] = " - ",
+    [GSK_SL_OPERATION_LSHIFT] = " << ",
+    [GSK_SL_OPERATION_RSHIFT] = " >> ",
+    [GSK_SL_OPERATION_LESS] = " < ",
+    [GSK_SL_OPERATION_GREATER] = " > ",
+    [GSK_SL_OPERATION_LESS_EQUAL] = " <= ",
+    [GSK_SL_OPERATION_GREATER_EQUAL] = " >= ",
+    [GSK_SL_OPERATION_EQUAL] = " == ",
+    [GSK_SL_OPERATION_NOT_EQUAL] = " != ",
+    [GSK_SL_OPERATION_AND] = " & ",
+    [GSK_SL_OPERATION_XOR] = " ^ ",
+    [GSK_SL_OPERATION_OR] = " | ",
+    [GSK_SL_OPERATION_LOGICAL_AND] = " && ",
+    [GSK_SL_OPERATION_LOGICAL_XOR] = " ^^ ",
+    [GSK_SL_OPERATION_LOGICAL_OR] = " || "
+  };
+  GskSlNodeOperation *operation = (GskSlNodeOperation *) node;
+
+  /* XXX: figure out the need for bracketing here */
+
+  gsk_sl_node_print (operation->left, string);
+  g_string_append (string, op_str[operation->op]);
+  gsk_sl_node_print (operation->right, string);
+}
+
+static GskSlType *
+gsk_sl_node_operation_get_return_type (GskSlNode *node)
+{
+  GskSlNodeOperation *operation = (GskSlNodeOperation *) node;
+  GskSlType *ltype, *rtype;
+
+  ltype = gsk_sl_node_get_return_type (operation->left);
+  rtype = gsk_sl_node_get_return_type (operation->right);
+
+  if (gsk_sl_type_can_convert (ltype, rtype))
+    return ltype;
+  else
+    return rtype;
+}
+
+static gboolean
+gsk_sl_node_operation_is_constant (GskSlNode *node)
+{
+  GskSlNodeOperation *operation = (GskSlNodeOperation *) node;
+
+  return gsk_sl_node_is_constant (operation->left)
+      && gsk_sl_node_is_constant (operation->right);
+}
+
+static const GskSlNodeClass GSK_SL_NODE_OPERATION = {
+  gsk_sl_node_operation_free,
+  gsk_sl_node_operation_print,
+  gsk_sl_node_operation_get_return_type,
+  gsk_sl_node_operation_is_constant
+};
+
 /* DECLARATION */
 
 typedef struct _GskSlNodeDeclaration GskSlNodeDeclaration;
@@ -398,7 +509,7 @@ typedef struct _GskSlNodeConstant GskSlNodeConstant;
 struct _GskSlNodeConstant {
   GskSlNode parent;
 
-  GskSlBuiltinType type;
+  GskSlScalarType type;
   union {
     gint32       i32;
     guint32      u32;
@@ -453,10 +564,6 @@ gsk_sl_node_constant_print (GskSlNode *node,
       break;
 
     case GSK_SL_VOID:
-    case GSK_SL_VEC2:
-    case GSK_SL_VEC3:
-    case GSK_SL_VEC4:
-    case GSK_SL_N_BUILTIN_TYPES:
     default:
       g_assert_not_reached ();
       break;
@@ -468,7 +575,7 @@ gsk_sl_node_constant_get_return_type (GskSlNode *node)
 {
   GskSlNodeConstant *constant = (GskSlNodeConstant *) node;
 
-  return gsk_sl_type_get_builtin (constant->type);
+  return gsk_sl_type_get_scalar (constant->type);
 }
 
 static gboolean
@@ -605,6 +712,194 @@ gsk_sl_node_parse_primary_expression (GskSlNodeProgram  *program,
   }
 }
 
+static GskSlNode *
+gsk_sl_node_parse_or_expression (GskSlNodeProgram  *program,
+                                 GskSlScope        *scope,
+                                 GskSlPreprocessor *stream)
+{
+  return gsk_sl_node_parse_primary_expression (program, scope, stream);
+}
+
+static GskSlNode *
+gsk_sl_node_parse_logical_and_expression (GskSlNodeProgram  *program,
+                                          GskSlScope        *scope,
+                                          GskSlPreprocessor *stream)
+{
+  const GskSlToken *token;
+  GskSlNode *node;
+  GskSlNodeOperation *operation;
+
+  node = gsk_sl_node_parse_or_expression (program, scope, stream);
+  if (node == NULL)
+    return NULL;
+
+  while (TRUE)
+    {
+      token = gsk_sl_preprocessor_get (stream);
+      if (!gsk_sl_token_is (token, GSK_SL_TOKEN_AND_OP))
+        return node;
+
+      operation = gsk_sl_node_new (GskSlNodeOperation, &GSK_SL_NODE_OPERATION);
+      operation->left = node;
+      operation->op = GSK_SL_OPERATION_LOGICAL_AND;
+      gsk_sl_preprocessor_consume (stream, (GskSlNode *) operation);
+      operation->right = gsk_sl_node_parse_or_expression (program, scope, stream);
+      if (operation->right == NULL)
+        {
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (operation->right)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (operation->right));
+          gsk_sl_preprocessor_error (stream, "Right operand of && expression is not bool but %s", type_name);
+          g_free (type_name);
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (node)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (node));
+          gsk_sl_preprocessor_error (stream, "Left operand of && expression is not bool but %s", type_name);
+          g_free (type_name);
+          node = operation->right;
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else
+        {
+          node = (GskSlNode *) operation;
+        }
+    }
+
+  return node;
+}
+
+static GskSlNode *
+gsk_sl_node_parse_logical_xor_expression (GskSlNodeProgram  *program,
+                                          GskSlScope        *scope,
+                                          GskSlPreprocessor *stream)
+{
+  const GskSlToken *token;
+  GskSlNode *node;
+  GskSlNodeOperation *operation;
+
+  node = gsk_sl_node_parse_logical_and_expression (program, scope, stream);
+  if (node == NULL)
+    return NULL;
+
+  while (TRUE)
+    {
+      token = gsk_sl_preprocessor_get (stream);
+      if (!gsk_sl_token_is (token, GSK_SL_TOKEN_XOR_OP))
+        return node;
+
+      operation = gsk_sl_node_new (GskSlNodeOperation, &GSK_SL_NODE_OPERATION);
+      operation->left = node;
+      operation->op = GSK_SL_OPERATION_LOGICAL_XOR;
+      gsk_sl_preprocessor_consume (stream, (GskSlNode *) operation);
+      operation->right = gsk_sl_node_parse_logical_and_expression (program, scope, stream);
+      if (operation->right == NULL)
+        {
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (operation->right)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (operation->right));
+          gsk_sl_preprocessor_error (stream, "Right operand of || expression is not bool but %s", type_name);
+          g_free (type_name);
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (node)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (node));
+          gsk_sl_preprocessor_error (stream, "Left operand of || expression is not bool but %s", type_name);
+          g_free (type_name);
+          node = operation->right;
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else
+        {
+          node = (GskSlNode *) operation;
+        }
+    }
+
+  return node;
+}
+
+static GskSlNode *
+gsk_sl_node_parse_logical_or_expression (GskSlNodeProgram  *program,
+                                         GskSlScope        *scope,
+                                         GskSlPreprocessor *stream)
+{
+  const GskSlToken *token;
+  GskSlNode *node;
+  GskSlNodeOperation *operation;
+
+  node = gsk_sl_node_parse_logical_xor_expression (program, scope, stream);
+  if (node == NULL)
+    return NULL;
+
+  while (TRUE)
+    {
+      token = gsk_sl_preprocessor_get (stream);
+      if (!gsk_sl_token_is (token, GSK_SL_TOKEN_OR_OP))
+        return node;
+
+      operation = gsk_sl_node_new (GskSlNodeOperation, &GSK_SL_NODE_OPERATION);
+      operation->left = node;
+      operation->op = GSK_SL_OPERATION_LOGICAL_OR;
+      gsk_sl_preprocessor_consume (stream, (GskSlNode *) operation);
+      operation->right = gsk_sl_node_parse_logical_xor_expression (program, scope, stream);
+      if (operation->right == NULL)
+        {
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (operation->right)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (operation->right));
+          gsk_sl_preprocessor_error (stream, "Right operand of ^^ expression is not bool but %s", type_name);
+          g_free (type_name);
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else if (!gsk_sl_type_can_convert (gsk_sl_type_get_scalar (GSK_SL_BOOL),
+                                         gsk_sl_node_get_return_type (node)))
+        {
+          char *type_name = gsk_sl_type_to_string (gsk_sl_node_get_return_type (node));
+          gsk_sl_preprocessor_error (stream, "Left operand of ^^ expression is not bool but %s", type_name);
+          g_free (type_name);
+          node = operation->right;
+          gsk_sl_node_ref (node);
+          gsk_sl_node_unref ((GskSlNode *) operation);
+        }
+      else
+        {
+          node = (GskSlNode *) operation;
+        }
+    }
+
+  return node;
+}
+
+static GskSlNode *
+gsk_sl_node_parse_conditional_expression (GskSlNodeProgram  *program,
+                                          GskSlScope        *scope,
+                                          GskSlPreprocessor *stream)
+{
+  /* XXX: support conditionals */
+  return gsk_sl_node_parse_logical_or_expression (program, scope, stream);
+}
+
 static GskSlNode *
 gsk_sl_node_parse_assignment_expression (GskSlNodeProgram  *program,
                                          GskSlScope        *scope,
@@ -614,7 +909,7 @@ gsk_sl_node_parse_assignment_expression (GskSlNodeProgram  *program,
   GskSlNode *lvalue;
   GskSlNodeAssignment *assign;
 
-  lvalue = gsk_sl_node_parse_primary_expression (program, scope, stream);
+  lvalue = gsk_sl_node_parse_conditional_expression (program, scope, stream);
   if (lvalue == NULL)
     return NULL;
 
diff --git a/gsk/gsksltype.c b/gsk/gsksltype.c
index 5edfbc694a..dcd55bcc55 100644
--- a/gsk/gsksltype.c
+++ b/gsk/gsksltype.c
@@ -25,30 +25,143 @@
 
 #include <string.h>
 
+#define N_SCALAR_TYPES 6
+
+typedef struct _GskSlTypeClass GskSlTypeClass;
+
 struct _GskSlType
 {
-  int ref_count;
+  const GskSlTypeClass *class;
 
-  GskSlBuiltinType builtin;
+  int ref_count;
 };
 
-static GskSlType
-builtin_types[GSK_SL_N_BUILTIN_TYPES] = {
-  [GSK_SL_VOID] = { 1, GSK_SL_VOID },
-  [GSK_SL_FLOAT] = { 1, GSK_SL_FLOAT },
-  [GSK_SL_DOUBLE] = { 1, GSK_SL_DOUBLE },
-  [GSK_SL_INT] = { 1, GSK_SL_INT },
-  [GSK_SL_UINT] = { 1, GSK_SL_UINT },
-  [GSK_SL_BOOL] = { 1, GSK_SL_BOOL },
-  [GSK_SL_VEC2] = { 1, GSK_SL_VEC2 },
-  [GSK_SL_VEC3] = { 1, GSK_SL_VEC3 },
-  [GSK_SL_VEC4] = { 1, GSK_SL_VEC4 }
+struct _GskSlTypeClass {
+  void                  (* free)                                (GskSlType           *type);
+
+  void                  (* print)                               (const GskSlType     *type,
+                                                                 GString             *string);
+  GskSlScalarType       (* get_scalar_type)                     (const GskSlType     *type);
+  gboolean              (* can_convert)                         (const GskSlType     *target,
+                                                                 const GskSlType     *source);
+};
+
+static gboolean
+gsk_sl_scalar_type_can_convert (GskSlScalarType target,
+                                GskSlScalarType source)
+{
+  if (target == source)
+    return TRUE;
+
+  switch (source)
+  {
+    case GSK_SL_INT:
+      return target == GSK_SL_UINT
+          || target == GSK_SL_FLOAT
+          || target == GSK_SL_DOUBLE;
+    case GSK_SL_UINT:
+      return target == GSK_SL_FLOAT
+          || target == GSK_SL_DOUBLE;
+    case GSK_SL_FLOAT:
+      return target == GSK_SL_DOUBLE;
+    case GSK_SL_DOUBLE:
+    case GSK_SL_BOOL:
+    case GSK_SL_VOID:
+    default:
+      return FALSE;
+  }
+}
+
+/* SCALAR */
+
+typedef struct _GskSlTypeScalar GskSlTypeScalar;
+
+struct _GskSlTypeScalar {
+  GskSlType parent;
+
+  GskSlScalarType scalar;
+};
+
+static void
+gsk_sl_type_scalar_free (GskSlType *type)
+{
+  g_assert_not_reached ();
+}
+
+static void
+gsk_sl_type_scalar_print (const GskSlType *type,
+                          GString         *string)
+{
+  GskSlTypeScalar *scalar = (GskSlTypeScalar *) type;
+
+  switch (scalar->scalar)
+  {
+    case GSK_SL_VOID:
+      g_string_append (string, "void");
+      break;
+    case GSK_SL_FLOAT:
+      g_string_append (string, "float");
+      break;
+    case GSK_SL_DOUBLE:
+      g_string_append (string, "double");
+      break;
+    case GSK_SL_INT:
+      g_string_append (string, "int");
+      break;
+    case GSK_SL_UINT:
+      g_string_append (string, "uint");
+      break;
+    case GSK_SL_BOOL:
+      g_string_append (string, "bool");
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
+static GskSlScalarType
+gsk_sl_type_scalar_get_scalar_type (const GskSlType *type)
+{
+  GskSlTypeScalar *scalar = (GskSlTypeScalar *) type;
+
+  return scalar->scalar;
+}
+
+static gboolean
+gsk_sl_type_scalar_can_convert (const GskSlType *target,
+                                const GskSlType *source)
+{
+  const GskSlTypeScalar *target_scalar = (const GskSlTypeScalar *) target;
+  const GskSlTypeScalar *source_scalar = (const GskSlTypeScalar *) source;
+
+  if (target->class != source->class)
+    return FALSE;
+  
+  return gsk_sl_scalar_type_can_convert (target_scalar->scalar, source_scalar->scalar);
+}
+
+static const GskSlTypeClass GSK_SL_TYPE_SCALAR = {
+  gsk_sl_type_scalar_free,
+  gsk_sl_type_scalar_print,
+  gsk_sl_type_scalar_get_scalar_type,
+  gsk_sl_type_scalar_can_convert
+};
+
+static GskSlTypeScalar
+builtin_types[N_SCALAR_TYPES] = {
+  [GSK_SL_VOID] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_VOID },
+  [GSK_SL_FLOAT] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_FLOAT },
+  [GSK_SL_DOUBLE] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_DOUBLE },
+  [GSK_SL_INT] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_INT },
+  [GSK_SL_UINT] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_UINT },
+  [GSK_SL_BOOL] = { { &GSK_SL_TYPE_SCALAR, 1 }, GSK_SL_BOOL },
 };
 
 GskSlType *
 gsk_sl_type_new_parse (GskSlPreprocessor *stream)
 {
-  GskSlBuiltinType builtin;
+  GskSlType *type;
   const GskSlToken *token;
 
   token = gsk_sl_preprocessor_get (stream);
@@ -56,31 +169,22 @@ gsk_sl_type_new_parse (GskSlPreprocessor *stream)
   switch ((guint) token->type)
   {
     case GSK_SL_TOKEN_VOID:
-      builtin = GSK_SL_VOID;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_VOID));
       break;
     case GSK_SL_TOKEN_FLOAT:
-      builtin = GSK_SL_FLOAT;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_FLOAT));
       break;
     case GSK_SL_TOKEN_DOUBLE:
-      builtin = GSK_SL_DOUBLE;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_DOUBLE));
       break;
     case GSK_SL_TOKEN_INT:
-      builtin = GSK_SL_INT;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_INT));
       break;
     case GSK_SL_TOKEN_UINT:
-      builtin = GSK_SL_UINT;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_UINT));
       break;
     case GSK_SL_TOKEN_BOOL:
-      builtin = GSK_SL_BOOL;
-      break;
-    case GSK_SL_TOKEN_VEC2:
-      builtin = GSK_SL_VEC2;
-      break;
-    case GSK_SL_TOKEN_VEC3:
-      builtin = GSK_SL_VEC3;
-      break;
-    case GSK_SL_TOKEN_VEC4:
-      builtin = GSK_SL_VEC4;
+      type = gsk_sl_type_ref (gsk_sl_type_get_scalar (GSK_SL_BOOL));
       break;
     default:
       gsk_sl_preprocessor_error (stream, "Expected type specifier");
@@ -88,15 +192,16 @@ gsk_sl_type_new_parse (GskSlPreprocessor *stream)
   }
 
   gsk_sl_preprocessor_consume (stream, NULL);
-  return gsk_sl_type_ref (gsk_sl_type_get_builtin (builtin));
+
+  return type;
 }
 
 GskSlType *
-gsk_sl_type_get_builtin (GskSlBuiltinType builtin)
+gsk_sl_type_get_scalar (GskSlScalarType scalar)
 {
-  g_assert (builtin < GSK_SL_N_BUILTIN_TYPES);
+  g_assert (scalar < N_SCALAR_TYPES);
 
-  return &builtin_types[builtin];
+  return &builtin_types[scalar].parent;
 }
 
 GskSlType *
@@ -119,46 +224,30 @@ gsk_sl_type_unref (GskSlType *type)
   if (type->ref_count > 0)
     return;
 
-  g_assert_not_reached ();
+  type->class->free (type);
 }
 
 void
 gsk_sl_type_print (const GskSlType *type,
                    GString         *string)
 {
-  switch (type->builtin)
-  {
-    case GSK_SL_VOID:
-      g_string_append (string, "void");
-      break;
-    case GSK_SL_FLOAT:
-      g_string_append (string, "float");
-      break;
-    case GSK_SL_DOUBLE:
-      g_string_append (string, "double");
-      break;
-    case GSK_SL_INT:
-      g_string_append (string, "int");
-      break;
-    case GSK_SL_UINT:
-      g_string_append (string, "uint");
-      break;
-    case GSK_SL_BOOL:
-      g_string_append (string, "bool");
-      break;
-    case GSK_SL_VEC2:
-      g_string_append (string, "vec2");
-      break;
-    case GSK_SL_VEC3:
-      g_string_append (string, "vec3");
-      break;
-    case GSK_SL_VEC4:
-      g_string_append (string, "vec4");
-      break;
-    /* add more above */
-    case GSK_SL_N_BUILTIN_TYPES:
-    default:
-      g_assert_not_reached ();
-      break;
-  }
+  return type->class->print (type, string);
 }
+
+char *
+gsk_sl_type_to_string (const GskSlType *type)
+{
+  GString *string;
+
+  string = g_string_new (NULL);
+  gsk_sl_type_print (type, string);
+  return g_string_free (string, FALSE);
+}
+
+gboolean
+gsk_sl_type_can_convert (const GskSlType *target,
+                         const GskSlType *source)
+{
+  return target->class->can_convert (target, source);
+}
+
diff --git a/gsk/gsksltypeprivate.h b/gsk/gsksltypeprivate.h
index 5337e38aa3..238db3e0f5 100644
--- a/gsk/gsksltypeprivate.h
+++ b/gsk/gsksltypeprivate.h
@@ -31,22 +31,21 @@ typedef enum {
   GSK_SL_DOUBLE,
   GSK_SL_INT,
   GSK_SL_UINT,
-  GSK_SL_BOOL,
-  GSK_SL_VEC2,
-  GSK_SL_VEC3,
-  GSK_SL_VEC4,
-  /* add more above */
-  GSK_SL_N_BUILTIN_TYPES
-} GskSlBuiltinType;
+  GSK_SL_BOOL
+} GskSlScalarType;
 
 GskSlType *             gsk_sl_type_new_parse                   (GskSlPreprocessor   *stream);
-GskSlType *             gsk_sl_type_get_builtin                 (GskSlBuiltinType     builtin);
+GskSlType *             gsk_sl_type_get_scalar                  (GskSlScalarType      scalar);
 
 GskSlType *             gsk_sl_type_ref                         (GskSlType           *type);
 void                    gsk_sl_type_unref                       (GskSlType           *type);
 
 void                    gsk_sl_type_print                       (const GskSlType     *type,
                                                                  GString             *string);
+char *                  gsk_sl_type_to_string                   (const GskSlType     *type);
+
+gboolean                gsk_sl_type_can_convert                 (const GskSlType     *target,
+                                                                 const GskSlType     *source);
 
 G_END_DECLS