vala: Add GenericSymbol interface for symbols supporting type-parameters

8 files changed, 69 insertions, 18 deletions

diff --git a/vala/Makefile.am b/vala/Makefile.am
index 09f3c0672..8f9f81cf2 100644
--- a/vala/Makefile.am
+++ b/vala/Makefile.am
@@ -93,6 +93,7 @@ libvala_la_VALASOURCES = \
 	valagirparser.vala \
 	valagenericdestroyfield.vala \
 	valagenericdupfield.vala \
+	valagenericsymbol.vala \
 	valagenerictype.vala \
 	valagenieparser.vala \
 	valageniescanner.vala \
diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index a7ba03856..fec7e9010 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -676,12 +676,8 @@ public abstract class Vala.DataType : CodeNode {
 		int n_type_args = get_type_arguments ().size;
 		int expected_n_type_args = 0;
 
-		if (type_symbol is ObjectTypeSymbol) {
-			expected_n_type_args = ((ObjectTypeSymbol) type_symbol).get_type_parameters ().size;
-		} else if (type_symbol is Struct) {
-			expected_n_type_args = ((Struct) type_symbol).get_type_parameters ().size;
-		} else if (type_symbol is Delegate) {
-			expected_n_type_args = ((Delegate) type_symbol).get_type_parameters ().size;
+		if (type_symbol is GenericSymbol) {
+			expected_n_type_args = ((GenericSymbol) type_symbol).get_type_parameters ().size;
 		} else if (n_type_args > 0) {
 			Report.error (source_reference, "`%s' does not support type arguments", type_symbol.get_full_name ());
 			error = true;
diff --git a/vala/valadelegate.vala b/vala/valadelegate.vala
index cb53d2e91..97d61c010 100644
--- a/vala/valadelegate.vala
+++ b/vala/valadelegate.vala
@@ -25,7 +25,7 @@ using GLib;
 /**
  * Represents a function callback type.
  */
-public class Vala.Delegate : TypeSymbol, Callable {
+public class Vala.Delegate : TypeSymbol, Callable, GenericSymbol {
 	/**
 	 * The return type of this callback.
 	 */
diff --git a/vala/valagenericsymbol.vala b/vala/valagenericsymbol.vala
new file mode 100644
index 000000000..54de02145
--- /dev/null
+++ b/vala/valagenericsymbol.vala
@@ -0,0 +1,56 @@
+/* valagenericsymbol.vala
+ *
+ * Copyright (C) 2023  Rico Tzschichholz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
+ *
+ * Author:
+ * 	Rico Tzschichholz <ricotz@ubuntu.com>
+ */
+
+using GLib;
+
+/**
+ * The interface for symbols which support type parameters.
+ */
+public interface Vala.GenericSymbol : Symbol {
+	/**
+	 * Appends the specified parameter to the list of type parameters.
+	 *
+	 * @param p a type parameter
+	 */
+	public abstract void add_type_parameter (TypeParameter p);
+
+	/**
+	 * Returns the type parameter list.
+	 *
+	 * @return list of type parameters
+	 */
+	public abstract unowned List<TypeParameter> get_type_parameters ();
+
+	/**
+	 * Returns whether this symbol has type parameters.
+	 *
+	 * @return true if there are type parameters
+	 */
+	public abstract bool has_type_parameters ();
+
+	/**
+	 * Returns the index of the type parameter with the given name.
+	 *
+	 * @return index of a type parameter, or -1
+	 */
+	public abstract int get_type_parameter_index (string name);
+}
diff --git a/vala/valamethod.vala b/vala/valamethod.vala
index 8c5c3af56..c95d3ae43 100644
--- a/vala/valamethod.vala
+++ b/vala/valamethod.vala
@@ -27,7 +27,7 @@ using GLib;
 /**
  * Represents a type or namespace method.
  */
-public class Vala.Method : Subroutine, Callable {
+public class Vala.Method : Subroutine, Callable, GenericSymbol {
 	List<TypeParameter> type_parameters;
 
 	/**
diff --git a/vala/valaobjecttypesymbol.vala b/vala/valaobjecttypesymbol.vala
index 97f1f0f2c..7594d4657 100644
--- a/vala/valaobjecttypesymbol.vala
+++ b/vala/valaobjecttypesymbol.vala
@@ -28,7 +28,7 @@
  * be defined in Vala source code or imported from an external library with a
  * Vala API file.
  */
-public abstract class Vala.ObjectTypeSymbol : TypeSymbol {
+public abstract class Vala.ObjectTypeSymbol : TypeSymbol, GenericSymbol {
 	private List<TypeParameter> type_parameters = new ArrayList<TypeParameter> ();
 
 	private List<Symbol> members = new ArrayList<Symbol> ();
diff --git a/vala/valastruct.vala b/vala/valastruct.vala
index 5cce4b24b..198ff3462 100644
--- a/vala/valastruct.vala
+++ b/vala/valastruct.vala
@@ -25,7 +25,7 @@ using GLib;
 /**
  * Represents a struct declaration in the source code.
  */
-public class Vala.Struct : TypeSymbol {
+public class Vala.Struct : TypeSymbol, GenericSymbol {
 	private List<TypeParameter> type_parameters = new ArrayList<TypeParameter> ();
 	private List<Constant> constants = new ArrayList<Constant> ();
 	private List<Field> fields = new ArrayList<Field> ();
@@ -187,6 +187,10 @@ public class Vala.Struct : TypeSymbol {
 		return type_parameters;
 	}
 
+	public bool has_type_parameters () {
+		return (type_parameters != null && type_parameters.size > 0);
+	}
+
 	/**
 	 * Adds the specified constant as a member to this struct.
 	 *
diff --git a/vala/valasymbol.vala b/vala/valasymbol.vala
index ebee414ec..3dc9ea7c5 100644
--- a/vala/valasymbol.vala
+++ b/vala/valasymbol.vala
@@ -511,14 +511,8 @@ public abstract class Vala.Symbol : CodeNode {
 		var builder = new StringBuilder (get_full_name ());
 
 		unowned List<TypeParameter>? type_params = null;
-		if (this is Delegate) {
-			type_params = ((Delegate) this).get_type_parameters ();
-		} else if (this is Method) {
-			type_params = ((Method) this).get_type_parameters ();
-		} else if (this is ObjectTypeSymbol) {
-			type_params = ((ObjectTypeSymbol) this).get_type_parameters ();
-		} else if (this is Struct) {
-			type_params = ((Struct) this).get_type_parameters ();
+		if (this is GenericSymbol) {
+			type_params = ((GenericSymbol) this).get_type_parameters ();
 		}
 		if (type_params != null && type_params.size > 0) {
 			builder.append_c ('<');