[vala/0.40] vala: Add CodeNode.copy_attribute_*() helper methods

[Rico Tzschichholz <ricotz src gnome org>]

commit c2de45708a3724c16097833a1a8fbc7f349e5219
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Thu Nov 8 12:45:24 2018 +0100

    vala: Add CodeNode.copy_attribute_*() helper methods
    
    Provides an easy way to copy a specific attribute argument from another
    code node if the source has it set.

 vala/valacodenode.vala | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
---
diff --git a/vala/valacodenode.vala b/vala/valacodenode.vala
index 5413ed434..06a774a7f 100644
--- a/vala/valacodenode.vala
+++ b/vala/valacodenode.vala
@@ -334,6 +334,70 @@ public abstract class Vala.CodeNode {
                a.add_argument (argument, value.to_string ());
        }
 
+       /**
+        * Copy the string value of the specified attribute argument if available.
+        *
+        * @param source    codenode to copy from
+        * @param attribute attribute name
+        * @param argument  argument name
+        * @return          true if successful
+        */
+       public bool copy_attribute_string (CodeNode source, string attribute, string argument) {
+               if (source.has_attribute_argument (attribute, argument)) {
+                       set_attribute_string (attribute, argument, source.get_attribute_string (attribute, 
argument));
+                       return true;
+               }
+               return false;
+       }
+
+       /**
+        * Copy the integer value of the specified attribute argument if available.
+        *
+        * @param source    codenode to copy from
+        * @param attribute attribute name
+        * @param argument  argument name
+        * @return          true if successful
+        */
+       public bool copy_attribute_integer (CodeNode source, string attribute, string argument) {
+               if (source.has_attribute_argument (attribute, argument)) {
+                       set_attribute_integer (attribute, argument, source.get_attribute_integer (attribute, 
argument));
+                       return true;
+               }
+               return false;
+       }
+
+       /**
+        * Copy the double value of the specified attribute argument if available.
+        *
+        * @param source    codenode to copy from
+        * @param attribute attribute name
+        * @param argument  argument name
+        * @return          true if successful
+        */
+       public bool copy_attribute_double (CodeNode source, string attribute, string argument) {
+               if (source.has_attribute_argument (attribute, argument)) {
+                       set_attribute_double (attribute, argument, source.get_attribute_double (attribute, 
argument));
+                       return true;
+               }
+               return false;
+       }
+
+       /**
+        * Copy the boolean value of the specified attribute argument if available.
+        *
+        * @param source    codenode to copy from
+        * @param attribute attribute name
+        * @param argument  argument name
+        * @return          true if successful
+        */
+       public bool copy_attribute_bool (CodeNode source, string attribute, string argument) {
+               if (source.has_attribute_argument (attribute, argument)) {
+                       set_attribute_bool (attribute, argument, source.get_attribute_bool (attribute, 
argument));
+                       return true;
+               }
+               return false;
+       }
+
        /**
         * Returns the attribute cache at the specified index.
         *