Add fileValueGenerator parameter to gumshoe when using struct mode, w…

…hich is a function that takes the directory, file, extension, and index for the file and returns the value that should be set on the struct for that file

Add example of fileValueGenerator to test object
Add draw event to test object directing user to check the output log for the test case output

objects/obj_test/Create_0.gml

@@ -1,5 +1,9 @@
-show_debug_message("struct version:");
-show_debug_message(gumshoe("", "txt", true));
 show_debug_message("array version:");
 show_debug_message(gumshoe("", "txt", false));
+show_debug_message("struct version:");
+show_debug_message(gumshoe("", "txt", true));
+show_debug_message("struct version with value generator:");
+show_debug_message(gumshoe("", "txt", true, , function(directory, file, extension, index) {
+	return directory + file; // the full path to the file
+}));
 show_debug_message("end.");

objects/obj_test/Draw_64.gml

@@ -0,0 +1,3 @@
+/// @description 
+
+draw_text(10, 10, "See output log for test cases.");

scripts/gumshoe/gumshoe.gml

@@ -33,7 +33,8 @@ On Microsoft platforms this flag does nothing as the file system is not case sen
 /// @param fileExtension
 /// @param returnStruct
 /// @param [forceLCNames] Force lowercase names on non-MSFT platforms, see comment(s) above for an explanation.
-function gumshoe()
+/// @param [structValueGenerator] when returnStruct = true, function that generates the value for the file (params: directiory, file, extension, index)
+function gumshoe(_directory, _extension, _return_struct = false, _force_lcnames = true, _generator = undefined)
 {
     //Microsoft platforms handle wildcards and patterns slightly different than others (Linux or web based).
     static _is_microsoft =
@@ -53,10 +54,9 @@ function gumshoe()
     //(see comments above for more ramblings)
     static _match_all_mask         = _is_microsoft? "*.*" :  "*";
 
-    var _directory                 = argument[0];
-    var _extension                 = argument[1];
-    var _return_struct             = argument[2];
-    var _force_lcnames             = (argument_count > 3)? argument[3] : true;
+    if (_return_struct == false && _generator != undefined) {
+        throw "Gumshoe: structValueGenerator can only be specified when returning a struct";
+    }
 
     //The JS export does not support file search at all.
     if (os_browser != browser_not_a_browser)
@@ -87,7 +87,7 @@ function gumshoe()
     if (_return_struct)
     {
         global.__gumshoe_count = 0;
-        return __gumshoe_struct(_directory, _extension, _match_all_mask, _path_separator);
+        return __gumshoe_struct(_directory, _extension, _match_all_mask, _path_separator, _generator);
     }
     else
     {
@@ -131,7 +131,7 @@ function __gumshoe_array(_directory, _extension, _result, _match_all_mask, _path
     var _i = 0;
     repeat(array_length(_directories))
     {
-        __gumshoe_array(_directories[_i], _extension, _result);
+        __gumshoe_array(_directories[_i], _extension, _result, _match_all_mask, _path_sep);
         ++_i;
     }
 
@@ -142,7 +142,8 @@ function __gumshoe_array(_directory, _extension, _result, _match_all_mask, _path
 /// @param fileExtension
 /// @param matchAllMask
 /// @param pathSeparator
-function __gumshoe_struct(_directory, _extension, _match_all_mask, _path_sep)
+/// @param structValueGenerator
+function __gumshoe_struct(_directory, _extension, _match_all_mask, _path_sep, _generator)
 {
     var _directories = [];
     var _result = {};
@@ -162,7 +163,8 @@ function __gumshoe_struct(_directory, _extension, _match_all_mask, _path_sep)
         else if ((_extension == ".*") || (filename_ext(_file) == _extension))
         {
             //Add this matching file to the output array
-            variable_struct_set(_result, _file, global.__gumshoe_count);
+            var value = _generator ? _generator(_directory, _file, _extension, global.__gumshoe_count) : global.__gumshoe_count;
+            variable_struct_set(_result, _file, value);
             ++global.__gumshoe_count;
         }
     }
@@ -173,9 +175,9 @@ function __gumshoe_struct(_directory, _extension, _match_all_mask, _path_sep)
     var _i = 0;
     repeat(array_length(_directories))
     {
-        variable_struct_set(_result, _directories[_i], __gumshoe_struct(_directory + _directories[_i] + _path_sep, _extension));
+        variable_struct_set(_result, _directories[_i], __gumshoe_struct(_directory + _directories[_i] + _path_sep, _extension, _match_all_mask, _path_sep, _generator));
         ++_i;
     }
 
     return _result;
-}
+}