InnoSetup: How to pass a two dimensional string array to a function - inno-setup

Question

Innosetup is killing me. I am getting a RUNTIME 'Type Mismatch' error, where it is, to me, quite unexpected. I am using Inno-setup 5.5.3 (u)
(where the 'u' means the unicode version)
I am attempting to pass a two dimensional array into a method.
Here is my complete example.
[Setup]
AppName=EmptyProgram
AppVerName=EmptyProgram 1
UsePreviousAppDir=false
DefaultDirName={pf}\EmptyProgram
Uninstallable=false
OutputBaseFilename=HelloWorld
PrivilegesRequired=none
[Messages]
SetupAppTitle=My Title
[Code]
var
langMap : array[0..3] of array[0..1] of String;
function getMapVal(map : array of array[0..1] of String; key: String ) : String;
begin
Result:='not testing the body of the method';
end;
function InitializeSetup(): Boolean;
begin
MsgBox('Hello world.', mbInformation, MB_OK);
getMapVal(langMap, 'hello'); // this line here fails with type mismatch! Why?
Result := FALSE;
end;
This example would run, but for the invokation of the method:
getMapVal(langMap, 'hello');
It compiles, and therefore is happy with the declaration. But on invokation, mismatch error. What am I doing wrong?

Answer 1

First of all, you're not making a hash map, but a pure key value list. There's currently no way to make a real generics hash map in InnoSetup at this time. Anyway, your current code needs a complete refactor. I'd rather write it this way:
[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program
[Code]
type
TKey = string;
TValue = string;
TKeyValue = record
Key: TKey;
Value: TValue;
end;
TKeyValueList = array of TKeyValue;
function TryGetValue(const KeyValueList: TKeyValueList; const Key: TKey;
var Value: TValue): Boolean;
var
I: Integer;
begin
Result := False;
for I := 0 to GetArrayLength(KeyValueList) - 1 do
if KeyValueList[I].Key = Key then
begin
Result := True;
Value := KeyValueList[I].Value;
Exit;
end;
end;
procedure InitializeWizard;
var
I: Integer;
Value: TValue;
KeyValueList: TKeyValueList;
begin
SetArrayLength(KeyValueList, 3);
for I := 0 to 2 do
begin
KeyValueList[I].Key := 'Key' + IntToStr(I);
KeyValueList[I].Value := 'Value' + IntToStr(I);
end;
if TryGetValue(KeyValueList, 'Key2', Value) then
MsgBox('Value: ' + Value, mbInformation, MB_OK);
end;