Remap keys in loops - autohotkey

Question

Background: I'm trying to have a f-mode and d-mode which means if I press down the f key and press another key like i then nothing happens excepts a shortcut. let say it will send Up key instead of f and I.
Issue: how I can remap a pressed key (I in my example) to a shortcut (Up as example)?
Code:
d::
f::{
;...
loop{
if !GetKeyState("f","p") && !GetKeyState("d","p"){
break
}
if GetKeyState("i","p") {
OutputDebug "i"
send "{up}"
continue
}
; ...
}
}

Answer 1

Looks like you want to make a custom combination.
From the Docs:
You can define a custom combination of two keys (except joystick
buttons) by using " & " between them. In the below example, you would
hold down Numpad0 then press the second key to trigger the hotkey:
Numpad0 & Numpad1::MsgBox You pressed Numpad1 while holding down Numpad0.
Numpad0 & Numpad2::Run Notepad
But also note:
The prefix key loses its native function: In the above example,
Numpad0 becomes a prefix key; but this also causes Numpad0 to lose its
original/native function when it is pressed by itself. To avoid this,
a script may configure Numpad0 to perform a new action such as one of
the following:
Numpad0::WinMaximize A ; Maximize the active/foreground window.
Numpad0::Send {Numpad0} ; Make the release of Numpad0 produce a Numpad0 keystroke. See comment below.
This is to prevent holding down a key from spamming inputs while you wait to press the second part of a key combination. So essentially, your 'f' and 'd' keys will now perform their normal functions when you release them instead of initially pressing them down.
Anyways, the code would become:
f & i::
d & i::
Send {Up}
return
f::f
d::d