JSON_FromObj.ahk

; Copyright © 2013 VxE. All rights reserved.

; Serialize an object as JSON-like text OR format a string for inclusion therein.
; NOTE: scientific notation is treated as a string and hexadecimal as a number.
; NOTE: UTF-8 sequences are encoded as-is, NOT as their intended codepoint.
json_fromobj( obj ) {

	If IsObject( obj )
	{
		isarray := 0 ; an empty object could be an array... but it ain't, says I
		for key in obj
			if ( key != ++isarray )
			{
				isarray := 0
				Break
			}

		for key, val in obj
			str .= ( A_Index = 1 ? "" : "," ) ( isarray ? "" : json_fromObj( key ) ":" ) json_fromObj( val )

		return isarray ? "[" str "]" : "{" str "}"
	}
	else if obj IS NUMBER
		return obj
;	else if obj IN null,true,false ; AutoHotkey does not natively distinguish these
;		return obj

	; Encode control characters, starting with backslash.
	StringReplace, obj, obj, \, \\, A
	StringReplace, obj, obj, % Chr(08), \b, A
	StringReplace, obj, obj, % A_Tab, \t, A
	StringReplace, obj, obj, `n, \n, A
	StringReplace, obj, obj, % Chr(12), \f, A
	StringReplace, obj, obj, `r, \r, A
	StringReplace, obj, obj, ", \", A
	StringReplace, obj, obj, /, \/, A
	While RegexMatch( obj, "[^\x20-\x7e]", key )
	{
		str := Asc( key )
		val := "\u" . Chr( ( ( str >> 12 ) & 15 ) + ( ( ( str >> 12 ) & 15 ) < 10 ? 48 : 55 ) )
				. Chr( ( ( str >> 8 ) & 15 ) + ( ( ( str >> 8 ) & 15 ) < 10 ? 48 : 55 ) )
				. Chr( ( ( str >> 4 ) & 15 ) + ( ( ( str >> 4 ) & 15 ) < 10 ? 48 : 55 ) )
				. Chr( ( str & 15 ) + ( ( str & 15 ) < 10 ? 48 : 55 ) )
		StringReplace, obj, obj, % key, % val, A
	}
	return """" obj """"
} ; json_fromobj( obj )