vipsi -p <filename>

	parse <text>				-> error oder nicht
	parse "return " # <text>	-> für <value>
	parse file <filename>

	precheck
	validate
	chksyntax
	precompile
	compile

	<bool> = isvalid <text>
			 isexecutable
			 compiles

	eval -p <text>
	eval <text>, pretend
	eval <text>, option="pretend"
	eval "pretend " # text

	root.options.pretend = 1
	eval <text>
	root.options.pretend = 0

	<var> = eval "1?0:" # <text>

	eval "if 1 else " # <text> # "\n then"
	<var> = eval "proc(){ " # <text> # "\n } "