File_Position

//Constructors/Producers
File_Position() -> File_Position
File_Position(int, int) -> File_Position
end(AST_Node) -> File_Position
start(AST_Node) -> File_Position

//Methods
File_Position.column() -> int
File_Position.line() -> int

eval_error

//Methods
eval_error.call_stack() -> Vector
eval_error.pretty_print() -> string
eval_error.reason() -> string

exception

//Methods
exception.what() -> string