54 fn integer<I>() -> impl Parser<I, Output = i64>  in integer()  function
86     let immediate = integer().map(Operand::Integer);  in operand()
87     let memory = between(char('['), char(']'), (register(), optional(integer())))  in operand()
132     use super::{ident, instruction, integer, operand, parse, register, Instruction, Operand};
145         assert_eq!(integer().parse("0"), Ok((0, "")));  in test_integer()
146         assert_eq!(integer().parse("42"), Ok((42, "")));  in test_integer()
147         assert_eq!(integer().parse("+42"), Ok((42, "")));  in test_integer()
148         assert_eq!(integer().parse("-42"), Ok((-42, "")));  in test_integer()
149         assert_eq!(integer().parse("0x0"), Ok((0, "")));  in test_integer()
151             integer().parse("0x123456789abcdef0"),  in test_integer()
154         assert_eq!(integer().parse("-0x1f"), Ok((-31, "")));  in test_integer()