Crate btoi

Expand description

Parse integers from ASCII byte slices.

Provides functions similar to from_str_radix, but is faster when parsing directly from byte slices instead of strings.

Supports #![no_std].

Examples

use btoi::btoi;

assert_eq!(Ok(42), btoi(b"42"));
assert_eq!(Ok(-1000), btoi(b"-1000"));

All functions are generic over integer types. Use the turbofish syntax if a type cannot be inferred from the context.

// overflows the selected target type
assert!(btoi::<u32>(b"9876543210").is_err());

// underflows the selected target type (an unsigned integer)
assert!(btoi::<u32>(b"-1").is_err());

It is possible to use saturating arithmetic for overflow handling.

use btoi::btoi_saturating;

assert_eq!(Ok(0xffff_ffff), btoi_saturating::<u32>(b"9876543210"));
assert_eq!(Ok(0), btoi_saturating::<u32>(b"-1"));

Errors

All functions return ParseIntegerError for these error conditions:

The byte slice does not contain any digits.
Not all characters are 0-9, a-z, A-Z. Leading or trailing whitespace is not allowed. The btoi* functions accept an optional leading + or - sign. The btou* functions respectively do not allow signs.
Not all digits are valid in the given radix.
The number overflows or underflows the target type, but saturating arithmetic is not used.

Panics

Just like from_str_radix functions will panic if the given radix is not in the range 2..=36 (or in the pathological case that there is no representation of the radix in the target integer type).