Struct NumberFormat 

pub struct NumberFormat<const FORMAT: u128>;

Helper to access features from the packed format struct.

This contains accessory methods to read the formatting settings without using bitmasks directly on the underlying packed struct.

Some of the core functionality includes support for:

• Digit separators: ignored characters used to make numbers more readable, such as 100,000.
• Non-decimal radixes: writing or parsing numbers written in binary, hexadecimal, or other bases.
• Special numbers: disabling support for special floating-point, such as NaN.
• Number components: require signs, significant digits, and more.

This should always be constructed via NumberFormatBuilder. See NumberFormatBuilder for the fields for the packed struct.

Examples

use lexical_util::format::{RUST_LITERAL, NumberFormat};

let format = NumberFormat::<{ RUST_LITERAL }> {};
assert!(format.no_positive_mantissa_sign());
assert!(format.no_special());
assert!(format.internal_digit_separator());
assert!(format.trailing_digit_separator());
assert!(format.consecutive_digit_separator());
assert!(!format.no_exponent_notation());

Implementations

impl<const FORMAT: u128> NumberFormat<FORMAT>

pub const REQUIRED_INTEGER_DIGITS: bool

If digits are required before the decimal point.

See required_integer_digits.

pub const REQUIRED_FRACTION_DIGITS: bool

If digits are required after the decimal point.

See required_fraction_digits.

pub const REQUIRED_EXPONENT_DIGITS: bool

If digits are required after the exponent character.

See required_exponent_digits.

pub const REQUIRED_MANTISSA_DIGITS: bool

If significant digits are required.

See required_mantissa_digits.

pub const REQUIRED_DIGITS: bool

If at least 1 digit in the number is required.

See required_digits.

pub const NO_POSITIVE_MANTISSA_SIGN: bool

If a positive sign before the mantissa is not allowed.

See no_positive_mantissa_sign.

pub const REQUIRED_MANTISSA_SIGN: bool

If a sign symbol before the mantissa is required.

See required_mantissa_sign.

pub const NO_EXPONENT_NOTATION: bool

If exponent notation is not allowed.

See no_exponent_notation.

pub const NO_POSITIVE_EXPONENT_SIGN: bool

If a positive sign before the exponent is not allowed.

See no_positive_exponent_sign.

pub const REQUIRED_EXPONENT_SIGN: bool

If a sign symbol before the exponent is required.

See required_exponent_sign.

pub const NO_EXPONENT_WITHOUT_FRACTION: bool

If an exponent without fraction is not allowed.

See no_exponent_without_fraction.

pub const NO_SPECIAL: bool

If special (non-finite) values are not allowed.

See no_special.

pub const CASE_SENSITIVE_SPECIAL: bool

If special (non-finite) values are case-sensitive.

See case_sensitive_special.

pub const NO_INTEGER_LEADING_ZEROS: bool

If leading zeros before an integer are not allowed.

See no_integer_leading_zeros.

pub const NO_FLOAT_LEADING_ZEROS: bool

If leading zeros before a float are not allowed.

See no_float_leading_zeros.

pub const REQUIRED_EXPONENT_NOTATION: bool

If exponent notation is required.

See required_exponent_notation.

pub const CASE_SENSITIVE_EXPONENT: bool

If exponent characters are case-sensitive.

See case_sensitive_exponent.

pub const CASE_SENSITIVE_BASE_PREFIX: bool

If base prefixes are case-sensitive.

See case_sensitive_base_prefix.

pub const CASE_SENSITIVE_BASE_SUFFIX: bool

If base suffixes are case-sensitive.

See case_sensitive_base_suffix.

pub const INTEGER_INTERNAL_DIGIT_SEPARATOR: bool

If digit separators are allowed between integer digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits.

See integer_internal_digit_separator.

pub const FRACTION_INTERNAL_DIGIT_SEPARATOR: bool

If digit separators are allowed between fraction digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits.

See fraction_internal_digit_separator.

pub const EXPONENT_INTERNAL_DIGIT_SEPARATOR: bool

If digit separators are allowed between exponent digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits.

See exponent_internal_digit_separator.

pub const INTERNAL_DIGIT_SEPARATOR: bool

If digit separators are allowed between digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits.

See internal_digit_separator.

pub const INTEGER_LEADING_DIGIT_SEPARATOR: bool

If a digit separator is allowed before any integer digits.

This will consider an input of only the digit separator to be a identical to empty input.

See integer_leading_digit_separator.

pub const FRACTION_LEADING_DIGIT_SEPARATOR: bool

If a digit separator is allowed before any integer digits.

This will consider an input of only the digit separator to be a identical to empty input.

See fraction_leading_digit_separator.

pub const EXPONENT_LEADING_DIGIT_SEPARATOR: bool

If a digit separator is allowed before any exponent digits.

This will consider an input of only the digit separator to be a identical to empty input.

See exponent_leading_digit_separator.

pub const LEADING_DIGIT_SEPARATOR: bool

If a digit separator is allowed before any digits.

This will consider an input of only the digit separator to be a identical to empty input.

See leading_digit_separator.

pub const INTEGER_TRAILING_DIGIT_SEPARATOR: bool

If a digit separator is allowed after any integer digits.

This will consider an input of only the digit separator to be a identical to empty input.

See integer_trailing_digit_separator.

pub const FRACTION_TRAILING_DIGIT_SEPARATOR: bool

If a digit separator is allowed after any fraction digits.

This will consider an input of only the digit separator to be a identical to empty input.

See fraction_trailing_digit_separator.

pub const EXPONENT_TRAILING_DIGIT_SEPARATOR: bool

If a digit separator is allowed after any exponent digits.

This will consider an input of only the digit separator to be a identical to empty input.

See exponent_trailing_digit_separator.

pub const TRAILING_DIGIT_SEPARATOR: bool

If a digit separator is allowed after any digits.

This will consider an input of only the digit separator to be a identical to empty input.

See trailing_digit_separator.

pub const INTEGER_CONSECUTIVE_DIGIT_SEPARATOR: bool

If multiple consecutive integer digit separators are allowed.

See integer_consecutive_digit_separator.

pub const FRACTION_CONSECUTIVE_DIGIT_SEPARATOR: bool

If multiple consecutive fraction digit separators are allowed.

See fraction_consecutive_digit_separator.

pub const EXPONENT_CONSECUTIVE_DIGIT_SEPARATOR: bool

If multiple consecutive exponent digit separators are allowed.

See exponent_consecutive_digit_separator.

pub const CONSECUTIVE_DIGIT_SEPARATOR: bool

If multiple consecutive digit separators are allowed.

See consecutive_digit_separator.

pub const SPECIAL_DIGIT_SEPARATOR: bool

If any digit separators are allowed in special (non-finite) values.

See special_digit_separator.

pub const DIGIT_SEPARATOR: u8

The digit separator character in the packed struct.

See digit_separator.

pub const BASE_PREFIX: u8

The base prefix character in the packed struct.

See base_prefix.

pub const BASE_SUFFIX: u8

The base suffix character in the packed struct.

See base_suffix.

pub const MANTISSA_RADIX: u32

The radix for the significant digits in the packed struct.

See mantissa_radix.

pub const RADIX: u32 = Self::MANTISSA_RADIX

The radix for the significant digits in the packed struct.

Alias for MANTISSA_RADIX.

pub const EXPONENT_BASE: u32

The base for the exponent.

See exponent_base.

pub const EXPONENT_RADIX: u32

The radix for the exponent digits.

See exponent_radix.

pub const fn new() -> NumberFormat<FORMAT>

Create new instance (for methods and validation).

This uses the same settings as in the FORMAT packed struct.

pub const fn is_valid(&self) -> bool

Determine if the number format is valid.

pub const fn error(&self) -> Error

Get the error type from the format.

If Error::Success is returned, then no error occurred.

pub const fn is_valid_radix(&self) -> bool

Determine if the radixes in the number format are valid.

pub const fn error_radix(&self) -> Error

Get the error type from the radix-only for the format.

If Error::Success is returned, then no error occurred.

pub const fn required_integer_digits(&self) -> bool

Get if digits are required before the decimal point.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1	✔️
0.1	✔️
1	✔️
.1	❌

Used For

• Parse Float

pub const fn required_fraction_digits(&self) -> bool

Get if digits are required after the decimal point.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1	✔️
1	✔️
1.	❌

Used For

• Parse Float

pub const fn required_exponent_digits(&self) -> bool

Get if digits are required after the exponent character.

Can only be modified with feature format. Defaults to true.

Examples

Input	Valid?
1.1e+3	✔️
1.1e3	✔️
1.1e+	❌
1.1e	❌

Used For

• Parse Float

pub const fn required_mantissa_digits(&self) -> bool

Get if at least 1 significant digit is required.

If not required, then values like . (0) are valid, but empty strings are still invalid. Can only be modified with feature format. Defaults to true.

Examples

Input	Valid?
1.1	✔️
.	✔️
e10	✔️
.e10	✔️
``	❌

Used For

• Parse Float

pub const fn required_digits(&self) -> bool

Get if at least 1 digit in the number is required.

This requires either mantissa or exponent digits.

pub const fn no_positive_mantissa_sign(&self) -> bool

Get if a positive sign before the mantissa is not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1	✔️
-1.1	✔️
+1.1	❌

Used For

• Parse Float
• Parse Integer
• Write Float

pub const fn required_mantissa_sign(&self) -> bool

Get if a sign symbol before the mantissa is required.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1	❌
-1.1	✔️
+1.1	✔️

Used For

• Parse Float
• Parse Integer
• Write Float

pub const fn no_exponent_notation(&self) -> bool

Get if exponent notation is not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1	✔️
1.1	✔️
1.1e	❌
1.1e5	❌

Used For

• Parse Float
• Write Float

pub const fn no_positive_exponent_sign(&self) -> bool

Get if a positive sign before the exponent is not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1e3	✔️
1.1e-3	✔️
1.1e+3	❌

Used For

• Parse Float
• Write Float

pub const fn required_exponent_sign(&self) -> bool

Get if a sign symbol before the exponent is required.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1.1e3	❌
1.1e-3	✔️
1.1e+3	✔️

Used For

• Parse Float
• Write Float

pub const fn no_exponent_without_fraction(&self) -> bool

Get if an exponent without fraction is not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1e3	❌
1.e3	❌
1.1e	✔️
.1e3	✔️

Used For

• Parse Float

pub const fn no_special(&self) -> bool

Get if special (non-finite) values are not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
NaN	❌
inf	❌
-Infinity	❌
1.1e	✔️

Used For

• Parse Float

pub const fn case_sensitive_special(&self) -> bool

Get if special (non-finite) values are case-sensitive.

If set to true, then NaN and nan are treated as the same value (Not a Number). Can only be modified with feature format. Defaults to false.

Used For

• Parse Float

pub const fn no_integer_leading_zeros(&self) -> bool

Get if leading zeros before an integer are not allowed.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
01	❌
0	✔️
10	✔️

Used For

• Parse Integer

pub const fn no_float_leading_zeros(&self) -> bool

Get if leading zeros before a float are not allowed.

This is before the significant digits of the float, that is, if there is 1 or more digits in the integral component and the leading digit is 0, Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
01	❌
01.0	❌
0	✔️
10	✔️
0.1	✔️

Used For

• Parse Float

pub const fn required_exponent_notation(&self) -> bool

Get if exponent notation is required.

Can only be modified with feature format. Defaults to false.

Examples

Input	Valid?
1	❌
1.0	❌
1e3	✔️
1.1e3	✔️

Used For

• Parse Float
• Write Float

pub const fn case_sensitive_exponent(&self) -> bool

Get if exponent characters are case-sensitive.

If set to true, then the exponent character e would be considered the different from E. Can only be modified with feature format. Defaults to false.

Used For

• Parse Float

pub const fn case_sensitive_base_prefix(&self) -> bool

Get if base prefixes are case-sensitive.

If set to true, then the base prefix x would be considered the different from X. Can only be modified with feature power-of-two or radix along with format. Defaults to false.

Used For

• Parse Float
• Parse Integer

pub const fn case_sensitive_base_suffix(&self) -> bool

Get if base suffixes are case-sensitive.

If set to true, then the base suffix x would be considered the different from X. Can only be modified with feature power-of-two or radix along with format. Defaults to false.

Used For

• Parse Float
• Parse Integer

pub const fn integer_internal_digit_separator(&self) -> bool

Get if digit separators are allowed between integer digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1	✔️
_	❌
1_1	✔️
1_	❌
_1	❌

Used For

• Parse Float
• Parse Integer

pub const fn fraction_internal_digit_separator(&self) -> bool

Get if digit separators are allowed between fraction digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1.1	✔️
1._	❌
1.1_1	✔️
1.1_	❌
1._1	❌

Used For

• Parse Float

pub const fn exponent_internal_digit_separator(&self) -> bool

Get if digit separators are allowed between exponent digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1.1e1	✔️
1.1e_	❌
1.1e1_1	✔️
1.1e1_	❌
1.1e_1	❌

Used For

• Parse Float

pub const fn internal_digit_separator(&self) -> bool

Get if digit separators are allowed between digits.

This will not consider an input of only the digit separator to be a valid separator: the digit separator must be surrounded by digits. This is equivalent to any of integer_internal_digit_separator, fraction_internal_digit_separator, or exponent_internal_digit_separator being set.

pub const fn integer_leading_digit_separator(&self) -> bool

Get if a digit separator is allowed before any integer digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1	✔️
_	❌
1_1	❌
1_	❌
_1	✔️

Used For

• Parse Float
• Parse Integer

pub const fn fraction_leading_digit_separator(&self) -> bool

Get if a digit separator is allowed before any fraction digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1.1	✔️
1._	❌
1.1_1	❌
1.1_	❌
1._1	✔️

Used For

• Parse Float

pub const fn exponent_leading_digit_separator(&self) -> bool

Get if a digit separator is allowed before any exponent digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1.1e1	✔️
1.1e_	❌
1.1e1_1	❌
1.1e1_	❌
1.1e_1	✔️

Used For

• Parse Float

pub const fn leading_digit_separator(&self) -> bool

Get if a digit separator is allowed before any digits.

This will consider an input of only the digit separator to be a identical to empty input. This is equivalent to any of integer_leading_digit_separator, fraction_leading_digit_separator, or exponent_leading_digit_separator being set.

pub const fn integer_trailing_digit_separator(&self) -> bool

Get if a digit separator is allowed after any integer digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1	✔️
_	❌
1_1	❌
1_	✔️
_1	❌

Used For

• Parse Float
• Parse Integer

pub const fn fraction_trailing_digit_separator(&self) -> bool

Get if a digit separator is allowed after any fraction digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false. # Examples

Using a digit separator of _.

Input	Valid?
1.1	✔️
1._	❌
1.1_1	❌
1.1_	✔️
1._1	❌

Used For

• Parse Float

pub const fn exponent_trailing_digit_separator(&self) -> bool

Get if a digit separator is allowed after any exponent digits.

This will consider an input of only the digit separator to be a identical to empty input. Can only be modified with feature format. Defaults to false.

Examples

Using a digit separator of _.

Input	Valid?
1.1e1	✔️
1.1e_	❌
1.1e1_1	❌
1.1e1_	✔️
1.1e_1	❌

Used For

• Parse Float

pub const fn trailing_digit_separator(&self) -> bool

Get if a digit separator is allowed after any digits.

This will consider an input of only the digit separator to be a identical to empty input. This is equivalent to any of integer_trailing_digit_separator, fraction_trailing_digit_separator, or exponent_trailing_digit_separator being set.

pub const fn integer_consecutive_digit_separator(&self) -> bool

Get if multiple consecutive integer digit separators are allowed.

That is, using _ as a digit separator __ would be allowed where any digit separators (leading, trailing, internal) are allowed in the integer. Can only be modified with feature format. Defaults to false.

Used For

• Parse Float
• Parse Integer

pub const fn fraction_consecutive_digit_separator(&self) -> bool

Get if multiple consecutive fraction digit separators are allowed.

That is, using _ as a digit separator __ would be allowed where any digit separators (leading, trailing, internal) are allowed in the fraction. Can only be modified with feature format. Defaults to false.

Used For

• Parse Float

pub const fn exponent_consecutive_digit_separator(&self) -> bool

Get if multiple consecutive exponent digit separators are allowed.

That is, using _ as a digit separator __ would be allowed where any digit separators (leading, trailing, internal) are allowed in the exponent. Can only be modified with feature format. Defaults to false.

Used For

• Parse Float

pub const fn consecutive_digit_separator(&self) -> bool

Get if multiple consecutive digit separators are allowed.

This is equivalent to any of integer_consecutive_digit_separator, fraction_consecutive_digit_separator, or exponent_consecutive_digit_separator being set.

pub const fn special_digit_separator(&self) -> bool

Get if any digit separators are allowed in special (non-finite) values.

This enables leading, trailing, internal, and consecutive digit separators for any special floats: for example, N__a_N_ is considered the same as NaN. Can only be modified with feature format. Defaults to false.

Used For

• Parse Float

pub const fn digit_separator(&self) -> u8

Get the digit separator for the number format.

Digit separators are frequently used in number literals to group digits: 1,000,000 is a lot more readable than 1000000, but the , characters should be ignored in the parsing of the number.

Can only be modified with feature format. Defaults to 0, or no digit separators allowed.

Examples

Using a digit separator of _ (note that the validity oh where a digit separator can appear depends on the other digit separator flags).

Input	Valid?
1	✔️
1_4	✔️
+_14	✔️
+14e3_5	✔️
1_d	❌

Used For

• Parse Float
• Parse Integer

pub const fn has_digit_separator(&self) -> bool

Get if the format has a digit separator.

pub const fn base_prefix(&self) -> u8

Get the optional character for the base prefix.

This character will come after a leading zero, so for example setting the base prefix to x means that a leading 0x will be ignore, if present. Can only be modified with feature power-of-two or radix along with format. Defaults to 0, or no base prefix allowed.

Examples

Using a base prefix of x.

Input	Valid?
0x1	✔️
x1	❌
1	✔️
1x	❌
1x1	❌

Used For

• Parse Float
• Parse Integer

pub const fn has_base_prefix(&self) -> bool

Get if the format has a base suffix.

pub const fn base_suffix(&self) -> u8

Get the optional character for the base suffix.

This character will at the end of the buffer, so for example setting the base prefix to x means that a trailing x will be ignored, if present. Can only be modified with feature power-of-two or radix along with format. Defaults to 0, or no base suffix allowed.

Examples

Using a base suffix of x.

Input	Valid?
1	✔️
1x	✔️
1d	❌

Used For

• Parse Float
• Parse Integer

pub const fn has_base_suffix(&self) -> bool

Get if the format has a base suffix.

pub const fn mantissa_radix(&self) -> u32

Get the radix for mantissa digits.

This is only used for the significant digits, that is, the integral and fractional components. Can only be modified with feature power-of-two or radix. Defaults to 10.

Radix	String	Number
2	“10011010010”	1234
3	“1200201”	1234
8	“2322”	1234
10	“1234”	1234
16	“4d2”	1234
31	“18p”	1234

Used For

• Parse Float
• Parse Integer
• Write Float
• Write Integer

pub const fn radix(&self) -> u32

Get the radix for the significant digits.

This is an alias for mantissa_radix.

pub const fn radix2(&self) -> u32

Get the radix^2 for the significant digits.

pub const fn radix4(&self) -> u32

Get the radix^4 for the significant digits.

pub const fn radix8(&self) -> u32

Get the radix^8 for the significant digits.

pub const fn exponent_base(&self) -> u32

Get the radix for the exponent.

For example, in 1.234e3, it means 1.234 * 10^3, and the exponent base here is 10. Some programming languages, like C, support hex floats with an exponent base of 2, for example 0x1.8p3, or 1.5 * 2^3. Defaults to 10. Can only be modified with feature power-of-two or radix. Defaults to 10.

Used For

• Parse Float
• Parse Integer

pub const fn exponent_radix(&self) -> u32

Get the radix for exponent digits.

This is only used for the exponent digits. We assume the radix for the significant digits (mantissa_radix) is 10 as is the exponent base. Defaults to 10. Can only be modified with feature power-of-two or radix. Defaults to 10.

Radix	String	Number
2	“1.234^1100”	1.234e9
3	“1.234^110”	1.234e9
8	“1.234^14”	1.234e9
10	“1.234^12”	1.234e9
16	“1.234^c”	1.234e9
31	“1.234^c”	1.234e9

Used For

• Parse Float
• Parse Integer

pub const fn flags(&self) -> u128

Get the flags from the number format.

This contains all the non-character and non-radix values in the packed struct.

pub const fn interface_flags(&self) -> u128

Get the interface flags from the number format.

This contains all the flags that dictate code flows, and therefore excludes logic like case-sensitive characters.

pub const fn digit_separator_flags(&self) -> u128

Get the digit separator flags from the number format.

pub const fn exponent_flags(&self) -> u128

Get the exponent flags from the number format.

This contains all the flags pertaining to exponent formats, including digit separators.

pub const fn integer_digit_separator_flags(&self) -> u128

Get the integer digit separator flags from the number format.

pub const fn fraction_digit_separator_flags(&self) -> u128

Get the fraction digit separator flags from the number format.

pub const fn exponent_digit_separator_flags(&self) -> u128

Get the exponent digit separator flags from the number format.

pub const fn builder() -> NumberFormatBuilder

Get NumberFormatBuilder as a static function.

pub const fn rebuild() -> NumberFormatBuilder

Create NumberFormatBuilder using existing values.

Trait Implementations

impl<const FORMAT: u128> Default for NumberFormat<FORMAT>

fn default() -> NumberFormat<FORMAT>

Returns the “default value” for a type.