Sorting Tables Numerically

Columns with numerical alignment hints (.) will be sorted according to their numerical values.

To do this, psv parses each value and looks for the last numerical value in each item in the column. While admittedly not perfect, this allows values such as 2 @ 1.99 EUR to be sorted in a, hopefully, meaningful manner.

Phyisical Constants Note: 9.1e-31 is MUCH smaller than 1.6e-19 ! | Symbol | Description | Value | -::||.^ | c | speed of light in a vacuum | 299792458 m/s | h | Planck constant | 6.62607015e−34 J/Hz | G | Newtonian constant of gravitation |6.67430e−11 m³/kg/s² | e|elementary charge|1.602176634e−19 C | m(e) |electron mass |9.1093837139e−31 kg | N(A)| Avogadro constant |6.02214076e+23 mol⁻¹

Supported Numerical Formats (introductory overview)

Example	Description
`1234`	decimal integers
`-1234`	signed numbers
`12.34`	decimal floating point numbers
`12.34e2`	decimal exponentiation
`+12.34e-2`	signed exponents
`0x0a10`	hexadecimal integers

Unicode Characters | Symbol | Unicode | decimal | Name | -:- | .^ | . | ä | 0XE4 | 228 | small letter a with diaeresis | a | 0x61 | 97 | small letter a | − | 0x2212 | 8722 | minus sign | - | 0x2d | 45 | hyphen-minus | + | 0x2b | 43 | plus

Number Parsing Details

What does psv understand as being a number?

Many common programming languages use a similar format for specifying literal numbers.

psv follows the specification used by golang.

Digit Grouping

Large numbers, such as the speed of light, 299792458 m/s, tend to be hard for people to read.

Many cultures allow such numbers to be "grouped" to make reading them easier. e.g. 299,792,458 (english), 299.792.458 (germany) or 2,99,79,24,58 (india).

Because psv has no way of knowing which format to expect, it only understands the . as the decimal point, and ignores , entirely.

However, psv does allow the _ character to be used within a number to visually group digits, i.e. the _ must appear between two digits, and is only valid in the integer part of a number!

The _ character was chosen to avoid confusion between . and , which are used interchangebly in many locales.

The _ character can be used between any two digits in the integer part of a number (not necessarily in groups of 3) and only serves the purpose of improved readability of large numbers.

So you could write the speed of light as 299_792_458, 2_99_79_24_58 or even 2_99_792_4_5_8 and psv would consider all of these to be identical.

Minus Signs

psv allows the use of the mathematical minus sign, unicode u+2212. This symbol looks exactly the same as the normal "hyphen-minus" character (ASCII 45 u+002d) which makes finding this error especially difficult.

| Symbol | HTML | Code Point | Name | - | - | - | u+002d | hyphen-minus | − | −| u+2212 | minus sign With actual numbers: | number | description | ----v. | --- | +1 | a normal number | 0 | a normal number | -1 | hyphen-minus | -2 | u+2212 minus sign | -3 | hyphen-minus

Can you see the difference? I certainly cannot!

This is to alleviate the pain of copy/pasting tables of data from e.g. wikipedia where this symbol is often used in tables of numerical data.

Decimal Numbers

{sign} {integer part} {point} {fraction part} {exponentiation e or E} {exponent sign} {integer exponent}

[+-]? [1-9][0-9]*(_[0-9]+)* [.] [0-9]+ [eE] [+-]? [0-9]+

Examples:

123 .123 123 .456 123 e 4 1 .23 e 4

Hexadecimal Numbers

{sign} {hexadecimal 0x prefix} {integer part} {point} {fraction part} {exponentiation p or P} {exponent sign} {integer exponent}

Unsupported Number Formats

any numbers which do not use so called arabic numerals, e.g. roman numerals, eastern arabic numerals, chinese, japanese, etc.
octal numbers are just treated as decimal values - probably wrong
imaginary numbers
numbers with units are not scaled in any way, e.g. 1kg will be sorted well before 100g
any kind of mathematical formula