Posted on 7 Oct 2022 by Edward Betts
In November 2021 I filed a feature request for the fish shell to add underscore as a thousand separator in numbers. My feature request has been implemented and is available in fish 3.5.0, released 16 June 2022.
The fish shell supports mathematical operations using the math command.
edward@x1c9 ~> math 2_000 + 22 2022 edward@x1c9 ~>
The underscore can be used as a thousand separator, but there are other uses for a number separator. Here's a list taken from a post by Mathias Bynens about the number separator in JavaScript:
// A decimal integer literal with its digits grouped per thousand: 1_000_000_000_000 // A decimal literal with its digits grouped per thousand: 1_000_000.220_720 // A binary integer literal with its bits grouped per octet: 0b01010110_00111000 // A binary integer literal with its bits grouped per nibble: 0b0101_0110_0011_1000 // A hexadecimal integer literal with its digits grouped by byte: 0x40_76_38_6A_73 // A BigInt literal with its digits grouped per thousand: 4_642_473_943_484_686_707n
Programming languages are gradually adding a number separator to their syntax, I think Perl was the first. Most are languages use underscore, but C++ 14 uses an apostrophe for the number separator.