Insert or remove grouping commas (or other grouping character) in the number under or adjacent to the cursor, or for all numbers within the region, with a single command. This is an otherwise tedious chore and one that is not easily done via a macro or other Emacs user-level facilities.
Add commify.el to your load-path and
(require 'commify)Simply install the commify package.
Commify has several variables that you can set to alter its behaviour, either
through the Emacs customize facility or with setq’s in your init file.
The following variables affect how commify treats decimal numbers:
- commify-group-char
- set this to a one-character string for inserting between groups of digits. By default it is set to “,”.
- commify-group-size
- set this to an integer specifying the number of decimal digits you want in each group. By default this is set to 3.
- commify-decimal-char
- set this to a one-character string that is recognized as the decimal point. By default this is set to “.”.
The following variables affect how commify treats numbers in other bases:
- commify-hex-enable
- set non-nil to enable grouping on hexadecimal numbers. By default it is set to t.
- commify-hex-group-char
- set this to a string for inserting between groups of hexadecimal digits. By default it is set to “_”.
- commify-hex-group-size
- set this to an integer specifying the number of hexadecimal digits you want in each group. By default this is set to 4.
- commify-hex-prefix-re
- set to a string regular expression that matches the beginning of a string by which hexadecimal numbers can be recognized. By default it is set to “0[xX]”
- commify-hex-digits
- set to a string that represents a character class (without the square brackets) of valid hexadecimal digits. This is not itself a regular expression, but is used to build one to recognize hexadecimal numbers. By default it is set to “0-9A-Fa-f”.
- commify-hex-suffix-re
- set to a string regular expression that matches the end of a string by which hexadecimal numbers can be recognized. By default it is set to “”
Similar variables control commify’s treatment of octal numbers:
- commify-oct-enable
- set non-nil to enable grouping on octal numbers. By default it is set to t.
- commify-oct-group-char
- set this to a string for inserting between groups of octal digits. By default it is set to “_”.
- commify-oct-group-size
- set this to an integer specifying the number of octal digits you want in each group. By default this is set to 2.
- commify-oct-prefix-re
- set to a string regular expression that matches the beginning of a string by which octal numbers can be recognized. By default it is set to “0[oO]”
- commify-oct-digits
- set to a string that represents a character class (without the square brackets) of valid octal digits. This is not itself a regular expression, but is used to build one to recognize octal numbers. By default it is set to “0-7”.
- commify-oct-suffix-re
- set to a string regular expression that matches the end of a string by which octal numbers can be recognized. By default it is set to “”
And, finally, another set of variables control commify’s treatment of binary numbers:
- commify-bin-enable
- set non-nil to enable grouping on binary numbers. By default it is set to t.
- commify-bin-group-char
- set this to a string for inserting between groups of binary digits. By default it is set to “_”.
- commify-bin-group-size
- set this to an integer specifying the number of binary digits you want in each group. By default this is set to 4.
- commify-bin-prefix-re
- set to a string regular expression that matches the beginning of a string by which binary numbers can be recognized. By default it is set to “0[bB]”.
- commify-bin-digits
- set to a string that represents a character class (without the square brackets) of valid binary digits. This is not itself a regular expression, but is used to build one to recognize binary numbers. By default it is set to “0-1”.
- commify-bin-suffix-re
- set to a string regular expression that matches the end of a string by which binary numbers can be recognized. By default it is set to “”
Bind the commify-toggle command to a convenient key. I have put it on the
“,,” keychord since it is rare in English to type two commas in a row.
(key-chord-define-global ",," 'commify-toggle)You may also want to change the default settings:
(setq commify-group-char "_")
(setq commify-decimal-char ",")
(setq commify-group-size 4)
(setq commify-bin-group-size 8)
(key-chord-define-global ",," 'commify-toggle)When editing a buffer, simply put your cursor before, after, or within a number, integer, or decimal, then invoke the command.
The factorial of 15 is 1307674368000.
With the cursor anywhere in or immediately adjacent to the number, hit “,,”
(or whatever you’ve bound the commify-toggle command to) and the buffer will
change to:
The factorial of 15 is 1,307,674,368,000.
If you invoke the command again, the commas are removed. commify-toggle
works on floating or scientific numbers as well, but it only ever affects the
digits before the decimal point as defined in the commify-decimal-char
variable.
Afterwards, the cursor will be moved to the point immediately after the affected number.
If a number appears to be (1) part of a date, (2) part of an identifier, or
(3) a decimal number starting with zero, commify will ignore it. Thus, if the
cursor is to the left of ‘2012-09-22’ invoking commify-toggle will leave the
text alone, but will still advance the cursor.
If the region is active when the you invoke commify-toggle, all numbers in
the region have commify-toggle invoked on them. This can be especially
handy when you want to commify numbers in a org-mode table, for example.
With the following table set as the region:
| Decimal | Binary | Octal | Hex | |--------------+--------------------------------------------+-----------------+--------------| | 4207868622 | 0b11111010110011101111101011001110 | 0o37263575316 | 0xFACEFACE | | 2882343476 | 0b10101011110011010001001000110100 | 0o25363211064 | 0xABCD1234 | | 3405695742 | 0b11001010111111101100101011111110 | 0o31277545376 | 0xCAFECAFE | | 802549529294 | 0b1011101011011011101011011111101011001110 | 0o3533353375316 | 0xBADBADFACE |
Running commify-toggle on the region yields:
| Decimal | Binary | Octal | Hex | |-----------------+-----------------------------------------------------+-----------------------+----------------| | 4,207,868,622 | 0b1111_1010_1100_1110_1111_1010_1100_1110 | 0o3_72_63_57_53_16 | 0xFACE_FACE | | 2,882,343,476 | 0b1010_1011_1100_1101_0001_0010_0011_0100 | 0o2_53_63_21_10_64 | 0xABCD_1234 | | 3,405,695,742 | 0b1100_1010_1111_1110_1100_1010_1111_1110 | 0o3_12_77_54_53_76 | 0xCAFE_CAFE | | 802,549,529,294 | 0b1011_1010_1101_1011_1010_1101_1111_1010_1100_1110 | 0o3_53_33_53_37_53_16 | 0xBA_DBAD_FACE |
Not much to it, but it saves me a lot of time.