https://github.com/jribbens/verbose-regexp
Verbose Regular Expressions
https://github.com/jribbens/verbose-regexp
javascript regex regexp regular-expression
Last synced: 4 months ago
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Verbose Regular Expressions
- Host: GitHub
- URL: https://github.com/jribbens/verbose-regexp
- Owner: jribbens
- License: mit
- Created: 2021-05-24T19:43:17.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2023-06-04T16:04:07.000Z (over 2 years ago)
- Last Synced: 2025-06-29T15:40:42.817Z (4 months ago)
- Topics: javascript, regex, regexp, regular-expression
- Language: TypeScript
- Homepage:
- Size: 209 KB
- Stars: 10
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# verbose-regexp
This module provides a way to use verbose regular expressions in
JavaScript and TypeScript, similar to `re.VERBOSE` in Python. It
provides that white-space at the start and end of lines are ignored,
as are newlines, and anything following `//` to the end of the line.
It allows you to easily write multi-line regular expressions, and to
make your regular expressions more self-documenting using formatting
and comments.
Example:
```javascript
import { rx } from 'verbose-regexp'
// or: const { rx } = require('verbose-regexp')
const dateTime = rx`
(\d{4}-\d{2}-\d{2}) // date
T // time separator
(\d{2}:\d{2}:\d{2}) // time
`
console.log(dateTime.exec(new Date().toISOString()))
```
You can also embed regular expressions within each other, to allow a
complicated regular expression to be built up in steps from simpler parts,
e.g.:
```javascript
const date = rx`\d{4}-\d{2}-\d{2}`
const time = rx`\d{2}:\d{2}:\d{2}`
const dateTime = rx`
(${date}) // date
T // time separator
(${time}) // time
`
console.log(dateTime.exec(new Date().toISOString()))
```
Note that embedded sub-expressions are automatically surrounded with `(?:`
and `)`, so that they are always treated as a self-contained unit. Also note
that embedded sub-expressions will be run using the flags of the parent
expression, regardless of what flags were on the sub-expression - so, for
example, if the sub-expression had the 'case insensitive' flag set but the
parent expression didn't, then the sub-expression will be executed in a
case sensitive manner.
You can use regular expression flags by accessing them as a property of `rx`,
e.g.:
```javascript
const alpha = rx.i`[a-z]+`
const allAlpha = rx.gi`[a-z]+`
```
If you want to use a string that would otherwise be ignored (i.e. whitespace
or `//`), you can simply escape it with backslashes or a character class:
```javascript
const url = rx.i`
[ ]*([a-z]+):\/\/ // scheme
([^/]+) // location
(?:/(.*)) // path
`
```
## History
### 3.0.0 (2023-06-04)
* Allow embedding of other RegExp objects.
### 2.0.0 (2022-05-03)
* Use 'Proxy' objects to avoid having to create static properties for
every permutation of the possible flags.
### 1.0.0 (2021-05-24)
* Initial release.