[CEP 26] Identifying Packages and Channels in the conda Ecosystem

cep-9999.md

@@ -0,0 +1,80 @@
+# CEP ???? - Names in conda packages and channels
+
+<table>
+<tr><td> Title </td><td> CEP ???? - Names in conda packages and channels </td>
+<tr><td> Status </td><td> Draft </td></tr>
+<tr><td> Author(s) </td><td> Jaime Rodríguez-Guerra &lt;jaime.rogue@gmail.com&gt; <br /> Matthew R. Becker &lt;becker.mr@gmail.com&gt;</td></tr>
+<tr><td> Created </td><td> Mar 11, 2025</td></tr>
+<tr><td> Updated </td><td> Mar 11, 2025</td></tr>
+<tr><td> Discussion </td><td> N/A </td></tr>
+<tr><td> Implementation </td><td> N/A </td></tr>
+</table>
+
+## Abstract
+
+This CEP aims to standardize names and other strings used throughout the conda ecosystem.
+
+## Specification
+
+### Artifacts
+
+The conda ecosystem distinguishes between two types of packages:
+
+- Distributable package names: represented by a concrete, downloadable, extractable conda artifact.
+- Virtual package names: not backed by any physical artifact. They only exist on the client side.
+
+### Package names
+
+A distributable package name MUST only consist of lowercase ASCII letters, numbers, hyphens, periods and underscores. It MUST start with a letter, a number, or a single underscore. It MUST NOT include two consecutive separators (hyphen, period, underscore). 
+
+Virtual package names MUST only consist of lowercase ASCII letters, numbers, hyphens, periods and underscores. They MUST NOT use two consecutive separators, with one exception: they MUST start with two underscores.
+
+This means that distributable package names MUST match the following case-insensitive regex: `^(([a-z0-9])|([a-z0-9_](?!_)))[._-]?([a-z0-9]+(\.|-|_|$))*$`.
+
+Virtual package names MUST follow this other regex: `^__[a-z0-9][._-]?([a-z0-9]+(\.|-|_|$))*$`.
+
+### Version strings
+
+Version strings MUST only consist of digits, periods, lowercase ASCII letters, underscores, plus
+signs and exclamation marks. Additional rules apply but are out of scope in this CEP and will be
+discussed separately.
+
+### Build strings
+
+Builds strings MUST only consist of ASCII letters, numbers, periods, and underscores. They MUST match this regex `^[a-zA-Z0-9_\.]+$`.
+
+### Filenames
+
+Regular conda artifacts MUST be named following this scheme:
+
+```
+<package name>-<version string>-<build string>.<extension>
+```
+
+Virtual conda packages SHOULD NOT need filename standardization.
+
+### Channels
+
+#### Channel names
+
+Channel names MUST only consist of lowercase ASCII letters, numbers, hyphens, periods and underscores. They MUST start and end with a letter or a digit. In other words, they MUST match  this regex:  `^[a-z0-9]+((-|_|.)[a-z0-9]+)*$`.
+
+#### Label names
+
+Channel label names MUST only consist of ASCII letters, digits, underscores, hyphens, forward slashes, periods, colons and whitespace. They MUST start with a letter. They MUST match this regex: `^[a-zA-Z][0-9a-zA-Z_\-\.\/:\s]*`. Even if allowed, label names SHOULD NOT contain any whitespace.
+
+The label `NOLABEL` is reserved and MUST only be used for conda packages which have no other labels. In other words, in the space of labels, the empty set is represented by the label `NOLABEL`.
+
+#### Subdir names
+
+Platform or subdir names MUST only consist of lowercase ASCII letters, numbers, hyphens, underscores and periods. They MUST start and end with a letter or a number. They MUST match this regex: `^[a-z0-9]+((-|_|.)[a-z0-9]+)*$`.
+
+## Backwards compatibility
+
+The conda channel, subdir, label, and package name regexes are backwards compatible with the current `conda` implementation (25.3) and all existing packages on the `defaults` and `conda-forge` channels, except the `__anaconda_core_depends` package on the `defaults` channel.
+
+The regex for labels above was pulled from an anaconda.org error message describing the set of valid labels. Finally, anaconda.org usernames/channel names are case insensitive and cannot begin with an underscore.
+
+## Copyright
+
+All CEPs are explicitly [CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/).