# Standard network working group reference

mime-extension-p Boolean String

The `mime-extension-p` predicates returns true if a media type extension - mime extension - is defined. Most of the time, media type extension can be seen as a file extension.

mime-value-p Boolean String

The `mime-value-p` predicates returns true if a media type - mime value - is defined.

extension-to-mime String String [Boolean]

The `extension-to-mime` function converts a media type extension into a media type. In the first form, without a second argument, if the media type extension does not exist, an exception is raised. In the second form, with the second argument set to true, if the media type extension does not exist, the default media type is returned. If the flag is set to false, an exception is raised like the first form.

normalize-uri-name String String

The `normalize-uri-name` function normalizes the string argument by adding a uri scheme if missing in the original string. If the function detects that the name starts with a host name, the "http" scheme is added. If the function detects that the string starts with a path, the "file" scheme is added. otherwise, the name argument is left untouched.

system-uri-name String String

The `system-uri-name` function normalizes the string argument by prioritizing the system name. The function attempts to find a file that match the string argument and eventually build a uri file scheme. If the file is not fond, the normalization process occurs with the `normalize-uri-name` function.