什么是xmlchars，Utilities for determining if characters belong to character classes defined by the XML specs.
Utilities for determining whether characters belong to character classes defined by the XML specs.
It used to be that the library was contained in a single file and you could just import/require/what-have-you the
xmlchars module. However, that setup did not work well for people who cared about code optimization. Importing
xmlchars meant importing all of the library and because of the way the code was generated there was no way to shake the resulting code tree.
Since version 1.3.0, importing
xmlchars is deprecated. Instead, you should directly load the file from
xmlchars/lib that you care about. Even without tree shaking being used, this results in a smaller footprint.
Different modules cover different standards. At the time this documentation was last updated, we had:
xmlchars/xml/1.0/ed5which covers XML 1.0 edition 5.
xmlchars/xml/1.0/ed4which covers XML 1.0 edition 4.
xmlchars/xmlns/1.0/ed3which covers XML Namespaces 1.0 edition 3.
The “things” each module contains can be categorized as follows:
“Fragments”: these are parts and pieces of regular expressions that correspond to the productions defined in the standard that the module covers. You’d use these to build regular expressions.
Regular expressions that correspond to the productions defined in the standard that the module covers.
Lists: these are arrays of characters that correspond to the productions.
Functions that test code points to verify whether they fit a production.