The IDNA and UTS 46 functionality in this library relies upon pre-calculated lookup tables for performance. These tables are derived from computing against eligibility criteria in the respective standards using the command-line script idna-data in this directory.
This tool will fetch relevant codepoint data from the Unicode repository and perform the required calculations to identify eligibility. There are three main modes:
idna-data make-libdata. Generates idnadata.py and uts46data.py, the pre-calculated lookup tables used for IDNA and UTS 46 conversions. Implementers who wish to track this library against a different Unicode version may use this tool to manually generate a different version of the idnadata.py and uts46data.py files.
idna-data make-table. Generate a table of the IDNA disposition (e.g. PVALID, CONTEXTJ, CONTEXTO) in the format found in Appendix B.1 of RFC 5892 and the pre-computed tables published by IANA.
idna-data U+0061. Prints debugging output on the various properties associated with an individual Unicode codepoint (in this case, U+0061), that are used to assess the IDNA and UTS 46 status of a codepoint. This is helpful in debugging or analysis.
The tool accepts a number of arguments, described using idna-data -h. Most notably, the --version argument allows the specification of the version of Unicode to be used in computing the table data. For example, idna-data --version 9.0.0 make-libdata will generate library data against Unicode 9.0.0.