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Encoding scheme to encode any Unicode stringwith only characters from[0-9a-zA-Z_].Therefore it's quite similar to URL percent-encoding.It's especially useful for GraphQL ID generation.

Constraints for the encoding scheme:

1. Common IDs likefile_format,fileFormat,FileFormat,FILE_FORMAT,__file_format__, … must not be altered
2. Support all Unicode characters
3. Characters of the ASCII range must lead to shorter encodings
4. Optional support for encoding leading digits (like in1_file_format)to fulfill constraints of some ID schemes (e.g. GraphQL's).

With encoding of leading digit and double underscore activated(necessary for GraphQL ID generation):

The encoding scheme is based on the following rules:

1. All characters in[0-9A-Za-z_] except forXX are encoded as is
2. XX is encoded asXXXXXX
3. All other printable characters inside the ASCII rangeare encoded as a sequence of 3 characters:XX[0-9A-W]
4. All other Unicode code points untilU+fffff (e.g. Emojis)are encoded as a sequence of 7 characters:XX[a-p]{5}, where the 5 characters are the hexadecimal representationwith an alternative hex alphabet ranging froma top instead of0 tof.
5. All Unicode code points in the Supplementary Private Use Area-B(U+100000 toU+10ffff) are encoded as a sequence of 9 characters:XXY[a-p]{6}

If the optional leading digit encoding is enabled,a leading digit is encoded asXXZ[0-9].

If the optional double underscore encoding is enabled,double underscores are encoded asXXRXXR.

• Haskell:Via Hackage
• Other languages:
  The code is not yet available via common package managers.Please copy the code into your project for the time being.