Add ASCII mode

[SicroAtGit]

This feature implements ASCII mode. When activated, the predefined character classes will only match the corresponding ASCII characters. For example, (?a)\w will then match only [a-zA-Z0-9_]. The character encoding remains UCS-2 in this mode, i.e. (?a)\W matches all UCS-2 characters, but not [a-zA-Z0-9_].

New Syntax

• (?a) — activates ASCII mode.
• (?-a) — deactivates ASCII mode (default).

New Parameter

• AddNfa(..., "\w", #RegExMode_Ascii) is the same as AddNfa(..., "(?a)\w")

This mode is also useful in combination with #RegExMode_NoCase when you want to lex keywords in a code, case-insensitive, but no case-folding should be applied. Example:

• (?i)set corresponds to [Ss\u017F][Ee][Tt]
• (?ia)set corresponds to [Ss][Ee][Tt]