[fpc-devel] TMask classes

José Mejuto joshyfun at gmail.com
Thu Dec 3 19:57:25 CET 2020


I've written a TMask class family and I would like to know if it could 
be of any interest for the fpc code base, if there is interest I must 
write some unit test code but if there is no interest I'll not write it ;-)

There is a TMask class in LazUtils but it lacks some features and has an 
speed problem in large strings when 2 or more '*' are involved.

My TMask family is:

TMaskAnsi, TMaskUTF8 and TMaskUnicode:

This three classes hold the logic for each "char" space, ANSI 1 char, 
UTF8 1 to 6 bytes and Unicode 2 or 4 bytes.

Available wildcards are:

* = Any text.
? = Just one character unit.
[abc] = Anyone of "abc"
[a-c] = Anyone of "abc" (range)
[!ab] = Negate a match "a" or "b"
[!a-c] = Negate a match group
[?] = One character unit or none.
\? = Escape character '\' (next char is a literal "?")

So the usual masks, nothing new under the sun.

TMaskAnsi does not allow high chars ranges, so "[á-ú]" is not valid as 
characters in ANSI usually does not follow expected order. UTF8 and 
Unicode allows them as usually they are in the "expected order".

Any feature can be toggled, so it can be set to ignore ranges, in 
example, so "[a-z]" will be interpreted as "a" or "-" or "z". Also the 
escape char can be configured, but it must be ASCII < 127.

Derived from this classes there are:

TMaskAnsiWindows, TMaskUTF8Windows and TMaskUnicodeWindows.

This classes implements the special wildcards of Windows, inherited from 
CP/M, like "*." must match all files without extension, "*.*" must match 
any file, "file.ext" must match "file.extension" or "file??.ext" must 
match "file.ext", "file1.ext" and "file1a.ext".

This special cases, are called Quirks and can be enabled or disabled one 
by one like ".ext" which in the past matches any file with ".ext" as 
extension, but this not happen in recent Windows versions, so in the 
code is disabled by default.

Thank you for reading such amount of text, have a nice day.


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