rust: simplify pattern file parsing
Previously we kept the pattern syntax as a &[u8] until the last
possible moment, which meant we had to handle potential errors when
parsing that &[u8]. But such errors could never actually occur, given
the structure of the code.
Now we parse it eagerly (in two places) and pass it around as a
PatternSyntax, so we can delete some error handling code.
parse_one_pattern is in particular useful for parsing patterns passed
on the command line, as we'll support later in this series.
#require test-repo execbit
$ . "$TESTDIR/helpers-testrepo.sh"
$ cd "`dirname "$TESTDIR"`"
look for python scripts without the execute bit
$ testrepohg files 'set:**.py and not exec() and grep(r"^#!.*?python")'
[1]
look for python scripts with execute bit but not shebang
$ testrepohg files 'set:**.py and exec() and not grep(r"^#!.*?python")'
[1]
look for shell scripts with execute bit but not shebang
$ testrepohg files 'set:**.sh and exec() and not grep(r"^#!.*(ba)?sh")'
[1]
look for non scripts with no shebang
$ testrepohg files 'set:exec() and not **.sh and not **.py and not grep(r"^#!")'
[1]