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Diffstat (limited to 'Doc/lib/libdifflib.tex')
| -rw-r--r-- | Doc/lib/libdifflib.tex | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/Doc/lib/libdifflib.tex b/Doc/lib/libdifflib.tex index 3bc103b85a..37e401e274 100644 --- a/Doc/lib/libdifflib.tex +++ b/Doc/lib/libdifflib.tex @@ -90,13 +90,19 @@ Optional keyword parameters \var{linejunk} and \var{charjunk} are for filter functions (or \code{None}): - \var{linejunk}: A function that should accept a single string - argument, and return true if the string is junk (or false if it is - not). The default is module-level function + \var{linejunk}: A function that accepts a single string + argument, and returns true if the string is junk, or false if not. + The default is (\code{None}), starting with Python 2.3. Before then, + the default was the module-level function \function{IS_LINE_JUNK()}, which filters out lines without visible characters, except for at most one pound character (\character{\#}). + As of Python 2.3, the underlying \class{SequenceMatcher} class + does a dynamic analysis of which lines are so frequent as to + constitute noise, and this usually works better than the pre-2.3 + default. - \var{charjunk}: A function that should accept a string of length 1. + \var{charjunk}: A function that accepts a character (a string of + length 1), and returns if the character is junk, or false if not. The default is module-level function \function{IS_CHARACTER_JUNK()}, which filters out whitespace characters (a blank or tab; note: bad idea to include newline in this!). @@ -150,7 +156,7 @@ emu Return true for ignorable lines. The line \var{line} is ignorable if \var{line} is blank or contains a single \character{\#}, otherwise it is not ignorable. Used as a default for parameter - \var{linejunk} in \function{ndiff()}. + \var{linejunk} in \function{ndiff()} before Python 2.3. \end{funcdesc} @@ -443,16 +449,14 @@ The \class{Differ} class has this constructor: Optional keyword parameters \var{linejunk} and \var{charjunk} are for filter functions (or \code{None}): - \var{linejunk}: A function that should accept a single string - argument, and return true if the string is junk. The default is - module-level function \function{IS_LINE_JUNK()}, which filters out - lines without visible characters, except for at most one pound - character (\character{\#}). + \var{linejunk}: A function that accepts a single string + argument, and returns true if the string is junk. The default is + \code{None}, meaning that no line is considered junk. - \var{charjunk}: A function that should accept a string of length 1. - The default is module-level function \function{IS_CHARACTER_JUNK()}, - which filters out whitespace characters (a blank or tab; note: bad - idea to include newline in this!). + \var{charjunk}: A function that accepts a single character argument + (a string of length 1), and returns true if the character is junk. + The default is \code{None}, meaning that no character is + considered junk. \end{classdesc} \class{Differ} objects are used (deltas generated) via a single |