diff options
| -rw-r--r-- | Doc/lib/libre.tex | 15 | ||||
| -rw-r--r-- | Doc/libre.tex | 15 |
2 files changed, 20 insertions, 10 deletions
diff --git a/Doc/lib/libre.tex b/Doc/lib/libre.tex index 3d0f376..a217418 100644 --- a/Doc/lib/libre.tex +++ b/Doc/lib/libre.tex @@ -420,7 +420,7 @@ previous match, so \samp{sub('x*', '-', 'abc')} returns \code{'-a-b-c-'}. If \var{repl} is a string, any backslash escapes in it are processed. That is, \samp{\e n} is converted to a single newline character, \samp{\e r} is converted to a linefeed, and so forth. Unknown escapes -such as \samp{\e j} are XXX. Backreferences, such as \samp{\e 6} are +such as \samp{\e j} are left alone. Backreferences, such as \samp{\e 6} are replaced with the substring matched by group 6 in the pattern. In addition to character escapes and backreferences as described @@ -521,13 +521,18 @@ Without arguments, \var{group1} defaults to zero (i.e. the whole match is returned). If a \var{groupN} argument is zero, the corresponding return value is the entire matching string; if it is in the inclusive range [1..99], it is -the string matching the the corresponding parenthesized group. If no -such group exists, the corresponding result is -\code{None}. +the string matching the the corresponding parenthesized group. If a +group number is negative or larger than the number of groups defined +in the pattern, an \exception{IndexError} exception is raised. +If a group is contained in a part of the pattern that did not match, +the corresponding result is \code{None}. If a group is contained in a +part of the pattern that matched multiple times, the last match is +returned. If the regular expression uses the \code{(?P<\var{name}>...)} syntax, the \var{groupN} arguments may also be strings identifying groups by -their group name. +their group name. If a string argument is not used as a group name in +the pattern, an \exception{IndexError} exception is raised. A moderately complicated example: diff --git a/Doc/libre.tex b/Doc/libre.tex index 3d0f376..a217418 100644 --- a/Doc/libre.tex +++ b/Doc/libre.tex @@ -420,7 +420,7 @@ previous match, so \samp{sub('x*', '-', 'abc')} returns \code{'-a-b-c-'}. If \var{repl} is a string, any backslash escapes in it are processed. That is, \samp{\e n} is converted to a single newline character, \samp{\e r} is converted to a linefeed, and so forth. Unknown escapes -such as \samp{\e j} are XXX. Backreferences, such as \samp{\e 6} are +such as \samp{\e j} are left alone. Backreferences, such as \samp{\e 6} are replaced with the substring matched by group 6 in the pattern. In addition to character escapes and backreferences as described @@ -521,13 +521,18 @@ Without arguments, \var{group1} defaults to zero (i.e. the whole match is returned). If a \var{groupN} argument is zero, the corresponding return value is the entire matching string; if it is in the inclusive range [1..99], it is -the string matching the the corresponding parenthesized group. If no -such group exists, the corresponding result is -\code{None}. +the string matching the the corresponding parenthesized group. If a +group number is negative or larger than the number of groups defined +in the pattern, an \exception{IndexError} exception is raised. +If a group is contained in a part of the pattern that did not match, +the corresponding result is \code{None}. If a group is contained in a +part of the pattern that matched multiple times, the last match is +returned. If the regular expression uses the \code{(?P<\var{name}>...)} syntax, the \var{groupN} arguments may also be strings identifying groups by -their group name. +their group name. If a string argument is not used as a group name in +the pattern, an \exception{IndexError} exception is raised. A moderately complicated example: |