diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 50 |
1 files changed, 31 insertions, 19 deletions
@@ -31869,17 +31869,19 @@ matching substring of .syne .desc The -.code match-regex -function tests whether +.code match-regex-right +function tests whether some substring of .meta string -contains a match which ends -precisely on the character just before -.metn end-position . +which terminates at the character position just before +.meta end-position +matches +.metn regex . If .meta end-position is not specified, it defaults to the length of the string, and the function performs a right-anchored regex match. + The .meta end-position argument can be a negative integer, in which case it denotes @@ -31890,23 +31892,26 @@ of the string, then .code nil is returned. +If +.meta end-position +is a positive value beyond the length of +.metn string , +then, likewise, +.code nil +is returned. + If a match is found, then the length of the match is returned. -The match must terminate just before -.meta end-position -in the sense that -additional characters at +A more precise way of articulating the role of .meta end-position -and beyond can no longer satisfy the -regular expression. More formally, the function searches, starting from -position zero, for positions where there occurs a match for the regular -expression, taking the longest possible match. The length of first such a match -which terminates on the character just before +is that for the purposes of matching, +.code string +is considered to terminate just before +.metn end-position : +in other words, that .meta end-position -is returned. -If no such a match is found, then -.code nil -is returned. +is the length of the string. The match is then anchored to the +end of this effective string. The .code match-regst-right @@ -31914,7 +31919,7 @@ differs from .code match-regst-right in the representation of the return value in the matching case. Rather than returning the length of the match, it returns -matching substring of +the matching substring of .metn string . .TP* Examples: @@ -45715,6 +45720,13 @@ the behavior. The function was also affected by this issue; however, since it returned nonsense result not corresponding to the matching text, it was repaired without backward compatibility. +Also affected by version 150 compatibility are the +.code match-regex-right +and +.code match-regst-right +functions. These functions worked as documented; however, their +specification changes after version 150 to a semantics which is +more useful and less surprising to the programmer. .IP 148 Up until version 148, the .code :postinit |