diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 21 |
1 files changed, 20 insertions, 1 deletions
@@ -43157,7 +43157,7 @@ A quasiliteral pattern matches in a linear fashion, from left to right. Variables bound earlier in the pattern can be referenced later in the pattern as bound variables. -Bound variables denote character strings in accordance with the usual +With one exception, bound variables denote character strings in accordance with the usual quasiliteral conversion and formatting rules. All of the modifier notations may be used. For instance, if .code x @@ -43167,6 +43167,11 @@ denotes the value of .code x converted to a string, and right-aligned in a forty-character-wide field. Consequently, the notation matches exactly such a forty-character text. +The exception is that if a bound variable has a regular expression modifier, +as in +.code "@{x #/re/}" +then it has a special meaning as a pattern. Moreover, this syntax has no +meaning in a quasiliteral. In the following description of the quasiliteral pattern-matching rules, the symbols @@ -43259,6 +43264,20 @@ then the match is successful and captures that prefix. The rest of the pattern .code {P} is then matched against the rest of the string after the prefix. +.meIP >> `@{ bv <> #/ regex /}{P}` +A bound variable +.meta bv +which carries a regular expression modifier specifies a regular expression +match exactly like an unbound variable. This syntax produces a successful +match if two conditions are met: a prefix of the input string matches +.metn regex , +and the matched prefix is +.meta equal +to the value of +.metn bv . +The rest of the pattern +.code {P} +is then matched against the rest of the string after the prefix. .meIP <> `@ bv {P}` The bound variable .meta bv |