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| -rw-r--r-- | txr.1 | 28 |
1 files changed, 28 insertions, 0 deletions
@@ -12018,6 +12018,34 @@ or an atom as .codn "(. sym)" . +This notation is implemented for the square brackets, according to this +transformation: + +.verb + [. expr] -> (dwim . expr) +.brev + +This is useful in Structural Pattern Matching, allowing a pattern like + +.verb + [. @args] +.brev + +to match a +.code dwim +expression and capture all of its arguments in a variable, without having +to resort to the internal notation: + +Compatibility Note: support for +.code "[. expr]" +was introduced in \*(TX 282. Older versions do not read the syntax, +but do print +.code "(dwim . @var)" +as +.code "[. @var]" +which is then unreadable in those versions, breaking read-print +consistency. + .NP* Referencing Dot A dot token which is flanked by expressions on both sides, without any |