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(?(assert)... assertion condition |
(?(assert)... assertion condition |
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. |
. |
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.SH "BACKTRACKING CONTROL" |
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.rs |
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.sp |
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The following act immediately they are reached: |
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.sp |
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(*ACCEPT) force successful match |
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(*FAIL) force backtrack; synonym (*F) |
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.sp |
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The following act only when a subsequent match failure causes a backtrack to |
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reach them. They all force a match failure, but they differ in what happens |
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afterwards. Those that advance the start-of-match point do so only if the |
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pattern is not anchored. |
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.sp |
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(*COMMIT) overall failure, no advance of starting point |
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(*PRUNE) advance to next starting character |
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(*SKIP) advance start to current matching position |
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(*THEN) local failure, backtrack to next alternation |
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. |
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. |
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.SH "CALLOUTS" |
.SH "CALLOUTS" |
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.rs |
.rs |
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.sp |
.sp |
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.rs |
.rs |
| 396 |
.sp |
.sp |
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.nf |
.nf |
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Last updated: 06 August 2007 |
Last updated: 08 August 2007 |
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Copyright (c) 1997-2007 University of Cambridge. |
Copyright (c) 1997-2007 University of Cambridge. |
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.fi |
.fi |