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| author | Kaz Kylheku <kaz@kylheku.com> | 2016-12-20 04:00:22 -0800 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2016-12-20 04:00:22 -0800 |
| commit | 7c5b70d7d17faf6543350dffe56292e3f7dff679 (patch) | |
| tree | 522550ef5e10d87961191dad88e4c6c2c10dac4d /txr.1 | |
| parent | 59ddd76e362196ac68ab291b9a76a55fd257d29c (diff) | |
| download | txr-7c5b70d7d17faf6543350dffe56292e3f7dff679.tar.gz txr-7c5b70d7d17faf6543350dffe56292e3f7dff679.tar.bz2 txr-7c5b70d7d17faf6543350dffe56292e3f7dff679.zip | |
awk macro: endpont-exclusive ranges.
* share/txr/stdlib/awk.tl (sys:awk-mac-let): Local macro
sys:rng generalized to support code generation for ranges that
exclude either endpoint. Local rng macro adjusted to target
this new form. Local macros rng-, -rng, and -rng- added.
* txr.1: Documented.
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 30 |
1 files changed, 29 insertions, 1 deletions
@@ -42464,9 +42464,12 @@ next one. If there is no next input source, .code awk terminates. -.coNP Macro @ rng +.coNP Macros @, rng @, -rng @ rng- and @ -rng- .synb .mets (rng < from-condition << to-condition ) +.mets (-rng < from-condition << to-condition ) +.mets (rng- < from-condition << to-condition ) +.mets (-rng- < from-condition << to-condition ) .syne .desc The awk macro @@ -42483,6 +42486,31 @@ is found to be true, and ends when is true. Over this interval, range is said to be .IR active . +The +.code rng +macro's result value is true for the starting record which matches +.metn from-condition , +the final record which matches +.metn to-condition , +and all records in between, if any. +The remaining macros work exactly like +.codn rng , +identifying the active range in the same manner. They differ +in that the Boolean value they produce excludes the starting record, +final record, or both, depending on which macro. The +.code -rng +macro yields +.code nil +for the initial record. The +.code rng- +macro yields +.code nil +for the final record. The +.code -rng- +macro yields +.code nil +for both the initial and final record. + Ranges expressed using .code rng may combine with other expressions, including |