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rend [-s] -i 'target_interp' -f reassign-file [inputfile ...]
Humdrum data tokens often contain more than one type of information
or type of signfier.
For example, the
**pitch
representation consists of three parts
(not including cents deviation):
the pitch letter name, the accidental, and the octave number (e.g. A#4).
In some tasks it may be useful to split such information into separate spines.
For example, a user may wish to reformat the following spine:
as three independent spines:
**pitch Ab3 Eb4 F#4 C5 *-
The
rend
command allows each occurrence of a target exclusive interpretation to be
replaced by specified output spines.
The user selects how the signfiers (characters) in the
input spines are to be distributed to the replacement output spines.
Signifiers (ASCII characters) are identified using UNIX
regular expression syntax (see regexp (6)).
**octave **note **accidental 3 Ab b 4 Eb b 4 F# # 5 C . *- *- *-
The above transformation may be achieved by invoking the following command:
rend -i '**pitch' -f reassign
The -i option specifies the target input interpretation, i.e.,
the input spine(s) to be processed.
The -f option specifies a reassignment-file
(named reassign) containing the following records:
Reassignment files consist of one or more records, each containing two
strings separated by a tab.
The left-most string identifies the name of the new spine to be generated.
The right-most string defines an associated regular expression.
Any input signifiers matching the regular expression will be echoed as output
in the associated spine.
In the above case, all numbers are echoed in the first spine
(
**octave [0-9] **note [A-Gb#x]+ **accidental [b#x]+ **octave),
all letters plus the sharp (#) and flat (b) signs are echoed in the
second spine (**note), whereas only sharp and flat signs are
echoed in the third spine (**accidental).
The order of the output spines preserves the order of the assignments
in the reassignment file.
In the above case, for example, the order of the output spines will be
**octave, **note, **accidental
for each input spine labelled
**pitch.
Options are specified in the command line.
-f reassign maps input tokens to output tokens according to definitions given in the file reassign -h displays a help screen summarizing the command syntax -i target_interp process all input spines whose exclusive interpretations are labelled target_interp -s matches a single instance of the given pattern rather than all instances
Consider the following example:
rend -i '**kern' -f noterest song01
and the associated reassignment file named noterest:
**notes []A-Ga-g[#-]+|^=+[0-9]*
**rests [\\.0-9r]+|^=+[0-9]*
This command specifies that each
**kern
spine in the file
song01
is to be split into two new spines dubbed
**notes
and
**rests.
The first regular expression -- '[]A-Ga-g[#-]+|^=+[0-9]*' --
indicates that the following strings should be echoed in the
data records for **notes:
the upper-case letters A to G
and the lower-case letters a to g,
plus the characters [, ], #, and -.
Alternatively,
rend
will echo any data token beginning with one or more equals-signs,
followed by zero or more numbers.
Similarly, the second
**rests
spine will contain characters that match the regular
expression '[\\.0-9r]+|^+=[0-9]*'.
This includes the period (.), all numbers (0-9), plus the letter
r.
Alternatively,
rend
will echo any data token beginning with one or more equals-signs,
followed by zero or more numbers.
Given this command, the following input:
will produce the following output:
**kern **lyrics **kern !! Commented input. 8.G Hi- 4r 16G# de- . =23 =23 =23 8A ho- 2r [8c . . 8c] . . 16r . . 16A . . =24 =24 =24 2C 2E hum. 2r === === === *- *- *-
Notice that
rend
correctly handles Humdrum multiple-stops (such as
**notes **rests **lyrics **notes **rests !! Commented input. G 8. Hi- . 4r G# 16 de- . . =23 =23 =23 =23 =23 A 8 ho- . 2r [c 8 . . . c] 8 . . . . 16r . . . A 16 . . . =24 =24 =24 =24 =24 C E 2 2 hum. . 2r === === === === === *- *- *- *- *- 2C 2E).
Notice also that if no match is made, a null token (.) is output.
cleave (4),
extract (4),
humsed (4),
recode (4),
regexp (4),
regexp (6)
If the interpretation targetted for processing appears in a spine starting with a different interpretation, the output will fail to generate the proper spine terminator and add-spine path indicators. The result is a non-Humdrum file. Consider the following command:
rend -i '**ex1' -f reassign input
and the associate reassignment file (reassign):
**let [a-z]
**num [0-9]
Given the following input:
the corresponding output is given below.
Note the absence of appropriate spine-path indicators
between lines 4 and 5 (hence the output is non-Humdrum).
**ex1 **ex2 a1 b2 *tand1 *tand2 c3 d4 * **ex1 e5 f6 *- *-
**let **num **ex2 a 1 b2 *tand1 *tand1 *tand2 c 3 d4 * * **let **num e 5 f 6 *- *- *- *-