The attached patch provides a modification to the recent fix/improvement
to do_grep already included in the most recent development version.
The original fix added new functionality to the grep function by adding
a new parameter, 'invert'. In the source code for the underlying
do_grep, the value of the parameter is used to invert the logical
match-no match flag vector ind. The modification is distributed across
several lines of code.
The patch systematizes the solution by inverting the logical match flag
vector in place, once for each element in the character vector passed to
grep as the argument 'x'. In the patched version, the invertion appears
just once in the code.
The patch does not modify the functionality of grep in any way. If the
respective documentation was updated to cover the new functionality
introduced by the original modification, it still applies to the patched
version.
The patch does not solve any immediate problem. However, due to
replacing the redundantly distributed original modification with a
one-line modofication, the patch is intended to make it easier to
understand, maintain, and further modify the source code.
The patch also renames the variable 'invert' introduced in the original
modification to 'invert_opt', for consistency with how (almost) all
other logical flag parameters in do_grep are named. This modification
is again functionally transparent and requires no modifications to the
documentation.
The patch was prepared as follows:
svn co https://svn.R-project.org/R/trunk/
cd trunk
tools/rsync-recommended
# modifications made to src/main/character.c
svn diff > do_grep.diff
The patched sources were successfully compiled and tested as follows:
svn revert -R .
patch -p0 < do_grep.diff
./configure
make
make check
Assuming that appropriate tests were prepared for the extended version
of grep as of the original modification, the patched version was
successfully tested.
The patched grep was also tested as follows:
bin/R --no-save -q <<END
x = replicate(10, paste(sample(letters, 10, replace=TRUE), collapse=''))
pattern = paste(sample(letters, 3), collapse='')
matched = grep(pattern=pattern, x=x, invert=FALSE)
unmatched = grep(pattern=pattern, x=x, invert=TRUE)
print(all.equal(1:length(x), sort(c(matched, unmatched))))
print(version)
END
with the output:
[1] TRUE
platform
i686-pc-linux-gnu
arch
i686
os
linux-gnu
system i686,
linux-gnu
status Under development
(unstable)
major
2
minor
9.0
year
2009
month
02
day
12
svn rev
47904
language
R
version.string R version 2.9.0 Under development (unstable) (2009-02-12
r47904)
vQ
--
-------------------------------------------------------------------------------
Wacek Kusnierczyk, MD PhD
Email: w...@idi.ntnu.no
Phone: +47 73591875, +47 72574609
Department of Computer and Information Science (IDI)
Faculty of Information Technology, Mathematics and Electrical Engineering (IME)
Norwegian University of Science and Technology (NTNU)
Sem Saelands vei 7, 7491 Trondheim, Norway
Room itv303
Bioinformatics & Gene Regulation Group
Department of Cancer Research and Molecular Medicine (IKM)
Faculty of Medicine (DMF)
Norwegian University of Science and Technology (NTNU)
Laboratory Center, Erling Skjalgsons gt. 1, 7030 Trondheim, Norway
Room 231.05.060
-------------------------------------------------------------------------------
Index: src/main/character.c
===================================================================
--- src/main/character.c (revision 47904)
+++ src/main/character.c (working copy)
@@ -1015,7 +1015,7 @@
SEXP pat, vec, ind, ans;
regex_t reg;
int i, j, n, nmatches = 0, cflags = 0, ov, erroffset, ienc, rc;
- int igcase_opt, extended_opt, value_opt, perl_opt, fixed_opt, useBytes, invert;
+ int igcase_opt, extended_opt, value_opt, perl_opt, fixed_opt, useBytes, invert_opt;
const char *cpat, *errorptr;
pcre *re_pcre = NULL /* -Wall */;
pcre_extra *re_pe = NULL;
@@ -1031,14 +1031,14 @@
perl_opt = asLogical(CAR(args)); args = CDR(args);
fixed_opt = asLogical(CAR(args)); args = CDR(args);
useBytes = asLogical(CAR(args)); args = CDR(args);
- invert = asLogical(CAR(args));
+ invert_opt = asLogical(CAR(args));
if (igcase_opt == NA_INTEGER) igcase_opt = 0;
if (extended_opt == NA_INTEGER) extended_opt = 1;
if (value_opt == NA_INTEGER) value_opt = 0;
if (perl_opt == NA_INTEGER) perl_opt = 0;
if (fixed_opt == NA_INTEGER) fixed_opt = 0;
if (useBytes == NA_INTEGER) useBytes = 0;
- if (invert == NA_INTEGER) invert = 0;
+ if (invert_opt == NA_INTEGER) invert_opt = 0;
if (fixed_opt && igcase_opt)
warning(_("argument '%s' will be ignored"), "ignore.case = TRUE");
if (fixed_opt && perl_opt)
@@ -1148,7 +1148,8 @@
INTEGER(ind)[i] = 1;
} else if (regexec(®, s, 0, NULL, 0) == 0) LOGICAL(ind)[i] = 1;
}
- if (invert ^ LOGICAL(ind)[i]) nmatches++;
+ LOGICAL(ind)[i] ^= invert_opt;
+ if (LOGICAL(ind)[i]) nmatches++;
}
if (fixed_opt);
else if (perl_opt) {
@@ -1167,13 +1168,13 @@
SEXP nmold = getAttrib(vec, R_NamesSymbol), nm;
ans = allocVector(STRSXP, nmatches);
for (i = 0, j = 0; i < n ; i++)
- if (invert ^ LOGICAL(ind)[i])
+ if (LOGICAL(ind)[i])
SET_STRING_ELT(ans, j++, STRING_ELT(vec, i));
/* copy across names and subset */
if (!isNull(nmold)) {
nm = allocVector(STRSXP, nmatches);
for (i = 0, j = 0; i < n ; i++)
- if (invert ^ LOGICAL(ind)[i])
+ if (LOGICAL(ind)[i])
SET_STRING_ELT(nm, j++, STRING_ELT(nmold, i));
setAttrib(ans, R_NamesSymbol, nm);
}
@@ -1181,7 +1182,7 @@
ans = allocVector(INTSXP, nmatches);
j = 0;
for (i = 0 ; i < n ; i++)
- if (invert ^ LOGICAL(ind)[i]) INTEGER(ans)[j++] = i + 1;
+ if (LOGICAL(ind)[i]) INTEGER(ans)[j++] = i + 1;
}
UNPROTECT(1);
return ans;
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