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PATCH: 3.1.6-pws-4: backreferences
- X-seq: zsh-workers 7825
- From: Peter Stephenson <pws@xxxxxxxxxxxxxxxxx>
- To: zsh-workers@xxxxxxxxxxxxxx (Zsh hackers list)
- Subject: PATCH: 3.1.6-pws-4: backreferences
- Date: Tue, 14 Sep 1999 15:45:38 +0200
- Mailing-list: contact zsh-workers-help@xxxxxxxxxxxxxx; run by ezmlm
This implements the following.
- The (#b) globbing flag turns on backreferencing. This does not work in
filename generation because it seemed too much work for too little gain.
It makes matched parentheses in patterns set the arrays $match, $mbegin and
$mend to the matched string, and the index of the begining and end of the
match in ordinary zsh indexing notation, respecting KSHARRAYS. So
[[ fooxbar = (#b)*x(?)* ]]
sets
match=(b) mbegin=(5) mend=(5)
Failed matches leave the existing values for the parameters. This is
natural enough in a test, but could perhaps lead to confusion for use in
parameter matches.
- The (#m) globbing flag sets MATCH, MBEGIN and MEND in a similar way for
the whole matched string. I did this separately because there's no
overhead, unlike for (#b), and it's useful in things like the example given
in the manual,
array=(veldt jynx grimps waqf zho buck)
print ${array//(#m)[aeiou]/${(U)MATCH}}
prints
vEldt jynx grImps wAqf zhO bUck
Again, this does not work in filename generation. If anyone has an example
where it might be useful...?
- The (#B) and (#M) flags turn off the respective features. (#M) is not
very useful because (#m) has to be in effect at the end of the string to
work anyway; it's just there for orthogonality.
- Really stringy strings are now optimized during pattern compilation, not
just execution: if there is no remaining token after remnulargs(), normal
compilation is skipped and the string saved as it is. This should help
with all the case labels we now have in the completion functions, which are
mostly straight strings.
This was all a compromise between speed and simplicity; it didn't seem to
gain much having separate operators to set $match, $mbegin and $mend, while
it did seem to gain by having hard-wired names for them --- it should make
the code where they're used clearer, too. I am delighted to hear other
people's opinions on whether bits of this are too complicated or too simple.
This is about all I really plan to do with the pattern matching code;
anything more hairy is liable to slow down compilation significantly for
limited gain. So if you're still not happy, now is the time to complain.
--- Doc/Zsh/expn.yo.bref Fri Sep 3 17:18:48 1999
+++ Doc/Zsh/expn.yo Tue Sep 14 15:42:32 1999
@@ -211,7 +211,7 @@
)
item(tt(&))(
Repeat the previous tt(s) substitution. Like tt(s), may be preceded
-immediately by a tt(g). In variable expansion the tt(&) must appear
+immediately by a tt(g). In parameter expansion the tt(&) must appear
inside braces, and in filename generation it must be quoted with a
backslash.
)
@@ -988,7 +988,7 @@
is replaced with a `tt(~)' followed by the name of the directory.
The shortest way of referring to the directory is used,
with ties broken in favour of using a named directory,
-except when the directory is tt(/) itself. The variables tt($PWD) and
+except when the directory is tt(/) itself. The parameters tt($PWD) and
tt($OLDPWD) are never abbreviated in this fashion.
If a word begins with an unquoted `tt(=)'
@@ -1202,6 +1202,70 @@
item(I)(
Case sensitive: locally negates the effect of tt(i) or tt(l) from
that point on.
+)
+item(b)(
+Activate backreferences for parenthesised groups in the pattern;
+this does not work in filename generation. When a pattern with a set of
+active parentheses is matched, the strings matched by the groups are
+stored in the array tt($match), the indices of the beginning of the matched
+parentheses in the array tt($mbegin), and the indices of the end in the array
+tt($mend), with the first element of each array corresponding to the first
+parenthesised group, and so on. These arrays are not otherwise special to
+the shell. The indices use the same convention as does parameter
+substitution, so that elements of tt($mend) and tt($mbegin) may be used in
+subscripts; the tt(KSH_ARRAYS) option is respected. Sets of globbing flags
+are not considered parenthesised groups.
+
+For example,
+
+example(foo="a string with a message"
+if [[ $foo = (a|an)' '(#b)(*)' '* ]]; then
+ print ${foo[$mbegin[1],$mend[1]]}
+fi)
+
+prints `tt(string with a)'. Note that the first parenthesis is before the
+tt((#b)) and does not create a backreference.
+
+Backreferences work with all forms of pattern matching other than filename
+generation, but note that when performing matches on an entire array, such
+as tt(${)var(array)tt(#)var(pattern)tt(}), or a global substitution, such
+as tt(${)var(param)tt(//)var(pat)tt(/)var(repl)tt(}), only the data for the
+last match remains available. In the case of global replacements this may
+still be useful. See the example for the tt(m) flag below.
+
+If the match fails none of the parameters is altered, so in some cases it
+may be necessary to initialise them beforehand.
+
+Pattern matching with backreferences is slightly slower than without.
+)
+item(B)(
+Deactivate backreferences, negating the effect of the tt(b) flag from that
+point on.
+)
+item(m)(
+Set references to the match data for the entire string matched; this is
+similar to backreferencing and does not work in filename generation. The
+flag must be in effect at the end of the pattern, i.e. not local to a
+group. The parameters tt($MATCH), tt($MBEGIN) and tt($MEND) will be set to
+the string matched and to the indices of the beginning and end of the
+string, respectively. This is most useful in parameter substitutions, as
+otherwise the string matched is obvious.
+
+For example,
+
+example(arr=(veldt jynx grimps waqf zho buck)
+print ${arr//(#m)[aeiou]/${(U)MATCH}})
+
+forces all the matches (i.e. all vowels) into uppercase, printing
+`tt(vEldt jynx grImps wAqf zhO bUck)'.
+
+Unlike backreferences, there is no speed penalty for using match
+references, other than the extra substitutions required for the
+replacement strings in cases such as the example shown.
+)
+item(M)(
+Deactivate the tt(m) flag, hence no references to match data will be
+created.
)
item(tt(a)var(num))(
Approximate matching: var(num) errors are allowed in the string matched by
--- Src/glob.c.bref Fri Sep 3 16:48:15 1999
+++ Src/glob.c Tue Sep 14 13:43:43 1999
@@ -1815,6 +1815,7 @@
struct repldata {
int b, e; /* beginning and end of chunk to replace */
+ char *replstr; /* replacement string to use */
};
typedef struct repldata *Repldata;
@@ -1844,11 +1845,17 @@
int ll = 0, l = strlen(s), bl = 0, t = 0, i;
if (replstr) {
+ if (fl & SUB_DOSUBST) {
+ replstr = dupstring(replstr);
+ singsub(&replstr);
+ untokenize(replstr);
+ }
if ((fl & SUB_GLOBAL) && repllist) {
/* We are replacing the chunk, just add this to the list */
Repldata rd = (Repldata) zhalloc(sizeof(*rd));
rd->b = b;
rd->e = e;
+ rd->replstr = replstr;
addlinknode(repllist, rd);
return s;
}
@@ -1910,6 +1917,45 @@
return r;
}
+static Patprog
+compgetmatch(char *pat, int *flp, char **replstrp)
+{
+ Patprog p;
+ /*
+ * Flags to pattern compiler: use static buffer since we only
+ * have one pattern at a time; we will try the must-match test ourselves,
+ * so tell the pattern compiler we are scanning.
+ */
+ int patflags = PAT_STATIC|PAT_SCAN|PAT_NOANCH;
+
+ /*
+ * Search is anchored to the end of the string if we want to match
+ * it all, or if we are matching at the end of the string and not
+ * using substrings.
+ */
+ if ((*flp & SUB_ALL) || ((*flp & SUB_END) && !(*flp & SUB_SUBSTR)))
+ patflags &= ~PAT_NOANCH;
+ p = patcompile(pat, patflags, NULL);
+ if (!p) {
+ zerr("bad pattern: %s", pat, 0);
+ return NULL;
+ }
+ if (*replstrp) {
+ if (p->patnpar || (p->globend & GF_MATCHREF)) {
+ /*
+ * Either backreferences or match references, so we
+ * need to re-substitute replstr each time round.
+ */
+ *flp |= SUB_DOSUBST;
+ } else {
+ singsub(replstrp);
+ untokenize(*replstrp);
+ }
+ }
+
+ return p;
+}
+
/*
* This is called from paramsubst to get the match for ${foo#bar} etc.
* fl is a set of the SUB_* flags defined in zsh.h
@@ -1928,17 +1974,10 @@
getmatch(char **sp, char *pat, int fl, int n, char *replstr)
{
Patprog p;
- int patflags = PAT_STATIC|PAT_SCAN|PAT_NOANCH;
- MUSTUSEHEAP("getmatch"); /* presumably covered by prefork() test */
+ if (!(p = compgetmatch(pat, &fl, &replstr)))
+ return 1;
- if ((fl & SUB_ALL) || ((fl & SUB_END) && !(fl & SUB_SUBSTR)))
- patflags &= ~PAT_NOANCH;
- p = patcompile(pat, patflags, NULL);
- if (!p) {
- zerr("bad pattern: %s", pat, 0);
- return 1;
- }
return igetmatch(sp, p, fl, n, replstr);
}
@@ -1948,27 +1987,10 @@
{
char **arr = *ap, **pp;
Patprog p;
- /*
- * Flags to pattern compiler: use static buffer since we only
- * have one pattern at a time; we will try the must-match test ourselves,
- * so tell the pattern compiler we are scanning.
- */
- int patflags = PAT_STATIC|PAT_SCAN|PAT_NOANCH;
- MUSTUSEHEAP("getmatch"); /* presumably covered by prefork() test */
-
- /*
- * Search is anchored to the end of the string if we want to match
- * it all, or if we are matching at the end of the string and not
- * using substrings.
- */
- if ((fl & SUB_ALL) || ((fl & SUB_END) && !(fl & SUB_SUBSTR)))
- patflags &= ~PAT_NOANCH;
- p = patcompile(pat, patflags, NULL);
- if (!p) {
- zerr("bad pattern: %s", pat, 0);
+ if (!(p = compgetmatch(pat, &fl, &replstr)))
return;
- }
+
*ap = pp = ncalloc(sizeof(char *) * (arrlen(arr) + 1));
while ((*pp = *arr++))
if (igetmatch(pp, p, fl, n, replstr))
@@ -1982,6 +2004,7 @@
char *s = *sp, *t, *start, sav;
int i, l = strlen(*sp), matched = 1;
+ MUSTUSEHEAP("igetmatch"); /* presumably covered by prefork() test */
repllist = NULL;
/* perform must-match test for complex closures */
@@ -2031,13 +2054,16 @@
* move back down string until we get a match. *
* There's no optimization here. */
for (t = s + l; t >= s; t--) {
+ patoffset = t - s;
if (pattry(p, t)) {
*sp = get_match_ret(*sp, t - s, l, fl, replstr);
+ patoffset = 0;
return 1;
}
if (t > s+1 && t[-2] == Meta)
t--;
}
+ patoffset = 0;
break;
case (SUB_END|SUB_LONG):
@@ -2045,13 +2071,16 @@
* move forward along string until we get a match. *
* Again there's no optimisation. */
for (i = 0, t = s; i < l; i++, t++) {
+ patoffset = i;
if (pattry(p, t)) {
*sp = get_match_ret(*sp, i, l, fl, replstr);
+ patoffset = 0;
return 1;
}
if (*t == Meta)
i++, t++;
}
+ patoffset = 0;
break;
case SUB_SUBSTR:
@@ -2070,6 +2099,7 @@
matched = 0;
for (t = start; t < s + l; t++) {
/* Find the longest match from this position. */
+ patoffset = t - start;
if (pattry(p, t) && patinput > t) {
char *mpos = patinput;
if (!(fl & SUB_LONG) && !(p->flags & PAT_PURES)) {
@@ -2099,8 +2129,10 @@
* with what we just found.
*/
continue;
- } else
+ } else {
+ patoffset = 0;
return 1;
+ }
}
/*
* For a global match, we need to skip the stuff
@@ -2114,6 +2146,7 @@
t++;
}
} while (matched);
+ patoffset = 0;
/*
* check if we can match a blank string, if so do it
* at the start. Goodness knows if this is a good idea
@@ -2128,13 +2161,17 @@
case (SUB_END|SUB_SUBSTR):
/* Shortest at end with substrings */
+ patoffset = l;
if (pattry(p, s + l) && !--n) {
*sp = get_match_ret(*sp, l, l, fl, replstr);
+ patoffset = 0;
return 1;
} /* fall through */
+ patoffset = 0;
case (SUB_END|SUB_LONG|SUB_SUBSTR):
/* Longest/shortest at end, matching substrings. */
for (t = s + l - 1; t >= s; t--) {
+ patoffset = t - s;
if (t > s && t[-1] == Meta)
t--;
if (pattry(p, t) && patinput > t && !--n) {
@@ -2154,13 +2191,17 @@
}
}
*sp = get_match_ret(*sp, t-s, mpos-s, fl, replstr);
+ patoffset = 0;
return 1;
}
}
+ patoffset = l;
if ((fl & SUB_LONG) && pattry(p, s + l) && !--n) {
*sp = get_match_ret(*sp, l, l, fl, replstr);
+ patoffset = 0;
return 1;
}
+ patoffset = 0;
break;
}
}
@@ -2169,15 +2210,14 @@
/* Put all the bits of a global search and replace together. */
LinkNode nd;
Repldata rd;
- int rlen;
int lleft = 0; /* size of returned string */
+ char *ptr;
i = 0; /* start of last chunk we got from *sp */
- rlen = strlen(replstr);
for (nd = firstnode(repllist); nd; incnode(nd)) {
rd = (Repldata) getdata(nd);
lleft += rd->b - i; /* previous chunk of *sp */
- lleft += rlen; /* the replaced bit */
+ lleft += strlen(rd->replstr); /* the replaced bit */
i = rd->e; /* start of next chunk of *sp */
}
lleft += l - i; /* final chunk from *sp */
@@ -2187,8 +2227,9 @@
rd = (Repldata) getdata(nd);
memcpy(t, s + i, rd->b - i);
t += rd->b - i;
- memcpy(t, replstr, rlen);
- t += rlen;
+ ptr = rd->replstr;
+ while (*ptr)
+ *t++ = *ptr++;
i = rd->e;
}
memcpy(t, s + i, l - i);
--- Src/pattern.c.bref Tue Sep 14 10:10:01 1999
+++ Src/pattern.c Tue Sep 14 15:07:09 1999
@@ -70,11 +70,8 @@
#include "pattern.pro"
-/*
- * Globbing flags: lower 8 bits gives approx count
- */
-#define C_LCMATCHUC 0x0100
-#define C_IGNCASE 0x0200
+/* Number of active parenthesised expressions allowed in backreferencing */
+#define NSUBEXP 9
/* definition number opnd? meaning */
#define P_END 0x00 /* no End of program. */
@@ -205,8 +202,8 @@
* Characters which terminate a pattern segment. We actually use
* a pointer patendseg which skips the first character if we are not
* parsing a file pattern.
- * Note that the size of this and the next array are hard-wired into
- * patcompile.
+ * Note that the size of this and the next array are hard-wired
+ * via the definitions.
*/
static char endseg[] = {
@@ -215,6 +212,9 @@
Tilde /* extended glob only */
};
+#define PATENDSEGLEN_NORM 4
+#define PATENDSEGLEN_EXT 5
+
/* Characters which terminate a simple string */
static char endstr[] = {
@@ -224,6 +224,10 @@
Tilde, Hat, Pound /* extended glob only */
};
+#define PATENDSTRLEN_NORM 9
+#define PATENDSTRLEN_EXT 12
+
+
/* Default size for pattern buffer */
#define P_DEF_ALLOC 256
@@ -291,18 +295,13 @@
Patprog
patcompile(char *exp, int inflags, char **endexp)
{
- int flags, len;
+ int flags = 0, len = 0;
long startoff;
Upat pscan;
- char *lng;
+ char *lng, *strp = NULL;
Patprog p;
-#ifdef BACKREFERENCES
- startoff = (inflags & PAT_BACKR) ? sizeof(struct patprog) :
- sizeof(struct patprog_short);
-#else
startoff = sizeof(struct patprog);
-#endif
/* Ensure alignment of start of program string */
startoff = (startoff + sizeof(union upat) - 1) & ~(sizeof(union upat) - 1);
@@ -312,13 +311,17 @@
patcode = patout + startoff;
patsize = patcode - patout;
patstart = patparse = exp;
+ /*
+ * Note global patnpar numbers parentheses 1..9, while patnpar
+ * in struct is actual count of parentheses.
+ */
patnpar = 1;
- patflags = inflags;
+ patflags = inflags & ~PAT_PURES;
patendseg = endseg;
- patendseglen = isset(EXTENDEDGLOB) ? 5 : 4;
+ patendseglen = isset(EXTENDEDGLOB) ? PATENDSEGLEN_EXT : PATENDSEGLEN_NORM;
patendstr = endstr;
- patendstrlen = isset(EXTENDEDGLOB) ? 12 : 9;
+ patendstrlen = isset(EXTENDEDGLOB) ? PATENDSTRLEN_EXT : PATENDSTRLEN_NORM;
if (!(patflags & PAT_FILE)) {
patendseg++;
@@ -333,66 +336,87 @@
*/
((Patprog)patout)->globflags = patglobflags;
- if (patflags & PAT_ANY)
- flags = 0;
- else if (patcompswitch(0, &flags) == 0)
- return NULL;
+ if (!(patflags & PAT_ANY)) {
+ /* Look for a really pure string, with no tokens at all. */
+ for (strp = exp; *strp &&
+ (!(patflags & PAT_FILE) || *strp != '/') && !itok(*strp);
+ strp++)
+ ;
+ if (*strp && *strp != '/') {
+ /* No, do normal compilation. */
+ strp = NULL;
+ if (patcompswitch(0, &flags) == 0)
+ return NULL;
+ } else {
+ /* Yes, copy the string and skip compilation altogether */
+ patparse = strp;
+ len = strp - exp;
+ patadd(exp, 0, len + 1, 0);
+ patout[startoff + len] = '\0';
+ patflags |= PAT_PURES;
+ }
+ }
/* end of compilation: safe to use pointers */
p = (Patprog)patout;
p->startoff = startoff;
p->patstartch = '\0';
p->globend = patglobflags;
- p->flags = (patflags & ~PAT_PURES);
+ p->flags = patflags;
p->mustoff = 0;
p->size = patsize;
- p->patmlen = 0;
- pscan = (Upat)(patout + startoff);
+ p->patmlen = len;
+ p->patnpar = patnpar-1;
- if (!(patflags & PAT_ANY) && P_OP(PATNEXT(pscan)) == P_END) {
- /* only one top level choice */
- pscan = P_OPERAND(pscan);
+ if (!strp) {
+ pscan = (Upat)(patout + startoff);
- if (flags & P_PURESTR) {
- /*
- * The pattern can be matched with a simple strncmp/strcmp.
- * Careful in case we've overwritten the node for the next ptr.
- */
- char *dst = patout + startoff;
- Upat next;
- p->flags |= PAT_PURES;
- for (; pscan; pscan = next) {
- next = PATNEXT(pscan);
- if (P_OP(pscan) == P_EXACTLY) {
- char *opnd = (char *)P_OPERAND(pscan);
- while ((*dst = *opnd++))
- dst++;
+ if (!(patflags & PAT_ANY) && P_OP(PATNEXT(pscan)) == P_END) {
+ /* only one top level choice */
+ pscan = P_OPERAND(pscan);
+
+ if (flags & P_PURESTR) {
+ /*
+ * The pattern can be matched with a simple strncmp/strcmp.
+ * Careful in case we've overwritten the node for the next ptr.
+ */
+ char *dst = patout + startoff;
+ Upat next;
+ p->flags |= PAT_PURES;
+ for (; pscan; pscan = next) {
+ next = PATNEXT(pscan);
+ if (P_OP(pscan) == P_EXACTLY) {
+ char *opnd = (char *)P_OPERAND(pscan);
+ while ((*dst = *opnd++))
+ dst++;
+ }
}
- }
- *dst++ = '\0';
- p->size = dst - patout;
- /* patmlen is really strlen, don't include null byte */
- p->patmlen = p->size - startoff - 1;
- } else {
- /* starting point info */
- if (P_OP(pscan) == P_EXACTLY && !p->globflags)
- p->patstartch = *(char *)P_OPERAND(pscan);
- /* Find the longest literal string in something expensive.
- * This is itself not all that cheap if we have case-insensitive
- * matching or approximation, so don't.
- */
- if ((flags & P_HSTART) && !p->globflags) {
- lng = NULL;
- len = 0;
- for (; pscan; pscan = PATNEXT(pscan))
- if (P_OP(pscan) == P_EXACTLY &&
- strlen((char *)P_OPERAND(pscan)) >= len) {
- lng = (char *)P_OPERAND(pscan);
- len = strlen(lng);
+ *dst++ = '\0';
+ p->size = dst - patout;
+ /* patmlen is really strlen, don't include null byte */
+ p->patmlen = p->size - startoff - 1;
+ } else {
+ /* starting point info */
+ if (P_OP(pscan) == P_EXACTLY && !p->globflags)
+ p->patstartch = *(char *)P_OPERAND(pscan);
+ /*
+ * Find the longest literal string in something expensive.
+ * This is itself not all that cheap if we have
+ * case-insensitive matching or approximation, so don't.
+ */
+ if ((flags & P_HSTART) && !p->globflags) {
+ lng = NULL;
+ len = 0;
+ for (; pscan; pscan = PATNEXT(pscan))
+ if (P_OP(pscan) == P_EXACTLY &&
+ strlen((char *)P_OPERAND(pscan)) >= len) {
+ lng = (char *)P_OPERAND(pscan);
+ len = strlen(lng);
+ }
+ if (lng) {
+ p->mustoff = lng - patout;
+ p->patmlen = len;
}
- if (lng) {
- p->mustoff = lng - patout;
- p->patmlen = len;
}
}
}
@@ -424,26 +448,22 @@
patcompswitch(int paren, int *flagp)
{
long starter, br, ender, excsync = 0;
-#ifdef BACKREFERENCES
int parno = 0;
-#endif
int flags, gfchanged = 0, savglobflags = patglobflags;
Upat ptr;
*flagp = 0;
-#ifdef BACKREFERENCES
- if (paren && (patflags & PAT_BACKR)) {
+ if (paren && (patglobflags & GF_BACKREF) && patnpar <= NSUBEXP) {
/*
* parenthesized: make an open node.
* We can only refer to the first nine parentheses.
* For any others, we just use P_OPEN on its own; there's
* no gain in arbitrarily limiting the number of parentheses.
*/
- parno = patnpar >= NSUBEXP ? 0 : patnpar++;
+ parno = patnpar++;
starter = patnode(P_OPEN + parno);
} else
-#endif
starter = 0;
br = patnode(P_BRANCH);
@@ -559,12 +579,7 @@
* branch at that point would indicate the current choices continue,
* which they don't.
*/
-#ifdef BACKREFERENCES
- ender = patnode(paren ? (patflags & PAT_BACKR) ? P_CLOSE+parno
- : P_NOTHING : P_END);
-#else
- ender = patnode(paren ? P_NOTHING : P_END);
-#endif
+ ender = patnode(paren ? parno ? P_CLOSE+parno : P_NOTHING : P_END);
pattail(starter, ender);
/*
@@ -708,17 +723,37 @@
case 'l':
/* Lowercase in pattern matches lower or upper in target */
- patglobflags = (patglobflags & ~C_IGNCASE) | C_LCMATCHUC;
+ patglobflags = (patglobflags & ~GF_IGNCASE) | GF_LCMATCHUC;
break;
case 'i':
/* Fully case insensitive */
- patglobflags = (patglobflags & ~C_LCMATCHUC) | C_IGNCASE;
+ patglobflags = (patglobflags & ~GF_LCMATCHUC) | GF_IGNCASE;
break;
case 'I':
/* Restore case sensitivity */
- patglobflags &= ~(C_LCMATCHUC|C_IGNCASE);
+ patglobflags &= ~(GF_LCMATCHUC|GF_IGNCASE);
+ break;
+
+ case 'b':
+ /* Make backreferences */
+ patglobflags |= GF_BACKREF;
+ break;
+
+ case 'B':
+ /* Don't make backreferences */
+ patglobflags &= ~GF_BACKREF;
+ break;
+
+ case 'm':
+ /* Make references to complete match */
+ patglobflags |= GF_MATCHREF;
+ break;
+
+ case 'M':
+ /* Don't */
+ patglobflags &= ~GF_MATCHREF;
break;
default:
@@ -1204,11 +1239,20 @@
/* Length of input string, plus null byte, if needed */
static int patinlen;
-#ifdef BACKREFERENCES
-static char **patstartp; /* Pointer to backref starts */
-static char **patendp; /* Pointer to backref ends */
-static int parsfound; /* parentheses found */
-#endif
+
+/*
+ * Offset of string at which we are trying to match.
+ * This is added in to the positions recorded in patbeginp and patendp
+ * when we are looking for substrings. Currently this only happens
+ * in the parameter substitution code.
+ */
+/**/
+int patoffset;
+
+static char *patbeginp[NSUBEXP]; /* Pointer to backref beginnings */
+static char *patendp[NSUBEXP]; /* Pointer to backref ends */
+static int parsfound; /* parentheses (with backrefs) found */
+
static int globdots; /* Glob initial dots? */
/*
@@ -1233,10 +1277,8 @@
int
pattry(Patprog prog, char *string)
{
-#ifdef BACKREFERENCES
int i;
char **sp, **ep;
-#endif
char *progstr = (char *)prog + prog->startoff;
/* inherited from domatch, but why, exactly? */
@@ -1274,40 +1316,78 @@
errsfound = 0;
}
globdots = !(patflags & PAT_NOGLD);
-#ifdef BACKREFERENCES
parsfound = 0;
- if (patflags & PAT_BACKR) {
- patstartp = prog->ppStartp;
- patendp = prog->ppEndp;
- } else {
- patstartp = patendp = NULL;
- }
-#endif
if (patmatch((Upat)progstr)) {
-#ifdef BACKREFERENCES
- if (patflags & PAT_BACKR) {
- prog->ppStartp[0] = string;
- prog->ppEndp[0] = patinput;
-
- sp = patstartp+1;
- ep = patendp + 1;
- for (i = 1; i < NSUBEXP; i++) {
- if (!(parsfound & (1 << (i - 1))))
- *sp = 0;
- if (!(parsfound & (1 << (i + 15))))
- *ep = 0;
- sp++;
- ep++;
- }
-
- }
-#endif
/*
* we were lazy and didn't save the globflags if an exclusion
* failed, so set it now
*/
patglobflags = prog->globend;
+ /*
+ * Should we clear backreferences and matches on a failed
+ * match?
+ */
+ if ((patglobflags & GF_MATCHREF) && !(patflags & PAT_FILE)) {
+ /*
+ * m flag: for global match. This carries no overhead
+ * in the pattern matching part.
+ */
+ char *str;
+ int len = patinput - patinstart;
+
+ PERMALLOC {
+ str = dupstrpfx(patinstart, len);
+ } LASTALLOC;
+ setsparam("MATCH", str);
+ setiparam("MBEGIN", (zlong)(patoffset + !isset(KSHARRAYS)));
+ setiparam("MEND",
+ (zlong)(len + patoffset + !isset(KSHARRAYS) - 1));
+ }
+ if (prog->patnpar && !(patflags & PAT_FILE)) {
+ /*
+ * b flag: for backreferences using parentheses.
+ */
+ int palen = prog->patnpar+1;
+ char **matcharr, **mbeginarr, **mendarr;
+ char numbuf[DIGBUFSIZE];
+
+ matcharr = zcalloc(palen*sizeof(char *));
+ mbeginarr = zcalloc(palen*sizeof(char *));
+ mendarr = zcalloc(palen*sizeof(char *));
+
+ sp = patbeginp;
+ ep = patendp;
+
+ PERMALLOC {
+ for (i = 0; i < prog->patnpar; i++) {
+ DPUTS(!*sp || !*ep, "BUG: backrefs not set.");
+ matcharr[i] = dupstrpfx(*sp, *ep - *sp);
+ /*
+ * mbegin and mend give indexes into the string
+ * in the standard notation, i.e. respecting
+ * KSHARRAYS, and with the end index giving
+ * the last character, not one beyond.
+ * For example, foo=foo; [[ $foo = (f)oo ]] gives
+ * (without KSHARRAYS) indexes 1 and 1, which
+ * corresponds to indexing as ${foo[1,1]}.
+ */
+ sprintf(numbuf, "%ld",
+ (long)((*sp - patinstart) + patoffset +
+ !isset(KSHARRAYS)));
+ mbeginarr[i] = ztrdup(numbuf);
+ sprintf(numbuf, "%ld",
+ (long)((*ep - patinstart) + patoffset +
+ !isset(KSHARRAYS) - 1));
+ mendarr[i] = ztrdup(numbuf);
+ sp++;
+ ep++;
+ }
+ } LASTALLOC;
+ setaparam("match", matcharr);
+ setaparam("mbegin", mbeginarr);
+ setaparam("mend", mendarr);
+ }
return 1;
} else
return 0;
@@ -1319,10 +1399,10 @@
* comes from the input string, the second the current pattern.
*/
#define CHARMATCH(chin, chpa) (chin == chpa || \
- ((patglobflags & C_IGNCASE) ? \
+ ((patglobflags & GF_IGNCASE) ? \
((isupper(chin) ? tolower(chin) : chin) == \
(isupper(chpa) ? tolower(chpa) : chpa)) : \
- (patglobflags & C_LCMATCHUC) ? \
+ (patglobflags & GF_LCMATCHUC) ? \
(islower(chpa) && toupper(chpa) == chin) : 0))
/*
@@ -1480,7 +1560,6 @@
case P_GFLAGS:
patglobflags = P_OPERAND(scan)->l;
break;
-#ifdef BACKREFERENCES
case P_OPEN:
case P_OPEN+1:
case P_OPEN+2:
@@ -1495,13 +1574,12 @@
save = patinput;
if (patmatch(next)) {
- DPUTS(!patstartp, "patstartp not set for backreferencing");
/*
- * Don't set ppStartp if some later invocation of
+ * Don't set patbeginp if some later invocation of
* the same parentheses already has.
*/
if (no && !(parsfound & (1 << (no - 1)))) {
- patstartp[no] = save;
+ patbeginp[no-1] = save;
parsfound |= 1 << (no - 1);
}
return 1;
@@ -1524,14 +1602,13 @@
if (patmatch(next)) {
DPUTS(!patendp, "patendp not set for backreferencing");
if (no && !(parsfound & (1 << (no + 15)))) {
- patendp[no] = save;
+ patendp[no-1] = save;
parsfound |= 1 << (no + 15);
}
return 1;
} else
return 0;
break;
-#endif
case P_EXCSYNC:
/* See the P_EXCLUDE code below for where syncptr comes from */
{
@@ -1605,9 +1682,7 @@
unsigned char *oldsyncstr;
char *matchpt = NULL;
int ret, savglobdots, matchederrs = 0;
-#ifdef BACKREFERENCES
int savparsfound = parsfound;
-#endif
DPUTS(P_OP(scan) == P_WBRANCH,
"BUG: excluded WBRANCH");
syncstrp = P_OPERAND(next);
@@ -1674,14 +1749,12 @@
}
if (patmatch(opnd)) {
ret = 0;
-#ifdef BACKREFERENCES
/*
* Another subtlety: if we exclude the
* match, any parentheses just found
* become invalidated.
*/
parsfound = savparsfound;
-#endif
}
if (buf)
zfree(buf, pathpos + patinlen);
@@ -2184,18 +2257,16 @@
printf("start `%c' ", r->patstartch);
if (!(r->flags & PAT_NOANCH))
printf("EOL-anchor ");
-#ifdef BACKREFERENCES
- if (r->flags & PAT_BACKR)
- printf("backreferences ");
-#endif
+ if (r->patnpar)
+ printf("%d active backreferences ", r->patnpar);
if (r->mustoff)
printf("must have \"%s\"", (char *)r + r->mustoff);
printf("\n");
if (r->globflags) {
printf("Globbing flags: ");
- if (r->globflags & C_LCMATCHUC)
+ if (r->globflags & GF_LCMATCHUC)
printf("LC matches UC ");
- if (r->globflags & C_IGNCASE)
+ if (r->globflags & GF_IGNCASE)
printf("Ignore case");
printf("\n");
if (r->globflags & 0xff)
@@ -2317,16 +2388,11 @@
bin_patdebug(char *name, char **args, char *ops, int func)
{
Patprog prog;
- int ret = 0, flags;
+ int ret = 0;
tokenize(*args);
-#ifdef BACKREFERENCES
- flags = ops['b'] ? PAT_BACKR : 0;
-#else
- flags = 0;
-#endif
- if (!(prog = patcompile((char *)*args, flags, 0)))
+ if (!(prog = patcompile((char *)*args, 0, 0)))
return 1;
if (ops['p'] || !args[1]) {
patdump(prog);
--- Src/zsh.h.bref Fri Sep 3 11:31:37 1999
+++ Src/zsh.h Tue Sep 14 13:07:38 1999
@@ -911,7 +911,6 @@
* happily be ints.
*/
-#define NSUBEXP 10
struct patprog {
long startoff; /* length before start of programme */
long size; /* total size from start of struct */
@@ -919,28 +918,9 @@
int globflags; /* globbing flags to set at start */
int globend; /* globbing flags set after finish */
int flags; /* PAT_* flags */
- int patmlen;
+ int patmlen; /* length of pure string or longest match */
+ int patnpar; /* number of active parentheses */
char patstartch;
-#ifdef BACKREFERENCES
- unsigned char * ppStartp[NSUBEXP];
- unsigned char * ppEndp[NSUBEXP];
-};
-
-/* Same as patprog, but without the backreference storage.
- * Note the calling code must test PAT_BACKR to know which is
- * which, since they are both passed back as a Patprog.
- */
-
-struct patprog_short {
- long startoff;
- long size;
- long mustoff;
- int globflags;
- int globend;
- int flags;
- int patmlen;
- char patstartch;
-#endif
};
/* Flags used in pattern matchers (Patprog) and passed down to patcompile */
@@ -953,9 +933,12 @@
#define PAT_PURES 0x0020 /* Pattern is a pure string: set internally */
#define PAT_STATIC 0x0040 /* Don't copy pattern to heap as per default */
#define PAT_SCAN 0x0080 /* Scanning, so don't try must-match test */
-#ifdef BACKREFERENCES
-#define PAT_BACKR 0x0100 /* Parentheses make backreferences */
-#endif
+
+/* Globbing flags: lower 8 bits gives approx count */
+#define GF_LCMATCHUC 0x0100
+#define GF_IGNCASE 0x0200
+#define GF_BACKREF 0x0400
+#define GF_MATCHREF 0x0800
/* node used in parameter hash table (paramtab) */
@@ -1067,6 +1050,7 @@
#define SUB_LEN 0x0080 /* length of match */
#define SUB_ALL 0x0100 /* match complete string */
#define SUB_GLOBAL 0x0200 /* global substitution ${..//all/these} */
+#define SUB_DOSUBST 0x0400 /* replacement string needs substituting */
/* Flags as the second argument to prefork */
#define PF_TYPESET 0x01 /* argument handled like typeset foo=bar */
--
Peter Stephenson <pws@xxxxxxxxxxxxxxxxx> Tel: +39 050 844536
WWW: http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarroti 2, 56127 Pisa, Italy
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