139 lines
3.9 KiB
C
139 lines
3.9 KiB
C
/*
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* Utility functions for handling cvecs
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* This file is #included by regcomp.c.
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*
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* Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
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*
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* Development of this software was funded, in part, by Cray Research Inc.,
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* UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
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* Corporation, none of whom are responsible for the results. The author
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* thanks all of them.
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*
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* Redistribution and use in source and binary forms -- with or without
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* modification -- are permitted for any purpose, provided that
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* redistributions in source form retain this entire copyright notice and
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* indicate the origin and nature of any modifications.
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*
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* I'd appreciate being given credit for this package in the documentation
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* of software which uses it, but that is not a requirement.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* src/backend/regex/regc_cvec.c
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*
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*/
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/*
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* Notes:
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* Only (selected) functions in _this_ file should treat the chr arrays
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* of a cvec as non-constant.
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*/
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/*
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* newcvec - allocate a new cvec
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*/
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static struct cvec *
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newcvec(int nchrs, /* to hold this many chrs... */
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int nranges) /* ... and this many ranges */
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{
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size_t nc = (size_t) nchrs + (size_t) nranges * 2;
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size_t n = sizeof(struct cvec) + nc * sizeof(chr);
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struct cvec *cv = (struct cvec *) MALLOC(n);
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if (cv == NULL)
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return NULL;
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cv->chrspace = nchrs;
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cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
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cv->ranges = cv->chrs + nchrs;
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cv->rangespace = nranges;
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return clearcvec(cv);
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}
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/*
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* clearcvec - clear a possibly-new cvec
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* Returns pointer as convenience.
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*/
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static struct cvec *
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clearcvec(struct cvec *cv)
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{
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assert(cv != NULL);
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cv->nchrs = 0;
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cv->nranges = 0;
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cv->cclasscode = -1;
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return cv;
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}
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/*
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* addchr - add a chr to a cvec
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*/
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static void
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addchr(struct cvec *cv, /* character vector */
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chr c) /* character to add */
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{
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assert(cv->nchrs < cv->chrspace);
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cv->chrs[cv->nchrs++] = c;
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}
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/*
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* addrange - add a range to a cvec
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*/
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static void
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addrange(struct cvec *cv, /* character vector */
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chr from, /* first character of range */
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chr to) /* last character of range */
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{
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assert(cv->nranges < cv->rangespace);
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cv->ranges[cv->nranges * 2] = from;
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cv->ranges[cv->nranges * 2 + 1] = to;
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cv->nranges++;
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}
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/*
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* getcvec - get a transient cvec, initialized to empty
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*
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* The returned cvec is valid only until the next call of getcvec, which
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* typically will recycle the space. Callers should *not* free the cvec
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* explicitly; it will be cleaned up when the struct vars is destroyed.
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*
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* This is typically used while interpreting bracket expressions. In that
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* usage the cvec is only needed momentarily until we build arcs from it,
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* so transientness is a convenient behavior.
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*/
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static struct cvec *
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getcvec(struct vars *v, /* context */
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int nchrs, /* to hold this many chrs... */
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int nranges) /* ... and this many ranges */
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{
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/* recycle existing transient cvec if large enough */
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if (v->cv != NULL && nchrs <= v->cv->chrspace &&
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nranges <= v->cv->rangespace)
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return clearcvec(v->cv);
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/* nope, make a new one */
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if (v->cv != NULL)
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freecvec(v->cv);
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v->cv = newcvec(nchrs, nranges);
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if (v->cv == NULL)
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ERR(REG_ESPACE);
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return v->cv;
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}
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/*
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* freecvec - free a cvec
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*/
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static void
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freecvec(struct cvec *cv)
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{
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FREE(cv);
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}
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