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// Scintilla source code edit control
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** Regular expression search library.
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* regex - Regular expression pattern matching and replacement
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* By: Ozan S. Yigit (oz)
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* Dept. of Computer Science
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* Original code available from http://www.cs.yorku.ca/~oz/
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* Translation to C++ by Neil Hodgson neilh@scintilla.org
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* Removed all use of register.
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* Converted to modern function prototypes.
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* Put all global/static variables into an object so this code can be
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* used from multiple threads, etc.
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* Some extensions by Philippe Lhoste PhiLho(a)GMX.net
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* These routines are the PUBLIC DOMAIN equivalents of regex
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* routines as found in 4.nBSD UN*X, with minor extensions.
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* These routines are derived from various implementations found
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* in software tools books, and Conroy's grep. They are NOT derived
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* from licensed/restricted software.
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* For more interesting/academic/complicated implementations,
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* see Henry Spencer's regexp routines, or GNU Emacs pattern
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* Modification history removed.
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* RESearch::Compile: compile a regular expression into a NFA.
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* const char *RESearch::Compile(const char *pattern, int length,
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* bool caseSensitive, bool posix)
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* Returns a short error string if they fail.
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* RESearch::Execute: execute the NFA to match a pattern.
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* int RESearch::Execute(characterIndexer &ci, int lp, int endp)
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* RESearch::Substitute: substitute the matched portions in a new string.
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* int RESearch::Substitute(CharacterIndexer &ci, char *src, char *dst)
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* re_fail: failure routine for RESearch::Execute. (no longer used)
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* void re_fail(char *msg, char op)
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* Regular Expressions:
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* [1] char matches itself, unless it is a special
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* character (metachar): . \ [ ] * + ^ $
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* and ( ) if posix option.
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* [2] . matches any character.
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* [3] \ matches the character following it, except:
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* - \a, \b, \f, \n, \r, \t, \v match the corresponding C
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* escape char, respectively BEL, BS, FF, LF, CR, TAB and VT;
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* Note that \r and \n are never matched because Scintilla
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* regex searches are made line per line
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* (stripped of end-of-line chars).
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* - if not in posix mode, when followed by a
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* left or right round bracket (see [7]);
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* - when followed by a digit 1 to 9 (see [8]);
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* - when followed by a left or right angle bracket
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* - when followed by d, D, s, S, w or W (see [10]);
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* - when followed by x and two hexa digits (see [11].
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* Backslash is used as an escape character for all
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* other meta-characters, and itself.
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* [4] [set] matches one of the characters in the set.
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* If the first character in the set is "^",
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* it matches the characters NOT in the set, i.e.
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* complements the set. A shorthand S-E (start dash end)
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* is used to specify a set of characters S up to
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* E, inclusive. S and E must be characters, otherwise
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* the dash is taken literally (eg. in expression [\d-a]).
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* The special characters "]" and "-" have no special
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* meaning if they appear as the first chars in the set.
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* To include both, put - first: [-]A-Z]
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* (or just backslash them).
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* [-]|] matches these 3 chars,
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* []-|] matches from ] to | chars
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* [a-z] any lowercase alpha
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* [^-]] any char except - and ]
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* [^A-Z] any char except uppercase
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* [5] * any regular expression form [1] to [4]
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* (except [7], [8] and [9] forms of [3]),
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* followed by closure char (*)
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* matches zero or more matches of that form.
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* [6] + same as [5], except it matches one or more.
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* Both [5] and [6] are greedy (they match as much as possible).
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* [7] a regular expression in the form [1] to [12], enclosed
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* as \(form\) (or (form) with posix flag) matches what
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* form matches. The enclosure creates a set of tags,
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* used for [8] and for pattern substitution.
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* The tagged forms are numbered starting from 1.
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* [8] a \ followed by a digit 1 to 9 matches whatever a
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* previously tagged regular expression ([7]) matched.
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* [9] \< a regular expression starting with a \< construct
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* \> and/or ending with a \> construct, restricts the
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* pattern matching to the beginning of a word, and/or
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* the end of a word. A word is defined to be a character
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* string beginning and/or ending with the characters
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* A-Z a-z 0-9 and _. Scintilla extends this definition
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* by user setting. The word must also be preceded and/or
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* followed by any character outside those mentioned.
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* [10] \l a backslash followed by d, D, s, S, w or W,
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* becomes a character class (both inside and
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* D: any char except decimal digits
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* s: whitespace (space, \t \n \r \f \v)
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* S: any char except whitespace (see above)
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* w: alphanumeric & underscore (changed by user setting)
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* W: any char except alphanumeric & underscore (see above)
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* [11] \xHH a backslash followed by x and two hexa digits,
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* becomes the character whose Ascii code is equal
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* to these digits. If not followed by two digits,
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* it is 'x' char itself.
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* [12] a composite regular expression xy where x and y
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* are in the form [1] to [11] matches the longest
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* match of x followed by a match for y.
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* [13] ^ a regular expression starting with a ^ character
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* $ and/or ending with a $ character, restricts the
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* pattern matching to the beginning of the line,
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* or the end of line. [anchors] Elsewhere in the
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* pattern, ^ and $ are treated as ordinary characters.
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* HCR's Hugh Redelmeier has been most helpful in various
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* stages of development. He convinced me to include BOW
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* and EOW constructs, originally invented by Rob Pike at
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* the University of Toronto.
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* Software tools Kernighan & Plauger
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* Software tools in Pascal Kernighan & Plauger
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* Grep [rsx-11 C dist] David Conroy
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* ed - text editor Un*x Programmer's Manual
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* Advanced editing on Un*x B. W. Kernighan
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* RegExp routines Henry Spencer
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* This implementation uses a bit-set representation for character
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* classes for speed and compactness. Each character is represented
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* by one bit in a 256-bit block. Thus, CCL always takes a
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* constant 32 bytes in the internal nfa, and RESearch::Execute does a single
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* bit comparison to locate the character in the set.
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* compile: CHR f CHR o CLO CHR o END CLO ANY END END
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* matches: fo foo fooo foobar fobar foxx ...
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* pattern: fo[ob]a[rz]
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* compile: CHR f CHR o CCL bitset CHR a CCL bitset END
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* matches: fobar fooar fobaz fooaz
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* compile: CHR f CHR o CHR o CHR \ CLO CHR \ END END
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* matches: foo\ foo\\ foo\\\ ...
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* pattern: \(foo\)[1-3]\1 (same as foo[1-3]foo)
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* compile: BOT 1 CHR f CHR o CHR o EOT 1 CCL bitset REF 1 END
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* matches: foo1foo foo2foo foo3foo
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* pattern: \(fo.*\)-\1
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* compile: BOT 1 CHR f CHR o CLO ANY END EOT 1 CHR - REF 1 END
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* matches: foo-foo fo-fo fob-fob foobar-foobar ...
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#include "CharClassify.h"
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#include "RESearch.h"
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// Shut up annoying Visual C++ warnings:
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#pragma warning(disable: 4514)
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using namespace Scintilla;
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* The following defines are not meant to be changeable.
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* They are for readability only.
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const char bitarr[] = { 1, 2, 4, 8, 16, 32, 64, '\200' };
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#define badpat(x) (*nfa = END, x)
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* Character classification table for word boundary operators BOW
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* and EOW is passed in by the creator of this object (Scintilla
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* Document). The Document default state is that word chars are:
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* 0-9, a-z, A-Z and _
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RESearch::RESearch(CharClassify *charClassTable) {
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charClass = charClassTable;
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RESearch::~RESearch() {
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void RESearch::Init() {
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sta = NOP; /* status of lastpat */
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for (int i = 0; i < MAXTAG; i++)
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for (int j = 0; j < BITBLK; j++)
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void RESearch::Clear() {
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for (int i = 0; i < MAXTAG; i++) {
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bool RESearch::GrabMatches(CharacterIndexer &ci) {
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for (unsigned int i = 0; i < MAXTAG; i++) {
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if ((bopat[i] != NOTFOUND) && (eopat[i] != NOTFOUND)) {
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unsigned int len = eopat[i] - bopat[i];
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pat[i] = new char[len + 1];
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for (unsigned int j = 0; j < len; j++)
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pat[i][j] = ci.CharAt(bopat[i] + j);
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void RESearch::ChSet(unsigned char c) {
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bittab[((c) & BLKIND) >> 3] |= bitarr[(c) & BITIND];
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void RESearch::ChSetWithCase(unsigned char c, bool caseSensitive) {
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if ((c >= 'a') && (c <= 'z')) {
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ChSet(static_cast<unsigned char>(c - 'a' + 'A'));
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} else if ((c >= 'A') && (c <= 'Z')) {
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ChSet(static_cast<unsigned char>(c - 'A' + 'a'));
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const unsigned char escapeValue(unsigned char ch) {
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case 'a': return '\a';
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case 'b': return '\b';
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case 'f': return '\f';
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case 'n': return '\n';
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case 'r': return '\r';
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case 't': return '\t';
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case 'v': return '\v';
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static int GetHexaChar(unsigned char hd1, unsigned char hd2) {
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if (hd1 >= '0' && hd1 <= '9') {
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hexValue += 16 * (hd1 - '0');
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} else if (hd1 >= 'A' && hd1 <= 'F') {
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hexValue += 16 * (hd1 - 'A' + 10);
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} else if (hd1 >= 'a' && hd1 <= 'f') {
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hexValue += 16 * (hd1 - 'a' + 10);
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if (hd2 >= '0' && hd2 <= '9') {
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hexValue += hd2 - '0';
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} else if (hd2 >= 'A' && hd2 <= 'F') {
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hexValue += hd2 - 'A' + 10;
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} else if (hd2 >= 'a' && hd2 <= 'f') {
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hexValue += hd2 - 'a' + 10;
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* Called when the parser finds a backslash not followed
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* by a valid expression (like \( in non-Posix mode).
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* @param pattern: pointer on the char after the backslash.
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* @param incr: (out) number of chars to skip after expression evaluation.
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* @return the char if it resolves to a simple char,
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* or -1 for a char class. In this case, bittab is changed.
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int RESearch::GetBackslashExpression(
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// Since error reporting is primitive and messages are not used anyway,
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// I choose to interpret unexpected syntax in a logical way instead
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// of reporting errors. Otherwise, we can stick on, eg., PCRE behavior.
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incr = 0; // Most of the time, will skip the char "naturally".
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unsigned char bsc = *pattern;
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result = '\\'; // \ at end of pattern, take it literally
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result = escapeValue(bsc);
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unsigned char hd1 = *(pattern + 1);
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unsigned char hd2 = *(pattern + 2);
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int hexValue = GetHexaChar(hd1, hd2);
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incr = 2; // Must skip the digits
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result = 'x'; // \x without 2 digits: see it as 'x'
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for (c = '0'; c <= '9'; c++) {
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ChSet(static_cast<unsigned char>(c));
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for (c = 0; c < MAXCHR; c++) {
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if (c < '0' || c > '9') {
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ChSet(static_cast<unsigned char>(c));
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for (c = 0; c < MAXCHR; c++) {
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if (c != ' ' && !(c >= 0x09 && c <= 0x0D)) {
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ChSet(static_cast<unsigned char>(c));
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for (c = 0; c < MAXCHR; c++) {
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if (iswordc(static_cast<unsigned char>(c))) {
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ChSet(static_cast<unsigned char>(c));
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for (c = 0; c < MAXCHR; c++) {
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if (!iswordc(static_cast<unsigned char>(c))) {
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ChSet(static_cast<unsigned char>(c));
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const char *RESearch::Compile(const char *pattern, int length, bool caseSensitive, bool posix) {
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char *mp=nfa; /* nfa pointer */
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char *lp; /* saved pointer */
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char *sp=nfa; /* another one */
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char *mpMax = mp + MAXNFA - BITBLK - 10;
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int tagi = 0; /* tag stack index */
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int tagc = 1; /* actual tag count */
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char mask; /* xor mask -CCL/NCL */
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int c1, c2, prevChar;
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if (!pattern || !length) {
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return badpat("No previous regular expression");
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const char *p=pattern; /* pattern pointer */
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for (int i=0; i<length; i++, p++) {
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return badpat("Pattern too long");
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case '.': /* match any char */
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case '^': /* match beginning */
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case '$': /* match endofline */
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case '[': /* match char class */
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if (*p == '-') { /* real dash */
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if (*p == ']') { /* real brace */
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while (*p && *p != ']') {
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// Previous def. was a char class like \d, take dash literally
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if (!*(p+1)) // End of RE
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return badpat("Missing ]");
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c2 = GetBackslashExpression(p, incr);
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// Convention: \c (c is any char) is case sensitive, whatever the option
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ChSet(static_cast<unsigned char>(c2));
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// bittab is already changed
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// Char after dash is char class like \d, take dash literally
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// Put all chars between c1 and c2 included in the char set
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ChSetWithCase(static_cast<unsigned char>(c1++), caseSensitive);
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// Dash before the ], take it literally
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return badpat("Missing ]");
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} else if (*p == '\\' && *(p+1)) {
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int c = GetBackslashExpression(p, incr);
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// Convention: \c (c is any char) is case sensitive, whatever the option
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ChSet(static_cast<unsigned char>(c));
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// bittab is already changed
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ChSetWithCase(*p, caseSensitive);
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return badpat("Missing ]");
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for (n = 0; n < BITBLK; bittab[n++] = 0)
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*mp++ = static_cast<char>(mask ^ bittab[n]);
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case '*': /* match 0 or more... */
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case '+': /* match 1 or more... */
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return badpat("Empty closure");
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lp = sp; /* previous opcode */
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if (*lp == CLO) /* equivalence... */
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return badpat("Illegal closure");
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for (sp = mp; lp < sp; lp++)
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case '\\': /* tags, backrefs... */
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return badpat("Null pattern inside \\<\\>");
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if (tagi > 0 && tagstk[tagi] == n)
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return badpat("Cyclical reference");
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*mp++ = static_cast<char>(REF);
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*mp++ = static_cast<char>(n);
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return badpat("Undetermined reference");
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if (!posix && *p == '(') {
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tagstk[++tagi] = tagc;
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*mp++ = static_cast<char>(tagc++);
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return badpat("Too many \\(\\) pairs");
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} else if (!posix && *p == ')') {
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return badpat("Null pattern inside \\(\\)");
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*mp++ = static_cast<char>(EOT);
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*mp++ = static_cast<char>(tagstk[tagi--]);
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return badpat("Unmatched \\)");
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int c = GetBackslashExpression(p, incr);
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*mp++ = static_cast<unsigned char>(c);
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for (n = 0; n < BITBLK; bittab[n++] = 0)
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*mp++ = static_cast<char>(mask ^ bittab[n]);
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default : /* an ordinary char */
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if (posix && *p == '(') {
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tagstk[++tagi] = tagc;
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*mp++ = static_cast<char>(tagc++);
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return badpat("Too many () pairs");
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} else if (posix && *p == ')') {
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return badpat("Null pattern inside ()");
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*mp++ = static_cast<char>(EOT);
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*mp++ = static_cast<char>(tagstk[tagi--]);
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return badpat("Unmatched )");
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unsigned char c = *p;
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c = '\\'; // We take it as raw backslash
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if (caseSensitive || !iswordc(c)) {
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ChSetWithCase(c, false);
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for (n = 0; n < BITBLK; bittab[n++] = 0)
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*mp++ = static_cast<char>(mask ^ bittab[n]);
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return badpat((posix ? "Unmatched (" : "Unmatched \\("));
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* execute nfa to find a match.
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* special cases: (nfa[0])
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* Match only once, starting from the
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* First locate the character without
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* calling PMatch, and if found, call
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* PMatch for the remaining string.
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* RESearch::Compile failed, poor luser did not
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* check for it. Fail fast.
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* If a match is found, bopat[0] and eopat[0] are set
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* to the beginning and the end of the matched fragment,
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int RESearch::Execute(CharacterIndexer &ci, int lp, int endp) {
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case BOL: /* anchored: match from BOL only */
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ep = PMatch(ci, lp, endp, ap);
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case EOL: /* just searching for end of line normal path doesn't work */
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if (*(ap+1) == END) {
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case CHR: /* ordinary char: locate it fast */
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while ((lp < endp) && (ci.CharAt(lp) != c))
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if (lp >= endp) /* if EOS, fail, else fall thru. */
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default: /* regular matching all the way. */
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ep = PMatch(ci, lp, endp, ap);
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case END: /* munged automaton. fail always */
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* PMatch: internal routine for the hard part
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* This code is partly snarfed from an early grep written by
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* David Conroy. The backref and tag stuff, and various other
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* innovations are by oz.
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* special case optimizations: (nfa[n], nfa[n+1])
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* We KNOW .* will match everything upto the
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* end of line. Thus, directly go to the end of
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* line, without recursive PMatch calls. As in
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* the other closure cases, the remaining pattern
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* must be matched by moving backwards on the
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* string recursively, to find a match for xy
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* (x is ".*" and y is the remaining pattern)
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* where the match satisfies the LONGEST match for
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* x followed by a match for y.
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* We can again scan the string forward for the
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* single char and at the point of failure, we
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* execute the remaining nfa recursively, same as
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* At the end of a successful match, bopat[n] and eopat[n]
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* are set to the beginning and end of subpatterns matched
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* by tagged expressions (n = 1 to 9).
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extern void re_fail(char *,char);
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#define isinset(x,y) ((x)[((y)&BLKIND)>>3] & bitarr[(y)&BITIND])
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* skip values for CLO XXX to skip past the closure
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#define ANYSKIP 2 /* [CLO] ANY END */
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#define CHRSKIP 3 /* [CLO] CHR chr END */
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#define CCLSKIP 34 /* [CLO] CCL 32 bytes END */
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int RESearch::PMatch(CharacterIndexer &ci, int lp, int endp, char *ap) {
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int e; /* extra pointer for CLO */
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int bp; /* beginning of subpat... */
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int ep; /* ending of subpat... */
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int are; /* to save the line ptr. */
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while ((op = *ap++) != END)
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if (ci.CharAt(lp++) != *ap++)
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if ((lp!=bol && iswordc(ci.CharAt(lp-1))) || !iswordc(ci.CharAt(lp)))
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if (lp==bol || !iswordc(ci.CharAt(lp-1)) || iswordc(ci.CharAt(lp)))
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if (ci.CharAt(bp++) != ci.CharAt(lp++))
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while ((lp < endp) && (c == ci.CharAt(lp)))
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while ((lp < endp) && isinset(ap+1,ci.CharAt(lp)))
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//re_fail("closure: bad nfa.", *ap);
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if ((e = PMatch(ci, lp, endp, ap)) != NOTFOUND)
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//re_fail("RESearch::Execute: bad nfa.", static_cast<char>(op));
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* RESearch::Substitute:
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* substitute the matched portions of the src in dst.
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* & substitute the entire matched pattern.
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* \digit substitute a subpattern, with the given tag number.
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* Tags are numbered from 1 to 9. If the particular
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* tagged subpattern does not exist, null is substituted.
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int RESearch::Substitute(CharacterIndexer &ci, char *src, char *dst) {
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if (!*src || !bopat[0])
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while ((c = *src++) != 0) {
967
if (c >= '0' && c <= '9') {
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if ((bp = bopat[pin]) != 0 && (ep = eopat[pin]) != 0) {
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while (ci.CharAt(bp) && bp < ep)
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*dst++ = ci.CharAt(bp++);
added
removed
scintilla/RESearch.cxx
