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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use:
// regexcmp.h
// Copyright (C) 2002-2016, International Business Machines Corporation and others.
// All Rights Reserved.
// This file contains declarations for the class RegexCompile
// This class is internal to the regular expression implementation.
// For the public Regular Expression API, see the file "unicode/regex.h"
#ifndef RBBISCAN_H
#define RBBISCAN_H
#include "unicode/utypes.h"
#include "unicode/parseerr.h"
#include "unicode/uniset.h"
#include "unicode/uobject.h"
#include "unicode/utext.h"
#include "uhash.h"
#include "uvector.h"
#include "uvectr32.h"
// class RegexCompile Contains the regular expression compiler.
struct RegexTableEl;
class RegexPattern;
class U_I18N_API RegexCompile : public UMemory {
enum {
kStackSize = 100 // The size of the state stack for
}; // pattern parsing. Corresponds roughly
// to the depth of parentheses nesting
// that is allowed in the rules.
struct RegexPatternChar {
UChar32 fChar;
UBool fQuoted;
RegexCompile(RegexPattern *rp, UErrorCode &e);
void compile(const UnicodeString &pat, UParseError &pp, UErrorCode &e);
void compile(UText *pat, UParseError &pp, UErrorCode &e);
virtual ~RegexCompile();
void nextChar(RegexPatternChar &c); // Get the next char from the input stream.
static void cleanup(); // Memory cleanup
// Categories of parentheses in pattern.
// The category is saved in the compile-time parentheses stack frame, and
// determines the code to be generated when the matching close ) is encountered.
enum EParenClass {
plain = -1, // No special handling
capturing = -2,
atomic = -3,
lookAhead = -4,
negLookAhead = -5,
flags = -6,
lookBehind = -7,
lookBehindN = -8
UBool doParseActions(int32_t a);
void error(UErrorCode e); // error reporting convenience function.
UChar32 nextCharLL();
UChar32 peekCharLL();
UnicodeSet *scanProp();
UnicodeSet *scanPosixProp();
void handleCloseParen();
int32_t blockTopLoc(UBool reserve); // Locate a position in the compiled pattern
// at the top of the just completed block
// or operation, and optionally ensure that
// there is space to add an opcode there.
void compileSet(UnicodeSet *theSet); // Generate the compiled pattern for
// a reference to a UnicodeSet.
void compileInterval(int32_t InitOp, // Generate the code for a {min,max} quantifier.
int32_t LoopOp);
UBool compileInlineInterval(); // Generate inline code for a {min,max} quantifier
void literalChar(UChar32 c); // Compile a literal char
void fixLiterals(UBool split=false); // Generate code for pending literal characters.
void insertOp(int32_t where); // Open up a slot for a new op in the
// generated code at the specified location.
void appendOp(int32_t op); // Append a new op to the compiled pattern.
void appendOp(int32_t type, int32_t val); // Build & append a new op to the compiled pattern.
int32_t buildOp(int32_t type, int32_t val); // Construct a new pcode instruction.
int32_t allocateData(int32_t size); // Allocate space in the matcher data area.
// Return index of the newly allocated data.
int32_t allocateStackData(int32_t size); // Allocate space in the match back-track stack frame.
// Return offset index in the frame.
int32_t minMatchLength(int32_t start,
int32_t end);
int32_t maxMatchLength(int32_t start,
int32_t end);
void matchStartType();
void stripNOPs();
void setEval(int32_t op);
void setPushOp(int32_t op);
UChar32 scanNamedChar();
UnicodeSet *createSetForProperty(const UnicodeString &propName, UBool negated);
public: // Public for testing only.
static void U_EXPORT2 findCaseInsensitiveStarters(UChar32 c, UnicodeSet *starterChars);
UErrorCode *fStatus;
RegexPattern *fRXPat;
UParseError *fParseErr;
// Data associated with low level character scanning
int64_t fScanIndex; // Index of current character being processed
// in the rule input string.
UBool fQuoteMode; // Scan is in a \Q...\E quoted region
UBool fInBackslashQuote; // Scan is between a '\' and the following char.
UBool fEOLComments; // When scan is just after '(?', inhibit #... to
// end of line comments, in favor of (?#...) comments.
int64_t fLineNum; // Line number in input file.
int64_t fCharNum; // Char position within the line.
UChar32 fLastChar; // Previous char, needed to count CR-LF
// as a single line, not two.
UChar32 fPeekChar; // Saved char, if we've scanned ahead.
RegexPatternChar fC; // Current char for parse state machine
// processing.
// Data for the state machine that parses the regular expression.
RegexTableEl **fStateTable; // State Transition Table for regex Rule
// parsing. index by p[state][char-class]
uint16_t fStack[kStackSize]; // State stack, holds state pushes
int32_t fStackPtr; // and pops as specified in the state
// transition rules.
// Data associated with the generation of the pcode for the match engine
int32_t fModeFlags; // Match Flags. (Case Insensitive, etc.)
// Always has high bit (31) set so that flag values
// on the paren stack are distinguished from relocatable
// pcode addresses.
int32_t fNewModeFlags; // New flags, while compiling (?i, holds state
// until last flag is scanned.
UBool fSetModeFlag; // true for (?ismx, false for (?-ismx
UnicodeString fLiteralChars; // Literal chars or strings from the pattern are accumulated here.
// Once completed, meaning that some non-literal pattern
// construct is encountered, the appropriate opcodes
// to match the literal will be generated, and this
// string will be cleared.
int64_t fPatternLength; // Length of the input pattern string.
UVector32 fParenStack; // parentheses stack. Each frame consists of
// the positions of compiled pattern operations
// needing fixup, followed by negative value. The
// first entry in each frame is the position of the
// spot reserved for use when a quantifier
// needs to add a SAVE at the start of a (block)
// The negative value (-1, -2,...) indicates
// the kind of paren that opened the frame. Some
// need special handling on close.
int32_t fMatchOpenParen; // The position in the compiled pattern
// of the slot reserved for a state save
// at the start of the most recently processed
// parenthesized block. Updated when processing
// a close to the location for the corresponding open.
int32_t fMatchCloseParen; // The position in the pattern of the first
// location after the most recently processed
// parenthesized block.
int32_t fIntervalLow; // {lower, upper} interval quantifier values.
int32_t fIntervalUpper; // Placed here temporarily, when pattern is
// initially scanned. Each new interval
// encountered overwrites these values.
// -1 for the upper interval value means none
// was specified (unlimited occurences.)
int64_t fNameStartPos; // Starting position of a \N{NAME} name in a
// pattern, valid while remainder of name is
// scanned.
UStack fSetStack; // Stack of UnicodeSets, used while evaluating
// (at compile time) set expressions within
// the pattern.
UStack fSetOpStack; // Stack of pending set operators (&&, --, union)
UChar32 fLastSetLiteral; // The last single code point added to a set.
// needed when "-y" is scanned, and we need
// to turn "x-y" into a range.
UnicodeString *fCaptureName; // Named Capture, the group name is built up
// in this string while being scanned.
// Constant values to be pushed onto fSetOpStack while scanning & evalueating [set expressions]
// The high 16 bits are the operator precedence, and the low 16 are a code for the operation itself.
enum SetOperations {
setStart = 0 << 16 | 1,
setEnd = 1 << 16 | 2,
setNegation = 2 << 16 | 3,
setCaseClose = 2 << 16 | 9,
setDifference2 = 3 << 16 | 4, // '--' set difference operator
setIntersection2 = 3 << 16 | 5, // '&&' set intersection operator
setUnion = 4 << 16 | 6, // implicit union of adjacent items
setDifference1 = 4 << 16 | 7, // '-', single dash difference op, for compatibility with old UnicodeSet.
setIntersection1 = 4 << 16 | 8 // '&', single amp intersection op, for compatibility with old UnicodeSet.
#endif // RBBISCAN_H