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icu46/source/i18n/regexcmp.h

+//
+//  regexcmp.h
+//
+//  Copyright (C) 2002-2010, 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"
+#if !UCONFIG_NO_REGULAR_EXPRESSIONS
+
+#include "unicode/uobject.h"
+#include "unicode/uniset.h"
+#include "unicode/parseerr.h"
+#include "uhash.h"
+#include "uvector.h"
+
+
+
+U_NAMESPACE_BEGIN
+
+
+//--------------------------------------------------------------------------------
+//
+//  class RegexCompile    Contains the regular expression compiler.
+//
+//--------------------------------------------------------------------------------
+struct  RegexTableEl;
+class   RegexPattern;
+
+
+class RegexCompile : public UMemory {
+public:
+
+    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
+    };
+
+private:
+
+
+    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);      // Fix literal strings.
+    void        insertOp(int32_t where);             // Open up a slot for a new op in the
+                                                     //   generated code at the specified location.
+    void        emitONE_CHAR(UChar32 c);             // Emit a ONE_CHAR op into the compiled code,
+                                                     //   taking case mode into account.
+    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);
+
+
+    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
+
+
+    int32_t                       fStringOpStart;    // While a literal string is being scanned
+                                                     //   holds the start index within RegexPattern.
+                                                     //   fLiteralText where the string is being stored.
+
+    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.
+    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.
+};
+
+// 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.
+    };
+
+U_NAMESPACE_END
+#endif   // !UCONFIG_NO_REGULAR_EXPRESSIONS
+#endif   // RBBISCAN_H