scintilla/StyleContext.h

   1 // Scintilla source code edit control
   2 /** @file StyleContext.cxx
   3  ** Lexer infrastructure.
   4  **/
   5 // Copyright 1998-2004 by Neil Hodgson <neilh@scintilla.org>
   6 // This file is in the public domain.
   7
   8 #ifdef SCI_NAMESPACE
   9 namespace Scintilla {
  10 #endif
  11
  12 // All languages handled so far can treat all characters >= 0x80 as one class
  13 // which just continues the current token or starts an identifier if in default.
  14 // DBCS treated specially as the second character can be < 0x80 and hence
  15 // syntactically significant. UTF-8 avoids this as all trail bytes are >= 0x80
  16 class StyleContext {
  17         Accessor &styler;
  18         unsigned int endPos;
  19         StyleContext& operator=(const StyleContext&);
  20         void GetNextChar(unsigned int pos) {
  21                 chNext = static_cast<unsigned char>(styler.SafeGetCharAt(pos+1));
  22                 if (styler.IsLeadByte(static_cast<char>(chNext))) {
  23                         chNext = chNext << 8;
  24                         chNext |= static_cast<unsigned char>(styler.SafeGetCharAt(pos+2));
  25                 }
  26                 // End of line?
  27                 // Trigger on CR only (Mac style) or either on LF from CR+LF (Dos/Win)
  28                 // or on LF alone (Unix). Avoid triggering two times on Dos/Win.
  29                 atLineEnd = (ch == '\r' && chNext != '\n') ||
  30                                         (ch == '\n') ||
  31                                         (currentPos >= endPos);
  32         }
  33
  34 public:
  35         unsigned int currentPos;
  36         bool atLineStart;
  37         bool atLineEnd;
  38         int state;
  39         int chPrev;
  40         int ch;
  41         int chNext;
  42
  43         StyleContext(unsigned int startPos, unsigned int length,
  44                         int initStyle, Accessor &styler_, char chMask=31) :
  45                 styler(styler_),
  46                 endPos(startPos + length),
  47                 currentPos(startPos),
  48                 atLineStart(true),
  49                 atLineEnd(false),
  50                 state(initStyle & chMask), // Mask off all bits which aren't in the chMask.
  51                 chPrev(0),
  52                 ch(0),
  53                 chNext(0) {
  54                 styler.StartAt(startPos, chMask);
  55                 styler.StartSegment(startPos);
  56                 unsigned int pos = currentPos;
  57                 ch = static_cast<unsigned char>(styler.SafeGetCharAt(pos));
  58                 if (styler.IsLeadByte(static_cast<char>(ch))) {
  59                         pos++;
  60                         ch = ch << 8;
  61                         ch |= static_cast<unsigned char>(styler.SafeGetCharAt(pos));
  62                 }
  63                 GetNextChar(pos);
  64         }
  65         void Complete() {
  66                 styler.ColourTo(currentPos - 1, state);
  67         }
  68         bool More() {
  69                 return currentPos < endPos;
  70         }
  71         void Forward() {
  72                 if (currentPos < endPos) {
  73                         atLineStart = atLineEnd;
  74                         chPrev = ch;
  75                         currentPos++;
  76                         if (ch >= 0x100)
  77                                 currentPos++;
  78                         ch = chNext;
  79                         GetNextChar(currentPos + ((ch >= 0x100) ? 1 : 0));
  80                 } else {
  81                         atLineStart = false;
  82                         chPrev = ' ';
  83                         ch = ' ';
  84                         chNext = ' ';
  85                         atLineEnd = true;
  86                 }
  87         }
  88         void Forward(int nb) {
  89                 for (int i = 0; i < nb; i++) {
  90                         Forward();
  91                 }
  92         }
  93         void ChangeState(int state_) {
  94                 state = state_;
  95         }
  96         void SetState(int state_) {
  97                 styler.ColourTo(currentPos - 1, state);
  98                 state = state_;
  99         }
 100         void ForwardSetState(int state_) {
 101                 Forward();
 102                 styler.ColourTo(currentPos - 1, state);
 103                 state = state_;
 104         }
 105         int LengthCurrent() {
 106                 return currentPos - styler.GetStartSegment();
 107         }
 108         int GetRelative(int n) {
 109                 return static_cast<unsigned char>(styler.SafeGetCharAt(currentPos+n));
 110         }
 111         bool Match(char ch0) {
 112                 return ch == static_cast<unsigned char>(ch0);
 113         }
 114         bool Match(char ch0, char ch1) {
 115                 return (ch == static_cast<unsigned char>(ch0)) && (chNext == static_cast<unsigned char>(ch1));
 116         }
 117         bool Match(const char *s) {
 118                 if (ch != static_cast<unsigned char>(*s))
 119                         return false;
 120                 s++;
 121                 if (!*s)
 122                         return true;
 123                 if (chNext != static_cast<unsigned char>(*s))
 124                         return false;
 125                 s++;
 126                 for (int n=2; *s; n++) {
 127                         if (*s != styler.SafeGetCharAt(currentPos+n))
 128                                 return false;
 129                         s++;
 130                 }
 131                 return true;
 132         }
 133         bool MatchIgnoreCase(const char *s) {
 134                 if (tolower(ch) != static_cast<unsigned char>(*s))
 135                         return false;
 136                 s++;
 137                 if (tolower(chNext) != static_cast<unsigned char>(*s))
 138                         return false;
 139                 s++;
 140                 for (int n=2; *s; n++) {
 141                         if (static_cast<unsigned char>(*s) !=
 142                                 tolower(static_cast<unsigned char>(styler.SafeGetCharAt(currentPos+n))))
 143                                 return false;
 144                         s++;
 145                 }
 146                 return true;
 147         }
 148         // Non-inline
 149         void GetCurrent(char *s, unsigned int len);
 150         void GetCurrentLowered(char *s, unsigned int len);
 151 };
 152
 153 #ifdef SCI_NAMESPACE
 154 }
 155 #endif
 156
 157 inline bool IsASpace(unsigned int ch) {
 158     return (ch == ' ') || ((ch >= 0x09) && (ch <= 0x0d));
 159 }
 160
 161 inline bool IsASpaceOrTab(unsigned int ch) {
 162         return (ch == ' ') || (ch == '\t');
 163 }
 164
 165 inline bool IsADigit(unsigned int ch) {
 166         return (ch >= '0') && (ch <= '9');
 167 }
 168
 169 inline bool IsADigit(unsigned int ch, unsigned int base) {
 170         if (base <= 10) {
 171                 return (ch >= '0') && (ch < '0' + base);
 172         } else {
 173                 return ((ch >= '0') && (ch <= '9')) ||
 174                        ((ch >= 'A') && (ch < 'A' + base - 10)) ||
 175                        ((ch >= 'a') && (ch < 'a' + base - 10));
 176         }
 177 }