contrib/src/stc/scintilla/src/LexPython.cxx

   1 // Scintilla source code edit control
   2 /** @file LexPython.cxx
   3  ** Lexer for Python.
   4  **/
   5 // Copyright 1998-2002 by Neil Hodgson <neilh@scintilla.org>
   6 // The License.txt file describes the conditions under which this software may be distributed.
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <ctype.h>
  11 #include <stdio.h>
  12 #include <stdarg.h>
  13
  14 #include "Platform.h"
  15
  16 #include "PropSet.h"
  17 #include "Accessor.h"
  18 #include "StyleContext.h"
  19 #include "KeyWords.h"
  20 #include "Scintilla.h"
  21 #include "SciLexer.h"
  22
  23 enum kwType { kwOther, kwClass, kwDef, kwImport };
  24
  25 static bool IsPyComment(Accessor &styler, int pos, int len) {
  26         return len > 0 && styler[pos] == '#';
  27 }
  28
  29 static bool IsPyStringStart(int ch, int chNext, int chNext2) {
  30         if (ch == '\'' || ch == '"')
  31                 return true;
  32         if (ch == 'u' || ch == 'U') {
  33                 if (chNext == '"' || chNext == '\'')
  34                         return true;
  35                 if ((chNext == 'r' || chNext == 'R') && (chNext2 == '"' || chNext2 == '\''))
  36                         return true;
  37         }
  38         if ((ch == 'r' || ch == 'R') && (chNext == '"' || chNext == '\''))
  39                 return true;
  40
  41         return false;
  42 }
  43
  44 /* Return the state to use for the string starting at i; *nextIndex will be set to the first index following the quote(s) */
  45 static int GetPyStringState(Accessor &styler, int i, unsigned int *nextIndex) {
  46         char ch = styler.SafeGetCharAt(i);
  47         char chNext = styler.SafeGetCharAt(i + 1);
  48
  49         // Advance beyond r, u, or ur prefix, but bail if there are any unexpected chars
  50         if (ch == 'r' || ch == 'R') {
  51                 i++;
  52                 ch = styler.SafeGetCharAt(i);
  53                 chNext = styler.SafeGetCharAt(i + 1);
  54         } else if (ch == 'u' || ch == 'U') {
  55                 if (chNext == 'r' || chNext == 'R')
  56                         i += 2;
  57                 else
  58                         i += 1;
  59                 ch = styler.SafeGetCharAt(i);
  60                 chNext = styler.SafeGetCharAt(i + 1);
  61         }
  62
  63         if (ch != '"' && ch != '\'') {
  64                 *nextIndex = i + 1;
  65                 return SCE_P_DEFAULT;
  66         }
  67
  68         if (ch == chNext && ch == styler.SafeGetCharAt(i + 2)) {
  69                 *nextIndex = i + 3;
  70
  71                 if (ch == '"')
  72                         return SCE_P_TRIPLEDOUBLE;
  73                 else
  74                         return SCE_P_TRIPLE;
  75         } else {
  76                 *nextIndex = i + 1;
  77
  78                 if (ch == '"')
  79                         return SCE_P_STRING;
  80                 else
  81                         return SCE_P_CHARACTER;
  82         }
  83 }
  84
  85 static inline bool IsAWordChar(int ch) {
  86         return (ch < 0x80) && (isalnum(ch) || ch == '.' || ch == '_');
  87 }
  88
  89 static inline bool IsAWordStart(int ch) {
  90         return (ch < 0x80) && (isalnum(ch) || ch == '_');
  91 }
  92
  93 static void ColourisePyDoc(unsigned int startPos, int length, int initStyle,
  94                            WordList *keywordlists[], Accessor &styler) {
  95
  96         int endPos = startPos + length;
  97
  98         // Backtrack to previous line in case need to fix its tab whinging
  99         int lineCurrent = styler.GetLine(startPos);
 100         if (startPos > 0) {
 101                 if (lineCurrent > 0) {
 102                         lineCurrent--;
 103                         startPos = styler.LineStart(lineCurrent);
 104                         if (startPos == 0)
 105                                 initStyle = SCE_P_DEFAULT;
 106                         else
 107                                 initStyle = styler.StyleAt(startPos - 1);
 108                 }
 109         }
 110
 111         WordList &keywords = *keywordlists[0];
 112
 113         const int whingeLevel = styler.GetPropertyInt("tab.timmy.whinge.level");
 114
 115         initStyle = initStyle & 31;
 116         if (initStyle == SCE_P_STRINGEOL) {
 117                 initStyle = SCE_P_DEFAULT;
 118         }
 119
 120         kwType kwLast = kwOther;
 121         int spaceFlags = 0;
 122         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 123         bool hexadecimal = false;
 124
 125         // Python uses a different mask because bad indentation is marked by oring with 32
 126         StyleContext sc(startPos, endPos - startPos, initStyle, styler, 0x7f);
 127
 128         for (; sc.More(); sc.Forward()) {
 129
 130                 if (sc.atLineStart) {
 131                         const char chBad = static_cast<char>(64);
 132                         const char chGood = static_cast<char>(0);
 133                         char chFlags = chGood;
 134                         if (whingeLevel == 1) {
 135                                 chFlags = (spaceFlags & wsInconsistent) ? chBad : chGood;
 136                         } else if (whingeLevel == 2) {
 137                                 chFlags = (spaceFlags & wsSpaceTab) ? chBad : chGood;
 138                         } else if (whingeLevel == 3) {
 139                                 chFlags = (spaceFlags & wsSpace) ? chBad : chGood;
 140                         } else if (whingeLevel == 4) {
 141                                 chFlags = (spaceFlags & wsTab) ? chBad : chGood;
 142                         }
 143                         sc.SetState(sc.state);
 144                         styler.SetFlags(chFlags, static_cast<char>(sc.state));
 145                 }
 146
 147                 if (sc.atLineEnd) {
 148                         if ((sc.state == SCE_P_DEFAULT) ||
 149                                 (sc.state == SCE_P_TRIPLE) ||
 150                                 (sc.state == SCE_P_TRIPLEDOUBLE)) {
 151                                 // Perform colourisation of white space and triple quoted strings at end of each line to allow
 152                                 // tab marking to work inside white space and triple quoted strings
 153                                 sc.SetState(sc.state);
 154                         }
 155                         lineCurrent++;
 156                         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 157                         if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 158                                 sc.ChangeState(SCE_P_STRINGEOL);
 159                                 sc.ForwardSetState(SCE_P_DEFAULT);
 160                         }
 161                         if (!sc.More())
 162                                 break;
 163                 }
 164
 165                 bool needEOLCheck = false;
 166
 167                 // Check for a state end
 168                 if (sc.state == SCE_P_OPERATOR) {
 169                         kwLast = kwOther;
 170                         sc.SetState(SCE_P_DEFAULT);
 171                 } else if (sc.state == SCE_P_NUMBER) {
 172                         if (!IsAWordChar(sc.ch) &&
 173                                 !(!hexadecimal && ((sc.ch == '+' || sc.ch == '-') && (sc.chPrev == 'e' || sc.chPrev == 'E')))) {
 174                                 sc.SetState(SCE_P_DEFAULT);
 175                         }
 176                 } else if (sc.state == SCE_P_IDENTIFIER) {
 177                         if ((sc.ch == '.') || (!IsAWordChar(sc.ch))) {
 178                                 char s[100];
 179                                 sc.GetCurrent(s, sizeof(s));
 180                                 int style = SCE_P_IDENTIFIER;
 181                                 if ((kwLast == kwImport) && (strcmp(s, "as") == 0)) {
 182                                         style = SCE_P_WORD;
 183                                 } else if (keywords.InList(s)) {
 184                                         style = SCE_P_WORD;
 185                                 } else if (kwLast == kwClass) {
 186                                         style = SCE_P_CLASSNAME;
 187                                 } else if (kwLast == kwDef) {
 188                                         style = SCE_P_DEFNAME;
 189                                 }
 190                                 sc.ChangeState(style);
 191                                 sc.SetState(SCE_P_DEFAULT);
 192                                 if (style == SCE_P_WORD) {
 193                                         if (0 == strcmp(s, "class"))
 194                                                 kwLast = kwClass;
 195                                         else if (0 == strcmp(s, "def"))
 196                                                 kwLast = kwDef;
 197                                         else if (0 == strcmp(s, "import"))
 198                                                 kwLast = kwImport;
 199                                         else
 200                                                 kwLast = kwOther;
 201                                 } else if (style == SCE_P_CLASSNAME) {
 202                                         kwLast = kwOther;
 203                                 } else if (style == SCE_P_DEFNAME) {
 204                                         kwLast = kwOther;
 205                                 }
 206                         }
 207                 } else if ((sc.state == SCE_P_COMMENTLINE) || (sc.state == SCE_P_COMMENTBLOCK)) {
 208                         if (sc.ch == '\r' || sc.ch == '\n') {
 209                                 sc.SetState(SCE_P_DEFAULT);
 210                         }
 211                 } else if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 212                         if (sc.ch == '\\') {
 213                                 if ((sc.chNext == '\r') && (sc.GetRelative(2) == '\n')) {
 214                                         sc.Forward();
 215                                 }
 216                                 sc.Forward();
 217                         } else if ((sc.state == SCE_P_STRING) && (sc.ch == '\"')) {
 218                                 sc.ForwardSetState(SCE_P_DEFAULT);
 219                                 needEOLCheck = true;
 220                         } else if ((sc.state == SCE_P_CHARACTER) && (sc.ch == '\'')) {
 221                                 sc.ForwardSetState(SCE_P_DEFAULT);
 222                                 needEOLCheck = true;
 223                         }
 224                 } else if (sc.state == SCE_P_TRIPLE) {
 225                         if (sc.ch == '\\') {
 226                                 sc.Forward();
 227                         } else if (sc.Match("\'\'\'")) {
 228                                 sc.Forward();
 229                                 sc.Forward();
 230                                 sc.ForwardSetState(SCE_P_DEFAULT);
 231                                 needEOLCheck = true;
 232                         }
 233                 } else if (sc.state == SCE_P_TRIPLEDOUBLE) {
 234                         if (sc.ch == '\\') {
 235                                 sc.Forward();
 236                         } else if (sc.Match("\"\"\"")) {
 237                                 sc.Forward();
 238                                 sc.Forward();
 239                                 sc.ForwardSetState(SCE_P_DEFAULT);
 240                                 needEOLCheck = true;
 241                         }
 242                 }
 243
 244                 // State exit code may have moved on to end of line
 245                 if (needEOLCheck && sc.atLineEnd) {
 246                         lineCurrent++;
 247                         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 248                         if (!sc.More())
 249                                 break;
 250                 }
 251
 252                 // Check for a new state starting character
 253                 if (sc.state == SCE_P_DEFAULT) {
 254                         if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
 255                                 if (sc.ch == '0' && (sc.chNext == 'x' || sc.chNext == 'X')) {
 256                                         hexadecimal = true;
 257                                 } else {
 258                                         hexadecimal = false;
 259                                 }
 260                                 sc.SetState(SCE_P_NUMBER);
 261                         } else if (isascii(sc.ch) && isoperator(static_cast<char>(sc.ch)) || sc.ch == '`') {
 262                                 sc.SetState(SCE_P_OPERATOR);
 263                         } else if (sc.ch == '#') {
 264                                 sc.SetState(sc.chNext == '#' ? SCE_P_COMMENTBLOCK : SCE_P_COMMENTLINE);
 265                         } else if (IsPyStringStart(sc.ch, sc.chNext, sc.GetRelative(2))) {
 266                                 unsigned int nextIndex = 0;
 267                                 sc.SetState(GetPyStringState(styler, sc.currentPos, &nextIndex));
 268                                 while (nextIndex > (sc.currentPos + 1) && sc.More()) {                                  sc.Forward();
 269                                 }
 270                         } else if (IsAWordStart(sc.ch)) {
 271                                 sc.SetState(SCE_P_IDENTIFIER);
 272                         }
 273                 }
 274         }
 275         sc.Complete();
 276 }
 277
 278 static bool IsCommentLine(int line, Accessor &styler) {
 279         int pos = styler.LineStart(line);
 280         int eol_pos = styler.LineStart(line + 1) - 1;
 281         for (int i = pos; i < eol_pos; i++) {
 282                 char ch = styler[i];
 283                 if (ch == '#')
 284                         return true;
 285                 else if (ch != ' ' && ch != '\t')
 286                         return false;
 287         }
 288         return false;
 289 }
 290
 291 static bool IsQuoteLine(int line, Accessor &styler) {
 292         int style = styler.StyleAt(styler.LineStart(line)) & 31;
 293         return ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 294 }
 295
 296
 297 static void FoldPyDoc(unsigned int startPos, int length, int /*initStyle - unused*/,
 298                       WordList *[], Accessor &styler) {
 299         const int maxPos = startPos + length;
 300         const int maxLines = styler.GetLine(maxPos - 1);             // Requested last line
 301         const int docLines = styler.GetLine(styler.Length() - 1);  // Available last line
 302         const bool foldComment = styler.GetPropertyInt("fold.comment.python") != 0;
 303         const bool foldQuotes = styler.GetPropertyInt("fold.quotes.python") != 0;
 304
 305         // Backtrack to previous non-blank line so we can determine indent level
 306         // for any white space lines (needed esp. within triple quoted strings)
 307         // and so we can fix any preceding fold level (which is why we go back
 308         // at least one line in all cases)
 309         int spaceFlags = 0;
 310         int lineCurrent = styler.GetLine(startPos);
 311         int indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 312         while (lineCurrent > 0) {
 313                 lineCurrent--;
 314                 indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 315                 if (!(indentCurrent & SC_FOLDLEVELWHITEFLAG) &&
 316                         (!IsCommentLine(lineCurrent, styler)) &&
 317                         (!IsQuoteLine(lineCurrent, styler)))
 318                         break;
 319         }
 320         int indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 321
 322         // Set up initial loop state
 323         startPos = styler.LineStart(lineCurrent);
 324         int prev_state = SCE_P_DEFAULT & 31;
 325         if (lineCurrent >= 1)
 326                 prev_state = styler.StyleAt(startPos - 1) & 31;
 327         int prevQuote = foldQuotes && ((prev_state == SCE_P_TRIPLE) || (prev_state == SCE_P_TRIPLEDOUBLE));
 328         int prevComment = 0;
 329         if (lineCurrent >= 1)
 330                 prevComment = foldComment && IsCommentLine(lineCurrent - 1, styler);
 331
 332         // Process all characters to end of requested range or end of any triple quote
 333         // or comment that hangs over the end of the range.  Cap processing in all cases
 334         // to end of document (in case of unclosed quote or comment at end).
 335         while ((lineCurrent <= docLines) && ((lineCurrent <= maxLines) || prevQuote || prevComment)) {
 336
 337                 // Gather info
 338                 int lev = indentCurrent;
 339                 int lineNext = lineCurrent + 1;
 340                 int indentNext = indentCurrent;
 341                 int quote = false;
 342                 if (lineNext <= docLines) {
 343                         // Information about next line is only available if not at end of document
 344                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 345                         int style = styler.StyleAt(styler.LineStart(lineNext)) & 31;
 346                         quote = foldQuotes && ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 347                 }
 348                 const int quote_start = (quote && !prevQuote);
 349                 const int quote_continue = (quote && prevQuote);
 350                 const int comment = foldComment && IsCommentLine(lineCurrent, styler);
 351                 const int comment_start = (comment && !prevComment && (lineNext <= docLines) &&
 352                                            IsCommentLine(lineNext, styler) && (lev > SC_FOLDLEVELBASE));
 353                 const int comment_continue = (comment && prevComment);
 354                 if ((!quote || !prevQuote) && !comment)
 355                         indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 356                 if (quote)
 357                         indentNext = indentCurrentLevel;
 358                 if (indentNext & SC_FOLDLEVELWHITEFLAG)
 359                         indentNext = SC_FOLDLEVELWHITEFLAG | indentCurrentLevel;
 360
 361                 if (quote_start) {
 362                         // Place fold point at start of triple quoted string
 363                         lev |= SC_FOLDLEVELHEADERFLAG;
 364                 } else if (quote_continue || prevQuote) {
 365                         // Add level to rest of lines in the string
 366                         lev = lev + 1;
 367                 } else if (comment_start) {
 368                         // Place fold point at start of a block of comments
 369                         lev |= SC_FOLDLEVELHEADERFLAG;
 370                 } else if (comment_continue) {
 371                         // Add level to rest of lines in the block
 372                         lev = lev + 1;
 373                 }
 374
 375                 // Skip past any blank lines for next indent level info; we skip also
 376                 // comments (all comments, not just those starting in column 0)
 377                 // which effectively folds them into surrounding code rather
 378                 // than screwing up folding.
 379
 380                 while (!quote &&
 381                         (lineNext < docLines) &&
 382                         ((indentNext & SC_FOLDLEVELWHITEFLAG) ||
 383                          (lineNext <= docLines && IsCommentLine(lineNext, styler)))) {
 384
 385                         lineNext++;
 386                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 387                 }
 388
 389                 const int levelAfterComments = indentNext & SC_FOLDLEVELNUMBERMASK;
 390                 const int levelBeforeComments = Platform::Maximum(indentCurrentLevel,levelAfterComments);
 391
 392                 // Now set all the indent levels on the lines we skipped
 393                 // Do this from end to start.  Once we encounter one line
 394                 // which is indented more than the line after the end of
 395                 // the comment-block, use the level of the block before
 396
 397                 int skipLine = lineNext;
 398                 int skipLevel = levelAfterComments;
 399
 400                 while (--skipLine > lineCurrent) {
 401                         int skipLineIndent = styler.IndentAmount(skipLine, &spaceFlags, NULL);
 402
 403                         if ((skipLineIndent & SC_FOLDLEVELNUMBERMASK) > levelAfterComments)
 404                                 skipLevel = levelBeforeComments;
 405
 406                         int whiteFlag = skipLineIndent & SC_FOLDLEVELWHITEFLAG;
 407
 408                         styler.SetLevel(skipLine, skipLevel | whiteFlag);
 409                 }
 410
 411                 // Set fold header on non-quote/non-comment line
 412                 if (!quote && !comment && !(indentCurrent & SC_FOLDLEVELWHITEFLAG) ) {
 413                         if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) < (indentNext & SC_FOLDLEVELNUMBERMASK))
 414                                 lev |= SC_FOLDLEVELHEADERFLAG;
 415                 }
 416
 417                 // Keep track of triple quote and block comment state of previous line
 418                 prevQuote = quote;
 419                 prevComment = comment_start || comment_continue;
 420
 421                 // Set fold level for this line and move to next line
 422                 styler.SetLevel(lineCurrent, lev);
 423                 indentCurrent = indentNext;
 424                 lineCurrent = lineNext;
 425         }
 426
 427         // NOTE: Cannot set level of last line here because indentCurrent doesn't have
 428         // header flag set; the loop above is crafted to take care of this case!
 429         //styler.SetLevel(lineCurrent, indentCurrent);
 430 }
 431
 432 static const char * const pythonWordListDesc[] = {
 433         "Keywords",
 434         0
 435 };
 436
 437 LexerModule lmPython(SCLEX_PYTHON, ColourisePyDoc, "python", FoldPyDoc,
 438                                          pythonWordListDesc);