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         WordList &keywords2 = *keywordlists[1];
 113
 114         const int whingeLevel = styler.GetPropertyInt("tab.timmy.whinge.level");
 115
 116         initStyle = initStyle & 31;
 117         if (initStyle == SCE_P_STRINGEOL) {
 118                 initStyle = SCE_P_DEFAULT;
 119         }
 120
 121         kwType kwLast = kwOther;
 122         int spaceFlags = 0;
 123         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 124         bool hexadecimal = false;
 125
 126         // Python uses a different mask because bad indentation is marked by oring with 32
 127         StyleContext sc(startPos, endPos - startPos, initStyle, styler, 0x7f);
 128
 129         for (; sc.More(); sc.Forward()) {
 130
 131                 if (sc.atLineStart) {
 132                         const char chBad = static_cast<char>(64);
 133                         const char chGood = static_cast<char>(0);
 134                         char chFlags = chGood;
 135                         if (whingeLevel == 1) {
 136                                 chFlags = (spaceFlags & wsInconsistent) ? chBad : chGood;
 137                         } else if (whingeLevel == 2) {
 138                                 chFlags = (spaceFlags & wsSpaceTab) ? chBad : chGood;
 139                         } else if (whingeLevel == 3) {
 140                                 chFlags = (spaceFlags & wsSpace) ? chBad : chGood;
 141                         } else if (whingeLevel == 4) {
 142                                 chFlags = (spaceFlags & wsTab) ? chBad : chGood;
 143                         }
 144                         sc.SetState(sc.state);
 145                         styler.SetFlags(chFlags, static_cast<char>(sc.state));
 146                 }
 147
 148                 if (sc.atLineEnd) {
 149                         if ((sc.state == SCE_P_DEFAULT) ||
 150                                 (sc.state == SCE_P_TRIPLE) ||
 151                                 (sc.state == SCE_P_TRIPLEDOUBLE)) {
 152                                 // Perform colourisation of white space and triple quoted strings at end of each line to allow
 153                                 // tab marking to work inside white space and triple quoted strings
 154                                 sc.SetState(sc.state);
 155                         }
 156                         lineCurrent++;
 157                         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 158                         if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 159                                 sc.ChangeState(SCE_P_STRINGEOL);
 160                                 sc.ForwardSetState(SCE_P_DEFAULT);
 161                         }
 162                         if (!sc.More())
 163                                 break;
 164                 }
 165
 166                 bool needEOLCheck = false;
 167
 168                 // Check for a state end
 169                 if (sc.state == SCE_P_OPERATOR) {
 170                         kwLast = kwOther;
 171                         sc.SetState(SCE_P_DEFAULT);
 172                 } else if (sc.state == SCE_P_NUMBER) {
 173                         if (!IsAWordChar(sc.ch) &&
 174                                 !(!hexadecimal && ((sc.ch == '+' || sc.ch == '-') && (sc.chPrev == 'e' || sc.chPrev == 'E')))) {
 175                                 sc.SetState(SCE_P_DEFAULT);
 176                         }
 177                 } else if (sc.state == SCE_P_IDENTIFIER) {
 178                         if ((sc.ch == '.') || (!IsAWordChar(sc.ch))) {
 179                                 char s[100];
 180                                 sc.GetCurrent(s, sizeof(s));
 181                                 int style = SCE_P_IDENTIFIER;
 182                                 if ((kwLast == kwImport) && (strcmp(s, "as") == 0)) {
 183                                         style = SCE_P_WORD;
 184                                 } else if (keywords.InList(s)) {
 185                                         style = SCE_P_WORD;
 186                                 } else if (kwLast == kwClass) {
 187                                         style = SCE_P_CLASSNAME;
 188                                 } else if (kwLast == kwDef) {
 189                                         style = SCE_P_DEFNAME;
 190                                 } else if (keywords2.InList(s)) {
 191                                         style = SCE_P_WORD2;
 192                                 }
 193                                 sc.ChangeState(style);
 194                                 sc.SetState(SCE_P_DEFAULT);
 195                                 if (style == SCE_P_WORD) {
 196                                         if (0 == strcmp(s, "class"))
 197                                                 kwLast = kwClass;
 198                                         else if (0 == strcmp(s, "def"))
 199                                                 kwLast = kwDef;
 200                                         else if (0 == strcmp(s, "import"))
 201                                                 kwLast = kwImport;
 202                                         else
 203                                                 kwLast = kwOther;
 204                                 } else {
 205                                         kwLast = kwOther;
 206                                 }
 207                         }
 208                 } else if ((sc.state == SCE_P_COMMENTLINE) || (sc.state == SCE_P_COMMENTBLOCK)) {
 209                         if (sc.ch == '\r' || sc.ch == '\n') {
 210                                 sc.SetState(SCE_P_DEFAULT);
 211                         }
 212                 } else if (sc.state == SCE_P_DECORATOR) {
 213                         if (sc.ch == '\r' || sc.ch == '\n') {
 214                                 sc.SetState(SCE_P_DEFAULT);
 215                         }
 216                 } else if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 217                         if (sc.ch == '\\') {
 218                                 if ((sc.chNext == '\r') && (sc.GetRelative(2) == '\n')) {
 219                                         sc.Forward();
 220                                 }
 221                                 sc.Forward();
 222                         } else if ((sc.state == SCE_P_STRING) && (sc.ch == '\"')) {
 223                                 sc.ForwardSetState(SCE_P_DEFAULT);
 224                                 needEOLCheck = true;
 225                         } else if ((sc.state == SCE_P_CHARACTER) && (sc.ch == '\'')) {
 226                                 sc.ForwardSetState(SCE_P_DEFAULT);
 227                                 needEOLCheck = true;
 228                         }
 229                 } else if (sc.state == SCE_P_TRIPLE) {
 230                         if (sc.ch == '\\') {
 231                                 sc.Forward();
 232                         } else if (sc.Match("\'\'\'")) {
 233                                 sc.Forward();
 234                                 sc.Forward();
 235                                 sc.ForwardSetState(SCE_P_DEFAULT);
 236                                 needEOLCheck = true;
 237                         }
 238                 } else if (sc.state == SCE_P_TRIPLEDOUBLE) {
 239                         if (sc.ch == '\\') {
 240                                 sc.Forward();
 241                         } else if (sc.Match("\"\"\"")) {
 242                                 sc.Forward();
 243                                 sc.Forward();
 244                                 sc.ForwardSetState(SCE_P_DEFAULT);
 245                                 needEOLCheck = true;
 246                         }
 247                 }
 248
 249                 // State exit code may have moved on to end of line
 250                 if (needEOLCheck && sc.atLineEnd) {
 251                         lineCurrent++;
 252                         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 253                         if (!sc.More())
 254                                 break;
 255                 }
 256
 257                 // Check for a new state starting character
 258                 if (sc.state == SCE_P_DEFAULT) {
 259                         if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
 260                                 if (sc.ch == '0' && (sc.chNext == 'x' || sc.chNext == 'X')) {
 261                                         hexadecimal = true;
 262                                 } else {
 263                                         hexadecimal = false;
 264                                 }
 265                                 sc.SetState(SCE_P_NUMBER);
 266                         } else if (isascii(sc.ch) && isoperator(static_cast<char>(sc.ch)) || sc.ch == '`') {
 267                                 sc.SetState(SCE_P_OPERATOR);
 268                         } else if (sc.ch == '#') {
 269                                 sc.SetState(sc.chNext == '#' ? SCE_P_COMMENTBLOCK : SCE_P_COMMENTLINE);
 270                         } else if (sc.ch == '@') {
 271                                 sc.SetState(SCE_P_DECORATOR);
 272                         } else if (IsPyStringStart(sc.ch, sc.chNext, sc.GetRelative(2))) {
 273                                 unsigned int nextIndex = 0;
 274                                 sc.SetState(GetPyStringState(styler, sc.currentPos, &nextIndex));
 275                                 while (nextIndex > (sc.currentPos + 1) && sc.More()) {
 276                                         sc.Forward();
 277                                 }
 278                         } else if (IsAWordStart(sc.ch)) {
 279                                 sc.SetState(SCE_P_IDENTIFIER);
 280                         }
 281                 }
 282         }
 283         sc.Complete();
 284 }
 285
 286 static bool IsCommentLine(int line, Accessor &styler) {
 287         int pos = styler.LineStart(line);
 288         int eol_pos = styler.LineStart(line + 1) - 1;
 289         for (int i = pos; i < eol_pos; i++) {
 290                 char ch = styler[i];
 291                 if (ch == '#')
 292                         return true;
 293                 else if (ch != ' ' && ch != '\t')
 294                         return false;
 295         }
 296         return false;
 297 }
 298
 299 static bool IsQuoteLine(int line, Accessor &styler) {
 300         int style = styler.StyleAt(styler.LineStart(line)) & 31;
 301         return ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 302 }
 303
 304
 305 static void FoldPyDoc(unsigned int startPos, int length, int /*initStyle - unused*/,
 306                       WordList *[], Accessor &styler) {
 307         const int maxPos = startPos + length;
 308         const int maxLines = styler.GetLine(maxPos - 1);             // Requested last line
 309         const int docLines = styler.GetLine(styler.Length() - 1);  // Available last line
 310         const bool foldComment = styler.GetPropertyInt("fold.comment.python") != 0;
 311         const bool foldQuotes = styler.GetPropertyInt("fold.quotes.python") != 0;
 312
 313         // Backtrack to previous non-blank line so we can determine indent level
 314         // for any white space lines (needed esp. within triple quoted strings)
 315         // and so we can fix any preceding fold level (which is why we go back
 316         // at least one line in all cases)
 317         int spaceFlags = 0;
 318         int lineCurrent = styler.GetLine(startPos);
 319         int indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 320         while (lineCurrent > 0) {
 321                 lineCurrent--;
 322                 indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 323                 if (!(indentCurrent & SC_FOLDLEVELWHITEFLAG) &&
 324                         (!IsCommentLine(lineCurrent, styler)) &&
 325                         (!IsQuoteLine(lineCurrent, styler)))
 326                         break;
 327         }
 328         int indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 329
 330         // Set up initial loop state
 331         startPos = styler.LineStart(lineCurrent);
 332         int prev_state = SCE_P_DEFAULT & 31;
 333         if (lineCurrent >= 1)
 334                 prev_state = styler.StyleAt(startPos - 1) & 31;
 335         int prevQuote = foldQuotes && ((prev_state == SCE_P_TRIPLE) || (prev_state == SCE_P_TRIPLEDOUBLE));
 336         int prevComment = 0;
 337         if (lineCurrent >= 1)
 338                 prevComment = foldComment && IsCommentLine(lineCurrent - 1, styler);
 339
 340         // Process all characters to end of requested range or end of any triple quote
 341         // or comment that hangs over the end of the range.  Cap processing in all cases
 342         // to end of document (in case of unclosed quote or comment at end).
 343         while ((lineCurrent <= docLines) && ((lineCurrent <= maxLines) || prevQuote || prevComment)) {
 344
 345                 // Gather info
 346                 int lev = indentCurrent;
 347                 int lineNext = lineCurrent + 1;
 348                 int indentNext = indentCurrent;
 349                 int quote = false;
 350                 if (lineNext <= docLines) {
 351                         // Information about next line is only available if not at end of document
 352                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 353                         int style = styler.StyleAt(styler.LineStart(lineNext)) & 31;
 354                         quote = foldQuotes && ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 355                 }
 356                 const int quote_start = (quote && !prevQuote);
 357                 const int quote_continue = (quote && prevQuote);
 358                 const int comment = foldComment && IsCommentLine(lineCurrent, styler);
 359                 const int comment_start = (comment && !prevComment && (lineNext <= docLines) &&
 360                                            IsCommentLine(lineNext, styler) && (lev > SC_FOLDLEVELBASE));
 361                 const int comment_continue = (comment && prevComment);
 362                 if ((!quote || !prevQuote) && !comment)
 363                         indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 364                 if (quote)
 365                         indentNext = indentCurrentLevel;
 366                 if (indentNext & SC_FOLDLEVELWHITEFLAG)
 367                         indentNext = SC_FOLDLEVELWHITEFLAG | indentCurrentLevel;
 368
 369                 if (quote_start) {
 370                         // Place fold point at start of triple quoted string
 371                         lev |= SC_FOLDLEVELHEADERFLAG;
 372                 } else if (quote_continue || prevQuote) {
 373                         // Add level to rest of lines in the string
 374                         lev = lev + 1;
 375                 } else if (comment_start) {
 376                         // Place fold point at start of a block of comments
 377                         lev |= SC_FOLDLEVELHEADERFLAG;
 378                 } else if (comment_continue) {
 379                         // Add level to rest of lines in the block
 380                         lev = lev + 1;
 381                 }
 382
 383                 // Skip past any blank lines for next indent level info; we skip also
 384                 // comments (all comments, not just those starting in column 0)
 385                 // which effectively folds them into surrounding code rather
 386                 // than screwing up folding.
 387
 388                 while (!quote &&
 389                         (lineNext < docLines) &&
 390                         ((indentNext & SC_FOLDLEVELWHITEFLAG) ||
 391                          (lineNext <= docLines && IsCommentLine(lineNext, styler)))) {
 392
 393                         lineNext++;
 394                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 395                 }
 396
 397                 const int levelAfterComments = indentNext & SC_FOLDLEVELNUMBERMASK;
 398                 const int levelBeforeComments = Platform::Maximum(indentCurrentLevel,levelAfterComments);
 399
 400                 // Now set all the indent levels on the lines we skipped
 401                 // Do this from end to start.  Once we encounter one line
 402                 // which is indented more than the line after the end of
 403                 // the comment-block, use the level of the block before
 404
 405                 int skipLine = lineNext;
 406                 int skipLevel = levelAfterComments;
 407
 408                 while (--skipLine > lineCurrent) {
 409                         int skipLineIndent = styler.IndentAmount(skipLine, &spaceFlags, NULL);
 410
 411                         if ((skipLineIndent & SC_FOLDLEVELNUMBERMASK) > levelAfterComments)
 412                                 skipLevel = levelBeforeComments;
 413
 414                         int whiteFlag = skipLineIndent & SC_FOLDLEVELWHITEFLAG;
 415
 416                         styler.SetLevel(skipLine, skipLevel | whiteFlag);
 417                 }
 418
 419                 // Set fold header on non-quote/non-comment line
 420                 if (!quote && !comment && !(indentCurrent & SC_FOLDLEVELWHITEFLAG) ) {
 421                         if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) < (indentNext & SC_FOLDLEVELNUMBERMASK))
 422                                 lev |= SC_FOLDLEVELHEADERFLAG;
 423                 }
 424
 425                 // Keep track of triple quote and block comment state of previous line
 426                 prevQuote = quote;
 427                 prevComment = comment_start || comment_continue;
 428
 429                 // Set fold level for this line and move to next line
 430                 styler.SetLevel(lineCurrent, lev);
 431                 indentCurrent = indentNext;
 432                 lineCurrent = lineNext;
 433         }
 434
 435         // NOTE: Cannot set level of last line here because indentCurrent doesn't have
 436         // header flag set; the loop above is crafted to take care of this case!
 437         //styler.SetLevel(lineCurrent, indentCurrent);
 438 }
 439
 440 static const char * const pythonWordListDesc[] = {
 441         "Keywords",
 442         "Highlighted identifiers",
 443         0
 444 };
 445
 446 LexerModule lmPython(SCLEX_PYTHON, ColourisePyDoc, "python", FoldPyDoc,
 447                                          pythonWordListDesc);