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, 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                         startPos = styler.LineStart(lineCurrent - 1);
 103                         if (startPos == 0)
 104                                 initStyle = SCE_P_DEFAULT;
 105                         else
 106                                 initStyle = styler.StyleAt(startPos - 1);
 107                 }
 108         }
 109
 110         WordList &keywords = *keywordlists[0];
 111
 112         const int whingeLevel = styler.GetPropertyInt("tab.timmy.whinge.level");
 113
 114         initStyle = initStyle & 31;
 115         if (initStyle == SCE_P_STRINGEOL) {
 116                 initStyle = SCE_P_DEFAULT;
 117         }
 118
 119         kwType kwLast = kwOther;
 120         int spaceFlags = 0;
 121         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 122         bool hexadecimal = false;
 123
 124         // Python uses a different mask because bad indentation is marked by oring with 32
 125         StyleContext sc(startPos, endPos - startPos, initStyle, styler, 0x7f);
 126
 127         for (; sc.More(); sc.Forward()) {
 128
 129                 if (sc.atLineStart) {
 130                         const char chBad = static_cast<char>(64);
 131                         const char chGood = static_cast<char>(0);
 132                         char chFlags = chGood;
 133                         if (whingeLevel == 1) {
 134                                 chFlags = (spaceFlags & wsInconsistent) ? chBad : chGood;
 135                         } else if (whingeLevel == 2) {
 136                                 chFlags = (spaceFlags & wsSpaceTab) ? chBad : chGood;
 137                         } else if (whingeLevel == 3) {
 138                                 chFlags = (spaceFlags & wsSpace) ? chBad : chGood;
 139                         } else if (whingeLevel == 4) {
 140                                 chFlags = (spaceFlags & wsTab) ? chBad : chGood;
 141                         }
 142                         styler.SetFlags(chFlags, static_cast<char>(sc.state));
 143                 }
 144
 145                 if (sc.atLineEnd) {
 146                         if ((sc.state == SCE_P_DEFAULT) ||
 147                                 (sc.state == SCE_P_TRIPLE) ||
 148                                 (sc.state == SCE_P_TRIPLEDOUBLE)) {
 149                                 // Perform colourisation of white space and triple quoted strings at end of each line to allow
 150                                 // tab marking to work inside white space and triple quoted strings
 151                                 sc.ForwardSetState(sc.state);
 152                         }
 153                         lineCurrent++;
 154                         styler.IndentAmount(lineCurrent, &spaceFlags, IsPyComment);
 155                         if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 156                                 sc.ChangeState(SCE_P_STRINGEOL);
 157                                 sc.ForwardSetState(SCE_P_DEFAULT);
 158                         }
 159                         if (!sc.More())
 160                                 break;
 161                 }
 162
 163                 // Check for a state end
 164                 if (sc.state == SCE_P_OPERATOR) {
 165                         kwLast = kwOther;
 166                         sc.SetState(SCE_P_DEFAULT);
 167                 } else if (sc.state == SCE_P_NUMBER) {
 168                         if (!IsAWordChar(sc.ch) &&
 169                                 !(!hexadecimal && ((sc.ch == '+' || sc.ch == '-') && (sc.chPrev == 'e' || sc.chPrev == 'E')))) {
 170                                 sc.SetState(SCE_P_DEFAULT);
 171                         }
 172                 } else if (sc.state == SCE_P_IDENTIFIER) {
 173                         if ((sc.ch == '.') || (!IsAWordChar(sc.ch))) {
 174                                 char s[100];
 175                                 sc.GetCurrent(s, sizeof(s));
 176                                 int style = SCE_P_IDENTIFIER;
 177                                 if ((kwLast == kwImport) && (strcmp(s, "as") == 0)) {
 178                                         style = SCE_P_WORD;
 179                                 } else if (keywords.InList(s)) {
 180                                         style = SCE_P_WORD;
 181                                 } else if (kwLast == kwClass) {
 182                                         style = SCE_P_CLASSNAME;
 183                                 } else if (kwLast == kwDef) {
 184                                         style = SCE_P_DEFNAME;
 185                                 }
 186                                 sc.ChangeState(style);
 187                                 sc.SetState(SCE_P_DEFAULT);
 188                                 if (style == SCE_P_WORD) {
 189                                         if (0 == strcmp(s, "class"))
 190                                                 kwLast = kwClass;
 191                                         else if (0 == strcmp(s, "def"))
 192                                                 kwLast = kwDef;
 193                                         else if (0 == strcmp(s, "import"))
 194                                                 kwLast = kwImport;
 195                                         else
 196                                                 kwLast = kwOther;
 197                                 } else if (style == SCE_P_CLASSNAME) {
 198                                         kwLast = kwOther;
 199                                 } else if (style == SCE_P_DEFNAME) {
 200                                         kwLast = kwOther;
 201                                 }
 202                         }
 203                 } else if ((sc.state == SCE_P_COMMENTLINE) || (sc.state == SCE_P_COMMENTBLOCK)) {
 204                         if (sc.ch == '\r' || sc.ch == '\n') {
 205                                 sc.SetState(SCE_P_DEFAULT);
 206                         }
 207                 } else if ((sc.state == SCE_P_STRING) || (sc.state == SCE_P_CHARACTER)) {
 208                         if (sc.ch == '\\') {
 209                                 if ((sc.chNext == '\r') && (sc.GetRelative(2) == '\n')) {
 210                                         sc.Forward();
 211                                 }
 212                                 sc.Forward();
 213                         } else if ((sc.state == SCE_P_STRING) && (sc.ch == '\"')) {
 214                                 sc.ForwardSetState(SCE_P_DEFAULT);
 215                         } else if ((sc.state == SCE_P_CHARACTER) && (sc.ch == '\'')) {
 216                                 sc.ForwardSetState(SCE_P_DEFAULT);
 217                         }
 218                 } else if (sc.state == SCE_P_TRIPLE) {
 219                         if (sc.ch == '\\') {
 220                                 sc.Forward();
 221                         } else if (sc.Match("\'\'\'")) {
 222                                 sc.Forward();
 223                                 sc.Forward();
 224                                 sc.ForwardSetState(SCE_P_DEFAULT);
 225                         }
 226                 } else if (sc.state == SCE_P_TRIPLEDOUBLE) {
 227                         if (sc.ch == '\\') {
 228                                 sc.Forward();
 229                         } else if (sc.Match("\"\"\"")) {
 230                                 sc.Forward();
 231                                 sc.Forward();
 232                                 sc.ForwardSetState(SCE_P_DEFAULT);
 233                         }
 234                 }
 235
 236                 // Check for a new state starting character
 237                 if (sc.state == SCE_P_DEFAULT) {
 238                         if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
 239                                 if (sc.ch == '0' && (sc.chNext == 'x' || sc.chNext == 'X')) {
 240                                         hexadecimal = true;
 241                                 } else {
 242                                         hexadecimal = false;
 243                                 }
 244                                 sc.SetState(SCE_P_NUMBER);
 245                         } else if (isascii(sc.ch) && isoperator(static_cast<char>(sc.ch)) || sc.ch == '`') {
 246                                 sc.SetState(SCE_P_OPERATOR);
 247                         } else if (sc.ch == '#') {
 248                                 sc.SetState(sc.chNext == '#' ? SCE_P_COMMENTBLOCK : SCE_P_COMMENTLINE);
 249                         } else if (IsPyStringStart(sc.ch, sc.chNext, sc.GetRelative(2))) {
 250                                 int nextIndex = 0;
 251                                 sc.SetState(GetPyStringState(styler, sc.currentPos, &nextIndex));
 252                                 while (nextIndex > (sc.currentPos + 1)) {
 253                                         sc.Forward();
 254                                 }
 255                         } else if (IsAWordStart(sc.ch)) {
 256                                 sc.SetState(SCE_P_IDENTIFIER);
 257                         }
 258                 }
 259         }
 260         sc.Complete();
 261 }
 262
 263 static bool IsCommentLine(int line, Accessor &styler) {
 264         int pos = styler.LineStart(line);
 265         int eol_pos = styler.LineStart(line + 1) - 1;
 266         for (int i = pos; i < eol_pos; i++) {
 267                 char ch = styler[i];
 268                 if (ch == '#')
 269                         return true;
 270                 else if (ch != ' ' && ch != '\t')
 271                         return false;
 272         }
 273         return false;
 274 }
 275
 276 static bool IsQuoteLine(int line, Accessor &styler) {
 277         int style = styler.StyleAt(styler.LineStart(line)) & 31;
 278         return ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 279 }
 280
 281
 282 static void FoldPyDoc(unsigned int startPos, int length, int /*initStyle - unused*/,
 283                       WordList *[], Accessor &styler) {
 284         const int maxPos = startPos + length;
 285         const int maxLines = styler.GetLine(maxPos - 1);             // Requested last line
 286         const int docLines = styler.GetLine(styler.Length() - 1);  // Available last line
 287         const bool foldComment = styler.GetPropertyInt("fold.comment.python") != 0;
 288         const bool foldQuotes = styler.GetPropertyInt("fold.quotes.python") != 0;
 289
 290         // Backtrack to previous non-blank line so we can determine indent level
 291         // for any white space lines (needed esp. within triple quoted strings)
 292         // and so we can fix any preceding fold level (which is why we go back
 293         // at least one line in all cases)
 294         int spaceFlags = 0;
 295         int lineCurrent = styler.GetLine(startPos);
 296         int indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 297         while (lineCurrent > 0) {
 298                 lineCurrent--;
 299                 indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);
 300                 if (!(indentCurrent & SC_FOLDLEVELWHITEFLAG) &&
 301                         (!IsCommentLine(lineCurrent, styler)) &&
 302                         (!IsQuoteLine(lineCurrent, styler)))
 303                         break;
 304         }
 305         int indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 306
 307         // Set up initial loop state
 308         startPos = styler.LineStart(lineCurrent);
 309         int prev_state = SCE_P_DEFAULT & 31;
 310         if (lineCurrent >= 1)
 311                 prev_state = styler.StyleAt(startPos - 1) & 31;
 312         int prevQuote = foldQuotes && ((prev_state == SCE_P_TRIPLE) || (prev_state == SCE_P_TRIPLEDOUBLE));
 313         int prevComment = 0;
 314         if (lineCurrent >= 1)
 315                 prevComment = foldComment && IsCommentLine(lineCurrent - 1, styler);
 316
 317         // Process all characters to end of requested range or end of any triple quote
 318         // or comment that hangs over the end of the range.  Cap processing in all cases
 319         // to end of document (in case of unclosed quote or comment at end).
 320         while ((lineCurrent <= docLines) && ((lineCurrent <= maxLines) || prevQuote || prevComment)) {
 321
 322                 // Gather info
 323                 int lev = indentCurrent;
 324                 int lineNext = lineCurrent + 1;
 325                 int indentNext = indentCurrent;
 326                 int quote = false;
 327                 if (lineNext <= docLines) {
 328                         // Information about next line is only available if not at end of document
 329                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 330                         int style = styler.StyleAt(styler.LineStart(lineNext)) & 31;
 331                         quote = foldQuotes && ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));
 332                 }
 333                 const int quote_start = (quote && !prevQuote);
 334                 const int quote_continue = (quote && prevQuote);
 335                 const int comment = foldComment && IsCommentLine(lineCurrent, styler);
 336                 const int comment_start = (comment && !prevComment && (lineNext <= docLines) &&
 337                                            IsCommentLine(lineNext, styler) && (lev > SC_FOLDLEVELBASE));
 338                 const int comment_continue = (comment && prevComment);
 339                 if ((!quote || !prevQuote) && !comment)
 340                         indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;
 341                 if (quote)
 342                         indentNext = indentCurrentLevel;
 343                 if (indentNext & SC_FOLDLEVELWHITEFLAG)
 344                         indentNext = SC_FOLDLEVELWHITEFLAG | indentCurrentLevel;
 345
 346                 if (quote_start) {
 347                         // Place fold point at start of triple quoted string
 348                         lev |= SC_FOLDLEVELHEADERFLAG;
 349                 } else if (quote_continue || prevQuote) {
 350                         // Add level to rest of lines in the string
 351                         lev = lev + 1;
 352                 } else if (comment_start) {
 353                         // Place fold point at start of a block of comments
 354                         lev |= SC_FOLDLEVELHEADERFLAG;
 355                 } else if (comment_continue) {
 356                         // Add level to rest of lines in the block
 357                         lev = lev + 1;
 358                 }
 359
 360                 // Skip past any blank lines for next indent level info; we skip also comments
 361                 // starting in column 0 which effectively folds them into surrounding code rather
 362                 // than screwing up folding.
 363                 const int saveIndentNext = indentNext;
 364                 while (!quote &&
 365                         (lineNext < docLines) &&
 366                         ((indentNext & SC_FOLDLEVELWHITEFLAG) ||
 367                          (lineNext <= docLines && styler[styler.LineStart(lineNext)] == '#'))) {
 368
 369                         lineNext++;
 370                         indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);
 371                 }
 372
 373                 // Next compute max indent level of current line and next non-blank line.
 374                 // This is the level to which we set all the intervening blank or comment lines.
 375                 const int skip_level = Platform::Maximum(indentCurrentLevel,
 376                                        indentNext & SC_FOLDLEVELNUMBERMASK);
 377
 378                 // Now set all the indent levels on the lines we skipped
 379                 int skipLine = lineCurrent + 1;
 380                 int skipIndentNext = saveIndentNext;
 381                 while (skipLine < lineNext) {
 382                         int skipLineLevel = skip_level;
 383                         if (skipIndentNext & SC_FOLDLEVELWHITEFLAG)
 384                                 skipLineLevel = SC_FOLDLEVELWHITEFLAG | skipLineLevel;
 385                         styler.SetLevel(skipLine, skipLineLevel);
 386                         skipLine++;
 387                         skipIndentNext = styler.IndentAmount(skipLine, &spaceFlags, NULL);
 388                 }
 389
 390                 // Set fold header on non-quote/non-comment line
 391                 if (!quote && !comment && !(indentCurrent & SC_FOLDLEVELWHITEFLAG) ) {
 392                         if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) < (indentNext & SC_FOLDLEVELNUMBERMASK))
 393                                 lev |= SC_FOLDLEVELHEADERFLAG;
 394                 }
 395
 396                 // Keep track of triple quote and block comment state of previous line
 397                 prevQuote = quote;
 398                 prevComment = comment_start || comment_continue;
 399
 400                 // Set fold level for this line and move to next line
 401                 styler.SetLevel(lineCurrent, lev);
 402                 indentCurrent = indentNext;
 403                 lineCurrent = lineNext;
 404         }
 405
 406         // NOTE: Cannot set level of last line here because indentCurrent doesn't have
 407         // header flag set; the loop above is crafted to take care of this case!
 408         //styler.SetLevel(lineCurrent, indentCurrent);
 409 }
 410
 411 static const char * const pythonWordListDesc[] = {
 412         "Python keywords",
 413         0
 414 };
 415
 416 LexerModule lmPython(SCLEX_PYTHON, ColourisePyDoc, "python", FoldPyDoc,
 417                                          pythonWordListDesc);