/ext/scintilla/lexers/LexNimrod.cxx

// Scintilla source code edit control

// Nimrod lexer

// (c) 2009 Andreas Rumpf

/** @file LexNimrod.cxx

 ** Lexer for Nimrod.

 **/

// Copyright 1998-2002 by Neil Hodgson <neilh@scintilla.org>

// The License.txt file describes the conditions under which this software may be distributed.



#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <stdarg.h>

#include <assert.h>

#include <ctype.h>



#include "ILexer.h"

#include "Scintilla.h"

#include "SciLexer.h"



#include "WordList.h"

#include "LexAccessor.h"

#include "Accessor.h"

#include "StyleContext.h"

#include "CharacterSet.h"

#include "LexerModule.h"



#ifdef SCI_NAMESPACE

using namespace Scintilla;

#endif



static inline bool IsAWordChar(int ch) {

	return (ch >= 0x80) || isalnum(ch) || ch == '_';

}



static Sci_Position tillEndOfTripleQuote(Accessor &styler, Sci_Position pos, Sci_Position max) {

  /* search for """ */

  for (;;) {

    if (styler.SafeGetCharAt(pos, '\0') == '\0') return pos;

    if (pos >= max) return pos;

    if (styler.Match(pos, "\"\"\"")) {

      return pos + 2;

    }

    pos++;

  }

}



#define CR 13 /* use both because Scite allows changing the line ending */

#define LF 10



static bool inline isNewLine(int ch) {

  return ch == CR || ch == LF;

}



static Sci_Position scanString(Accessor &styler, Sci_Position pos, Sci_Position max, bool rawMode) {

  for (;;) {

    if (pos >= max) return pos;

    char ch = styler.SafeGetCharAt(pos, '\0');

    if (ch == CR || ch == LF || ch == '\0') return pos;

    if (ch == '"') return pos;

    if (ch == '\\' && !rawMode) {

      pos += 2;

    } else {

      pos++;

    }

  }

}



static Sci_Position scanChar(Accessor &styler, Sci_Position pos, Sci_Position max) {

  for (;;) {

    if (pos >= max) return pos;

    char ch = styler.SafeGetCharAt(pos, '\0');

    if (ch == CR || ch == LF || ch == '\0') return pos;

    if (ch == '\'' && !isalnum(styler.SafeGetCharAt(pos+1, '\0')) )

      return pos;

    if (ch == '\\') {

      pos += 2;

    } else {

      pos++;

    }

  }

}



static Sci_Position scanIdent(Accessor &styler, Sci_Position pos, WordList &keywords) {

  char buf[100]; /* copy to lowercase and ignore underscores */

  Sci_Position i = 0;



  for (;;) {

    char ch = styler.SafeGetCharAt(pos, '\0');

    if (!IsAWordChar(ch)) break;

    if (ch != '_' && i < ((int)sizeof(buf))-1) {

      buf[i] = static_cast<char>(tolower(ch));

      i++;

    }

    pos++;

  }

  buf[i] = '\0';

  /* look for keyword */

  if (keywords.InList(buf)) {

    styler.ColourTo(pos-1, SCE_P_WORD);

  } else {

    styler.ColourTo(pos-1, SCE_P_IDENTIFIER);

  }

  return pos;

}



static Sci_Position scanNumber(Accessor &styler, Sci_Position pos) {

  char ch, ch2;

  ch = styler.SafeGetCharAt(pos, '\0');

  ch2 = styler.SafeGetCharAt(pos+1, '\0');

  if (ch == '0' && (ch2 == 'b' || ch2 == 'B')) {

    /* binary number: */

    pos += 2;

    for (;;) {

      ch = styler.SafeGetCharAt(pos, '\0');

      if (ch == '_' || (ch >= '0' && ch <= '1')) ++pos;

      else break;

    }

  } else if (ch == '0' &&

            (ch2 == 'o' || ch2 == 'O' || ch2 == 'c' || ch2 == 'C')) {

    /* octal number: */

    pos += 2;

    for (;;) {

      ch = styler.SafeGetCharAt(pos, '\0');

      if (ch == '_' || (ch >= '0' && ch <= '7')) ++pos;

      else break;

    }

  } else if (ch == '0' && (ch2 == 'x' || ch2 == 'X')) {

    /* hexadecimal number: */

    pos += 2;

    for (;;) {

      ch = styler.SafeGetCharAt(pos, '\0');

      if (ch == '_' || (ch >= '0' && ch <= '9')

          || (ch >= 'a' && ch <= 'f')

          || (ch >= 'A' && ch <= 'F')) ++pos;

      else break;

    }

  } else {

    // skip decimal part:

    for (;;) {

      ch = styler.SafeGetCharAt(pos, '\0');

      if (ch == '_' || (ch >= '0' && ch <= '9')) ++pos;

      else break;

    }

    ch2 = styler.SafeGetCharAt(pos+1, '\0');

    if (ch == '.' && ch2 >= '0' && ch2 <= '9') {

      ++pos; // skip '.'

      for (;;) {

        ch = styler.SafeGetCharAt(pos, '\0');

        if (ch == '_' || (ch >= '0' && ch <= '9')) ++pos;

        else break;

      }

    }

    if (ch == 'e' || ch == 'E') {

      ++pos;

      ch = styler.SafeGetCharAt(pos, '\0');

      if (ch == '-' || ch == '+') ++pos;

      for (;;) {

        ch = styler.SafeGetCharAt(pos, '\0');

        if (ch == '_' || (ch >= '0' && ch <= '9')) ++pos;

        else break;

      }

    }

  }

  if (ch == '\'') {

    /* a type suffix: */

    pos++;

    for (;;) {

      ch = styler.SafeGetCharAt(pos);

      if ((ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'Z')

         || (ch >= 'a' && ch <= 'z') || ch == '_') ++pos;

      else break;

    }

  }

  styler.ColourTo(pos-1, SCE_P_NUMBER);

  return pos;

}



/* rewritten from scratch, because I couldn't get rid of the bugs...

   (A character based approach sucks!)

*/

static void ColouriseNimrodDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,

                                WordList *keywordlists[], Accessor &styler) {

  Sci_Position pos = startPos;

  Sci_Position max = startPos + length;

  char ch;

  WordList &keywords = *keywordlists[0];



  styler.StartAt(startPos);

  styler.StartSegment(startPos);



  switch (initStyle) {

    /* check where we are: */

    case SCE_P_TRIPLEDOUBLE:

      pos = tillEndOfTripleQuote(styler, pos, max);

      styler.ColourTo(pos, SCE_P_TRIPLEDOUBLE);

      pos++;

    break;

    default: /* nothing to do: */

    break;

  }

  while (pos < max) {

    ch = styler.SafeGetCharAt(pos, '\0');

    switch (ch) {

      case '\0': return;

      case '#': {

        bool doccomment = (styler.SafeGetCharAt(pos+1) == '#');

        while (pos < max && !isNewLine(styler.SafeGetCharAt(pos, LF))) pos++;

        if (doccomment)

          styler.ColourTo(pos, SCE_C_COMMENTLINEDOC);

        else

          styler.ColourTo(pos, SCE_P_COMMENTLINE);

      } break;

      case 'r': case 'R': {

        if (styler.SafeGetCharAt(pos+1) == '"') {

          pos = scanString(styler, pos+2, max, true);

          styler.ColourTo(pos, SCE_P_STRING);

          pos++;

        } else {

          pos = scanIdent(styler, pos, keywords);

        }

      } break;

      case '"':

        if (styler.Match(pos+1, "\"\"")) {

          pos = tillEndOfTripleQuote(styler, pos+3, max);

          styler.ColourTo(pos, SCE_P_TRIPLEDOUBLE);

        } else {

          pos = scanString(styler, pos+1, max, false);

          styler.ColourTo(pos, SCE_P_STRING);

        }

        pos++;

      break;

      case '\'':

        pos = scanChar(styler, pos+1, max);

        styler.ColourTo(pos, SCE_P_CHARACTER);

        pos++;

      break;

      default: // identifers, numbers, operators, whitespace

        if (ch >= '0' && ch <= '9') {

          pos = scanNumber(styler, pos);

        } else if (IsAWordChar(ch)) {

          pos = scanIdent(styler, pos, keywords);

        } else if (ch == '`') {

          pos++;

          while (pos < max) {

            ch = styler.SafeGetCharAt(pos, LF);

            if (ch == '`') {

              ++pos;

              break;

            }

            if (ch == CR || ch == LF) break;

            ++pos;

          }

          styler.ColourTo(pos, SCE_P_IDENTIFIER);

        } else if (strchr("()[]{}:=;-\\/&%$!+<>|^?,.*~@", ch)) {

          styler.ColourTo(pos, SCE_P_OPERATOR);

          pos++;

        } else {

          styler.ColourTo(pos, SCE_P_DEFAULT);

          pos++;

        }

      break;

    }

  }

}



static bool IsCommentLine(Sci_Position line, Accessor &styler) {

	Sci_Position pos = styler.LineStart(line);

	Sci_Position eol_pos = styler.LineStart(line + 1) - 1;

	for (Sci_Position i = pos; i < eol_pos; i++) {

		char ch = styler[i];

		if (ch == '#')

			return true;

		else if (ch != ' ' && ch != '\t')

			return false;

	}

	return false;

}



static bool IsQuoteLine(Sci_Position line, Accessor &styler) {

	int style = styler.StyleAt(styler.LineStart(line)) & 31;

	return ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));

}





static void FoldNimrodDoc(Sci_PositionU startPos, Sci_Position length,

                          int /*initStyle - unused*/,

                          WordList *[], Accessor &styler) {

	const Sci_Position maxPos = startPos + length;

	const Sci_Position maxLines = styler.GetLine(maxPos - 1); // Requested last line

	const Sci_Position docLines = styler.GetLine(styler.Length() - 1); // Available last line

	const bool foldComment = styler.GetPropertyInt("fold.comment.nimrod") != 0;

	const bool foldQuotes = styler.GetPropertyInt("fold.quotes.nimrod") != 0;



	// Backtrack to previous non-blank line so we can determine indent level

	// for any white space lines (needed esp. within triple quoted strings)

	// and so we can fix any preceding fold level (which is why we go back

	// at least one line in all cases)

	int spaceFlags = 0;

	Sci_Position lineCurrent = styler.GetLine(startPos);

	int indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);

	while (lineCurrent > 0) {

		lineCurrent--;

		indentCurrent = styler.IndentAmount(lineCurrent, &spaceFlags, NULL);

		if (!(indentCurrent & SC_FOLDLEVELWHITEFLAG) &&

		        (!IsCommentLine(lineCurrent, styler)) &&

		        (!IsQuoteLine(lineCurrent, styler)))

			break;

	}

	int indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;



	// Set up initial loop state

	startPos = styler.LineStart(lineCurrent);

	int prev_state = SCE_P_DEFAULT & 31;

	if (lineCurrent >= 1)

		prev_state = styler.StyleAt(startPos - 1) & 31;

	int prevQuote = foldQuotes && ((prev_state == SCE_P_TRIPLE) ||

	                               (prev_state == SCE_P_TRIPLEDOUBLE));

	int prevComment = 0;

	if (lineCurrent >= 1)

		prevComment = foldComment && IsCommentLine(lineCurrent - 1, styler);



	// Process all characters to end of requested range or end of any triple quote

	// or comment that hangs over the end of the range.  Cap processing in all cases

	// to end of document (in case of unclosed quote or comment at end).

	while ((lineCurrent <= docLines) && ((lineCurrent <= maxLines) ||

	                                      prevQuote || prevComment)) {



		// Gather info

		int lev = indentCurrent;

		Sci_Position lineNext = lineCurrent + 1;

		int indentNext = indentCurrent;

		int quote = false;

		if (lineNext <= docLines) {

			// Information about next line is only available if not at end of document

			indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);

			int style = styler.StyleAt(styler.LineStart(lineNext)) & 31;

			quote = foldQuotes && ((style == SCE_P_TRIPLE) || (style == SCE_P_TRIPLEDOUBLE));

		}

		const int quote_start = (quote && !prevQuote);

		const int quote_continue = (quote && prevQuote);

		const int comment = foldComment && IsCommentLine(lineCurrent, styler);

		const int comment_start = (comment && !prevComment && (lineNext <= docLines) &&

		                           IsCommentLine(lineNext, styler) &&

		                           (lev > SC_FOLDLEVELBASE));

		const int comment_continue = (comment && prevComment);

		if ((!quote || !prevQuote) && !comment)

			indentCurrentLevel = indentCurrent & SC_FOLDLEVELNUMBERMASK;

		if (quote)

			indentNext = indentCurrentLevel;

		if (indentNext & SC_FOLDLEVELWHITEFLAG)

			indentNext = SC_FOLDLEVELWHITEFLAG | indentCurrentLevel;



		if (quote_start) {

			// Place fold point at start of triple quoted string

			lev |= SC_FOLDLEVELHEADERFLAG;

		} else if (quote_continue || prevQuote) {

			// Add level to rest of lines in the string

			lev = lev + 1;

		} else if (comment_start) {

			// Place fold point at start of a block of comments

			lev |= SC_FOLDLEVELHEADERFLAG;

		} else if (comment_continue) {

			// Add level to rest of lines in the block

			lev = lev + 1;

		}



		// Skip past any blank lines for next indent level info; we skip also

		// comments (all comments, not just those starting in column 0)

		// which effectively folds them into surrounding code rather

		// than screwing up folding.



		while (!quote &&

		        (lineNext < docLines) &&

		        ((indentNext & SC_FOLDLEVELWHITEFLAG) ||

		         (lineNext <= docLines && IsCommentLine(lineNext, styler)))) {



			lineNext++;

			indentNext = styler.IndentAmount(lineNext, &spaceFlags, NULL);

		}



		const int levelAfterComments = indentNext & SC_FOLDLEVELNUMBERMASK;

		const int levelBeforeComments =

		    Maximum(indentCurrentLevel,levelAfterComments);



		// Now set all the indent levels on the lines we skipped

		// Do this from end to start.  Once we encounter one line

		// which is indented more than the line after the end of

		// the comment-block, use the level of the block before



		Sci_Position skipLine = lineNext;

		int skipLevel = levelAfterComments;



		while (--skipLine > lineCurrent) {

			int skipLineIndent = styler.IndentAmount(skipLine, &spaceFlags, NULL);



			if ((skipLineIndent & SC_FOLDLEVELNUMBERMASK) > levelAfterComments)

				skipLevel = levelBeforeComments;



			int whiteFlag = skipLineIndent & SC_FOLDLEVELWHITEFLAG;



			styler.SetLevel(skipLine, skipLevel | whiteFlag);

		}



		// Set fold header on non-quote/non-comment line

		if (!quote && !comment && !(indentCurrent & SC_FOLDLEVELWHITEFLAG) ) {

			if ((indentCurrent & SC_FOLDLEVELNUMBERMASK) <

			     (indentNext & SC_FOLDLEVELNUMBERMASK))

				lev |= SC_FOLDLEVELHEADERFLAG;

		}



		// Keep track of triple quote and block comment state of previous line

		prevQuote = quote;

		prevComment = comment_start || comment_continue;



		// Set fold level for this line and move to next line

		styler.SetLevel(lineCurrent, lev);

		indentCurrent = indentNext;

		lineCurrent = lineNext;

	}



	// NOTE: Cannot set level of last line here because indentCurrent doesn't have

	// header flag set; the loop above is crafted to take care of this case!

	//styler.SetLevel(lineCurrent, indentCurrent);

}



static const char * const nimrodWordListDesc[] = {

	"Keywords",

	0

};



LexerModule lmNimrod(SCLEX_NIMROD, ColouriseNimrodDoc, "nimrod", FoldNimrodDoc,

				     nimrodWordListDesc);