public static ScanWordCursor PositionBegin()
{
ScanWordCursor cursor = new ScanWordCursor();
cursor.Position = RelativePosition.Begin;
return(cursor);
}
public ScanWordCursor(ScanWordCursor Cursor)
{
this.Word = Cursor.Word;
this.WordBx = Cursor.WordBx;
this.Position = Cursor.Position;
this.DelimBx = Cursor.DelimBx;
this.DelimPattern = Cursor.DelimPattern;
this.StayAtFlag = Cursor.StayAtFlag;
}
// ----------------------- CalcScanNextStart ---------------------------
// calc start position from which to start scan to the next word.
private static int CalcScanNextStart(
ScanStream ScanStream,
TextTraits Traits, ScanWordCursor Cursor)
{
int bx;
switch (Cursor.Position)
{
case RelativePosition.Begin:
bx = 0;
break;
case RelativePosition.Before:
bx = Cursor.CursorBx.ToStreamLocation(ScanStream).Value;
break;
case RelativePosition.After:
case RelativePosition.At:
if (Traits.IsNonWordPattern(Cursor.DelimPattern))
{
bx = Cursor.DelimEx.ToStreamLocation(ScanStream).Value + 1;
}
else if (Cursor.WordIsDelim == true)
{
bx = Cursor.WordEx.ToStreamLocation(ScanStream).Value + 1;
}
else
{
bx = Cursor.DelimBx.ToStreamLocation(ScanStream).Value;
}
break;
case RelativePosition.End:
bx = ScanStream.Stream.Length;
break;
case RelativePosition.None:
bx = -1;
break;
default:
bx = -1;
break;
}
if (bx > (ScanStream.Stream.Length - 1))
{
bx = -1;
}
return(bx);
}
// ------------------------ ScanNextWord -------------------------
// Scans to the next word in the string. ( a word being the text bounded by the
// delimeter and whitespace characters as spcfd in the TextTraits argument )
// Return null when end of string.
public static ScanWordCursor ScanNextWord(
ScanStream ScanStream,
TextTraits Traits, ScanWordCursor CurrentWord)
{
// components of the next word.
TextWord wordPart = null;
TextLocation wordBx = null;
ScanPattern nonWordPat = null;
TextLocation nonWordLoc = null;
int nonWordIx = -1;
// stay at the current location. return copy of the cursor, but with stayatflag
// turned off.
if (CurrentWord.StayAtFlag == true)
{
nonWordPat = CurrentWord.DelimPattern;
nonWordLoc = CurrentWord.DelimBx;
wordPart = CurrentWord.Word;
wordBx = CurrentWord.WordBx;
}
else
{
#region STEP1 setup the begin pos of the next word.
// ----------------------------- STEP 1 ------------------------------
// setup the begin pos of the next word.
int bx;
{
// calc scan start position
bx = ScanWord.CalcScanNextStart(ScanStream, Traits, CurrentWord);
// advance past whitespace
if (bx != -1)
{
bx = Scanner.ScanNotEqual(ScanStream.Stream, Traits.WhitespacePatterns, bx);
}
}
// end STEP 1.
#endregion
#region STEP 2. Isolate either numeric lib, quoted lit or scan to non word pattern
// ------------------------------- STEP 2 ----------------------------------
// Isolate either numeric literal, quoted literal or scan to the next non word
// pattern.
LiteralType?litType = null;
string litText = null;
{
// got a decimal digit. isolate the numeric literal string.
if ((bx != -1) && (Char.IsDigit(ScanStream.Stream[bx]) == true))
{
var rv = ScanWord.IsolateNumericLiteral(ScanStream, Traits, bx);
litType = rv.Item1;
litText = rv.Item2;
nonWordPat = rv.Item3; // the non word pattern immed after numeric literal
nonWordIx = rv.Item4; // pos of foundPat
}
// got something. now scan forward for the pattern that delimits the word.
else if (bx != -1)
{
{
var rv = Scanner.ScanEqualAny(ScanStream.Stream, bx, Traits.DelimPatterns);
nonWordPat = rv.Item1;
nonWordIx = rv.Item2;
}
// got a quote char. Isolate the quoted string, then find the delim that follows
// the quoted string.
if ((nonWordPat != null) &&
(nonWordPat.DelimClassification == DelimClassification.Quote) &&
(nonWordIx == bx))
{
var rv = IsolateQuotedWord(ScanStream, Traits, nonWordIx);
litType = rv.Item1;
litText = rv.Item2;
nonWordPat = rv.Item3; // the non word pattern immed after quoted literal
nonWordIx = rv.Item4; // pos of foundPat.
}
}
}
// end STEP 2.
#endregion
#region STEP 3 - setup wordBx and wordPart with the found word.
{
// got nothing.
if (bx == -1)
{
}
// no delim found. word text all the way to the end.
else if (nonWordIx == -1)
{
var rv = ScanWord.IsolateWordText(
ScanStream, Traits, litType, litText, bx, null);
wordBx = rv.Item1;
wordPart = rv.Item2;
#if skip
wordBx = new StreamLocation(bx).ToTextLocation(ScanStream);
if (litType != null)
{
wordPart = new TextWord(litText, WordClassification.Quoted, Traits);
}
else
{
wordPart = new TextWord(
ScanStream.Substring(bx), WordClassification.Identifier, Traits);
}
#endif
}
// got a word and a non word pattern.
else if (nonWordIx > bx)
{
var rv = ScanWord.IsolateWordText(
ScanStream, Traits, litType, litText, bx, nonWordIx);
wordBx = rv.Item1;
wordPart = rv.Item2;
#if skip
wordBx = new StreamLocation(bx).ToTextLocation(ScanStream);
int lx = foundIx - bx;
wordPart = new TextWord(
ScanStream.Substring(bx, lx), WordClassification.Identifier, Traits);
#endif
nonWordLoc = new StreamLocation(nonWordIx).ToTextLocation(ScanStream);
}
// no word. just delim.
else
{
nonWordLoc = new StreamLocation(nonWordIx).ToTextLocation(ScanStream);
// the delim is comment to end. store as a word.
if (nonWordPat.DelimClassification == DelimClassification.CommentToEnd)
{
var rv = Scanner.ScanEqualAny(ScanStream.Stream, bx, Traits.NewLinePatterns);
var eolPat = rv.Item1;
var eolIx = rv.Item2;
if (eolPat == null)
{
wordBx = new StreamLocation(nonWordIx).ToTextLocation(ScanStream);
wordPart = new TextWord(
ScanStream.Substring(nonWordIx), WordClassification.CommentToEnd, Traits);
nonWordLoc = null;
nonWordPat = null;
}
else
{
wordBx = new StreamLocation(nonWordIx).ToTextLocation(ScanStream);
int lx = eolIx - nonWordIx;
var sloc = wordBx.ToStreamLocation(ScanStream);
wordPart = new TextWord(
ScanStream.Substring(sloc.Value, lx), WordClassification.CommentToEnd, Traits);
nonWordLoc = new StreamLocation(eolIx).ToTextLocation(ScanStream);
nonWordPat = eolPat;
}
}
// if the delim pattern is not non word ( a divider ), store the pattern also
// as the word.
else if (Traits.DelimPatternsThatAreNonWords.Contains(nonWordPat) == false)
{
wordBx = nonWordLoc;
wordPart = new TextWord(
nonWordPat.PatternValue,
nonWordPat.DelimClassification.ToWordClassification().Value,
Traits);
}
}
}
#endregion
// delim is whitespace. scan ahead for something more meaningful than whitespace.
if ((nonWordPat != null) && (Traits.IsWhitespace(nonWordPat)))
{
StreamLocation dx = nonWordLoc.ToStreamLocation(ScanStream);
int fx = Scanner.ScanNotEqual(
ScanStream.Stream, Traits.WhitespacePatterns, dx.Value + nonWordPat.Length);
var pat = Traits.DelimPatterns.MatchAt(ScanStream.Stream, fx);
if (pat != null)
{
nonWordLoc = new StreamLocation(fx).ToTextLocation(ScanStream);
nonWordPat = pat;
}
}
}
// store the results in the return cursor.
ScanWordCursor nx = null;
if ((wordPart == null) && (nonWordPat == null))
{
nx = new ScanWordCursor( );
nx.Position = RelativePosition.End;
}
else
{
nx = new ScanWordCursor(wordPart, wordBx, nonWordLoc, nonWordPat);
nx.Position = RelativePosition.At;
}
return(nx);
}
