public LocatedString GetChar(int Pos)
{
LocatedString locStr = null;
if ((Pos >= this.BeginPos) && (Pos <= this.EndPos))
{
int ix = Pos - this.BeginPos;
var s1 = this.Text.Substring(ix, 1);
locStr = new LocatedString(Pos, s1);
}
return(locStr);
}
public static LocatedString Union(LocatedString s1, LocatedString s2)
{
int unionBx = Math.Min(s1.BeginPos, s2.BeginPos);
// segment of text in s2 which is before s1.
string bfrText = "";
if (s2.BeginPos < s1.BeginPos)
{
int lx = s1.BeginPos - s2.BeginPos;
if (lx > s2.Length)
{
lx = s2.Length;
}
bfrText = s2.Text.Substring(0, lx);
// pad before text wih blanks to make sure begin text in s2 reaches to right
// before begin of s1.
int padLx = (s1.BeginPos - s2.BeginPos) - bfrText.Length;
if (padLx > 0)
{
bfrText = bfrText.PadRight(bfrText.Length + padLx);
}
}
// segment of text in s2 with is after s1.
string aftText = "";
if (s2.EndPos > s1.EndPos)
{
int lx = s2.EndPos - s1.EndPos;
if (lx > s2.Length)
{
lx = s2.Length;
}
int bx = s2.Length - lx;
aftText = s2.Text.Substring(bx, lx);
// pad after text wih before blanks in the case where there is a gap between the
// end of s1 and the start of s2.
int padLx = s2.BeginPos - s1.EndPos - 1;
if (padLx > 0)
{
aftText = aftText.PadLeft(aftText.Length + padLx);
}
}
// the union text.
string unionText = bfrText + s1.Text + aftText;
return(new LocatedString(unionBx, unionText));
}
/// <summary>
/// remove the located string from this located string.
/// The string to remove must be an entire subset of the remove from string.
/// Use the absolute position of each string to calc the actual location of the
/// string to remove.
/// </summary>
/// <param name="RemoveText"></param>
/// <returns></returns>
public LocatedString Remove(LocatedString RemoveText)
{
LocatedString afterRemoveText;
// remove text must be entirely within the text of this item.
if ((this.IsWithin(RemoveText.BeginPos) == true) &&
(this.IsWithin(RemoveText.EndPos) == true))
{
var ix = StringPosToTextPos(RemoveText);
var s1 = this.Text.Remove(ix, RemoveText.Length);
afterRemoveText = new LocatedString(this.BeginPos, s1);
}
else
{
throw new ApplicationException("location of text to remove is not within range " +
"of the text.");
}
return(afterRemoveText);
}
/// <summary>
/// convert absolute pos of input located string to relative position within the
/// Text of this located string.
/// </summary>
/// <param name="InString"></param>
/// <returns></returns>
private int StringPosToTextPos(LocatedString InString)
{
int textPos = InString.BeginPos - this.BeginPos;
return(textPos);
}
