/// <summary>
/// Optimizes the specified tokens.
/// </summary>
/// <param name="tokens">The tokens to be optimized.</param>
/// <returns>A Enumerable of tokens.</returns>
public static IEnumerable <Token.Token> Optimize(this IEnumerable <Token.Token> tokens)
{
RawTextToken prevToken = null;
foreach (var current in tokens)
{
if (current is RawTextToken)
{
prevToken = new RawTextToken(prevToken, current);
}
else
{
if (prevToken != null)
{
yield return(prevToken);
}
prevToken = null;
yield return(current);
}
}
if (prevToken != null)
{
yield return(prevToken);
}
}
/// <summary>
/// fail return null
/// </summary>
/// <returns></returns>
public static TextDataBindExpress Parse(string input)
{
if (input == null || "".Equals(input))
{
return(null);
}
List <RawTextToken> rawList = new List <RawTextToken>();
for (int i = 0; i < input.Length; i++)
{
var curr = input[i];
if (curr == '{' && i + 1 < input.Length && input[i + 1] == '{')
{
rawList.Add(new RawTextToken(-1, ' '));
i++;
}
else if (curr == '}' && i + 1 < input.Length && input[i + 1] == '}')
{
rawList.Add(new RawTextToken(1, ' '));
i++;
}
else
{
rawList.Add(new RawTextToken(0, curr));
}
}
// RawTextToken to TextToken
List <TextToken> tokenList = new List <TextToken>();
for (int i = 0; i < rawList.Count;)
{
if (rawList[i].type == -1)
{
int startIndex = i + 1;
i++;
while (i < rawList.Count && rawList[i].type != 1)
{
i++;
}
var str = RawTextToken.ToString(rawList, startIndex, i - startIndex);
if (i == rawList.Count) // EOF
{
// normal text
tokenList.Add(new TextToken(str));
break;
}
var express = ObjectDataBindExpress.Parse(str);
if (express != null)
{
tokenList.Add(new TextToken(express));
}
i++;
}
else
{
int startIndex = i;
while (i < rawList.Count && rawList[i].type != -1)
{
i++;
}
int length = i - startIndex;
if (length > 0)
{
var str = RawTextToken.ToString(rawList, startIndex, length);
tokenList.Add(new TextToken(str));
}
}
}
return(tokenList.Count > 0 ? new TextDataBindExpress(tokenList) : null);
}
