/// <summary>
/// Internal implemention of the message reference and interpolation token
/// Parsing used by tokenizeInterpolation() and replaceMessageReferences().
/// </summary>
public static List <string> TokenizeInterpolation(string message, bool parseInterpolationTokens = true)
{
var tokens = new List <string>();
var chars = message.ToCharArray().ToList();
// Parse the message with a finite state machine.
// 0 - Base case.
// 1 - % found
// 2 - Digit found.
// 3 - Message ref found
var state = 0;
var buffer = new List <string>();
string number = "";
for (var i = 0; i < chars.Count + 1; i++)
{
var c = i == chars.Count ? ' ' : chars[i];
if (state == 0 && i != chars.Count)
{
if (c == '%')
{
var text = string.Join("", buffer.ToArray());
if (!string.IsNullOrEmpty(text))
{
tokens.Add(text);
}
buffer.Clear();
state = 1; // Start escape.
}
else
{
buffer.Add(c.ToString()); // Regular char
}
}
else if (state == 1)
{
if (c == '%')
{
buffer.Add(c.ToString()); // Escaped %: %%
state = 0;
}
else if (parseInterpolationTokens && '0' <= c && c <= '9')
{
state = 2;
number = c.ToString();
buffer.Add("");
var text = string.Join("", buffer.ToArray());
if (!string.IsNullOrEmpty(text))
{
tokens.Add(text);
}
buffer.Clear();
}
else if (c == '{')
{
state = 3;
}
else
{
buffer.Add("%"); // Not recognized. Return as literal.
if (i != chars.Count)
{
buffer.Add(c.ToString());
}
state = 0; // add parse as string literl
}
}
else if (state == 2)
{
if ('0' <= c && c <= '9')
{
number += c; // Multi-digit number.
}
else
{
tokens.Add(int.Parse(number).ToString());
i--; // Parse this char agian.
state = 0;
}
}
else if (state == 3)
{
if (i == chars.Count)
{
// Premature end before closing '}'
buffer.Insert(0, "%{"); // Re-insert leading delimiter
i--; // Parse this char again.
state = 0; // add parse as string literal.
}
else if (c != '}')
{
buffer.Add(c.ToString());
}
else
{
var rawKey = string.Join("", buffer.ToArray());
if (new Regex("[a-zA-Z][a-zAZ0-9_]").Match(rawKey).Success) // Strict matching
{
// Found a valied string key. Attempt case insensitive match.
var keyUpper = rawKey.ToUpper();
// BKY_ is the prefix used to namespace the string s used in Blockly
// core files adn the predefined blocks in ../blocks/. These strings
// are defined in ../msgs/ files.
var bklyKey = keyUpper.StartsWith("BKY_") ? keyUpper.Substring(4) : null;
if (!string.IsNullOrEmpty(bklyKey) && I18n.Contains(bklyKey))
{
var rawValue = I18n.Get(bklyKey);
tokens.AddRange(TokenizeInterpolation(rawValue));
}
else
{
tokens.Add("%{" + rawKey + "}");
}
buffer.Clear(); // Clear the array
state = 0;
}
else
{
tokens.Add("%{" + rawKey + "}");
buffer.Clear();
state = 0; // and parse as string literal.
}
}
}
}
var text1 = string.Join("", buffer.ToArray());
if (!string.IsNullOrEmpty(text1))
{
tokens.Add(text1);
}
// Merge adjacent text tokens into a single string.
var mergedTokens = new List <string>();
buffer.Clear();
for (int i = 0; i < tokens.Count; i++)
{
int tokenNum = 0;
if (int.TryParse(tokens[i], out tokenNum))
{
text1 = string.Join("", buffer.ToArray());
if (!string.IsNullOrEmpty(text1))
{
mergedTokens.Add(text1);
}
buffer.Clear();
mergedTokens.Add(tokens[i]);
}
else
{
buffer.Add(tokens[i]);
}
}
text1 = string.Join("", buffer.ToArray());
if (!string.IsNullOrEmpty(text1))
{
mergedTokens.Add(text1);
}
buffer.Clear();
// remove last
return(mergedTokens);
}