public override void BuildTransitions(HashSet <RegexState> states, RegexState startState, RegexState endState)
{
foreach (var node in _nodes)
{
node.BuildTransitions(states, startState, endState);
}
}
/// <summary>
/// Builds a finite state machine from the RegexNode.
/// </summary>
/// <returns></returns>
public RegexFSM BuildFSM()
{
var states = new HashSet <RegexState>();
var startState = new RegexState();
var endState = new RegexState();
BuildTransitions(states, startState, endState);
return(new RegexFSM(states, startState, endState));
}
private void PushState(ExpressionContext context, int length = 1)
{
var options = state.Count == 0 ? GroupRegexOptions.None : Options;
var newState = new RegexState()
{
Context = context,
Options = options,
Position = 0,
Length = length
};
state.Push(newState);
}
public override void BuildTransitions(HashSet <RegexState> states, RegexState startState, RegexState endState)
{
var lastState = startState;
for (int i = 0; i < _nodes.Count - 1; i++)
{
var node = _nodes[i];
var nextState = new RegexState();
node.BuildTransitions(states, lastState, nextState);
states.Add(nextState);
lastState = nextState;
}
_nodes[_nodes.Count - 1].BuildTransitions(states, lastState, endState);
}
public override void BuildTransitions(HashSet <RegexState> states, RegexState startState, RegexState endState)
{
Node.BuildTransitions(states, startState, endState);
startState.Add(endState);
}
public override void BuildTransitions(HashSet <RegexState> states, RegexState startState, RegexState endState)
{
startState.Add(endState, CharacterClass);
}
/// <summary> /// Build the necessary transitions between the start and end states of the RegexNode. /// </summary> /// <param name="states">The list of requied states.</param> /// <param name="startState">The starting state.</param> /// <param name="endState">The end (completed) state.</param> public abstract void BuildTransitions(HashSet <RegexState> states, RegexState startState, RegexState endState);
/// <summary>
/// It receives a regular expression, and returns its coloring represented by an array, where the i-th element contains the color of the i-th character of the expression.
/// </summary>
/// <param name="regex">The regular expression to color</param>
/// <returns>The coloring</returns>
public static Color[] Colorize(string regex)
{
Color[] colors = new Color[regex.Length];
int buffer_cntr = 0;
RegexState state = RegexState.text;
RegexState previous = RegexState.text; // for the "backslash state" to know where it came from
for (int i = 0; i < regex.Length; i++)
{
char c = regex[i];
switch (state)
{
case RegexState.text:
if (c == ')' || c == '|')
{
colors[i] = Color.OrangeRed;
}
else if (c == '?' || c == '+' || c == '*')
{
colors[i] = Color.Purple;
}
else if (c == '.' || c == '^' || c == '$')
{
colors[i] = Color.DarkRed;
}
else if (c == '\\')
{
previous = RegexState.text;
state = RegexState.backslash;
colors[i] = Color.Blue;
}
else if (c == '(')
{
if (i + 1 < regex.Length && regex[i + 1] == '?')
{
state = RegexState.parenthesisStart;
}
colors[i] = Color.OrangeRed;
}
else if (c == '[')
{
state = RegexState.squareBracketBlock;
colors[i] = Color.Green;
}
else if (c == '{')
{
state = RegexState.curlyBracketBlock;
colors[i] = Color.Purple;
}
else
{
colors[i] = Color.FromArgb(100, 100, 100);
}
break;
case RegexState.parenthesisStart:
colors[i] = Color.OrangeRed;
if (c == '!' || c == ':' || c == '#' || c == '=' || c == '>' || c == ')')
{
state = RegexState.text;
}
break;
case RegexState.backslash:
colors[i] = Color.Blue;
if (regex[i - 1] == '\\')
{
if (c != 'x' && c != 'c' && c != 'u' && c != 'p' && c != 'k' && !(Char.IsDigit(c) && i + 1 < regex.Length && Char.IsDigit(regex[i + 1])))
{
state = previous;
}
else
{
if (c == 'x')
{
buffer_cntr = 2;
}
else if (c == 'u')
{
buffer_cntr = 4;
}
else if (c == 'c')
{
buffer_cntr = 1;
}
else if (Char.IsDigit(c))
{
if (i + 2 < regex.Length && Char.IsDigit(regex[i + 2]))
{
buffer_cntr = 2;
}
else
{
buffer_cntr = 1;
}
}
}
}
else
{
if (buffer_cntr > 1)
{
buffer_cntr--;
}
else if (buffer_cntr == 1)
{
buffer_cntr = 0;
state = previous;
}
else if (c == '}' || c == '>')
{
state = previous;
}
}
break;
case RegexState.squareBracketBlock:
if (c == '\\')
{
colors[i] = Color.Blue;
previous = RegexState.squareBracketBlock;
state = RegexState.backslash;
}
else if (c == ']')
{
colors[i] = Color.Green;
state = RegexState.text;
}
else if (c == '^' && regex[i - 1] == '[' && (i < 2 || regex[i - 2] != '\\'))
{
colors[i] = Color.Green;
}
else if (c == '-' && regex[i - 1] != '[')
{
colors[i] = Color.Green;
}
else
{
colors[i] = Color.DarkGreen;
}
break;
case RegexState.curlyBracketBlock:
colors[i] = Color.Purple;
if (c == '}')
{
state = RegexState.text;
}
break;
}
}
return(colors);
}
