/// <summary>
/// Initializer all fields, used also by deserializer of SymbolicRegexMatcher
/// </summary>
private void InitilizeFields(ICharAlgebra <S> solver)
{
this.solver = solver;
this.nothing = SymbolicRegexNode <S> .MkFalse(this, solver.False);
this.dot = SymbolicRegexNode <S> .MkTrue(this, solver.True);
this.dotStar = SymbolicRegexNode <S> .MkDotStar(this, this.dot);
this.newLine = SymbolicRegexNode <S> .MkNewline(this, solver.MkCharConstraint('\n'));
this.bolRegex = SymbolicRegexNode <S> .MkLoop(this, SymbolicRegexNode <S> .MkConcat(this, this.dotStar, this.newLine), 0, 1);
this.eolRegex = SymbolicRegexNode <S> .MkLoop(this, SymbolicRegexNode <S> .MkConcat(this, this.newLine, this.dotStar), 0, 1);
// --- initialize caches ---
this.singletonCache[this.solver.False] = this.nothing;
this.singletonCache[this.newLine.set] = this.newLine;
this.singletonCache[this.solver.True] = this.dot;
//---
this.nodeCache[this.nothing] = this.nothing;
this.nodeCache[this.dot] = this.dot;
this.nodeCache[this.dotStar] = this.dotStar;
this.nodeCache[this.newLine] = this.newLine;
this.nodeCache[this.bolRegex] = this.bolRegex;
this.nodeCache[this.eolRegex] = this.eolRegex;
}
/// <summary>
/// Make a concatenation of given regexes, if any regex is nothing then return nothing, eliminate
/// intermediate epsilons
/// </summary>
public SymbolicRegexNode <S> MkConcat(params SymbolicRegexNode <S>[] regexes)
{
if (regexes.Length == 0)
{
return(this.epsilon);
}
var sr = regexes[regexes.Length - 1];
if (sr == this.nothing)
{
return(this.nothing);
}
else
{
//exclude epsilons from the concatenation
for (int i = regexes.Length - 2; i >= 0; i--)
{
if (regexes[i] == this.nothing)
{
return(this.nothing);
}
else if (sr.IsEpsilon)
{
sr = regexes[i];
}
else if (!regexes[i].IsEpsilon)
{
sr = SymbolicRegexNode <S> .MkConcat(this, regexes[i], sr);
}
}
return(sr);
}
}
/// <summary>
/// Make a concatenation of given regexes, if any regex is nothing then return nothing, eliminate
/// intermediate epsilons, if toplevel, add watchdog at the end
/// </summary>
public SymbolicRegexNode <S> MkConcat(SymbolicRegexNode <S>[] regexes, bool topLevel)
{
if (regexes.Length == 0)
{
return(this.epsilon);
}
var sr = this.epsilon;
int length = CalculateFixedLength(regexes);
if (topLevel && length >= 0)
{
sr = MkWatchDog(length);
}
//exclude epsilons from the concatenation
for (int i = regexes.Length - 1; i >= 0; i--)
{
if (regexes[i] == this.nothing)
{
return(this.nothing);
}
else if (sr.IsEpsilon)
{
sr = regexes[i];
}
else if (!regexes[i].IsEpsilon)
{
sr = SymbolicRegexNode <S> .MkConcat(this, regexes[i], sr);
}
}
return(sr);
}
/// <summary>
/// Make a concatenation of given regexes, if any regex is nothing then return nothing, eliminate
/// intermediate epsilons
/// </summary>
public SymbolicRegexNode <S> MkConcat(SymbolicRegexNode <S> node1, SymbolicRegexNode <S> node2)
{
if (node1.IsEpsilon)
{
return(node2);
}
else if (node2.IsEpsilon)
{
return(node1);
}
else
{
return(SymbolicRegexNode <S> .MkConcat(this, node1, node2));
}
}
internal SymbolicRegexNode <S> Parse(string s, int i, out int i_next)
{
switch (s[i])
{
case '.':
{
#region character class of all characters
i_next = i + 1;
return(this.dot);
#endregion
}
case '[':
{
#region parse character class
if (s[i + 1] == ']')
{
i_next = i + 2;
return(this.nothing);
}
else
{
int j = s.IndexOf(']', i);
int[] atomIds = Array.ConvertAll(s.Substring(i + 1, j - (i + 1)).Split(','), x => int.Parse(x));
S[] bva = Array.ConvertAll(atomIds, id => this.solver.GetPartition()[id]);
var bv = this.solver.MkOr(bva);
SymbolicRegexNode <S> node;
if (!this.singletonCache.TryGetValue(bv, out node))
{
node = SymbolicRegexNode <S> .MkSingleton(this, bv);
this.singletonCache[bv] = node;
}
i_next = j + 1;
return(node);
}
#endregion
}
case 'E':
{
#region Epsilon
i_next = i + 1;
return(this.epsilon);
#endregion
}
case 'L': //L(l,u,body) for body{l,u} u may be *
{
#region Loop
int j = s.IndexOf(',', i + 2);
int lower = int.Parse(s.Substring(i + 2, j - (i + 2)));
int upper = int.MaxValue;
if (s[j + 1] == '*')
{
j = j + 3;
}
else
{
int k = s.IndexOf(',', j + 1);
upper = int.Parse(s.Substring(j + 1, k - (j + 1)));
j = k + 1;
}
int n;
var body = Parse(s, j, out n);
var node = SymbolicRegexNode <S> .MkLoop(this, body, lower, upper);
i_next = n + 1;
return(node);
#endregion
}
case 'S': //binary concat S(R1,R2)
{
#region concatenation
int n;
var first = Parse(s, i + 2, out n);
int m;
var second = Parse(s, n + 1, out m);
var seq = SymbolicRegexNode <S> .MkConcat(this, first, second);
i_next = m + 1;
return(seq);
#endregion
}
case 'C': //conjunction C(R1,R2,...,Rk)
{
#region conjunction
int n;
SymbolicRegexNode <S>[] nodes = ParseSequence(s, i + 2, out n);
var conj = SymbolicRegexNode <S> .MkAnd(this, nodes);
i_next = n;
return(conj);
#endregion
}
case 'D': //Disjunction D(R1,R2,...,Rk)
{
#region disjunction
int n;
SymbolicRegexNode <S>[] nodes = ParseSequence(s, i + 2, out n);
var disj = SymbolicRegexNode <S> .MkOr(this, nodes);
i_next = n;
return(disj);
#endregion
}
case 'I': //if then else I(x,y,z)
{
#region ITE
int n;
var cond = Parse(s, i + 2, out n);
int m;
var first = Parse(s, n + 1, out m);
int k;
var second = Parse(s, m + 1, out k);
var ite = SymbolicRegexNode <S> .MkIfThenElse(this, cond, first, second);
i_next = k + 1;
return(ite);
#endregion
}
case '^':
{
#region start anchor
i_next = i + 1;
return(this.startAnchor);
#endregion
}
case '$':
{
#region start anchor
i_next = i + 1;
return(this.endAnchor);
#endregion
}
default:
throw new NotImplementedException();
}
}
