public static List <LinguisticUnit> GetLast(LinguisticUnit nonTerminal)
{
var last = new List <LinguisticUnit>();
var rule = Grammar.First(r => r.LeftPart.Name == nonTerminal.Name);
foreach (var rightPart in rule.RightParts)
{
last.Add(rightPart.LinguisticUnits.Last());
}
return(last);
}
public static List <LinguisticUnit> GetLastPlus(LinguisticUnit nonTerminal, List <LinguisticUnit> lastPlus = null)
{
lastPlus = lastPlus ?? new List <LinguisticUnit>();
var rule = Grammar.First(r => r.LeftPart.Name == nonTerminal.Name);
foreach (var rightPart in rule.RightParts)
{
if (rightPart.LinguisticUnits.Last().Type == LinguisticUnitType.NonTerminal &&
!lastPlus.Any(l => l.Name == rightPart.LinguisticUnits.Last().Name))
{
lastPlus.Add(rightPart.LinguisticUnits.Last());
GetLastPlus(rightPart.LinguisticUnits.Last(), lastPlus);
}
else
{
if (!lastPlus.Any(l => l.Name == rightPart.LinguisticUnits.Last().Name))
{
lastPlus.Add(rightPart.LinguisticUnits.Last());
}
}
}
return(lastPlus);
}
public static void BuildTable()
{
LinguisticUnit dollar = new LinguisticUnit {
Name = "$"
};
void AddToRelationshipsTable(RelationshipToken relationshipToken)
{
if (Table.FirstOrDefault(rt => rt.FirstLinguisticUnit.Name.Equals(relationshipToken.FirstLinguisticUnit.Name) &&
rt.Relationship.Equals(relationshipToken.Relationship) &&
rt.SecondLinguisticUnit.Name.Equals(relationshipToken.SecondLinguisticUnit.Name)) is null)
{
Table.Add(relationshipToken);
}
}
foreach (var rule in Grammar)
{
foreach (var rightPart in rule.RightParts)
{
for (int i = 0; i < rightPart.LinguisticUnits.Count; i++)
{
if (i + 1 < rightPart.LinguisticUnits.Count)
{
var equalRelation = new RelationshipToken
{
FirstLinguisticUnit = rightPart.LinguisticUnits[i],
SecondLinguisticUnit = rightPart.LinguisticUnits[i + 1],
Relationship = "="
};
AddToRelationshipsTable(equalRelation);
if (equalRelation.SecondLinguisticUnit.Type == LinguisticUnitType.NonTerminal)
{
var firstPlus = GetFirstPlus(equalRelation.SecondLinguisticUnit);
foreach (var first in firstPlus)
{
var lowerRelation = new RelationshipToken
{
FirstLinguisticUnit = equalRelation.FirstLinguisticUnit,
SecondLinguisticUnit = first,
Relationship = "<"
};
AddToRelationshipsTable(lowerRelation);
}
}
if (equalRelation.FirstLinguisticUnit.Type == LinguisticUnitType.NonTerminal)
{
var lastPlus = GetLastPlus(equalRelation.FirstLinguisticUnit);
foreach (var last in lastPlus)
{
var higherRelation = new RelationshipToken
{
FirstLinguisticUnit = last,
SecondLinguisticUnit = equalRelation.SecondLinguisticUnit,
Relationship = ">"
};
AddToRelationshipsTable(higherRelation);
}
}
if (equalRelation.FirstLinguisticUnit.Type == LinguisticUnitType.NonTerminal &&
equalRelation.SecondLinguisticUnit.Type == LinguisticUnitType.NonTerminal)
{
var lastPlus = GetLastPlus(equalRelation.FirstLinguisticUnit);
var firstPlus = GetFirstPlus(equalRelation.SecondLinguisticUnit);
foreach (var last in lastPlus)
{
foreach (var first in firstPlus)
{
AddToRelationshipsTable(new RelationshipToken
{
FirstLinguisticUnit = last,
SecondLinguisticUnit = first,
Relationship = ">"
});
}
}
}
}
AddToRelationshipsTable(new RelationshipToken
{
FirstLinguisticUnit = rightPart.LinguisticUnits[i],
SecondLinguisticUnit = dollar,
Relationship = ">"
});
AddToRelationshipsTable(new RelationshipToken
{
FirstLinguisticUnit = dollar,
SecondLinguisticUnit = rightPart.LinguisticUnits[i],
Relationship = "<"
});
}
}
}
AddToRelationshipsTable(new RelationshipToken
{
FirstLinguisticUnit = dollar,
SecondLinguisticUnit = Grammar.First().LeftPart,
Relationship = "<"
});
AddToRelationshipsTable(new RelationshipToken
{
FirstLinguisticUnit = Grammar.First().LeftPart,
SecondLinguisticUnit = dollar,
Relationship = ">"
});
}
