public void TsQuery()
{
NpgsqlTsQuery query;
query = new NpgsqlTsQueryLexeme("a", NpgsqlTsQueryLexeme.Weight.A | NpgsqlTsQueryLexeme.Weight.B);
query = new NpgsqlTsQueryOr(query, query);
query = new NpgsqlTsQueryOr(query, query);
var str = query.ToString();
query = NpgsqlTsQuery.Parse("a & b | c");
Assert.AreEqual("'a' & 'b' | 'c'", query.ToString());
query = NpgsqlTsQuery.Parse("'a''':*ab&d:d&!c");
Assert.AreEqual("'a''':*AB & 'd':D & !'c'", query.ToString());
query = NpgsqlTsQuery.Parse("(a & !(c | d)) & (!!a&b) | c | d | e");
Assert.AreEqual("( ( 'a' & !( 'c' | 'd' ) & !( !'a' ) & 'b' | 'c' ) | 'd' ) | 'e'", query.ToString());
Assert.AreEqual(query.ToString(), NpgsqlTsQuery.Parse(query.ToString()).ToString());
query = NpgsqlTsQuery.Parse("(((a:*)))");
Assert.AreEqual("'a':*", query.ToString());
query = NpgsqlTsQuery.Parse(@"'a\\b''cde'");
Assert.AreEqual(@"a\b'cde", ((NpgsqlTsQueryLexeme)query).Text);
Assert.AreEqual(@"'a\\b''cde'", query.ToString());
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("a b c & &"));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("&"));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("|"));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("!"));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("("));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse(")"));
Assert.Throws(typeof(FormatException), () => NpgsqlTsQuery.Parse("()"));
}
/// <summary>
/// Parses a tsquery in PostgreSQL's text format.
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public static NpgsqlTsQuery Parse(string value)
{
if (value == null)
{
throw new ArgumentNullException(nameof(value));
}
var valStack = new Stack <NpgsqlTsQuery>();
var opStack = new Stack <NpgsqlTsQueryOperator>();
var sb = new StringBuilder();
var pos = 0;
var expectingBinOp = false;
var lastFollowedByOpDistance = -1;
NextToken:
if (pos >= value.Length)
{
goto Finish;
}
var ch = value[pos++];
if (ch == '\'')
{
goto WaitEndComplex;
}
if ((ch == ')' || ch == '|' || ch == '&') && !expectingBinOp || (ch == '(' || ch == '!') && expectingBinOp)
{
throw new FormatException("Syntax error in tsquery. Unexpected token.");
}
if (ch == '<')
{
var endOfOperatorConsumed = false;
var sbCurrentLength = sb.Length;
while (pos < value.Length)
{
var c = value[pos++];
if (c == '>')
{
endOfOperatorConsumed = true;
break;
}
sb.Append(c);
}
if (sb.Length == sbCurrentLength || !endOfOperatorConsumed)
{
throw new FormatException("Syntax error in tsquery. Malformed 'followed by' operator.");
}
var followedByOpDistanceString = sb.ToString(sbCurrentLength, sb.Length - sbCurrentLength);
if (followedByOpDistanceString == "-")
{
lastFollowedByOpDistance = 1;
}
else if (!int.TryParse(followedByOpDistanceString, out lastFollowedByOpDistance) ||
lastFollowedByOpDistance < 0)
{
throw new FormatException("Syntax error in tsquery. Malformed distance in 'followed by' operator.");
}
sb.Length -= followedByOpDistanceString.Length;
}
if (ch == '(' || ch == '!' || ch == '&' || ch == '<')
{
opStack.Push(new NpgsqlTsQueryOperator(ch, lastFollowedByOpDistance));
expectingBinOp = false;
lastFollowedByOpDistance = 0;
goto NextToken;
}
if (ch == '|')
{
if (opStack.Count > 0 && opStack.Peek() == '|')
{
if (valStack.Count < 2)
{
throw new FormatException("Syntax error in tsquery");
}
var right = valStack.Pop();
var left = valStack.Pop();
valStack.Push(new NpgsqlTsQueryOr(left, right));
// Implicit pop and repush |
}
else
{
opStack.Push('|');
}
expectingBinOp = false;
goto NextToken;
}
if (ch == ')')
{
while (opStack.Count > 0 && opStack.Peek() != '(')
{
if (valStack.Count < 2 || opStack.Peek() == '!')
{
throw new FormatException("Syntax error in tsquery");
}
var right = valStack.Pop();
var left = valStack.Pop();
var tsOp = opStack.Pop();
switch (tsOp)
{
case '&':
valStack.Push(new NpgsqlTsQueryAnd(left, right));
break;
case '|':
valStack.Push(new NpgsqlTsQueryOr(left, right));
break;
case '<':
valStack.Push(new NpgsqlTsQueryFollowedBy(left, tsOp.FollowedByDistance, right));
break;
default:
throw new FormatException("Syntax error in tsquery");
}
}
if (opStack.Count == 0)
{
throw new FormatException("Syntax error in tsquery: closing parenthesis without an opening parenthesis");
}
opStack.Pop();
goto PushedVal;
}
if (ch == ':')
{
throw new FormatException("Unexpected : while parsing tsquery");
}
if (char.IsWhiteSpace(ch))
{
goto NextToken;
}
pos--;
if (expectingBinOp)
{
throw new FormatException("Unexpected lexeme while parsing tsquery");
}
// Proceed to WaitEnd
WaitEnd:
if (pos >= value.Length || char.IsWhiteSpace(ch = value[pos]) || ch == '!' || ch == '&' || ch == '|' || ch == '(' || ch == ')')
{
valStack.Push(new NpgsqlTsQueryLexeme(sb.ToString()));
goto PushedVal;
}
pos++;
if (ch == ':')
{
valStack.Push(new NpgsqlTsQueryLexeme(sb.ToString()));
sb.Clear();
goto InWeightInfo;
}
if (ch == '\\')
{
if (pos >= value.Length)
{
throw new FormatException(@"Unexpected \ in end of value");
}
ch = value[pos++];
}
sb.Append(ch);
goto WaitEnd;
WaitEndComplex:
if (pos >= value.Length)
{
throw new FormatException("Missing terminating ' in string literal");
}
ch = value[pos++];
if (ch == '\'')
{
if (pos < value.Length && value[pos] == '\'')
{
ch = '\'';
pos++;
}
else
{
valStack.Push(new NpgsqlTsQueryLexeme(sb.ToString()));
if (pos < value.Length && value[pos] == ':')
{
pos++;
goto InWeightInfo;
}
goto PushedVal;
}
}
if (ch == '\\')
{
if (pos >= value.Length)
{
throw new FormatException(@"Unexpected \ in end of value");
}
ch = value[pos++];
}
sb.Append(ch);
goto WaitEndComplex;
InWeightInfo:
if (pos >= value.Length)
{
goto Finish;
}
ch = value[pos];
if (ch == '*')
{
((NpgsqlTsQueryLexeme)valStack.Peek()).IsPrefixSearch = true;
}
else if (ch == 'a' || ch == 'A')
{
((NpgsqlTsQueryLexeme)valStack.Peek()).Weights |= NpgsqlTsQueryLexeme.Weight.A;
}
else if (ch == 'b' || ch == 'B')
{
((NpgsqlTsQueryLexeme)valStack.Peek()).Weights |= NpgsqlTsQueryLexeme.Weight.B;
}
else if (ch == 'c' || ch == 'C')
{
((NpgsqlTsQueryLexeme)valStack.Peek()).Weights |= NpgsqlTsQueryLexeme.Weight.C;
}
else if (ch == 'd' || ch == 'D')
{
((NpgsqlTsQueryLexeme)valStack.Peek()).Weights |= NpgsqlTsQueryLexeme.Weight.D;
}
else
{
goto PushedVal;
}
pos++;
goto InWeightInfo;
PushedVal:
sb.Clear();
var processTightBindingOperator = true;
while (opStack.Count > 0 && processTightBindingOperator)
{
var tsOp = opStack.Peek();
switch (tsOp)
{
case '&':
if (valStack.Count < 2)
{
throw new FormatException("Syntax error in tsquery");
}
var andRight = valStack.Pop();
var andLeft = valStack.Pop();
valStack.Push(new NpgsqlTsQueryAnd(andLeft, andRight));
opStack.Pop();
break;
case '!':
if (valStack.Count == 0)
{
throw new FormatException("Syntax error in tsquery");
}
valStack.Push(new NpgsqlTsQueryNot(valStack.Pop()));
opStack.Pop();
break;
case '<':
if (valStack.Count < 2)
{
throw new FormatException("Syntax error in tsquery");
}
var followedByRight = valStack.Pop();
var followedByLeft = valStack.Pop();
valStack.Push(
new NpgsqlTsQueryFollowedBy(
followedByLeft,
tsOp.FollowedByDistance,
followedByRight));
opStack.Pop();
break;
default:
processTightBindingOperator = false;
break;
}
}
expectingBinOp = true;
goto NextToken;
Finish:
while (opStack.Count > 0)
{
if (valStack.Count < 2)
{
throw new FormatException("Syntax error in tsquery");
}
var right = valStack.Pop();
var left = valStack.Pop();
NpgsqlTsQuery query;
var tsOp = opStack.Pop();
switch (tsOp)
{
case '&':
query = new NpgsqlTsQueryAnd(left, right);
break;
case '|':
query = new NpgsqlTsQueryOr(left, right);
break;
case '<':
query = new NpgsqlTsQueryFollowedBy(left, tsOp.FollowedByDistance, right);
break;
default:
throw new FormatException("Syntax error in tsquery");
}
valStack.Push(query);
}
if (valStack.Count != 1)
{
throw new FormatException("Syntax error in tsquery");
}
return(valStack.Pop());
}
