/// <summary>
/// Processes the stream as far as it needs to to generate a fully qualiffied
/// <see cref="SyntaxNode" /> based on its internal ruleset. All implementations
/// are expected to validate the stream is at a location which it can consume
/// and throw an <see cref="GraphQLSyntaxException" /> as appropriate and consume
/// the last character in their phrase, leaving the stream primed for the next
/// maker in the series.
/// </summary>
/// <param name="tokenStream">The token stream.</param>
/// <returns>LexicalToken.</returns>
public SyntaxNode MakeNode(TokenStream tokenStream)
{
SyntaxNode node = null;
if (tokenStream.Match <NullToken>())
{
node = new ScalarValueNode(
tokenStream.Location,
ScalarValueType.Boolean,
ParserConstants.Keywords.Null);
}
else
{
tokenStream.MatchOrThrow <NameToken>();
if (tokenStream.Match(ParserConstants.Keywords.True, ParserConstants.Keywords.False))
{
node = new ScalarValueNode(
tokenStream.Location,
ScalarValueType.Boolean,
tokenStream.ActiveToken.Text);
}
else
{
GraphQLSyntaxException.ThrowFromExpectation(
tokenStream.Location,
"{true|false}",
tokenStream.ActiveToken.Text.ToString());
}
}
tokenStream.Next();
return(node);
}
/// <summary>
/// Matchs the text of the currnetly <see cref="ActiveToken"/> to the given keyword
/// or throws an exception.
/// </summary>
/// <param name="keyword">The keyword.</param>
public void MatchOrThrow(ReadOnlyMemory <char> keyword)
{
if (!this.Match(keyword))
{
GraphQLSyntaxException.ThrowFromExpectation(
this.Location,
keyword,
this.ActiveToken?.Text ?? ReadOnlyMemory <char> .Empty);
}
}
/// <summary>
/// Matches the currently <see cref="ActiveToken"/> to the provided <see cref="TokenType"/>
/// or throws an exception.
/// </summary>
/// <param name="tokenType">Type of the token.</param>
public void MatchOrThrow(TokenType tokenType)
{
if (!this.Match(tokenType))
{
GraphQLSyntaxException.ThrowFromExpectation(
this.Location,
tokenType.Description(),
this.ActiveTokenTypeDescrption);
}
}
/// <summary>
/// Matches the type of the <see cref="ActiveToken"/> to the provided type or throws
/// an exception.
/// </summary>
/// <typeparam name="TLexicalType">The type of the t lexical type.</typeparam>
public void MatchOrThrow <TLexicalType>()
where TLexicalType : LexicalToken
{
if (!this.Match <TLexicalType>())
{
var text = this.EndOfStream
? TokenType.EndOfFile.Description().ToString()
: this.ActiveToken.GetType().FriendlyName();
GraphQLSyntaxException.ThrowFromExpectation(
this.Location,
typeof(TLexicalType).FriendlyName(),
text);
}
}
/// <summary>
/// Processes the queue as far as it needs to to generate a fully qualiffied
/// <see cref="SyntaxNode" /> based on its ruleset.
/// </summary>
/// <param name="tokenStream">The token stream.</param>
/// <returns>LexicalToken.</returns>
public SyntaxNode MakeNode(TokenStream tokenStream)
{
var maker = ValueMakerFactory.CreateMaker(tokenStream.ActiveToken);
if (maker != null)
{
return(maker.MakeNode(tokenStream));
}
GraphQLSyntaxException.ThrowFromExpectation(
tokenStream.Location,
"<value>",
tokenStream.TokenType.Description().ToString());
throw new InvalidOperationException("Critical Failure, this exception should never be reached.");
}
/// <summary>
/// Matches the currently <see cref="ActiveToken" /> to any of the provided <see cref="TokenType" />.
/// The active token must match one of the provided values or an exception is thrown.
/// </summary>
/// <param name="primaryTokenType">Type of the primary token to check for.</param>
/// <param name="additionalTypes">Any additional tokens to check for.</param>
public void MatchOrThrow(TokenType primaryTokenType, params TokenType[] additionalTypes)
{
if (additionalTypes == null || additionalTypes.Length == 0)
{
this.MatchOrThrow(primaryTokenType);
}
else
{
var typeCollection = primaryTokenType.AsEnumerable().Concat(additionalTypes);
var tokensMatched = typeCollection.Where(this.Match);
if (!tokensMatched.Any())
{
var errors = "[" + string.Join(", ", typeCollection.Select(TokenTypeTextForErrorMessage).Select(x => x.ToString())) + "]";
GraphQLSyntaxException.ThrowFromExpectation(
this.Location,
errors,
this.ActiveTokenTypeDescrption.ToString());
}
}
}
