/// <summary>
/// Parse the method message pattern.
/// </summary>
protected virtual MethodNode ParseMessagePattern()
{
// PARSE: <message pattern> ::= <unary pattern> | <binary pattern> | <keyword pattern>
// <unary pattern> ::= unarySelector
// <binary pattern> ::= binarySelector <method argument>
// <keyword pattern> ::= (keyword <method argument>)+
MethodNode result = new MethodNode();
List<IMethodSelectorToken> selectorParts = new List<IMethodSelectorToken>();
List<MethodArgumentNode> arguments = new List<MethodArgumentNode>();
Token token = this.GetNextTokenxx(Preference.Default);
// PARSE: <message pattern> ::= <unary pattern> | <binary pattern> | <keyword pattern>
if (token is KeywordToken)
{
// <keyword pattern> ::= (keyword <method argument>)+
selectorParts.Add((IMethodSelectorToken)token);
token = this.GetNextTokenxx(Preference.Default);
arguments.Add(this.ParseMethodArgument(result, token));
while (true)
{
token = this.GetNextTokenxx(Preference.VerticalBar | Preference.NegativeSign);
if (token is KeywordToken)
{
selectorParts.Add((IMethodSelectorToken)token);
token = this.GetNextTokenxx(Preference.Default);
arguments.Add(this.ParseMethodArgument(result, token));
}
else
{
result.SetContents(selectorParts, arguments);
this.ResidueToken = token; // temp vars or statement
return result;
}
}
}
else if (token is BinarySelectorToken)
{
// <binary pattern> ::= binarySelector <method argument>
selectorParts.Add((IMethodSelectorToken)token);
token = this.GetNextTokenxx(Preference.Default);
arguments.Add(this.ParseMethodArgument(result, token));
result.SetContents(selectorParts, arguments);
return result;
}
else if (token is IdentifierToken)
{
// <unary pattern> ::= unarySelector
selectorParts.Add((IMethodSelectorToken)token);
result.SetContents(selectorParts, arguments);
return result;
}
else
{
this.ReportParserError(result, SemanticErrors.MissingMethodMessagePattern, token);
this.ResidueToken = token;
return result;
}
}