protected virtual BasicExpressionNode ParseBasicExpression(SemanticNode parent, Token token)
{
// PARSE: <basic expression> ::= <primary> [<messages> <cascaded messages>]
BasicExpressionNode result = new BasicExpressionNode(parent);
IPrimaryNode primary = this.ParsePrimary(result, token);
if (primary == null)
{
this.ReportParserError(result, SemanticErrors.MissingPrimary, token);
return result;
}
token = this.GetNextTokenxx(Preference.Default);
this.ParseBaseicExpressionMessages(result, primary, token);
return result;
}
// <expression> ::=
// <assignment> |
// <basic expression>
// <assignment> ::= <assignment target> assignmentOperator <expression>
// <basic expression> ::= <primary> [<messages> <cascaded messages>]
// <assignment target> := identifier
// <primary> ::=
// identifier |
// <literal> |
// <block constructor> |
// ( '(' <expression> ')' )
protected virtual ExpressionNode ParseExpression(SemanticNode parent, Token token)
{
// Tricky ... first try for <assignment>
if (token is IdentifierToken)
{
// In here, we either have an <assignment target> or <primary> of a <basic expression>
IdentifierToken identifier = (IdentifierToken)token;
// Try to check for assignmentOperator
token = this.GetNextTokenxx(Preference.Default);
if (token is AssignmentOperatorToken)
// OK, it's <assignment>
return this.ParseAssignment(parent, identifier, (AssignmentOperatorToken)token);
// Must recover ... it is a <basic expression> anyway.
// PARSE: identifier [<messages> <cascaded messages>]
BasicExpressionNode result = new BasicExpressionNode(parent);
this.ParseBaseicExpressionMessages(result, new VariableReferenceleNode(result, identifier), token);
return result;
};
return this.ParseBasicExpression(parent, token);
}
protected virtual void ParseBaseicExpressionMessages(BasicExpressionNode expression, IPrimaryNode primary, Token token)
{
MessageSequenceNode messages = this.ParseMessages(expression, token);
if (messages == null)
{
expression.SetContents(primary, null, null);
return;
}
token = this.GetNextTokenxx(Preference.Default);
CascadeMessageSequenceNode cascadeMessages = this.ParseCascadeMessageSequenceNode(expression, token);
expression.SetContents(primary, messages, cascadeMessages);
}
