private ArmExpressionToken Expect(ref ArmExpressionTokenizer tokenizer, ArmExpressionTokenType expectedTokenType)
{
ArmExpressionToken token = tokenizer.NextToken();
if (token.Type != expectedTokenType)
{
throw Error($"Expected token of type '{expectedTokenType}' but instead got '{token}' at index {tokenizer.PreviousIndex} in input '{tokenizer.Input}'");
}
return(token);
}
private ArmOperation ParseIdentifierExpression(ref ArmExpressionTokenizer tokenizer, ArmExpressionIdentifierToken identifier)
{
ArmExpressionToken token = tokenizer.NextToken();
switch (token.Type)
{
case ArmExpressionTokenType.OpenParen:
ArmOperation expression = ParseCallExpression(ref tokenizer, identifier);
return(ParseDotExpression(ref tokenizer, expression));
default:
throw Error($"Expected a token of type '{ArmExpressionTokenType.OpenParen}' but instead got '{token}' in '{tokenizer.Input}' at index '{tokenizer.PreviousIndex}'");
}
}
private IArmString ParseInnerExpression(ref ArmExpressionTokenizer tokenizer, bool noLiteral = false)
{
ArmExpressionToken token = tokenizer.NextToken();
switch (token.Type)
{
case ArmExpressionTokenType.String:
if (noLiteral)
{
throw Error($"Expected a literal token but found a string in '{tokenizer.Input}' at index {tokenizer.PreviousIndex}");
}
return(new ArmStringLiteral(token.CoerceToString()));
case ArmExpressionTokenType.Identifier:
return(ParseIdentifierExpression(ref tokenizer, (ArmExpressionIdentifierToken)token));
default:
throw Error($"Expected an expression token but found '{token}' in '{tokenizer.Input}' at index {tokenizer.PreviousIndex}");
}
}
private ArmOperation ParseDotExpression(ref ArmExpressionTokenizer tokenizer, ArmOperation lhs)
{
ArmExpressionToken token = tokenizer.NextToken();
switch (token.Type)
{
case ArmExpressionTokenType.Dot:
token = tokenizer.NextToken();
switch (token.Type)
{
case ArmExpressionTokenType.Identifier:
return(ParseDotExpression(ref tokenizer, new ArmMemberAccessExpression(lhs, new ArmStringLiteral(((ArmExpressionIdentifierToken)token).Identifier))));
default:
throw Error($"Expected token of type '{ArmExpressionTokenType.Identifier}' after '.' but instead got '{token}' at index {tokenizer.PreviousIndex} in input '{tokenizer.Input}'");
}
default:
tokenizer.UngetToken(token);
return(lhs);
}
}
public void UngetToken(ArmExpressionToken token)
{
_i = _oldIndex;
}
