Expression StringLiteral()
{
StringLiteral literal = new StringLiteral(lexer.Value, lexer.LineId);
Match(Token.String);
return literal;
}
private Statement InputStatement()
{
// Requires more than one token of lookahead. If we encounter a string variable
// after input, it could be an input prompt or the variable to store the input in.
// It's not until we look past that and check for a colon do we know.
LineId line = lexer.LineId;
Match(Token.Input);
List<Statement> inputs = new List<Statement>();
Expression inputPrompt;
// Assume that an input prompt is given and parse it as an expression
// If it later turns out that it is not the input prompt, then it must
// be convert to an assignment.
Expression expr = Expression();
if (lookahead == Token.Colon)
{
inputPrompt = expr;
Match(Token.Colon);
}
else // if there is no colon then what we read shouldn't be
// treated as an Expression, but as an Assignment.
{
inputPrompt = new StringLiteral("? ", LineId.None);
LocationReference vr = (LocationReference)expr; // The expr must have been a Location Reference
Location location = vr.Location;
inputs.Add(Assign.ReadConsole(location, line));
if (lookahead == Token.Comma) Match(Token.Comma);
}
while (lookahead != Token.EOF && lookahead != Token.EndOfLine)
{
Location location = Location();
inputs.Add(Assign.ReadConsole(location, line));
if (lookahead == Token.Comma) Match(Token.Comma);
}
return new Input(inputPrompt, new Block(inputs), line);
}
