private static Func <double, double> CompileNumber(TerminalSyntaxNode node, CompilationContext context)
{
if (!double.TryParse(node.Token.Text, NumberStyle, context.CultureInfo, out double constant))
{
context.AddError(ErrorType.InvalidNumber, node);
return(null);
}
return(x => constant);
}
private static Func <double, double> CompileIdentifier(TerminalSyntaxNode node, CompilationContext context)
{
string name = node.Token.Text;
if (string.Equals(name, "x", StringComparison.OrdinalIgnoreCase))
{
return(x => x);
}
double?constant = context.Symbols.ResolveIndentifier(name);
if (constant == null)
{
ErrorType error = context.Symbols.IsKnownFunction(name) ?
ErrorType.ParenthesesRequired
: ErrorType.UnknownIdentifier;
context.AddErrorWithParameter(error, node);
return(null);
}
return(x => constant.Value);
}
