private object CompileBinary(CompileHelper leftHelper, CompileHelper rightHelper, params string[] opers)
{
var node1 = leftHelper();
var oper = Runtime.Find(Token, opers);
if (oper != null)
{
Accept();
var node2 = rightHelper();
return(Runtime.MakeList(GetLispOperator(oper), node1, node2));
}
return(node1);
}
private void CompileList(Vector list, CompileHelper helper, params string[] opers)
{
var node1 = helper();
if (node1 == null)
{
return;
}
list.Add(node1);
if (Tokens.Count != 0)
{
var oper = Runtime.Find(Token, opers);
if (oper != null)
{
Accept();
list.Add(oper);
CompileList(list, helper, opers);
}
}
}
public Vector Scanner(string infix)
{
var v = new Vector();
var index = 0;
while (index < infix.Length)
{
int pos = index;
char ch = infix[index];
if (Char.IsWhiteSpace(ch))
{
// Skip white space
++index;
}
else if (Char.IsDigit(ch))
{
// Numbers can have decimal point.
// No commas allowed since this would break function parameter list syntax.
while (index < infix.Length)
{
ch = infix[index];
// Same as below. If there are letters, this will give runtime error.
if (!(Char.IsLetterOrDigit(ch) || ch == '.' || ch == '_'))
{
break;
}
++index;
}
var number = infix.Substring(pos, index - pos);
v.Add(number.ParseNumber());
}
else if (Char.IsLetter(ch) || ch == '_')
{
// ident
while (index < infix.Length)
{
ch = infix[index];
if (!(Char.IsLetterOrDigit(ch) || ch == '_'))
{
break;
}
++index;
}
var ident = infix.Substring(pos, index - pos);
v.Add(Runtime.FindSymbol(ident));
}
else if (index + 1 < infix.Length)
{
var oper = infix.Substring(index, 2);
if (Runtime.Find(oper, Opers) == null)
{
oper = infix.Substring(index, 1);
if (Runtime.Find(oper, Opers) == null)
{
throw new LispException("Invalid operator {0} in infix expression: {1}", oper, infix);
}
}
index += oper.Length;
v.Add(oper);
}
else
{
var oper = infix.Substring(index, 1);
if (Runtime.Find(oper, Opers) == null)
{
throw new LispException("Invalid operator {0} in infix expression: {1}", oper, infix);
}
index += oper.Length;
v.Add(oper);
}
}
return(v);
}
