public static Symbol get_symbol(string name, out bool was_defined)
{
Symbol sym;
was_defined = symbol_world.TryGetValue(name, out sym);
if (!was_defined) {
sym = new Symbol(name);
symbol_world.Add(name, sym);
}
return sym;
}
public object lookup(TxtLocation loc, Symbol sym)
{
object def;
if (definitions.TryGetValue(sym, out def)) {
return def;
} else if (m_parent != null) {
return m_parent.lookup(loc, sym);
} else if (m_trap(sym, out def)) {
return def;
} else {
throw new InterpreterException(loc, sym.name + " is undefined");
}
}
public static string get_abbrev(Symbol sym)
{
if (sym == quote) {
return "'";
} else if (sym == quasiquotation) {
return "`";
} else if (sym == unquote) {
return ",";
} else if (sym == unquote_splicing) {
return ",@";
} else {
return null;
}
}
public void visit_value(Symbol s)
{
scount++;
}
private bool GetSymbol(string name, out Symbol symbol) =>
symbols.TryGetValue(name, out symbol);
public override void visit(Symbol o)
{
if (m_atom != null) m_atom.visit(o);
}
bool write_abbrev(Symbol sym)
{
string abbrev = Abbrev.get_abbrev(sym);
if (abbrev != null) {
m_writer.Append(abbrev);
return true;
} else {
return false;
}
}
static bool no_trap(Symbol sym, out object def)
{
def = null;
return false;
}
public void AddMacro(Symbol sym, SpecialForm.Macro m)
{
definitions.Add(sym, new SpecialForm(m));
}
public void AddFn(Symbol sym, Closure.Fn fn)
{
definitions.Add(sym, new Closure(fn));
}
public void Add(Symbol sym, object def)
{
definitions.Add(sym, def);
}
public override void visit(Symbol o)
{
base.visit(o);
m_print.print(outbox);
}
public override void visit(Symbol o)
{
outbox.put(m_env.lookup(m_loc, o));
}
public virtual void visit(Symbol o)
{
visit((object)o);
}