static public IASTNode Compile(SymbolTable symTable, object exp)
{
if (exp is string)
{
return(new ASTNode_GetVar {
address = SymbolTable.Lookup(symTable, (string)exp)
});
}
else if (exp is INumber)
{
return(new ASTNode_Literal {
value = exp
});
}
List <object> form = exp as List <object>;
switch (form[0] as string)
{
case "quote":
return(new ASTNode_Literal {
value = ListProcess.ListExpToPairExp(form[1])
});
case "if":
return(new ASTNode_If {
predNode = Compile(symTable, form[1]), thenNode = Compile(symTable, form[2]), elseNode = Compile(symTable, form[3])
});
case "begin":
return(new ASTNode_Begin {
nodes = form.Skip(1).Select(e => Compile(symTable, e)).ToList()
});
case "lambda": {
SymbolTable newSymTable = new SymbolTable(symTable);
foreach (var name in ((List <object>)form[1]).Cast <string>())
{
newSymTable.DefineLocalSymbol(name);
}
List <string> defines = new List <string>();
ListProcess.FindDefinition(defines, (List <object>)form[2], 1);
foreach (var name in defines)
{
newSymTable.DefineLocalSymbol(name);
}
IASTNode body = Compile(newSymTable, form[2]);
return(new ASTNode_Lambda {
localVarCount = newSymTable.GetLocalSymbolCount(),
bodyNode = body,
freeAddresses = new ASTNodeVisitor_FindFreeAddresses(body).FreeAddresses,
});
}
case "define":
case "set!":
return(new ASTNode_SetVar {
address = SymbolTable.Lookup(symTable, (string)form[1]), rightNode = Compile(symTable, form[2])
});
default:
return(new ASTNode_Application {
procedureNode = Compile(symTable, form[0]),
actualNodes = form.Skip(1).Select(e => Compile(symTable, e)).ToList(),
});
}
}
public SymbolTable(SymbolTable prevTable)
{
mPrevTable = prevTable;
}