private Rule parseUpdateRule(string pname, string rule, Declarations decls)
{
int len = 1;
int equal = rule.IndexOf(":=");
if (equal < 0)
{
equal = rule.IndexOf('=');
}
else
{
len = 2;
}
if (equal < 0)
{
throw new ParseException(String.Format("Invalid update rule '{0}'!", rule));
}
string varname = rule.Substring(0, equal).Trim();
string upexpr = rule.Substring(equal + len).Trim();
VarDecl vd = decls.getVar(varname);
if (vd == null)
{
throw new ParseException(String.Format("Unknown variable {0}!", varname));
}
string expr = String.Format("int _UPDATE_{0} = {1};", varname, upexpr);
Declarations newdecls = parseDeclarations(expr, decls);
Expression e = newdecls.getFirstDecl().Expr;
return(new UpdateRule(varname, e));
}
private Rule parseSyncRule(string pname, string rule, Declarations decls)
{
SyncRule.Direction dir;
if (rule.EndsWith("?"))
{
dir = SyncRule.Direction.Receive;
}
else
if (rule.EndsWith("!"))
{
dir = SyncRule.Direction.Send;
}
else
{
throw new ParseException(String.Format("Synchronization rule '{0}' must end with '!' or '?'!"));
}
rule = rule.TrimEnd(new char[] { '?', '!' });
string expr = String.Format("chan _CHANNEL_ = {0};", rule);
Declarations newdecls = parseDeclarations(expr, decls);
Expression e = newdecls.getVar("_CHANNEL_").Expr;
return(new SyncRule(e, dir));
}
public TypeDecl GetType(Declarations symtab)
{
switch (Type)
{
case ExpType.Const:
return(new TypeDecl()
{
Type = VarType.Int
});
case ExpType.Var:
VarDecl v = symtab.getVar(Var);
if (v == null)
{
throw new ParseException(String.Format("Unknown variable {0}", Var));
}
return(v.Type);
case ExpType.Func:
// this should be improved later
return(new TypeDecl()
{
Type = VarType.Int
});
default:
throw new ParseException("Internal error 1");
}
}
private Rule parseGuardRule(string pname, string rule, Declarations decls)
{
string expr = String.Format("bool _GUARD_ = {0};", rule);
Declarations newdecls = parseDeclarations(expr, decls);
Expression e = newdecls.getVar("_GUARD_").Expr;
return(new GuardRule(e));
}