private Ast.DeclareStmt ParseDeclareStmt(TokenQueue q)
{
var stmt = new Ast.DeclareStmt {
SourceToken = q.SourceToken
};
q.Take("declare");
if (q.Peek() == "parameter")
{
q.Take();
stmt.IsParameter = true;
}
ParseAssignmentStmtCore(q, stmt);
return(stmt);
}
private void ExecuteDeclareStmt(Ast.DeclareStmt stmt, ScriptEnv env)
{
var name = stmt.VariableName.ToLower();
var declarationExists = env.Vars.ContainsKey(name);
if (stmt.IsParameter)
{
if (env.ParNames.Contains(name))
{
throw new ScriptException($"Duplicate DECLARE for parameter \"{stmt.VariableName}\".");
}
else
{
env.ParNames.Add(name);
}
if (declarationExists)
{
// do nothing; the parameter value was specified by the caller
}
else if (stmt.InitialValue != null)
{
// the caller did not specify a value, but there is an initial value in the DECLARE statement.
env.Vars[name] = EvaluateExpr(stmt.InitialValue, env);
}
else
{
throw new ScriptException(
$"An argument value was not provided for parameter \"{stmt.VariableName}\".");
}
}
else if (declarationExists)
{
throw new ScriptException($"Duplicate DECLARE for variable \"{stmt.VariableName}\".");
}
else
{
if (stmt.InitialValue != null)
{
env.Vars[name] = EvaluateExpr(stmt.InitialValue, env);
}
else
{
env.Vars[name] = 0L;
}
}
}