private Ast.Stmt ParseExecuteStmt(TokenQueue q)
{
var stmt = new Ast.ExecuteStmt {
SourceToken = q.SourceToken
};
q.Take("exec", "execute");
if (q.Peek(1) == "=")
{
stmt.ReturnVariableName = ParseVariableName(q);
q.Take("=");
}
if (q.PeekToken().Type == TokenType.String || q.PeekToken().Type == TokenType.Id)
{
stmt.ScriptName = q.Take().GetUnescapedText();
}
else
{
throw new SyntaxException(new[] { "string", "identifier" }, q);
}
if (IsVariableName(q.PeekToken()?.GetUnescapedText() ?? "") && q.Peek(1) == "=")
{
while (true)
{
var arg = new Ast.ArgumentPair();
arg.Name = ParseVariableName(q);
q.Take("=");
if (q.Peek() == "default")
{
q.Take();
}
else
{
arg.Value = ParseExpr(q);
}
stmt.Arguments.Add(arg);
if (!q.TakeMaybe(","))
{
break;
}
}
}
ConsumeSemicolon(q);
return(stmt);
}
private string ParseIdentifier(TokenQueue q) // or null
{
var token = q.PeekToken();
if (token.Type == TokenType.Id)
{
return(q.Take().GetUnescapedText());
}
else
{
return(null);
}
}
private static string ParseVariableName(TokenQueue q)
{
var t = q.PeekToken();
if (t.Type == TokenType.Variable && IsVariableName(t.GetUnescapedText()))
{
q.Take();
return(t.GetUnescapedText());
}
else
{
throw new SyntaxException(new[] { "variable name starting with @ $ :" }, q);
}
}
private Ast.IdentifierOrExpr ParseIdentifierOrExpr(TokenQueue q) // or null
{
var token = q.PeekToken();
if (token.Type == TokenType.Id)
{
q.Take();
return(new Ast.IdentifierOrExpr {
SourceToken = token, Identifier = token.GetUnescapedText()
});
}
else if (PeekExpr(q))
{
return(new Ast.IdentifierOrExpr {
SourceToken = token, Expr = ParseExpr(q)
});
}
else
{
return(null);
}
}