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ErrorStr

procedure ErrorStr(Message: string);

Example​

procedure RequireAssignment(Parser: TParser);
begin
  if Parser = nil then Exit;

  if Parser.Token <> '=' then
    Parser.ErrorStr('An assignment operator was expected');
end;

Usage​

ErrorStr raises an EParserError using supplied message text and the parser's current one-based source line.

Additional Technical Info​

ErrorStr reports a parser failure with caller-supplied text. For a parser created through Velox's exposed constructor, it raises EParserError whose message combines Message with the current one-based SourceLine.

The native implementation can first invoke an OnError callback and allow that callback to mark the error handled. Velox does not expose the constructor overload or property needed to install that callback, so a script-created parser follows the raising path.

Calling ErrorStr does not advance, reset or free the parser. If the caller catches the exception, the same current Token remains selected. Continuing after a semantic error is only safe if the script has an explicit recovery strategy, such as consuming to a known delimiter. Otherwise let the exception abort the parse.

Message is not a format string and receives no substitutions. Do not include secrets or complete confidential payloads: exception text can reach mapping errors, logs or support diagnostics. An empty message is accepted but still produces the native parse-error wrapper and line number.

Prefer this method over the exposed Error(Integer), whose importer declaration is incompatible with current Delphi overloads.

The example is source-reviewed only; no exception was raised.

External references

Created 2026-07-15