read the tutorial/manual. [https://nim-lang.org/docs/tut2.html#object-oriented-programming-method-call-syntax](https://nim-lang.org/docs/tut2.html#object-oriented-programming-method-call-syntax)
[https://nim-lang.github.io/Nim/manual.html#lexical-analysis-identifier-equality](https://nim-lang.github.io/Nim/manual.html#lexical-analysis-identifier-equality)