Technical requirements
All the code examples that you will see in this section can be found under the directory called chapter2 in the GitHub repository (https://github.com/PacktPublishing/Protocol-Buffers-Handbook).
In the following sections, I will be using some extended Backus-Naur form (EBNF) notation (https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form) to describe the syntax of all the elements. The following elements will be used:
| alternation (or)
() grouping
[] option (zero or one time)
{} repetition (any number of times) Do not worry too much, though. I am only writing in the EBNF for people who are interested and to emphasize that Protobuf is a language. If you feel like this is too overwhelming, you can just skip this part and look at the examples I will be providing.
On top of that, I will be omitting details for simplicity. However, all the details are available in the official specifications:
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