These examples show how to create a custom lexer. 

In both example a sequence of
[VarInts](https://developers.google.com/protocol-buffers/docs/encoding#varints)
are parsed. The sequence is provided in file `custom_lexer.bytes` and forms
numbers: 300, 42, and 57345. You can see files with `.ast` extensions for
results of parsing.

In the example `custom_lexer_1` lexer is in charge of recognizing each `VarInt`
while in the example `custom_lexer_2` lexer is recognizing constituent bytes of
`VarInts` while the grammar defines how these bytes are organized into
`VarInts`.

In both examples, the conversion to numeric values is done in the actions which
are generated by Rustemo and then manually edited at appropriate places to
provide the conversion.
