Error when parsing char literals 

Char literals are not accepted in REPL:
```
↪ 'a'
•• [E002] error: unable to parse input
╭─[0]─┬ repl:1..1 in function: @anonymous
│ 1   │ 'a'
│     ┴ ‾‾‾ Invalid literal: char can not contain more than one symbol
```