### Dotnet

- install dotnet 6
- install antlr
- cd WaifuGrammar
- antlr4 -Dlanguage=CSharp \
  -o WaifuGrammar/grammar_out/waifu \
  -package waifu -listener -visitor \
  -lib WaifuGrammar/grammar \
  WaifuGrammar/grammar/Waifu2.g4
- Develop in grammar/Waifu2.g4 and Program.cs


### Notes

-
- Final implementation in rust? Althought rantlr4 doesn't have rust support. So we will have to write parser and lexer from sctach


| character | meaning                   | p                                                                                                                                                                                                                                                          | z |
|-----------|---------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ~         | Unused                    | Negation                                                                                                                                                                                                                                                   |   |
| `         | Unused                    | Infix maybe                                                                                                                                                                                                                                                |   |
| !         | Unused                    | unsafe unwrap, far future                                                                                                                                                                                                                                  |   |
| @         | Unused                    | maybe a valid starting character for ID                                                                                                                                                                                                                    |   |
| #         | Comments                  | Use # for single line ## for multiline comments                                                                                                                                                                                                            |   |
| $         | Unused                    | I don't like using this anywhere. Useless.                                                                                                                                                                                                                 |   |
| %         | OP_MOD                    |                                                                                                                                                                                                                                                            |   |
| ^         | OP_POWER                  | Not xor.                                                                                                                                                                                                                                                           |   |
| &         | OP_AND                    | Not bitwise and.                                                                                                                                                                                                                                                           |   |
| *         | OP_MULT                   |                                                                                                                                                                                                                                                            |   |
| (         | Grouping                  | Also range, non inclusive                                                                                                                                                                                                                                  |   |
| )         | Grouping                  | Also range, non inclusive                                                                                                                                                                                                                                  |   |
| -         | OP_MINUS, Number negation | Maybe in ranges? - makes more sense than .. however that becomes a problem with negative numbers, unless we force the whistespace                                                                                                                          |   |
| _         | Unused                    | Not sure, doesn't seem like a useful symbol. we could use it for digit grouping in integers like a lot of modern languages do                                                                                                                              |   |
| =         | OP_EQUALS                 |                                                                                                                                                                                                                                                            |   |
| +         | OP_PLUS                   | Not allowed as a number prefix. It's ugly and serves no purpose. +X is X. - is useful to flip the sign, we shouldn't add this 'for symetries'                                                                                                              |   |
| [         | Unused                    | Inclusive Range                                                                                                                                                                                                                                            |   |
| ]         | Unused                    | Inclusive range                                                                                                                                                                                                                                            |   |
| {         | Unused                    | Should be used to define a struct. { WS NL fields functions NL } NL                                                                                                                                                                                        |   |
| }         | Unused                    | struct close                                                                                                                                                                                                                                               |   |
| ;         | Unused                    | no idea.                                                                                                                                                                                                                                                   |   |
| :         | Type prefix. very nice.   | Very nice.                                                                                                                                                                                                                                                 |   |
| "         | Unused                    | No idea.                                                                                                                                                                                                                                                   |   |
| '         | Strings                   | Should be used both for single and multiline strings. Should be able to specify multiple in a row in order to require that many to close without escaping any lower number of quotes in the string                                                         |   |
| PIPE LOl  | OP_OR                     |                                                                                                                                                                                                                                                            |   |
| <         | OP_LESS_THAN              |                                                                                                                                                                                                                                                            |   |
| >         | OP_GREATER_THAN           |                                                                                                                                                                                                                                                            |   |
| ,         | Unused                    | ?                                                                                                                                                                                                                                                          |   |
| .         | Unused                    | Object navigation is an obvious one, but I'd like to explore other possiblities. One idea is to have . act as a "value of the expression in the line above, which would be very useful for using values without assigning them to variables, 'auto piping' |   |
| ?         | Unused                    | Prefix for 'if' and 'switch' like thing. ? EXPR NL INDENT (VAL WS expr)+ (_ WS expr)?                                                                                                                                                                      |   |
| /         | OP_DIV                    |                                                                                                                                                                                                                                                            |   |
| \         | UNUSED                    | I'm not 100% opposed but i don't like the idea of using this as an escape character.                                                                                                                                                                       |   |