# iganaq OCaml

This is the OCaml implementation of the iganaq prototype. See the [root README](../README.md) for the general description.

## Configuration parser

Grammar v0.2:

    assignment  = { space }, key, { space }, equal, [ space ], value
    key         = letter, { letter | digit | "_" }, equal
    value       = valuable, { " " | valuable }, break
    valuable    = ( letter | digit | "_" | "-" | "~" | "/" ), { valuable }
    equal       = "="
    break       = "\n"
    space       = " " | "\t"

Written using the ISO 14977 EBNF Notation.

In this grammar, `digit` implies `decimal digit`. Spaces between the key and the `=` operator are lexed but meaningless. Spaces between the `=` operator and the first non-space character of the value are lexed and considered as part of the value. Spaces before the key and between the value and the newline are not lexed.

- Note: non-terminals `key` and `value` are ambiguous.
    - Resolved by specifying what character terminates each

## Task list

- [ ] Spec requirements integration test coverage
    - [x] Add log function
        - [x] Output begins with ` [log] `
        - [x] Only prints if `DEBUG` is set
    - [ ] Add interactive pkg tests (INS v0 B2.5)
    - [x] Get su command from `$XDG_CONFIG_HOME/tori/tori.conf`
        - [ ] Default to `su -c`
            - [ ] Handle fatal `Sys_error` if `tori.conf` doesn't exist
            - [ ] Handle checking `su -c` default with `which` when `tori.conf` exists but `su_command` is absent in it
            - [ ] Properly handle a compose `su_command` such as `su -c` in `System.Package`
        - [x] Validation
            - [x] Valid path or in `PATH`
            - [x] Executability
            - ~~`true` exits with status 0 (see note 3)~~
    - [x] Add logging
        - [x] Logs only if DEBUG is set
        - [x] Print each command executed, not just package names
    - [x] Case with no packages provided
        - [x] Prints a message
        - [x] MUST NOT run any system commands
    - [x] Unrecognized command: exit code 1
    - [x] Command `user`: print the output of `whoami`
    - [x] Command `os`: print the OS name
        - [x] log the contents of /etc/os-release

- [ ] Refactorings
    - [ ] Simplify and analyze `System.File`
    - [ ] Simplify Reader

- [ ] Additionals
    - [ ] Create remaining interface files
    - [ ] Expand unit tests coverage
    - [ ] Try out doc generation

- [ ] Check out
    - [ ] <https://github.com/janestreet/shexp>
    - [ ] <https://erratique.ch/software/bos>
    - [ ] <https://github.com/ninjaaron/ocaml-subprocess>
    - [ ] <https://github.com/charlesetc/feather>

### Notes

 1. INS = Iganaq Napkin Spec: <https://brew.bsd.cafe/tori/iganaq#specification>
 2. INS v0 B2.5 "MUST NOT run any system commands" is only testable if we wrap
    command execution properly in e.g. a list containing all executed commands
    and ensure no command is ever executed without being appended to it
 3. INS v0 A3.4 "running 'true' with exit code 0" requires the user to input
    their password every time. This should be dropped from the spec instead
 4. INS v0.1 changes requirement B2.3 to "MUST print the OS name and MUST log
    contents of /etc/os-release" in order to make the logging function testable
    without user input
 3. As per item 3 above, INS v0.2 drops "run 'true' with exit code 0" from A3.4

## References

- ISO 14977 EBNF Notation: <https://www.cl.cam.ac.uk/~mgk25/iso-14977.pdf>
- Comparison of BNF notations: <https://www.cs.man.ac.uk/~pjj/bnf/ebnf.html>
- W3C ABNF Notation: <https://www.w3.org/Notation.html>
- IETF RFC 5234 ABNF Notation (replaces 4234, 2234): <https://www.rfc-editor.org/rfc/rfc5234>