Boost your command line applications with potions!

This talk presents potions, a command-line parser library.

1. Boost your command-line
applications with potions!
Eric Torreborre

2. Options, flags, arguments, oh my!

3. Options, flags, arguments, oh my!
Arg
Flag, option, argument, switch
Option
Parameter

4. Feature set
No: man page, - - arguments, deriving

5. Help!

6. Show me the money!

7. Show me the money!

8. Anatomy of an option

9. Anything of value

10. Bring your own
Mandatory
Combinators

11. Option parsers
Option Flag Argument

12. Mind the environment
SOURCE_FILE
SOURCE
COPY_SOURCE

13. Flag <-> Enum

14. Repeated options

15. Commands

16. Commands

17. Fixing mistaeks

18. To the best of my abilities

19. Option
Option ≠ Flag ≠ Argument
Flag Argument
Named Positioned
Active value
Default valueExample

20. Declare everything

21. Builder pattern with abilities
ValueDsl
NameDsl
PositionalDsl
HelpDsl
EnvDsl
FlagDsl
RepeatedDsl
DefaultValueDsl

22. Builder pattern with abilities
This might fail!

23. Two steps building

24. Making repeated options: a -> [a]
Re-interpret expressions
Decode a list
Handler
Display repetition

25. From Option a to ‘{Parser} a
Handle with other abilities
Inputs
Option/command
ResultEffects

26. Help!
Not trivial!

27. Help!

28. What’s up Doc?

29. Suggestions

30. Programming at scale

31. Programming at scale
full-text search?
navigating code
readability?
fzf + editing code
view / test results lost in
typecheck errors

32. Programming at scale
jumps arounderror-proneperformance
update required to test
no doc renderer
commits?refactoring records

33. Programming at scale
Tests
Panes
WatchesTypecheck errors
DocFind/Replace
Status adornments
Navigation
Actions
Please give me an IDE!

34. Thanks!