Replace `State` module by `Link`

[upsiflu]

Motivation For the user, Ui, application and Link are the relevant Apis for construction. State is never constructed, and only stored in an application as a Url. As any Url is a valid State, we do a type alias.

Link.applyTo : State -> Link -> State

instead of

State.next : Link -> State -> State

[upsiflu]

Goal

Going with #29, State should not be a module because we don't treat it as a permanent data type. Instead, it is a collection of functions that map to and from the Url.

Situation now (Sept 5, 2023)

What does the Url map to and from?

• Link
• String
• Query
• Assignment
• Path
• Flag
• Fragment

Where is State used?

• Ui: only Link
• Html: only Link

Here are all Url-centric functions from the current State module. I excluded the Link-centric functions.

Create

• fromString : String -> Maybe State

Map

• next : Link -> State -> State
• setPath : Path -> State -> State
• setFragment : Fragment -> State -> State
• type UrlCmd = Set Assignment | Add Assignment | Clear String
• integrateAssignment : UrlCmd -> State -> State
• addAssignment : String -> String -> State -> State
• removeAssignments : List String -> State -> State
• toggleFlag : Flag -> State -> State
• turnOnFlag : Flag -> State -> State

Query

• hasFlag : Flag -> State -> Bool

Deconstruct

• getLocation : State -> ( Maybe Path, Fragment )
• getFragment : State -> Fragment
• getPath : State -> Path
• toString : State -> String
• queryParseLocation : String -> ( Maybe Path, Fragment )