Module

Transit.DSL

Package: purescript-transit
Repository: m-bock/purescript-transit

Domain-Specific Language (DSL) for building type-level transit specifications.

This module provides a type-level DSL for constructing state machine specifications in a declarative way. The DSL uses infix operators to create readable specifications that are automatically converted to transit cores.

Basic Usage

type MyTransit =
  Transit
    :* ("State1" :@ "Msg1" >| "State2")
    :* ("State2" :@ "Msg2" >| "State1")

Operators

:* - Add a match/transition to the specification
:@ - Combine state and message (e.g., "State1" :@ "Msg1")
>| - Add return state(s) to a match
|< - Create bidirectional edge (e.g., "State1" |< "Msg" >| "State2")
:? - Add guard condition to a return (e.g., "guard" :? "State2")

#type (:*) Source

Operator alias for Transit.DSL.AddMatch (right-associative / precedence 0)

Infix operator for adding matches to a transit specification.

Right-associative, allowing Transit to appear first for clean indentation.

Example: Transit :* ("State1" :@ "Msg1" >| "State2")

#AddMatch Source

data AddMatch :: forall k1 k2. k1 -> k2 -> Typedata AddMatch a b

Internal type for adding a match to a transit specification. Used with the :* operator.

Instances

(IsTransitSpec (AddMatch a b) o, Reflectable o TransitCore) => Reflectable (AddMatch a b) TransitCore
Allows DSL specifications to be reflected to runtime TransitCore values.
(ToTransitCore (AddMatch a b) c) => IsTransitSpec (AddMatch a b) c
Transit specification with matches added via :*.
(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch Transit xs) (MkTransitCoreTL ys)
(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch (AddOut (AddIn s1 ms) s2) xs) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) ys)))
(ToMatch x t, ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch x xs) (MkTransitCoreTL (Cons' t ys))

#type (:?) Source

Operator alias for Transit.DSL.WithGuard (left-associative / precedence 9)

Infix operator for adding guard conditions to returns.

Example: "guard" :? "State2"

#type (:@) Source

Operator alias for Transit.DSL.StateWithMsg (left-associative / precedence 5)

Infix operator for combining a state with a message.

Example: "State1" :@ "Msg1"

#type (>|) Source

Operator alias for Transit.DSL.AddOut (left-associative / precedence 5)

Infix operator for adding return states to a match.

Example: "State1" :@ "Msg1" >| "State2" >| "State3"

#type (|<) Source

Operator alias for Transit.DSL.AddIn (left-associative / precedence 5)

Infix operator for creating bidirectional edges.

Example: "State1" |< "Msg" >| "State2" creates edges in both directions.

#ToTransitCore Source

class ToTransitCore :: forall k. k -> TransitCoreTL -> Constraintclass ToTransitCore dsl a | dsl -> a

Type class that converts DSL expressions to transit core specifications.

This class is used internally to transform the DSL syntax into the underlying transit core type-level representation.

Instances

ToTransitCore Transit (MkTransitCoreTL Nil')
(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch Transit xs) (MkTransitCoreTL ys)
(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch (AddOut (AddIn s1 ms) s2) xs) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) ys)))
ToTransitCore (AddOut (AddIn s1 ms) s2) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) Nil')))
(ToMatch x t, ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch x xs) (MkTransitCoreTL (Cons' t ys))
(ToMatch x t) => ToTransitCore x (MkTransitCoreTL (Cons' t Nil'))

#ToMatch Source

class ToMatch :: forall k. k -> MatchTL -> Constraintclass ToMatch dsl a | dsl -> a

Type class that converts DSL match expressions to match specifications.

Handles conversion of state-message combinations and return states into the underlying match type-level representation.

Instances

(ToMatch x (MkMatchTL s m xs), ToReturn y y') => ToMatch (AddOut x y) (MkMatchTL s m (Cons' y' xs))
ToMatch (StateWithMsg x y) (MkMatchTL x y Nil')
ToMatch (AddOut (AddIn x y) z) (MkMatchTL x y Nil')

#ToReturn Source

class ToReturn :: forall k. k -> ReturnTL -> Constraintclass ToReturn dsl a | dsl -> a

Type class that converts DSL return expressions to return specifications.

Handles conversion of state names and guard conditions into the underlying return type-level representation.

Instances

ToReturn (WithGuard g s) (MkReturnViaTL g s)
ToReturn s (MkReturnTL s)

#Transit Source

data Transit

Base type for transit specifications (empty specification).

Start all transit specifications with Transit, then add matches using :*.

Example:

type MyTransit =
  Transit
    :* ("State1" :@ "Msg1" >| "State2")
    :* ("State2" :@ "Msg2" >| "State3")

Instances

IsTransitSpec Transit (MkTransitCoreTL Nil')
Empty transit specification (no matches).
ToTransitCore Transit (MkTransitCoreTL Nil')
(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch Transit xs) (MkTransitCoreTL ys)

#StateWithMsg Source

data StateWithMsg :: forall k1 k2. k1 -> k2 -> Typedata StateWithMsg a b

Internal type for combining a state with a message. Used with the :@ operator.

Instances

ToMatch (StateWithMsg x y) (MkMatchTL x y Nil')

#WithGuard Source

data WithGuard :: forall k1 k2. k1 -> k2 -> Typedata WithGuard a b

Internal type for adding a guard condition to a return. Used with the :? operator.

Instances

ToReturn (WithGuard g s) (MkReturnViaTL g s)

#AddOut Source

data AddOut :: forall k1 k2. k1 -> k2 -> Typedata AddOut a b

Internal type for adding an output (return state). Used with the >| operator.

Instances

(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch (AddOut (AddIn s1 ms) s2) xs) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) ys)))
ToTransitCore (AddOut (AddIn s1 ms) s2) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) Nil')))
(ToMatch x (MkMatchTL s m xs), ToReturn y y') => ToMatch (AddOut x y) (MkMatchTL s m (Cons' y' xs))
ToMatch (AddOut (AddIn x y) z) (MkMatchTL x y Nil')

#AddIn Source

data AddIn :: forall k1 k2. k1 -> k2 -> Typedata AddIn a b

Internal type for adding an input (bidirectional edge). Used with the |< operator.

Instances

(ToTransitCore xs (MkTransitCoreTL ys)) => ToTransitCore (AddMatch (AddOut (AddIn s1 ms) s2) xs) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) ys)))
ToTransitCore (AddOut (AddIn s1 ms) s2) (MkTransitCoreTL (Cons' (MkMatchTL s1 ms (Cons' (MkReturnTL s2) Nil')) (Cons' (MkMatchTL s2 ms (Cons' (MkReturnTL s1) Nil')) Nil')))
ToMatch (AddOut (AddIn x y) z) (MkMatchTL x y Nil')

Modules: Transit; Transit.Class.CheckReturn; Transit.Class.CurryN; Transit.Class.MkHandlerLookup; Transit.Class.MkUpdate; Transit.Core; Transit.DSL; Transit.Data.DotLang; Transit.Data.Graph; Transit.Data.Html; Transit.Data.MaybeChurch; Transit.Data.Table; Transit.HandlerLookup; Transit.Render.Graphviz; Transit.Render.Theme; Transit.Render.TransitionTable; Transit.StateGraph; Transit.VariantUtils