def step

stelliferous@0.0.2.0 · proofs/traversal_visit_witness.bend:20

import Base
import stelliferous@0.0.2.0/traversal_array.bend as Traversal
import stelliferous@0.0.2.0/proofs/traversal_witness.bend as TraversalWitness

20def step(~Reader: Type,~Element: Data,~Context: Data,~ReaderEvidence: @-reader: Reader -> Data,
21  ~read: Reader -> Context -> Reader & Traversal.Visited<Context,Element>,
22  ~read_preserves: @-reader: Reader -> @context: Context -> ReaderEvidence(reader) -> Sample<Reader,Element,Context,reader,read(reader,context)>,
23  +depth: Nat,-reader: Reader,-state: Traversal.State<&1,&1,Reader,Array<Element>,Context>,reader_evidence: ReaderEvidence(reader),
24  evidence: TraversalWitness.StateEvidence<Reader,Element,Context,reader,depth,state>) ->
25  TraversalWitness.StateEvidence<Reader,Element,Context,reader,depth,Traversal.visit_step(~Reader,~Element,~Context,~read,state)>:
26  match evidence:
27    case TraversalWitness.StateEvidence{output,position,context,equation,output_evidence}:
28      %Equal.sym(Traversal.State<&1,&1,Reader,Array<Element>,Context>,state,Traversal.State{reader,output,position,context},equation) :
29        TraversalWitness.StateEvidence<Reader,Element,Context,reader,depth,Traversal.visit_step(~Reader,~Element,~Context,~read,_)>
30      store(~Reader,~Element,~Context,depth,reader,position,output,read(reader,context),output_evidence,read_preserves(reader,context,reader_evidence))