def step

stelliferous@0.0.2.0 · proofs/traversal_witness.bend:29

import Base
import stelliferous@0.0.2.0/traversal_array.bend as Traversal

29def step(~Reader: Type,~Element: Data,~Context: Data,~ReaderEvidence: @-reader: Reader -> Data,
30  ~read: Reader -> Context -> U32 -> Reader & Element,~destination: Context -> U32 -> U32,
31  ~read_preserves: @-reader: Reader -> @context: Context -> @index: U32 -> ReaderEvidence(reader) ->
32    Sample<Reader,Element,reader,read(reader,context,index)>,
33  +depth: Nat,-reader: Reader,-state: Traversal.State<&1,&1,Reader,Array<Element>,Context>,
34  reader_evidence: ReaderEvidence(reader),evidence: StateEvidence<Reader,Element,Context,reader,depth,state>) ->
35  StateEvidence<Reader,Element,Context,reader,depth,Traversal.step(~Reader,~Element,~Context,~read,~destination,state)>:
36  match evidence:
37    case StateEvidence{output,+position,+context,equation,output_evidence}:
38      %Equal.sym(Traversal.State<&1,&1,Reader,Array<Element>,Context>,state,Traversal.State{reader,output,position,context},equation) :
39        StateEvidence<Reader,Element,Context,reader,depth,Traversal.step(~Reader,~Element,~Context,~read,~destination,_)>
40      store(~Reader,~Element,~Context,~destination,depth,reader,position,context,output,read(reader,context,position),output_evidence,
41        read_preserves(reader,context,position,reader_evidence))