phino-0.0.152: test-resources/evaluate-packs/defers-a-copy-whose-argument-is-a-bare-symbol.yaml

# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# yamllint disable rule:line-length
# The loop of #1729: 'joined' folds a tuple whose tail is the bare symbol '𝜎3',
# an object nobody knows. The right branch of the first fork is the copy
# 'step( acc ↦ …, tup ↦ 𝜎3 )', and nothing inside its body can succeed, since
# every round asks '𝜎3' for its 'length'. Before #1729 the walk entered that
# body, got stuck six times, and left it as written, so the join had a symbol
# on the left and a body on the right, and 'e' came to nothing. Now the walk
# does not enter a copy one of whose arguments reads to a bare symbol: it
# answers the copy with a fresh symbol and writes a 'deferred' line naming the
# copy it stands for, the join pairs that symbol with the one the left branch
# ends in, and 'e' comes to a symbol. Since #1732 that line spells the copy as
# a call of 'Φ.joined.step', the object of the world it was made of, rather
# than of 'Φ.e.step', the copy of 'joined' the walk wrote into 'e', since only
# the first one has voids the copy fills. Reading 'items.length' through the
# tuple, itself a copy over bare symbols, still reaches '𝜎1', since a copy with
# no φ has no body to defer.
symbolic: |
  - λ: L_bytes_eq
    dataize:
      𝛿1: $.ρ
      𝛿2: $.b
    𝑛: Φ.bool( if ↦ ⟦ λ ⤍ L_fork, left ↦ ∅, right ↦ ∅, φ ↦ ⟦ λ ⤍ 𝜎 ⟧ ⟧ )
  - λ: L_bytes_concat
    dataize:
      𝛿1: $.ρ
      𝛿2: $.b
    𝑛: Φ.bytes( φ ↦ ⟦ λ ⤍ 𝜎 ⟧ )
  - λ: L_dataized
    dataize:
      𝛿1: $.target
    𝑛: Φ.bytes( φ ↦ ⟦ λ ⤍ 𝜎 ⟧ )
  - λ: L_fork
    dataize:
      𝛿1: $.φ
    morph:
      𝑛1: $.left
      𝑛2: $.right
    symbolize:
      𝑛3: 𝑛1
      𝑛4: 𝑛2
    join:
      𝑛5: [𝑛3, 𝑛4]
    𝑛: 𝑛5
location: 'Q.e'
deep: true
partial: true
acyclic: plausible
result: '⟦ items ↦ Φ.tuple( length ↦ Φ.bytes( φ ↦ 𝜎1:λ ), head ↦ 𝜎2:λ, tail ↦ 𝜎3:λ ), φ ↦ 𝜎9:λ, step(acc, tup) ↦ Φ.dataized( target ↦ tup.length ).eq( b ↦ Φ.bytes( φ ↦ 00-:Δ ) ).if( acc, ρ.step( acc ↦ acc.concat( b ↦ Φ.dataized( target ↦ tup.head ) ), tup ↦ tup.tail ) ):φ ⟧'
input: |
  ⟦
    bool(if) ↦ ⟦ φ ↦ if( Φ.bytes( φ ↦ FF-:Δ ), Φ.bytes( φ ↦ 00-:Δ ) ) ⟧,
    bytes(φ) ↦ ⟦ eq(ρ, b) ↦ L_bytes_eq:λ, concat(ρ, b) ↦ L_bytes_concat:λ ⟧,
    dataized(target) ↦ L_dataized:λ,
    tuple(length, head, tail) ↦ ⟦⟧,
    joined(items) ↦ ⟦
      φ ↦ Φ.dataized( target ↦ items.length ).eq( b ↦ Φ.bytes( φ ↦ 00-:Δ ) ).if(
        Φ.bytes( φ ↦ --:Δ ),
        step( acc ↦ Φ.dataized( target ↦ items.head ), tup ↦ items.tail )
      ),
      step(ρ, acc, tup) ↦ Φ.dataized( target ↦ tup.length ).eq( b ↦ Φ.bytes( φ ↦ 00-:Δ ) ).if(
        acc,
        ρ.step( acc ↦ acc.concat( b ↦ Φ.dataized( target ↦ tup.head ) ), tup ↦ tup.tail )
      ):φ
    ⟧,
    e ↦ Φ.joined(
      items ↦ Φ.tuple( length ↦ Φ.bytes( φ ↦ 𝜎1:λ ), head ↦ 𝜎2:λ, tail ↦ 𝜎3:λ )
    )
  ⟧
protocol: |
  𝕄(Φ.e):
    𝑛·0·1 := Φ.joined( items ↦ Φ.tuple( length ↦ Φ.bytes( φ ↦ 𝜎1:λ ), head ↦ 𝜎2:λ, tail ↦ 𝜎3:λ ) )
    𝕄(Φ.e.items):
      𝑛·0·2 := Φ.bytes( φ ↦ 𝜎1:λ )
      𝑛·0·3 := Φ.tuple( length ↦ 𝑛·0·2 )
      𝑛·0·4 := Φ.tuple( length ↦ 𝑛·0·2 )
      𝑛·0·5 := 𝑛·0·4( head ↦ 𝜎2:λ )
      𝑛·0·6 := Φ.tuple( length ↦ 𝑛·0·2 )
      𝑛·0·7 := 𝑛·0·6( head ↦ 𝜎2:λ )
      𝑛·0·8 := 𝑛·0·7( tail ↦ 𝜎3:λ )
    𝕄(Φ.e.φ):
      𝑛·0·9 := Φ.tuple( length ↦ 𝑛·0·2 )
      𝑛·0·10 := 𝑛·0·9( head ↦ 𝜎2:λ )
      𝑛·0·11 := 𝑛·0·10( tail ↦ 𝜎3:λ )
      𝑛·0·12 := Φ.tuple( length ↦ 𝑛·0·2 )
      𝑛·0·13 := 𝑛·0·12( head ↦ 𝜎2:λ )
      𝑛·0·14 := 𝑛·0·13( tail ↦ 𝜎3:λ )
      𝑛·0·15 := Φ.bytes( φ ↦ 𝜎1:λ )
      𝑛·0·16 := Φ.dataized( target ↦ 𝑛·0·14.length )
      𝔼(L_dataized):
        𝔻(Φ.a🌵0):
          𝕄(Φ.a🌵0):
            𝑛·1·1 := Φ.tuple( length ↦ 𝑛·0·15 )
            𝑛·1·2 := 𝑛·1·1( head ↦ 𝜎2:λ )
            𝑛·1·3 := 𝑛·1·2( tail ↦ 𝜎3:λ )
            𝑛·1·4 := Φ.bytes( φ ↦ 𝜎1:λ )
        𝛿1·1 := 𝔻(𝜎1:λ)  # 𝔻(ξ.target)
        𝑛·1·5 := Φ.bytes( φ ↦ 𝜎4:λ )  # 𝑛
        𝕄(𝑛·1·5):
          𝑛·1·6 := Φ.bytes( φ ↦ 𝜎4:λ )
        𝑛·1·7 := 𝑛·1·6  # 𝕄(𝑛·1·5)
      𝑛·0·17 := Φ.bytes( φ ↦ 00-:Δ )
      𝑛·0·18 := 𝑛·1·6.eq( b ↦ 𝑛·0·17 )
      𝔼(L_bytes_eq):
        𝔻(Φ.a🌵1):
          𝕄(Φ.a🌵1):
            𝑛·2·1 := Φ.bytes( φ ↦ 𝜎4:λ )
        𝛿1·2 := 𝔻(𝜎4:λ)  # 𝔻(ξ.ρ)
        𝔻(Φ.a🌵2):
          𝕄(Φ.a🌵2):
            𝑛·2·2 := Φ.bytes( φ ↦ 00-:Δ )
          𝛿·2·1 := 00-
        𝛿2·2 := 𝛿·2·1  # 𝔻(ξ.b)
        𝑛·2·3 := Φ.bool( if(left, right) ↦ ⟦ λ ⤍ L_fork, φ ↦ 𝜎5:λ ⟧ )  # 𝑛
        𝕄(𝑛·2·3):
          𝑛·2·4 := Φ.bool( if(left, right) ↦ ⟦ λ ⤍ L_fork, φ ↦ 𝜎5:λ ⟧ )
        𝑛·2·5 := 𝑛·2·4  # 𝕄(𝑛·2·3)
      𝑛·0·19 := Φ.bytes( φ ↦ --:Δ )
      𝑛·0·20 := ⟦ λ ⤍ L_fork, left ↦ ∅, right ↦ ∅, φ ↦ 𝜎5:λ ⟧( left ↦ 𝑛·0·19 )
      𝑛·0·21 := Φ.tuple( length ↦ 𝑛·1·4 )
      𝑛·0·22 := 𝑛·0·21( head ↦ 𝜎2:λ )
      𝑛·0·23 := 𝑛·0·22( tail ↦ 𝜎3:λ )
      𝑛·0·24 := Φ.tuple( length ↦ 𝑛·1·4 )
      𝑛·0·25 := 𝑛·0·24( head ↦ 𝜎2:λ )
      𝑛·0·26 := 𝑛·0·25( tail ↦ 𝜎3:λ )
      𝑛·0·27 := Φ.dataized( target ↦ 𝑛·0·26.head )
      𝔼(L_dataized):
        𝔻(Φ.a🌵3):
          𝕄(Φ.a🌵3):
            𝑛·3·1 := Φ.tuple( length ↦ 𝑛·1·4 )
            𝑛·3·2 := 𝑛·3·1( head ↦ 𝜎2:λ )
            𝑛·3·3 := 𝑛·3·2( tail ↦ 𝜎3:λ )
        𝛿1·3 := 𝔻(𝜎2:λ)  # 𝔻(ξ.target)
        𝑛·3·4 := Φ.bytes( φ ↦ 𝜎6:λ )  # 𝑛
        𝕄(𝑛·3·4):
          𝑛·3·5 := Φ.bytes( φ ↦ 𝜎6:λ )
        𝑛·3·6 := 𝑛·3·5  # 𝕄(𝑛·3·4)
      𝑛·0·28 := ⟦ acc ↦ ∅, tup ↦ ∅, φ ↦ Φ.dataized( target ↦ tup.length ).eq( b ↦ 𝑛·2·2 ).if( acc, ρ.step( acc ↦ acc.concat( b ↦ Φ.dataized( target ↦ tup.head ) ), tup ↦ tup.tail ) ) ⟧( acc ↦ 𝑛·3·5 )
      𝑛·0·29 := Φ.tuple( length ↦ 𝑛·1·4 )
      𝑛·0·30 := 𝑛·0·29( head ↦ 𝜎2:λ )
      𝑛·0·31 := 𝑛·0·30( tail ↦ 𝜎3:λ )
      𝑛·0·32 := Φ.tuple( length ↦ 𝑛·1·4 )
      𝑛·0·33 := 𝑛·0·32( head ↦ 𝜎2:λ )
      𝑛·0·34 := 𝑛·0·33( tail ↦ 𝜎3:λ )
      𝑛·0·35 := ⟦ acc ↦ ∅, tup ↦ ∅, φ ↦ Φ.dataized( target ↦ tup.length ).eq( b ↦ 𝑛·2·2 ).if( acc, ρ.step( acc ↦ acc.concat( b ↦ Φ.dataized( target ↦ tup.head ) ), tup ↦ tup.tail ) ) ⟧( acc ↦ 𝑛·3·5 )
      𝑛·0·36 := 𝑛·0·35( tup ↦ 𝑛·0·34.tail )
      𝑛·0·37 := ⟦ λ ⤍ L_fork, left ↦ ∅, right ↦ ∅, φ ↦ 𝜎5:λ ⟧( left ↦ 𝑛·0·19 )
      𝑛·0·38 := ⟦ acc ↦ ∅, tup ↦ ∅, φ ↦ Φ.dataized( target ↦ tup.length ).eq( b ↦ 𝑛·2·2 ).if( acc, ρ.step( acc ↦ acc.concat( b ↦ Φ.dataized( target ↦ tup.head ) ), tup ↦ tup.tail ) ) ⟧( acc ↦ 𝑛·3·5 )
      𝑛·0·39 := 𝑛·0·38( tup ↦ 𝑛·0·34.tail )
      𝑛·0·40 := 𝑛·0·37( right ↦ 𝑛·0·39 )
      𝔼(L_fork):
        𝛿1·4 := 𝔻(𝜎5:λ)  # 𝔻(ξ.φ)
        𝕄(Φ.a🌵5):
          𝑛·4·1 := Φ.bytes( φ ↦ --:Δ )
        𝑛1·4 := 𝑛·4·1  # 𝕄(ξ.left)
        𝕄(Φ.a🌵6):
          deferred(𝜎7) := Φ.joined.step( acc ↦ 𝑛·3·5, tup ↦ 𝜎3:λ )
        𝑛2·4 := 𝜎7:λ  # 𝕄(ξ.right)
        𝔻(𝜎8:λ) == --
        𝑛3·4 := ⟦ φ ↦ 𝜎8:λ, eq(b) ↦ L_bytes_eq:λ, concat(b) ↦ L_bytes_concat:λ ⟧  # 𝑛1
        𝑛4·4 := 𝑛2·4  # 𝑛2
        𝔻(𝜎9:λ) ∈ { 𝔻(𝜎8:λ), 𝔻(𝜎7:λ) }
        𝑛5·4 := 𝜎9:λ  # [𝑛3, 𝑛4]
        𝑛·4·2 := 𝑛5·4  # 𝑛
        𝑛·4·3 := 𝑛5·4  # 𝕄(𝑛·4·2)