# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# @todo #85:60min Simplify Rcopy rule. Right now this rule is quite verbose.
#  It captures a lot objects around its targets. It's done in order to have
#  scope for contextualization of 𝑒2 right here right away. So it's a hack.
#  The origin Rcopy rule looks like this
#  pattern: ⟦ 𝐵1, 𝜏1 ↦ ∅, 𝐵3 ⟧(𝜏1 ↦ 𝑒1)
#  result: ⟦ 𝐵1, 𝜏1 ↦ 𝑒2, 𝐵3 ⟧
#  where 𝑒2 is an expression contextualized with 𝑒1 and some scope S.
#  But with such pattern we don't have this scope, we don't see it.
#  It should be calculated somehow. In general this scope is nearest
#  outer formation. So we need to create a way to calculate it and
#  rewrite this rule.
name: COPY
pattern: ⟦ 𝐵1, 𝜏1 ↦ ⟦ 𝐵2, 𝜏2 ↦ ∅, 𝐵3 ⟧(𝜏2 ↦ 𝑒1) * !t, 𝐵4 ⟧
result: ⟦ 𝐵1, 𝜏1 ↦ ⟦ 𝐵2, 𝜏2 ↦ 𝑒2, 𝐵3 ⟧ * !t, 𝐵4 ⟧
when:
  xi: 𝑒1
where:
  - meta: 𝑒2
    function: contextualize
    args:
      - 𝑒1
      - ⟦ 𝐵1, 𝜏1 ↦ ⟦ 𝐵2, 𝜏2 ↦ ∅, 𝐵3 ⟧(𝜏2 ↦ 𝑒1) * !t, 𝐵4 ⟧