From 319e83218a2d859b9fb6bb431c5142278ceb1c78 Mon Sep 17 00:00:00 2001
From: Son Ho
Date: Thu, 13 Jan 2022 19:39:15 +0100
Subject: Update the TODOs

---
 TODO.md | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 6 deletions(-)

(limited to 'TODO.md')

diff --git a/TODO.md b/TODO.md
index f7f44383..c317a8b1 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,20 +1,60 @@
-* Check what happens when symbolic borrows are not expanded (when looking for
-  borrows/abstractions to end).
+* write an interesting example to study with Jonathan
 
-* Detect loops in end_borrow/end_abstraction
+* update the assignment to move the destination value (which will be overriden)
+  to a dummy variable, and end all the outer borrows.
+  update pop_frame
+
+* add option for: `allow_borrow_overwrites_on_input_values`
+  (but always disallow borrow overwrites on returned values)
+  at the level of abstractions (not at the level of loans!)
+
+* set of types with mutable borrows (what to do when type variables appear under
+  shared borrows?)
 
 * split `apply_proj_borrows` into two:
   * `apply_proj_borrows_on_input_values` : ... -> value -> rty -> avalue
   * `apply_proj_borrows_on_given_back_values` : ... -> value -> avalue -> avalue
+  TODO: actually not sure
 
 * remove the rule which says that we can end a borrow under an abstraction if
   the corresponding loan is in the same abstraction.
 
-* add a `allow_borrow_overwrites` in the loan projectors.
+* Check what happens when symbolic borrows are not expanded (when looking for
+  borrows/abstractions to end).
 
-* add option for: `allow_borrow_overwrites_on_input_values`
-  (but always disallow borrow overwrites on returned values)
+* Reduce projectors to `_` (ignored) when there are no region intersections
+
+* update end_borrow_get_borrow to keep track of the ignored borrows/loans as
+  outer borrows, and track the ids of the ignored shared loans?
+  or: make sure there are no parent abstractions when ending inner loans in
+  abstractions.
+
+* expand symbolic values which are primitively copyable upon using them as
+  function arguments or putting them in the return value, in order to deduplicate
+  those values.
+
+* invariant: if a symbolic value is present multiple times in the concrete environment,
+  it means it is primitively copyable
+  
+* invariant: if there is a `proj_loans rset1 (s:rty)` where `s` contains mutable
+  borrows, then:
+  * either there is exactly one `s` in the current context
+  * or there is exactly one `proj_borrows rset2 (s:rty<:rty')` which intersects
+    the `proj_loans ...`
+  However, one `proj_borrows s` may intersect several `proj_loans` (in which
+  case we will need to split the value given back - for now: disallow this
+  behaviour?).
+
+* `ended_proj_loans` (with ghost value)
 
+* add a check in function inputs: ok to take as parameters symbolic values with
+  borrow parameters *if* they come from the "input abstractions"
+
+* make the projected shared borrows more structured? I don't think that's necessary
+
+* Detect loops in end_borrow/end_abstraction
+
+* add a `allow_borrow_overwrites` in the loan projectors.
 
 * During printing, contexts are often big, with many variables containing "bottom".
   Some variables also actually never get assigned, especially when they are used
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