Support for closures

[divarvel]

The goal of this branch is to explore how to add support for closures in the stack machine

• closures are represented as a list of ops and a list of parameter names

• closure parameters can be used like variables

• variable names must be unique, so shadowing is forbidden

• boolean operators use laziness and push the rhs closure on the ops list only if needed (without recursion)

• .any() and .all() use recursion to compute results

• [x] closure support in datalog::expression::Op

• [x] closure support in format::schema

• [x] closure support in parser

• [x] closures for lazy boolean operators

• [x] closures for .any() and .all()

• [x] prevent shadowing in closure arguments

  • [x] evaluation
  • ~parsing & deserialization depends on #179~ will be done in a dedicated PR

• [x] print And and Or with &&! and ||!, without parsing them.

• [x] v5 block detection depends on #220

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #202 will not alter performance

_{Comparing closures (6fe9bfd) with v5 (3e3f071)}

Summary

✅ 12 untouched benchmarks

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 88.65546% with 27 lines in your changes are missing coverage. Please review.

Project coverage is 68.57%. Comparing base (3e3f071) to head (6fe9bfd).

Files	Patch %	Lines
biscuit-auth/src/format/convert.rs	85.55%	13 Missing :warning:
biscuit-auth/src/datalog/expression.rs	92.75%	5 Missing :warning:
biscuit-parser/src/builder.rs	0.00%	5 Missing :warning:
biscuit-auth/src/token/builder.rs	80.00%	3 Missing :warning:
biscuit-auth/src/datalog/mod.rs	75.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## v5 #202 +/- ## ========================================== + Coverage 67.91% 68.57% +0.66% ========================================== Files 25 25 Lines 5507 5681 +174 ========================================== + Hits 3740 3896 +156 - Misses 1767 1785 +18 ```

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