Replace custom CEL evaluator with cel-rust

[nicolasburtey]

Summary

• replace the custom CEL evaluator path in cala-cel-interpreter with cel-rust's Program/Context execution
• add compatibility conversions between Cala CelValue and cel-rust Value, including opaque Decimal and Uuid wrappers
• re-register Cala-specific CEL functions: date, uuid, decimal, decimal.Add, and timestamp format
• remove the retired cala-cel-parser crate, generated LALRPOP parser, stale interpreter package modules, and release-script references to the parser crate
• adjust date default validation for the timestamp-backed date representation

Verification

• cargo check -p cala-cel-interpreter --features fail-on-warnings
• SQLX_OFFLINE=true cargo check --workspace
• SQLX_OFFLINE=true cargo test --workspace --lib

Performance

Compared main (69006ee9) against this branch (34548dbb).

Compile time

Check	main	CEL replacement	Delta
cargo check -p cala-cel-interpreter --features fail-on-warnings	13.30s	12.87s	~3% faster
SQLX_OFFLINE=true cargo check --workspace	50.34s	52.04s	~3.4% slower

Pure CEL microbenchmark

• context construction: ~4.4x slower (1.32us -> 5.80us)
• parsing: ~30x-55x slower depending on expression
• evaluation: mixed for simple expressions, but slower on velocity-style expressions:
  • context.vars.account.metadata.check_velocity: ~49% slower
  • context.vars.entry.units == decimal('100'): ~27% slower
  • closed-as-of velocity condition: ~67% slower

Parse cost may matter less for normal runtime if expressions are parsed once and reused, but context construction and velocity-style evaluation are on the hot path.

DB-backed cala-perf velocity benchmarks

Ran with a temporary local Postgres cluster and reset DB state before each branch:

cargo bench -p cala-perf --bench ledger_benchmarks -- velocity --sample-size 20 --warm-up-time 1 --measurement-time 5

Benchmark	main mean	CEL replacement mean	Delta
post_simple_transaction_with_velocity	1.077 ms	1.313 ms	~22% slower
post_simple_transaction_with_skipped_velocity	1.003 ms	1.103 ms	~10% slower
post_simple_transaction_with_hit_velocity	543 us	636 us	~17% slower

Overall: compile impact is small/mixed, but CEL-heavy runtime paths regress by roughly 10-22% in the DB-backed velocity benchmarks, and isolated CEL parsing/context construction are substantially slower.

Not run

• OTel/Jaeger runtime tracing. Docker/Podman were unavailable locally, so the runtime comparison used the DB-backed local Postgres benchmark instead.

---

Note

High Risk
High risk because it replaces the core CEL parsing/execution engine and rewires type/function handling, which can change evaluation semantics and error behavior across templates/params.

Overview
Switches cala-cel-interpreter from the in-repo cala-cel-parser + custom AST evaluator to cel::Program/cel::Context execution, compiling expressions once and executing them against a registered runtime context.

Reimplements Cala builtins on top of cel (e.g. date, uuid, decimal, decimal.Add, timestamp format) and adds bidirectional conversions between Cala CelValue/CelKey and cel::objects::Value using opaque wrappers for Decimal/Uuid.

Removes the retired cala-cel-parser crate (LALRPOP grammar/build scripts and related context “package” plumbing), updates workspace deps/lockfile accordingly (including new cel transitive deps and dual thiserror versions), and adjusts/coarsens some tests and date coercion to align with the new timestamp-backed representation.

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[cursor]

Decimal arithmetic and ordering operators lost with opaque wrapping

Medium Severity

Wrapping Decimal as Value::Opaque removes support for native +, -, * operators and <, <=, >, >= comparisons that the old evaluator explicitly provided. Only decimal.Add is re-implemented as a named function. There are no equivalents for subtraction or multiplication, and cel-rust cannot apply arithmetic or ordering operators to opaque types. In a financial ledger system, this regression in decimal capabilities is concerning even if current expressions happen to use decimal.Add() rather than the + operator.

Additional Locations (1)

• cala-cel-interpreter/src/value.rs#L127-L128

 

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[github-actions]

📊 Performance Report

Commit: 34548db
Updated: 2026-05-02 02:09:25 UTC

Cala Performance Benchmark Results (non-representative)

Criterion Benchmark Results (single-threaded)

Benchmark	Time per Run	Throughput	% vs Baseline
post_simple_transaction	8.609ms	116 tx/s	0 (baseline)
post_and_recalculate_ec_account_set	17.443ms	57 tx/s	-102.0%
post_and_batch_recalculate_ec_account_set	12.936ms	77 tx/s	-50.0%
post_multi_layer_transaction	7.618ms	131 tx/s	+11.0%
post_simple_transaction_with_effective_balances	9.329ms	107 tx/s	-8.0%
post_simple_transaction_with_skipped_velocity	6.621ms	151 tx/s	+23.0%
post_simple_transaction_with_velocity	8.204ms	121 tx/s	+4.0%
post_simple_transaction_with_hit_velocity	4.098ms	243 tx/s	+52.0%
post_simple_transaction_with_one_account_set	6.904ms	144 tx/s	+19.0%
post_simple_transaction_with_five_account_sets	8.164ms	122 tx/s	+5.0%
post_simple_transaction_with_ec_account_set	6.585ms	151 tx/s	+23.0%

Load Testing Results (parallel-execution)

Scenario	tx/s
1 parallel	87.99
2 parallel	122.59
5 parallel	154.84
10 parallel	158.71
20 parallel	155.93
2 contention	118.07
5 contention	134.09
2 acct_sets	113.15
5 acct_sets	122.25

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Note: Performance results may vary based on system resources and database state.

Last updated by commit 34548db

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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