Release v0.14.0

Features

• Support for protobuf JSON serialization of native object types [#616]
• Allow creation of custom types.Err structs [#630]

Optional Values

• Syntax, type-checking, and runtime support for optional list elements [#615]
• Support for optional on unparse [#673]

String Extensions

• Add string.format by [#617]
• Add version option to Strings extension library [#650]
• Add strings.quote [#639]
• Add estimated cost support to strings.quote [#664]
• Add compile-time string.format checking [#645]

REPL

• Appengine demo for web-based REPL [#646]
• Enable extensions for REPL [#653]
• Update REPL to use ext.Strings formatter when possible. [#659]

Fixes

• Fix long build times by upgrading gazelle [#637]
• Ensure that macro call tracking is updated during AST pruning [#619]
• Fix accidental alterations to 'decorators' slice [#620]
• Tests for race conditions in top-level cel package [#625]
• Potential index out of bounds fix by [#626]
• Fix conformance service proto field access for SourcePosition message [#627]
• Ensure that optional indices are within the range of elements [#663]
• Update repl README's standalone build commands [#636]
• Fix panic in optimized set membership test for byte values [#652]
• Fix regression of cost behavior for has() [#651]

Breaking Changes

• Remove the deprecated interpreter.Coster interface [#665]

Since the Env.EstimateCost() and Program.ActualCost() routines are available,
the deprecated cel.EstimateCost() routine is confusing and strictly less accurate
than the updated APIs.

While there are other cleanups desired for https://github.com/google/cel-go/issues/504,
this change will at least improves the clarity of the top-level APIs.

Note: this is a breaking change. Users should consult the referenced methods
to replace any legacy use of cel.EstimateCost()

New Contributors

• @inteon made their first contribution in #620
• @nlachfr made their first contribution in #630
• @davidjb made their first contribution in #636
• @dependabot made their first contribution in #647
• @SimonWaldherr made their first contribution in #670

Full Changelog: v0.13.0...v0.14.0