chore(main): release 0.21.0

[hugrbot]

🤖 I have created a release beep boop

0.21.0 (2025-08-04)

⚠ BREAKING CHANGES

• guppy.compile(foo) and guppy.check(foo) replaced with foo.check() and foo.compile()
• default HUGR output uses compressed binary encoding.
• guppylang.tracing.object.GuppyDefinition moved to guppylang.defs.GuppyDefinition guppylang.tracing.object.TypeVarGuppyDefinition moved and renamed to guppylang.defs.GuppyTypeVarDefinition
• All to_hugr methods on types, arguments, and parameters now require a ToHugrContext CompileableDef.compile_outer now requires a ToHugrContext guppy.hugr_op now passes the compiler context to the function generating the op CheckedFunctionDef now implements MonomorphizableDef instead of CompileableDef CompilerContext.build_compiled_def now requires an instantiation for the definition's type parameters The ToHugrContext protocol now requires two additional methods: type_var_to_hugr and const_var_to_hugr CompilerContext.{compiled, worklist} and CompilationEngine.compiled are now indexed by a tuple of DefId and optional PartiallyMonomorphizedArgs
• comptime code that previously used constant integers outside i64 will now fail to compile.
• Capturing closures are now disabled by default. Enabling them requires calling guppylang.enable_experimental_features(), however note that they are not supported throughout the stack.

Features

• Add Future type (#1075) (5ad7673)
• add error when constant integer out of bounds (#1084) (eee77ae)
• Add guppy version metadata to hugr entrypoint (#1039) (0eafbd9), closes #1037
• Add manual registration of extensions (#1045) (4b42936)
• add qsystem op for measure leaked (#1057) (c555727)
• add selene via optional feature and use for testing (#1081) (cefc70e)
• Add support for V and Vdg. (#1094) (6b0d44a)
• Allow indexing on tuples (#1038) (0e9097e), closes #711
• Declare WASM modules in guppy (#942) (e1240fb)
• Extend comptime arguments to arbitrary non-linear types (#1110) (384dd8c)
• Make decorator return types more precise (#1115) (c84e8b1)
• set hugr entrypoint to compiled function (#1063) (16bd267)
• store used extensions and versions in HUGR metadata (#1049) (a9a300c), closes #1048
• Support arbitrary const generics via monomorphisation (#1033) (bcf9865)
• Support Python 3.12 generic syntax (#1051) (ab2e118), closes #823
• Top level compile + emulate Interface (#1127) (5e2f595)
• update to hugr-py v0.13 (#1083) (8f071c8)
• use core. prefix for metadata keys (#1055) (2bf0d68)

Bug Fixes

• Allow array comprehension syntax in comptime functions (#1068) (da8f04a), closes #1067
• Allow struct redefinitions for Python < 3.13 (#1108) (959a4e4), closes #1107
• Correctly detect [@custom](https://github.com/custom)_guppy_decorator in nested scopes (#1086) (678583c)
• Fix diagnostics rendering for comptime entrypoints (#1099) (fdd2676), closes #1097
• Fix frame lookup for Python 3.12 annotation scopes (#1120) (a69e489), closes #1116
• Fix hugr conversion and bounds checks on numeric literals (#1100) (73d5e92)
• Fix Jupyter notebook diagnostic rendering (#1109) (6002474)
• Fix nested function definitions in Python 3.12 (#1064) (090f920)
• Stop showing temporary variables in comptime diagnostics (#1112) (63854c5), closes #1111
• support comptime entrypoint (#1079) (721e3dd)
• Turn capturing closures into experimental feature (#1065) (a959b18)

Documentation

• add docstrings for emulator module (#1131) (b33e065)
• add quantum and qsystem gate definitions (#912) (32a4bbc)
• Fix docstrings (#1128) (0aded85)
• Improve RNG docs (#1043) (8640f06)
• replace compile_module usage in README (#1041) (03ccf3a)
• Update guppy examples (#1121) (b994655)

---

This PR was generated with Release Please. See documentation.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.99%. Comparing base (b33e065) to head (cd62567).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1042   +/-   ##
=======================================
  Coverage   92.99%   92.99%           
=======================================
  Files         116      116           
  Lines       10807    10807           
=======================================
  Hits        10050    10050           
  Misses        757      757           

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