feat: Define modifiers as Python functions

guppylang/src/guppylang/std/builtins.py

@@ -3,7 +3,7 @@
 from guppylang.std.array import ArrayIter, FrozenarrayIter, array, frozenarray
 from guppylang.std.bool import bool
 from guppylang.std.iter import Range, SizedIter, range
-from guppylang.std.lang import comptime, owned, py
+from guppylang.std.lang import comptime, control, dagger, owned, power, py
 from guppylang.std.list import list
 from guppylang.std.mem import mem_swap
 from guppylang.std.num import (
@@ -102,6 +102,8 @@
     "compile",
     "complex",
     "comptime",
+    "control",
+    "dagger",
     "delattr",
     "dict",
     "dir",
@@ -145,6 +147,7 @@
     "owned",
     "panic",
     "pow",
+    "power",
     "print",
     "property",
     "py",

guppylang/src/guppylang/std/lang.py

@@ -1,5 +1,7 @@
 """Provides Python objects for builtin language keywords."""
 
+from collections.abc import Generator
+from contextlib import contextmanager
 from typing import Any, Protocol, TypeVar
 
 T = TypeVar("T")
@@ -42,3 +44,21 @@ class Copy(Protocol):
 
 class Drop(Protocol):
     """Bound to mark generic type parameters as being implicitly droppable."""
+
+
+@contextmanager
+def control() -> Generator[None]:
+    """Dummy context manager to support `with control(...):` blocks in Guppy code."""
+    yield
+
+
+@contextmanager
+def dagger() -> Generator[None]:
+    """Dummy context manager to support `with dagger:` blocks in Guppy code."""
+    yield
+
+
+@contextmanager
+def power() -> Generator[None]:
+    """Dummy context manager to support `with power(...):` blocks in Guppy code."""
+    yield

tests/error/modifier_errors/captured_var_inout_own.err

@@ -1,15 +1,15 @@
-Error: Not owned (at $FILE:14:16)
+Error: Not owned (at $FILE:16:16)
    | 
-12 |     a = qubit()
-13 |     with dagger:
-14 |         discard(a)
+14 |     a = qubit()
+15 |     with dagger:
+16 |         discard(a)
    |                 ^ Function `discard` wants to take ownership of this argument,
    |                   but `__modified__()` doesn't own `a`
 
 Help:
    | 
-11 | def test() -> None:
-12 |     a = qubit()
+13 | def test() -> None:
+14 |     a = qubit()
    |     - Argument `a` is only borrowed. Consider taking ownership:
    |       `a: qubit @owned`
 

tests/error/modifier_errors/captured_var_inout_own.py

@@ -1,5 +1,7 @@
 from guppylang.decorator import guppy
 from guppylang.std.quantum import qubit, owned
+from guppylang.std.builtins import dagger
+
 
 
 @guppy.declare(dagger=True)

tests/error/modifier_errors/captured_var_inout_reassign.err

@@ -1,8 +1,8 @@
-Error: Drop violation (at $FILE:11:4)
+Error: Drop violation (at $FILE:13:4)
    | 
- 9 | @guppy
-10 | def test() -> None:
-11 |     a = qubit()
+11 | @guppy
+12 | def test() -> None:
+13 |     a = qubit()
    |     ^ Variable `a` with non-droppable type `qubit` is leaked
 
 Help: Make sure that `a` is consumed or returned to avoid the leak

tests/error/modifier_errors/captured_var_inout_reassign.py

@@ -1,5 +1,7 @@
 from guppylang.decorator import guppy
 from guppylang.std.quantum import qubit
+from guppylang.std.builtins import dagger
+
 
 
 @guppy.declare(dagger=True)

tests/error/modifier_errors/ctrl_arg_array_many_arg.py

@@ -1,6 +1,6 @@
 from guppylang.decorator import guppy
 from guppylang.std.array import array
-from guppylang.std.builtins import owned
+from guppylang.std.builtins import owned, control
 from guppylang.std.quantum import qubit
 
 

tests/error/modifier_errors/ctrl_arg_body_copy.err

@@ -1,15 +1,15 @@
-Error: Copy violation (at $FILE:12:20)
+Error: Copy violation (at $FILE:13:20)
    | 
-10 | def test() -> None:
-11 |     q = qubit()
-12 |     with control(q, q):
+11 | def test() -> None:
+12 |     q = qubit()
+13 |     with control(q, q):
    |                     ^ Variable `q` with non-copyable type `qubit` cannot be
    |                       borrowed ...
 
 Note:
    | 
-11 |     q = qubit()
-12 |     with control(q, q):
+12 |     q = qubit()
+13 |     with control(q, q):
    |                  - Variable `q` already borrowed here
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/ctrl_arg_body_copy.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control
 from guppylang.std.quantum import qubit, owned
 
 

tests/error/modifier_errors/ctrl_arg_copy.err

@@ -1,15 +1,15 @@
-Error: Copy violation (at $FILE:17:12)
+Error: Copy violation (at $FILE:18:12)
    | 
-15 |     q = qubit()
-16 |     with control(q):
-17 |         use(q)
+16 |     q = qubit()
+17 |     with control(q):
+18 |         use(q)
    |             ^ Variable `q` with non-copyable type `qubit` cannot be
    |               borrowed ...
 
 Note:
    | 
-15 |     q = qubit()
-16 |     with control(q):
+16 |     q = qubit()
+17 |     with control(q):
    |                  - Variable `q` already borrowed here
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/ctrl_arg_copy.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control
 from guppylang.std.quantum import qubit, owned
 
 

tests/error/modifier_errors/ctrl_arg_not_assigned.err

@@ -1,8 +1,8 @@
-Error: Drop violation (at $FILE:7:17)
+Error: Drop violation (at $FILE:8:17)
   | 
-5 | @guppy
-6 | def test() -> None:
-7 |     with control(qubit()):
+6 | @guppy
+7 | def test() -> None:
+8 |     with control(qubit()):
   |                  ^^^^^^^ Expression with non-droppable type `qubit` is leaked
 
 Help: Consider assigning this value to a local variable

tests/error/modifier_errors/ctrl_arg_not_assigned.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control
 from guppylang.std.quantum import qubit
 
 

tests/error/modifier_errors/ctrl_arg_type.err

@@ -1,8 +1,8 @@
-Error: Type mismatch (at $FILE:7:20)
+Error: Type mismatch (at $FILE:9:20)
   | 
-5 | def test() -> None:
-6 |     x = qubit()
-7 |     with control(x, True):
+7 | def test() -> None:
+8 |     x = qubit()
+9 |     with control(x, True):
   |                     ^^^^ Expected expression of type `qubit`, got `bool`
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/ctrl_arg_type.py

@@ -1,4 +1,6 @@
 from guppylang.decorator import guppy
+from guppylang.std.quantum import qubit
+from guppylang.std.builtins import control
 
 
 @guppy

tests/error/modifier_errors/ctrl_arg_type_arr.err

@@ -1,8 +1,8 @@
-Error: Type mismatch (at $FILE:7:17)
+Error: Type mismatch (at $FILE:9:17)
   | 
-5 | def test() -> None:
-6 |     x = array(1, 2, 3)
-7 |     with control(x):
+7 | def test() -> None:
+8 |     x = array(1, 2, 3)
+9 |     with control(x):
   |                  ^ Expected expression of type `array[qubit, ?n]`, got
   |                    `array[int, 3]`
 

tests/error/modifier_errors/ctrl_arg_type_arr.py

@@ -1,4 +1,6 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import array
+from guppylang.std.builtins import control
 
 
 @guppy

tests/error/modifier_errors/ctrl_no_arg.err

@@ -1,8 +1,8 @@
-Error: Not enough arguments (at $FILE:8:16)
+Error: Not enough arguments (at $FILE:9:16)
   | 
-6 | @guppy
-7 | def test() -> None:
-8 |     with control():
+7 | @guppy
+8 | def test() -> None:
+9 |     with control():
   |                 ^^ Missing argument (expected 1, got 0)
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/ctrl_no_arg.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control
 
 
 # `control` is overloaded, so the number of arguments need not be fixed to 1.

tests/error/modifier_errors/dagger_arg.err

@@ -1,8 +1,8 @@
-Error: Too many arguments (at $FILE:6:16)
+Error: Too many arguments (at $FILE:7:16)
   | 
-4 | @guppy
-5 | def test() -> None:
-6 |     with dagger(1):
+5 | @guppy
+6 | def test() -> None:
+7 |     with dagger(1):
   |                 ^ Unexpected argument (expected 0, got 1)
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/dagger_arg.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import dagger
 
 
 @guppy

tests/error/modifier_errors/dagger_assign.err

@@ -1,14 +1,14 @@
-Error: Invalid expression in dagger (at $FILE:7:8)
+Error: Invalid expression in dagger (at $FILE:8:8)
   | 
-5 | def test() -> None:
-6 |     with dagger:
-7 |         a = 3
+6 | def test() -> None:
+7 |     with dagger:
+8 |         a = 3
   |         ^^^^^ Assignment found in a dagger context
 
 Note:
   | 
-5 | def test() -> None:
-6 |     with dagger:
+6 | def test() -> None:
+7 |     with dagger:
   |          ------ dagger modifier is used here
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/dagger_assign.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import dagger
 
 
 @guppy

tests/error/modifier_errors/dagger_loop.err

@@ -1,16 +1,16 @@
-Error: Invalid expression in dagger (at $FILE:7:8)
+Error: Invalid expression in dagger (at $FILE:8:8)
   | 
-5 | def test() -> None:
-6 |     with dagger:
-7 |         for _ in range(46):
+6 | def test() -> None:
+7 |     with dagger:
+8 |         for _ in range(46):
   |         ^^^^^^^^^^^^^^^^^^^
-8 |             pass
+9 |             pass
   | ^^^^^^^^^^^^^^^^ Loop found in a dagger context
 
 Note:
   | 
-5 | def test() -> None:
-6 |     with dagger:
+6 | def test() -> None:
+7 |     with dagger:
   |          ------ dagger modifier is used here
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/dagger_loop.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import dagger
 
 
 @guppy

tests/error/modifier_errors/flags_nested.err

@@ -1,8 +1,8 @@
-Error: Unitary constraint violation (at $FILE:15:12)
+Error: Unitary constraint violation (at $FILE:16:12)
    | 
-13 |     with dagger:
-14 |         with power(2):
-15 |             foo(q)
+14 |     with dagger:
+15 |         with power(2):
+16 |             foo(q)
    |             ^^^^^^ This function cannot be called in a dagger context
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/flags_nested.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import dagger, power
 from guppylang.std.quantum import qubit
 
 

tests/error/modifier_errors/flags_nested_combined_outer.err

@@ -1,8 +1,8 @@
-Error: Unitary constraint violation (at $FILE:15:12)
+Error: Unitary constraint violation (at $FILE:16:12)
    | 
-13 |     with control(ctrl), dagger:
-14 |         with power(2):
-15 |             foo(q)
+14 |     with control(ctrl), dagger:
+15 |         with power(2):
+16 |             foo(q)
    |             ^^^^^^ This function cannot be called in a unitary context
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/flags_nested_combined_outer.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control, dagger, power
 from guppylang.std.quantum import qubit
 
 

tests/error/modifier_errors/flags_nested_control_dagger.err

@@ -1,8 +1,8 @@
-Error: Unitary constraint violation (at $FILE:15:12)
+Error: Unitary constraint violation (at $FILE:16:12)
    | 
-13 |     with control(ctrl):
-14 |         with dagger:
-15 |             foo(q)
+14 |     with control(ctrl):
+15 |         with dagger:
+16 |             foo(q)
    |             ^^^^^^ This function cannot be called in a dagger context
 
 Guppy compilation failed due to 1 previous error

tests/error/modifier_errors/flags_nested_control_dagger.py

@@ -1,4 +1,5 @@
 from guppylang.decorator import guppy
+from guppylang.std.builtins import control, dagger
 from guppylang.std.quantum import qubit
 
 

tests/error/modifier_errors/flags_nested_missing_power.err

@@ -1,8 +1,8 @@
-Error: Unitary constraint violation (at $FILE:15:12)
+Error: Unitary constraint violation (at $FILE:16:12)
    | 
-13 |     with dagger:
-14 |         with power(2):
-15 |             foo(q)
+14 |     with dagger:
+15 |         with power(2):
+16 |             foo(q)
    |             ^^^^^^ This function cannot be called in a power context
 
 Guppy compilation failed due to 1 previous error