feat: Update top-level definitions to use new diagnostics (#604)

guppylang/checker/errors/generic.py

@@ -0,0 +1,45 @@
+from dataclasses import dataclass
+from typing import ClassVar
+
+from guppylang.diagnostic import Error
+
+
+@dataclass(frozen=True)
+class UnsupportedError(Error):
+    title: ClassVar[str] = "Unsupported"
+    span_label: ClassVar[str] = "{things} {is_are} not supported{extra}"
+    things: str
+    singular: bool = False
+    unsupported_in: str = ""
+
+    @property
+    def is_are(self) -> str:
+        return "is" if self.singular else "are"
+
+    @property
+    def extra(self) -> str:
+        return f" in {self.unsupported_in}" if self.unsupported_in else ""
+
+
+@dataclass(frozen=True)
+class UnexpectedError(Error):
+    title: ClassVar[str] = "Unexpected {things}"
+    span_label: ClassVar[str] = "Unexpected {things}{extra}"
+    things: str
+    unexpected_in: str = ""
+
+    @property
+    def extra(self) -> str:
+        return f" in {self.unexpected_in}" if self.unexpected_in else ""
+
+
+@dataclass(frozen=True)
+class ExpectedError(Error):
+    title: ClassVar[str] = "Expected {things}"
+    span_label: ClassVar[str] = "Expected {things}{extra}"
+    things: str
+    got: str = ""
+
+    @property
+    def extra(self) -> str:
+        return f", got {self.got}" if self.got else ""

guppylang/decorator.py

@@ -12,7 +12,7 @@
 from hugr.package import FuncDefnPointer, ModulePointer
 
 import guppylang
-from guppylang.ast_util import annotate_location, has_empty_body
+from guppylang.ast_util import annotate_location
 from guppylang.definition.common import DefId, Definition
 from guppylang.definition.const import RawConstDef
 from guppylang.definition.custom import (
@@ -28,7 +28,6 @@
 from guppylang.definition.function import (
     CompiledFunctionDef,
     RawFunctionDef,
-    parse_py_func,
 )
 from guppylang.definition.parameter import ConstVarDef, TypeVarDef
 from guppylang.definition.struct import RawStructDef
@@ -309,17 +308,12 @@ def custom(
         mod = module or self.get_module()
 
         def dec(f: PyFunc) -> RawCustomFunctionDef:
-            func_ast, docstring = parse_py_func(f, self._sources)
-            if not has_empty_body(func_ast):
-                raise GuppyError(
-                    "Body of custom function declaration must be empty",
-                    func_ast.body[0],
-                )
             call_checker = checker or DefaultCallChecker()
             func = RawCustomFunctionDef(
                 DefId.fresh(mod),
-                name or func_ast.name,
-                func_ast,
+                name or f.__name__,
+                None,
+                f,
                 call_checker,
                 compiler or NotImplementedCallCompiler(),
                 higher_order_value,

guppylang/definition/common.py

@@ -7,6 +7,7 @@
 
 from hugr.build.dfg import DefinitionBuilder, OpVar
 
+from guppylang.diagnostic import Fatal
 from guppylang.span import SourceMap
 
 if TYPE_CHECKING:
@@ -157,3 +158,12 @@ def compile_inner(self, globals: "CompiledGlobals") -> None:
         Opposed to `CompilableDef.compile()`, we have access to all other compiled
         definitions here, which allows things like mutual recursion.
         """
+
+
+@dataclass(frozen=True)
+class UnknownSourceError(Fatal):
+    title: ClassVar[str] = "Cannot find source"
+    message: ClassVar[str] = (
+        "Unable to look up the source code for Python object `{obj}`"
+    )
+    obj: object

guppylang/definition/custom.py

@@ -2,18 +2,20 @@
 from abc import ABC, abstractmethod
 from collections.abc import Callable, Sequence
 from dataclasses import dataclass, field
+from typing import TYPE_CHECKING, ClassVar
 
 from hugr import Wire, ops
 from hugr import tys as ht
 from hugr.build.dfg import DfBase
 
-from guppylang.ast_util import AstNode, get_type, with_loc, with_type
+from guppylang.ast_util import AstNode, get_type, has_empty_body, with_loc, with_type
 from guppylang.checker.core import Context, Globals
 from guppylang.checker.expr_checker import check_call, synthesize_call
 from guppylang.checker.func_checker import check_signature
 from guppylang.compiler.core import CompiledGlobals, DFContainer
 from guppylang.definition.common import ParsableDef
 from guppylang.definition.value import CallReturnWires, CompiledCallableDef
+from guppylang.diagnostic import Error, Help
 from guppylang.error import GuppyError, InternalGuppyError
 from guppylang.nodes import GlobalCall
 from guppylang.span import SourceMap
@@ -27,6 +29,42 @@
     type_to_row,
 )
 
+if TYPE_CHECKING:
+    from guppylang.definition.function import PyFunc
+
+
+@dataclass(frozen=True)
+class BodyNotEmptyError(Error):
+    title: ClassVar[str] = "Unexpected function body"
+    span_label: ClassVar[str] = "Body of custom function `{name}` must be empty"
+    name: str
+
+
+@dataclass(frozen=True)
+class NoSignatureError(Error):
+    title: ClassVar[str] = "Type signature missing"
+    span_label: ClassVar[str] = "Custom function `{name}` requires a type signature"
+    name: str
+
+    @dataclass(frozen=True)
+    class Suggestion(Help):
+        message: ClassVar[str] = (
+            "Annotate the type signature of `{name}` or disallow the use of `{name}` "
+            "as a higher-order value: `@guppy.custom(..., higher_order_value=False)`"
+        )
+
+    def __post_init__(self) -> None:
+        self.add_sub_diagnostic(NoSignatureError.Suggestion(None))
+
+
+@dataclass(frozen=True)
+class NotHigherOrderError(Error):
+    title: ClassVar[str] = "Not higher-order"
+    span_label: ClassVar[str] = (
+        "Function `{name}` may not be used as a higher-order value"
+    )
+    name: str
+
 
 @dataclass(frozen=True)
 class RawCustomFunctionDef(ParsableDef):
@@ -47,7 +85,7 @@ class RawCustomFunctionDef(ParsableDef):
         higher_order_value: Whether the function may be used as a higher-order value.
     """
 
-    defined_at: ast.FunctionDef
+    python_func: "PyFunc"
     call_checker: "CustomCallChecker"
     call_compiler: "CustomInoutCallCompiler"
 
@@ -69,12 +107,17 @@ def parse(self, globals: "Globals", sources: SourceMap) -> "CustomFunctionDef":
         code. The only information we need to access is that it's a function type and
         that there are no unsolved existential vars.
         """
-        sig = self._get_signature(globals)
+        from guppylang.definition.function import parse_py_func
+
+        func_ast, docstring = parse_py_func(self.python_func, sources)
+        if not has_empty_body(func_ast):
+            raise GuppyError(BodyNotEmptyError(func_ast.body[0], self.name))
+        sig = self._get_signature(func_ast, globals)
         ty = sig or FunctionType([], NoneType())
         return CustomFunctionDef(
             self.id,
             self.name,
-            self.defined_at,
+            func_ast,
             ty,
             self.call_checker,
             self.call_compiler,
@@ -104,7 +147,9 @@ def compile_call(
         )
         return self.call_compiler.compile_with_inouts(args).regular_returns
 
-    def _get_signature(self, globals: Globals) -> FunctionType | None:
+    def _get_signature(
+        self, node: ast.FunctionDef, globals: Globals
+    ) -> FunctionType | None:
         """Returns the type of the function, if known.
 
         Type annotations are needed if we rely on the default call checker or
@@ -117,19 +162,15 @@ def _get_signature(self, globals: Globals) -> FunctionType | None:
         requires_type_annotation = (
             isinstance(self.call_checker, DefaultCallChecker) or self.higher_order_value
         )
-        has_type_annotation = self.defined_at.returns or any(
-            arg.annotation for arg in self.defined_at.args.args
+        has_type_annotation = node.returns or any(
+            arg.annotation for arg in node.args.args
         )
 
         if requires_type_annotation and not has_type_annotation:
-            raise GuppyError(
-                f"Type signature for function `{self.name}` is required. "
-                "Alternatively, try passing `higher_order_value=False` on definition.",
-                self.defined_at,
-            )
+            raise GuppyError(NoSignatureError(node, self.name))
 
         if requires_type_annotation:
-            return check_signature(self.defined_at, globals)
+            return check_signature(node, globals)
         else:
             return None
 
@@ -196,10 +237,7 @@ def load_with_args(
         """
         # TODO: This should be raised during checking, not compilation!
         if not self.higher_order_value:
-            raise GuppyError(
-                "This function does not support usage in a higher-order context",
-                node,
-            )
+            raise GuppyError(NotHigherOrderError(node, self.name))
         assert len(self.ty.params) == len(type_args)
 
         # We create a `FunctionDef` that takes some inputs, compiles a call to the

guppylang/definition/declaration.py

@@ -1,5 +1,6 @@
 import ast
 from dataclasses import dataclass, field
+from typing import ClassVar
 
 from hugr import Node, Wire
 from hugr import tys as ht
@@ -14,13 +15,21 @@
 from guppylang.definition.common import CompilableDef, ParsableDef
 from guppylang.definition.function import PyFunc, parse_py_func
 from guppylang.definition.value import CallableDef, CallReturnWires, CompiledCallableDef
+from guppylang.diagnostic import Error
 from guppylang.error import GuppyError
 from guppylang.nodes import GlobalCall
 from guppylang.span import SourceMap
 from guppylang.tys.subst import Inst, Subst
 from guppylang.tys.ty import Type, type_to_row
 
 
+@dataclass(frozen=True)
+class BodyNotEmptyError(Error):
+    title: ClassVar[str] = "Unexpected function body"
+    span_label: ClassVar[str] = "Body of declared function `{name}` must be empty"
+    name: str
+
+
 @dataclass(frozen=True)
 class RawFunctionDecl(ParsableDef):
     """A raw function declaration provided by the user.
@@ -38,9 +47,7 @@ def parse(self, globals: Globals, sources: SourceMap) -> "CheckedFunctionDecl":
         func_ast, docstring = parse_py_func(self.python_func, sources)
         ty = check_signature(func_ast, globals.with_python_scope(self.python_scope))
         if not has_empty_body(func_ast):
-            raise GuppyError(
-                "Body of function declaration must be empty", func_ast.body[0]
-            )
+            raise GuppyError(BodyNotEmptyError(func_ast.body[0], self.name))
         return CheckedFunctionDecl(
             self.id,
             self.name,

guppylang/definition/function.py

@@ -14,6 +14,7 @@
 from guppylang.ast_util import AstNode, annotate_location, with_loc
 from guppylang.checker.cfg_checker import CheckedCFG
 from guppylang.checker.core import Context, Globals, Place, PyScope
+from guppylang.checker.errors.generic import ExpectedError, UnsupportedError
 from guppylang.checker.expr_checker import check_call, synthesize_call
 from guppylang.checker.func_checker import (
     check_global_func_def,
@@ -22,7 +23,12 @@
 )
 from guppylang.compiler.core import CompiledGlobals, DFContainer
 from guppylang.compiler.func_compiler import compile_global_func_def
-from guppylang.definition.common import CheckableDef, CompilableDef, ParsableDef
+from guppylang.definition.common import (
+    CheckableDef,
+    CompilableDef,
+    ParsableDef,
+    UnknownSourceError,
+)
 from guppylang.definition.value import CallableDef, CallReturnWires, CompiledCallableDef
 from guppylang.error import GuppyError
 from guppylang.ipython_inspect import find_ipython_def, is_running_ipython
@@ -60,9 +66,7 @@ def parse(self, globals: Globals, sources: SourceMap) -> "ParsedFunctionDef":
         func_ast, docstring = parse_py_func(self.python_func, sources)
         ty = check_signature(func_ast, globals.with_python_scope(self.python_scope))
         if ty.parametrized:
-            raise GuppyError(
-                "Generic function definitions are not supported yet", func_ast
-            )
+            raise GuppyError(UnsupportedError(func_ast, "Generic function definitions"))
         return ParsedFunctionDef(
             self.id, self.name, func_ast, ty, self.python_scope, docstring
         )
@@ -251,9 +255,9 @@ def parse_py_func(f: PyFunc, sources: SourceMap) -> tuple[ast.FunctionDef, str |
     else:
         file = inspect.getsourcefile(f)
         if file is None:
-            raise GuppyError("Couldn't determine source file for function")
+            raise GuppyError(UnknownSourceError(None, f))
         sources.add_file(file)
     annotate_location(func_ast, source, file, line_offset)
     if not isinstance(func_ast, ast.FunctionDef):
-        raise GuppyError("Expected a function definition", func_ast)
+        raise GuppyError(ExpectedError(func_ast, "a function definition"))
     return parse_function_with_docstring(func_ast)