Add Sphinx docs customization for multimethod (#1088)

* Add Sphinx docs customization for multimethod

* Customize sphinx autosummary for multimethod
Handle multimethod class methods in automodule customization
Update sphinx pin
Update .gitignore for vim

* Set override=True when adding autosummary directive

* Change .gitignore, only ignore hidden .swp

.gitignore

@@ -10,6 +10,7 @@ MANIFEST
 out.*
 res?.dxf
 .~*
+.*.swp
 assy.wrl
 assy.xml
 assy.zip

cadquery/sketch.py

@@ -782,7 +782,7 @@ def arc(
         forConstruction: bool = False,
     ) -> T:
         """
-        Construct an arc starting at p1, through p2, ending at p3
+        Construct an arc.
         """
 
         val = Edge.makeThreePointArc(Vector(p1), Vector(p2), Vector(p3))

doc/conf.py

@@ -24,7 +24,7 @@
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-# sys.path.insert(0, os.path.abspath('.'))
+sys.path.insert(0, os.path.abspath("./ext"))
 
 
 # -- General configuration -----------------------------------------------------
@@ -40,6 +40,7 @@
     "sphinx.ext.autosummary",
     "cadquery.cq_directive",
     "sphinx.ext.mathjax",
+    "sphinx_autodoc_multimethod",
 ]
 
 autodoc_typehints = "both"

doc/ext/sphinx_autodoc_multimethod.py

@@ -0,0 +1,305 @@
+from types import ModuleType
+from typing import Any, List, Tuple, ValuesView
+from multimethod import multimethod
+import re
+
+from sphinx.ext.autosummary import Autosummary
+from sphinx.ext.autosummary import (
+    get_import_prefixes_from_env,
+    ImportExceptionGroup,
+    mangle_signature,
+    extract_summary,
+)
+from docutils.statemachine import StringList
+from sphinx.pycode import ModuleAnalyzer, PycodeError
+
+from sphinx.ext.autodoc import MethodDocumenter as SphinxMethodDocumenter
+
+from sphinx.util import inspect, logging
+from sphinx.util.inspect import evaluate_signature, safe_getattr, stringify_signature
+from sphinx.util.typing import get_type_hints
+
+logger = logging.getLogger(__name__)
+
+
+def get_first(obj):
+    """Use to return first element (first param type annotation or first registered multimethod)."""
+    return next(iter(obj))
+
+
+patself = re.compile(r"\W*:\W*param\W+self.*")
+patparam = re.compile(r"\W*:\W*param.*")
+
+
+def process_docstring_multimethod(app, what, name, obj, options, lines):
+    """multimethod docstring customization
+
+    * formatting and remove extraneous signatures
+    * insert self in front of param field list for instance methods if type hinted
+    """
+
+    if what == "method" and isinstance(obj, multimethod):
+        # instance or static method
+
+        insert_first_param = False
+        if (
+            app.config.autodoc_typehints in ("both", "description")
+            and app.config.autodoc_typehints_description_target in ("all")
+            and get_first(get_type_hints(get_first(obj.values()))) == "self"
+        ):
+            insert_first_param = True
+
+        lines_replace = []
+
+        # handle functools.singledispatch style register (multiple names)
+        methods = set(m.__name__ for m in obj.values())
+        patsig = re.compile(rf"\W*[{'|'.join(methods)}]+\(.*\).*")
+
+        iparam = None
+        for i, line in enumerate(lines):
+            if patsig.match(line):
+                lines_replace.append("")
+                continue
+            if insert_first_param and patself.match(line):
+                # exists explicitly in field list
+                insert_first_param = False
+            elif insert_first_param and not iparam and patparam.match(line):
+                iparam = i
+            lines_replace.append(line.lstrip())
+
+        if insert_first_param and iparam:
+            lines_replace.insert(iparam, ":param self:")
+
+        del lines[:]
+        lines.extend(lines_replace)
+
+    elif what == "method" and inspect.isclassmethod(obj) and hasattr(obj, "pending"):
+
+        if obj.pending:
+            methods = set(m.__name__ for m in obj.pending)
+        else:
+            methods = set(m.__name__ for m in obj.__func__.values())
+
+        lines_replace = []
+        patsig = re.compile(rf"\W*[{'|'.join(methods)}]+\(.*\).*")
+
+        for line in lines:
+            if patsig.match(line):
+                lines_replace.append("")
+            else:
+                lines_replace.append(line.lstrip())
+
+        del lines[:]
+        lines.extend(lines_replace)
+
+
+class MultimethodAutosummary(Autosummary):
+    """Customize autosummary multimethod signature."""
+
+    def get_items(self, names: List[str]) -> List[Tuple[str, str, str, str]]:
+        """Try to import the given names, and return a list of
+        ``[(name, signature, summary_string, real_name), ...]``.
+        """
+        prefixes = get_import_prefixes_from_env(self.env)
+
+        items: List[Tuple[str, str, str, str]] = []
+
+        max_item_chars = 50
+
+        for name in names:
+            display_name = name
+            if name.startswith("~"):
+                name = name[1:]
+                display_name = name.split(".")[-1]
+
+            try:
+                real_name, obj, parent, modname = self.import_by_name(
+                    name, prefixes=prefixes
+                )
+            except ImportExceptionGroup as exc:
+                errors = list(
+                    set("* %s: %s" % (type(e).__name__, e) for e in exc.exceptions)
+                )
+                logger.warning(
+                    __("autosummary: failed to import %s.\nPossible hints:\n%s"),
+                    name,
+                    "\n".join(errors),
+                    location=self.get_location(),
+                )
+                continue
+
+            self.bridge.result = StringList()  # initialize for each documenter
+            full_name = real_name
+            if not isinstance(obj, ModuleType):
+                # give explicitly separated module name, so that members
+                # of inner classes can be documented
+                full_name = modname + "::" + full_name[len(modname) + 1 :]
+            # NB. using full_name here is important, since Documenters
+            #     handle module prefixes slightly differently
+            documenter = self.create_documenter(self.env.app, obj, parent, full_name)
+            if not documenter.parse_name():
+                logger.warning(
+                    __("failed to parse name %s"),
+                    real_name,
+                    location=self.get_location(),
+                )
+                items.append((display_name, "", "", real_name))
+                continue
+            if not documenter.import_object():
+                logger.warning(
+                    __("failed to import object %s"),
+                    real_name,
+                    location=self.get_location(),
+                )
+                items.append((display_name, "", "", real_name))
+                continue
+
+            # try to also get a source code analyzer for attribute docs
+            try:
+                documenter.analyzer = ModuleAnalyzer.for_module(
+                    documenter.get_real_modname()
+                )
+                # parse right now, to get PycodeErrors on parsing (results will
+                # be cached anyway)
+                documenter.analyzer.find_attr_docs()
+            except PycodeError as err:
+                logger.debug("[autodoc] module analyzer failed: %s", err)
+                # no source file -- e.g. for builtin and C modules
+                documenter.analyzer = None
+
+            # -- Grab the signature
+
+            try:
+                sig = documenter.format_signature(show_annotation=False)
+                # -- multimethod customization
+                if isinstance(obj, multimethod):
+                    sig = "(...)"
+                # -- end customization
+            except TypeError:
+                # the documenter does not support ``show_annotation`` option
+                sig = documenter.format_signature()
+
+            if not sig:
+                sig = ""
+            else:
+                max_chars = max(10, max_item_chars - len(display_name))
+                sig = mangle_signature(sig, max_chars=max_chars)
+
+            # -- Grab the summary
+
+            documenter.add_content(None)
+            summary = extract_summary(self.bridge.result.data[:], self.state.document)
+
+            items.append((display_name, sig, summary, real_name))
+
+        return items
+
+
+class MethodDocumenter(SphinxMethodDocumenter):
+    """Customize to append multimethod signatures."""
+
+    def append_signature_multiple_dispatch(self, methods: ValuesView[Any]):
+
+        sigs = []
+        for dispatchmeth in methods:
+            documenter = MethodDocumenter(self.directive, "")
+            documenter.parent = self.parent
+            documenter.object = dispatchmeth
+            documenter.objpath = [None]
+            sigs.append(documenter.format_signature())
+
+        return sigs
+
+    def format_signature(self, **kwargs: Any) -> str:
+        if self.config.autodoc_typehints_format == "short":
+            kwargs.setdefault("unqualified_typehints", True)
+
+        sigs = []
+        if (
+            self.analyzer
+            and ".".join(self.objpath) in self.analyzer.overloads
+            and self.config.autodoc_typehints != "none"
+        ):
+            # Use signatures for overloaded methods instead of the implementation method.
+            overloaded = True
+        else:
+            overloaded = False
+            sig = super(SphinxMethodDocumenter, self).format_signature(**kwargs)
+            sigs.append(sig)
+
+        meth = self.parent.__dict__.get(self.objpath[-1])
+        if inspect.is_singledispatch_method(meth):
+            # append signature of singledispatch'ed functions
+            for typ, func in meth.dispatcher.registry.items():
+                if typ is object:
+                    pass  # default implementation. skipped.
+                else:
+                    dispatchmeth = self.annotate_to_first_argument(func, typ)
+                    if dispatchmeth:
+                        documenter = MethodDocumenter(self.directive, "")
+                        documenter.parent = self.parent
+                        documenter.object = dispatchmeth
+                        documenter.objpath = [None]
+                        sigs.append(documenter.format_signature())
+        # -- multimethod customization
+        elif isinstance(meth, multimethod):
+            sigs = self.append_signature_multiple_dispatch(meth.values())
+        elif inspect.isclassmethod(self.object) and hasattr(self.object, "pending"):
+            if self.object.pending:
+                methods = self.object.pending
+            else:
+                methods = self.object.__func__.values()
+            sigs = self.append_signature_multiple_dispatch(methods)
+        elif inspect.isstaticmethod(meth) and isinstance(self.object, multimethod):
+            sigs = []
+            methods = self.object.values()
+            for dispatchmeth in methods:
+                actual = inspect.signature(
+                    dispatchmeth,
+                    bound_method=False,
+                    type_aliases=self.config.autodoc_type_aliases,
+                )
+                sig = stringify_signature(actual, **kwargs)
+                sigs.append(sig)
+        # -- end customization
+        if overloaded:
+            if inspect.isstaticmethod(
+                self.object, cls=self.parent, name=self.object_name
+            ):
+                actual = inspect.signature(
+                    self.object,
+                    bound_method=False,
+                    type_aliases=self.config.autodoc_type_aliases,
+                )
+            else:
+                actual = inspect.signature(
+                    self.object,
+                    bound_method=True,
+                    type_aliases=self.config.autodoc_type_aliases,
+                )
+
+            __globals__ = safe_getattr(self.object, "__globals__", {})
+            for overload in self.analyzer.overloads.get(".".join(self.objpath)):
+                overload = self.merge_default_value(actual, overload)
+                overload = evaluate_signature(
+                    overload, __globals__, self.config.autodoc_type_aliases
+                )
+
+                if not inspect.isstaticmethod(
+                    self.object, cls=self.parent, name=self.object_name
+                ):
+                    parameters = list(overload.parameters.values())
+                    overload = overload.replace(parameters=parameters[1:])
+                sig = stringify_signature(overload, **kwargs)
+                sigs.append(sig)
+
+        return "\n".join(sigs)
+
+
+def setup(app):
+
+    app.connect("autodoc-process-docstring", process_docstring_multimethod)
+    app.add_directive("autosummary", MultimethodAutosummary, override=True)
+    app.add_autodocumenter(MethodDocumenter, override=True)
+
+    return {"parallel_read_safe": True, "parallel_write_safe": True}

doc/quickstart.rst

@@ -4,7 +4,7 @@
 CadQuery QuickStart
 ***********************
 
-.. module:: cadquery
+.. currentmodule:: cadquery
 
 Want a quick glimpse of what CadQuery can do?  This quickstart will demonstrate the basics of CadQuery using a simple example
 

environment.yml

@@ -9,7 +9,7 @@ dependencies:
   - ocp=7.5.3
   - vtk=9.0.1
   - pyparsing>=2.1.9
-  - sphinx=4.4.0
+  - sphinx=5.0.1
   - sphinx_rtd_theme
   - black=19.10b0
   - click=8.0.4