import pack2d by default

README.md

@@ -33,9 +33,12 @@ pip install 'masque[oasis,dxf,svg,visualization,text]'
 ## Overview
 
 A layout consists of a hierarchy of `Pattern`s stored in a single `Library`.
-Each `Pattern` can contain `Ref`s pointing at other patterns, `Shape`s, and `Label`s.
+Each `Pattern` can contain `Ref`s pointing at other patterns, `Shape`s, `Label`s, and `Port`s.
+
 
 `masque` departs from several "classic" GDSII paradigms:
+- A `Pattern` object does not store its own name. A name is only assigned when the pattern is placed
+    into a `Library`, which is effectively a name->`Pattern` mapping.
 - Layer info for `Shape`ss and `Label`s is not stored in the individual shape and label objects.
     Instead, the layer is determined by the key for the container dict (e.g. `pattern.shapes[layer]`).
     * This simplifies many common tasks: filtering `Shape`s by layer, remapping layers, and checking if
@@ -70,6 +73,31 @@ Each `Pattern` can contain `Ref`s pointing at other patterns, `Shape`s, and `Lab
     * Ports can be exported into/imported from `Label`s stored directly in the layout,
         editable from standard tools (e.g. KLayout). A default format is provided.
 
+In one important way, `masque` stays very orthodox:
+References are accomplished by listing the target's name, not its `Pattern` object.
+
+- The main downside of this is that any operations that traverse the hierarchy require
+    both the `Pattern` and the `Library` which is contains its reference targets.
+- This guarantees that names within a `Library` remain unique at all times.
+    * Since this can be tedious in cases where you don't actually care about the name of a
+        pattern, patterns whose names start with `SINGLE_USE_PREFIX` (default: an underscore)
+        may be silently renamed in order to maintain uniqueness.
+        See `masque.library.SINGLE_USE_PREFIX`, `masque.library._rename_patterns()`,
+        and `ILibrary.add()` for more details.
+- Having all patterns accessible through the `Library` avoids having to perform a
+    tree traversal for every operation which needs to touch all `Pattern` objects
+    (e.g. deleting a layer everywhere or scaling all patterns).
+- Since `Pattern` doesn't know its own name, you can't create a reference by passing in
+    a `Pattern` object -- you need to know its name.
+- You *can* reference a `Pattern` before it is created, so long as you have already decided
+    on its name.
+- Functions like `Pattern.place()` and `Pattern.plug()` need to receive a pattern's name
+    in order to create a reference, but they also need to access the pattern's ports.
+    * One way to provide this data is through an `Abstract`, generated via
+        `Library.abstract()` or through a `Library.abstract_view()`.
+    * Another way is use `Builder.place()` or `Builder.plug()`, which automatically creates
+        an `Abstract` from its internally-referenced `Library`.
+
 
 ## Glossary
 - `Library`: A collection of named cells. OASIS or GDS "library" or file.

masque/__init__.py

@@ -1,7 +1,7 @@
 """
  masque 2D CAD library
 
- masque is an attempt to make a relatively small library for designing lithography
+ masque is an attempt to make a relatively compact library for designing lithography
   masks. The general idea is to implement something resembling the GDSII and OASIS file-formats,
   but with some additional vectorized element types (eg. ellipses, not just polygons), and the
   ability to interface with multiple file formats.
@@ -20,11 +20,12 @@
  NOTES ON INTERNALS
  ==========================
  - Many of `masque`'s classes make use of `__slots__` to make them faster / smaller.
-    Since `__slots__` doesn't play well with multiple inheritance, the `masque.utils.AutoSlots`
+    Since `__slots__` doesn't play well with multiple inheritance, often they are left
-    metaclass is used to auto-generate slots based on superclass type annotations.
+    empty for superclasses and it is the subclass's responsibility to set them correctly.
- - File I/O submodules are imported by `masque.file` to avoid creating hard dependencies on
+ - File I/O submodules are not imported by `masque.file` to avoid creating hard dependencies
-    external file-format reader/writers
+    on external file-format reader/writers
-
+- Try to accept the broadest-possible inputs: e.g., don't demand an `ILibraryView` if you
+    can accept a `Mapping[str, Pattern]` and wrap it in a `LibraryView` internally.
 """
 
 from .utils import layer_t, annotations_t, SupportsBool

masque/builder/pather.py

@@ -11,7 +11,7 @@ from numpy import pi
 from numpy.typing import ArrayLike
 
 from ..pattern import Pattern
-from ..library import ILibrary
+from ..library import ILibrary, SINGLE_USE_PREFIX
 from ..error import PortError, BuildError
 from ..ports import PortList, Port
 from ..abstract import Abstract
@@ -422,7 +422,7 @@ class Pather(Builder):
             set_rotation: float | None = None,
             tool_port_names: tuple[str, str] = ('A', 'B'),
             force_container: bool = False,
-            base_name: str = '_mpath',
+            base_name: str = SINGLE_USE_PREFIX + 'mpath',
             **kwargs,
             ) -> Self:
         """

masque/builder/tools.py

@@ -15,7 +15,7 @@ from ..utils import SupportsBool, rotation_matrix_2d, layer_t
 from ..ports import Port
 from ..pattern import Pattern
 from ..abstract import Abstract
-from ..library import ILibrary, Library
+from ..library import ILibrary, Library, SINGLE_USE_PREFIX
 from ..error import BuildError
 
 
@@ -288,13 +288,13 @@ class BasicTool(Tool, metaclass=ABCMeta):
             )
 
         gen_straight, sport_in, sport_out = self.straight
-        tree, pat = Library.mktree('_path')
+        tree, pat = Library.mktree(SINGLE_USE_PREFIX + 'path')
         pat.add_port_pair(names=port_names)
         if data.in_transition:
             ipat, iport_theirs, _iport_ours = data.in_transition
             pat.plug(ipat, {port_names[1]: iport_theirs})
         if not numpy.isclose(data.straight_length, 0):
-            straight = tree <= {'_straight': gen_straight(data.straight_length)}
+            straight = tree <= {SINGLE_USE_PREFIX + 'straight': gen_straight(data.straight_length)}
             pat.plug(straight, {port_names[1]: sport_in})
         if data.ccw is not None:
             bend, bport_in, bport_out = self.bend
@@ -391,7 +391,7 @@ class BasicTool(Tool, metaclass=ABCMeta):
             **kwargs,
             ) -> ILibrary:
 
-        tree, pat = Library.mktree('_path')
+        tree, pat = Library.mktree(SINGLE_USE_PREFIX + 'path')
         pat.add_port_pair(names=(port_names[0], port_names[1]))
 
         gen_straight, sport_in, _sport_out = self.straight
@@ -408,7 +408,7 @@ class BasicTool(Tool, metaclass=ABCMeta):
                     if append:
                         pat.plug(straight_pat, {port_names[1]: sport_in}, append=True)
                     else:
-                        straight = tree <= {'_straight': straight_pat}
+                        straight = tree <= {SINGLE_USE_PREFIX + 'straight': straight_pat}
                         pat.plug(straight, {port_names[1]: sport_in}, append=True)
                 if ccw is not None:
                     bend, bport_in, bport_out = self.bend
@@ -463,7 +463,7 @@ class PathTool(Tool, metaclass=ABCMeta):
             out_ptype=out_ptype,
             )
 
-        tree, pat = Library.mktree('_path')
+        tree, pat = Library.mktree(SINGLE_USE_PREFIX + 'path')
         pat.path(layer=self.layer, width=self.width, vertices=[(0, 0), (length, 0)])
 
         if ccw is None:
@@ -543,7 +543,7 @@ class PathTool(Tool, metaclass=ABCMeta):
             # If the path ends in a bend, we need to add the final vertex
             path_vertices.append(batch[-1].end_port.offset)
 
-        tree, pat = Library.mktree('_path')
+        tree, pat = Library.mktree(SINGLE_USE_PREFIX + 'path')
         pat.path(layer=self.layer, width=self.width, vertices=path_vertices)
         pat.ports = {
             port_names[0]: batch[0].start_port.copy().rotate(pi),

masque/library.py

@@ -1,9 +1,18 @@
 """
-Library classes for managing unique name->pattern mappings and
+Library classes for managing unique name->pattern mappings and deferred loading or execution.
- deferred loading or creation.
 
-# TODO documennt all library classes
+Classes include:
-# TODO toplevel documentation of library, classes, and abstracts
+- `ILibraryView`: Defines a general interface for read-only name->pattern mappings.
+- `LibraryView`: An implementation of `ILibraryView` backed by an arbitrary `Mapping`.
+    Can be used to wrap any arbitrary `Mapping` to give it all the functionality in `ILibraryView`
+- `ILibrary`: Defines a general interface for mutable name->pattern mappings.
+- `Library`: An implementation of `ILibrary` backed by an arbitrary `MutableMapping`.
+    Can be used to wrap any arbitrary `MutableMapping` to give it all the functionality in `ILibrary`.
+    By default, uses a `dict` as the underylingmapping.
+- `LazyLibrary`: An implementation of `ILibrary` which enables on-demand loading or generation
+    of patterns.
+- `AbstractView`: Provides a way to use []-indexing to generate abstracts for patterns in the linked
+    library. Generated with `ILibraryView.abstract_view()`.
 """
 from typing import Callable, Self, Type, TYPE_CHECKING, cast
 from typing import Iterator, Mapping, MutableMapping, Sequence
@@ -35,15 +44,24 @@ logger = logging.getLogger(__name__)
 
 visitor_function_t = Callable[..., 'Pattern']
 
+SINGLE_USE_PREFIX = '_'
+"""
+Names starting with this prefix are assumed to refer to single-use patterns,
+which may be renamed automatically by `ILibrary.add()` (via
+`rename_theirs=_rename_patterns()` )
+"""
+# TODO what are the consequences of making '_' special?  maybe we can make this decision everywhere?
+
 
 def _rename_patterns(lib: 'ILibraryView', name: str) -> str:
     """
     The default `rename_theirs` function for `ILibrary.add`.
 
-    Treats names starting with an underscore as "one-offs" for which name conflicts
+      Treats names starting with `SINGLE_USE_PREFIX` (default: one underscore) as
-      should be automatically resolved. Conflicts are resolved by calling
+    "one-offs" for which name conflicts should be automatically resolved.
-      `lib.get_name(name.split('$')[0])`.
+    Conflicts are resolved by calling `lib.get_name(SINGLE_USE_PREFIX + stem)`
-    Names without a leading underscore are directly returned.
+    where `stem = name.removeprefix(SINGLE_USE_PREFIX).split('$')[0]`.
+    Names lacking the prefix are directly returned (not renamed).
 
     Args:
         lib: The library into which `name` is to be added (but is presumed to conflict)
@@ -52,11 +70,11 @@ def _rename_patterns(lib: 'ILibraryView', name: str) -> str:
     Returns:
         The new name, not guaranteed to be conflict-free!
     """
-    if not name.startswith('_'):            # TODO what are the consequences of making '_' special?  maybe we can make this decision everywhere?
+    if not name.startswith(SINGLE_USE_PREFIX):
         return name
 
-    stem = name.split('$')[0]
+    stem = name.removeprefix(SINGLE_USE_PREFIX).split('$')[0]
-    return lib.get_name(stem)
+    return lib.get_name(SINGLE_USE_PREFIX + stem)
 
 
 class ILibraryView(Mapping[str, 'Pattern'], metaclass=ABCMeta):
@@ -284,7 +302,7 @@ class ILibraryView(Mapping[str, 'Pattern'], metaclass=ABCMeta):
 
     def get_name(
             self,
-            name: str = '__',
+            name: str = SINGLE_USE_PREFIX * 2,
             sanitize: bool = True,
             max_length: int = 32,
             quiet: bool | None = None,
@@ -295,17 +313,17 @@ class ILibraryView(Mapping[str, 'Pattern'], metaclass=ABCMeta):
         This function may be overridden in a subclass or monkey-patched to fit the caller's requirements.
 
         Args:
-            name: Preferred name for the pattern. Default '__'.
+            name: Preferred name for the pattern. Default is `SINGLE_USE_PREFIX * 2`.
             sanitize: Allows only alphanumeric charaters and _?$. Replaces invalid characters with underscores.
             max_length: Names longer than this will be truncated.
             quiet: If `True`, suppress log messages. Default `None` suppresses messages only if
-                the name starts with an underscore.
+                the name starts with `SINGLE_USE_PREFIX`.
 
         Returns:
             Name, unique within this library.
         """
         if quiet is None:
-            quiet = name.startswith('_')
+            quiet = name.startswith(SINGLE_USE_PREFIX)
 
         if sanitize:
             # Remove invalid characters
@@ -316,7 +334,7 @@ class ILibraryView(Mapping[str, 'Pattern'], metaclass=ABCMeta):
         ii = 0
         suffixed_name = sanitized_name
         while suffixed_name in self or suffixed_name == '':
-            suffix = base64.b64encode(struct.pack('>Q', ii), b'$?').decode('ASCII')
+            suffix = base64.b64encode(struct.pack('>Q', ii), altchars=b'$?').decode('ASCII')
 
             suffixed_name = sanitized_name + '$' + suffix[:-1].lstrip('A')
             ii += 1
@@ -602,16 +620,14 @@ class ILibrary(ILibraryView, MutableMapping[str, 'Pattern'], metaclass=ABCMeta):
         If `mutate_other=False` (default), all changes are made to a deepcopy of `other`.
 
         By default, `rename_theirs` makes no changes to the name (causing a `LibraryError`) unless the
-          name starts with an underscore. Underscored names are truncated to before their first '$'
+          name starts with `SINGLE_USE_PREFIX`. Prefixed names are truncated to before their first
-          and then passed to `self.get_name()` to create a new unique name.
+          non-prefix '$' and then passed to `self.get_name()` to create a new unique name.
 
         Args:
             other: The library to insert keys from.
             rename_theirs: Called as rename_theirs(self, name) for each duplicate name
                 encountered in `other`. Should return the new name for the pattern in
-                `other`.
+                `other`. See above for default behavior.
-                Default is effectively
-                    `self.get_name(name.split('$')[0]) if name.startswith('_') else name`
             mutate_other: If `True`, modify the original library and its contained patterns
                 (e.g. when renaming patterns and updating refs). Otherwise, operate on a deepcopy
                 (default).
@@ -703,7 +719,8 @@ class ILibrary(ILibraryView, MutableMapping[str, 'Pattern'], metaclass=ABCMeta):
             exclude_types: Shape types passed in this argument are always left untouched, for
                 speed or convenience. Default: `(shapes.Polygon,)`
             label2name: Given a label tuple as returned by `shape.normalized_form(...)`, pick
-                a name for the generated pattern. Default `self.get_name('_shape')`.
+                a name for the generated pattern.
+                Default `self.get_name(SINGLE_USE_PREIX + 'shape')`.
             threshold: Only replace shapes with refs if there will be at least this many
                 instances.
 
@@ -720,8 +737,7 @@ class ILibrary(ILibraryView, MutableMapping[str, 'Pattern'], metaclass=ABCMeta):
 
         if label2name is None:
             def label2name(label):
-                return self.get_name('_shape')
+                return self.get_name(SINGLE_USE_PREFIX + 'shape')
-            #label2name = lambda label: self.get_name('_shape')
 
         shape_counts: MutableMapping[tuple, int] = defaultdict(int)
         shape_funcs = {}
@@ -801,7 +817,8 @@ class ILibrary(ILibraryView, MutableMapping[str, 'Pattern'], metaclass=ABCMeta):
 
         Args:
             name_func: Function f(this_pattern, shape) which generates a name for the
-                        wrapping pattern. Default is `self.get_name('_rep')`.
+                        wrapping pattern.
+                        Default is `self.get_name(SINGLE_USE_PREFIX + 'rep')`.
 
         Returns:
             self
@@ -810,8 +827,7 @@ class ILibrary(ILibraryView, MutableMapping[str, 'Pattern'], metaclass=ABCMeta):
 
         if name_func is None:
             def name_func(_pat, _shape):
-                return self.get_name('_rep')
+                return self.get_name(SINGLE_USE_PREFIX = 'rep')
-            #name_func = lambda _pat, _shape: self.get_name('_rep')
 
         for pat in tuple(self.values()):
             for layer in pat.shapes:

masque/utils/__init__.py

@@ -15,4 +15,4 @@ from .transform import rotation_matrix_2d, normalize_mirror, rotate_offsets_arou
 
 from . import ports2data
 
-#from . import pack2d
+from . import pack2d