X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=logical_search.py;h=ef55a2bbdcbb5baafa5c29a53fc404fcfb4701bb;hb=1220ffcf56e968de31b62f6d0c5af250fed9028e;hp=76c2f86264be3fc49960166fe7a1b702f90e6c4b;hpb=713a609bd19d491de03debf8a4a6ddf2540b13dc;p=python_utils.git

diff --git a/logical_search.py b/logical_search.py
index 76c2f86..ef55a2b 100644
--- a/logical_search.py
+++ b/logical_search.py
@@ -1,27 +1,41 @@
 #!/usr/bin/env python3
 
-from __future__ import annotations
+"""This is a module concerned with the creation of and searching of a
+corpus of documents.  The corpus is held in memory for fast
+searching."""
 
+from __future__ import annotations
 import enum
 import sys
 from collections import defaultdict
-from typing import Any, Dict, List, NamedTuple, Optional, Sequence, Set, Tuple, Union
+from dataclasses import dataclass, field
+from typing import Any, Dict, List, Optional, Sequence, Set, Tuple, Union
 
 
 class ParseError(Exception):
     """An error encountered while parsing a logical search expression."""
 
     def __init__(self, message: str):
+        super().__init__()
         self.message = message
 
 
-class Document(NamedTuple):
-    """A tuple representing a searchable document."""
+@dataclass
+class Document:
+    """A class representing a searchable document."""
+
+    # A unique identifier for each document.
+    docid: str = ''
+
+    # A set of tag strings for this document.  May be empty.
+    tags: Set[str] = field(default_factory=set)
+
+    # A list of key->value strings for this document.  May be empty.
+    properties: List[Tuple[str, str]] = field(default_factory=list)
 
-    docid: str  # a unique idenfier for the document
-    tags: Set[str]  # an optional set of tags
-    properties: List[Tuple[str, str]]  # an optional set of key->value properties
-    reference: Any  # an optional reference to something else
+    # An optional reference to something else; interpreted only by
+    # caller code, ignored here.
+    reference: Optional[Any] = None
 
 
 class Operation(enum.Enum):
@@ -168,7 +182,7 @@ class Corpus(object):
     def invert_docid_set(self, original: Set[str]) -> Set[str]:
         """Invert a set of docids."""
 
-        return set([docid for docid in self.documents_by_docid.keys() if docid not in original])
+        return {docid for docid in self.documents_by_docid if docid not in original}
 
     def get_doc(self, docid: str) -> Optional[Document]:
         """Given a docid, retrieve the previously added Document."""