Rename various symbols and change various comments to refer to

normalization instead of canonicalization.

stix2/equivalence/pattern/__init__.py

@@ -14,17 +14,17 @@ from ...version import DEFAULT_VERSION
 from .compare.observation import observation_expression_cmp
 from .transform import ChainTransformer, SettleTransformer
 from .transform.observation import (
-    AbsorptionTransformer, CanonicalizeComparisonExpressionsTransformer,
+    AbsorptionTransformer, NormalizeComparisonExpressionsTransformer,
     DNFTransformer, FlattenTransformer, OrderDedupeTransformer,
 )
 
 # Lazy-initialize
-_pattern_canonicalizer = None
+_pattern_normalizer = None
 
 
-def _get_pattern_canonicalizer():
+def _get_pattern_normalizer():
     """
-    Get a canonicalization transformer for STIX patterns.
+    Get a normalization transformer for STIX patterns.
 
     Returns:
         The transformer
@@ -33,11 +33,11 @@ def _get_pattern_canonicalizer():
     # The transformers are either stateless or contain no state which changes
     # with each use.  So we can setup the transformers once and keep reusing
     # them.
-    global _pattern_canonicalizer
+    global _pattern_normalizer
 
-    if not _pattern_canonicalizer:
+    if not _pattern_normalizer:
-        canonicalize_comp_expr = \
+        normalize_comp_expr = \
-            CanonicalizeComparisonExpressionsTransformer()
+            NormalizeComparisonExpressionsTransformer()
 
         obs_expr_flatten = FlattenTransformer()
         obs_expr_order = OrderDedupeTransformer()
@@ -49,12 +49,12 @@ def _get_pattern_canonicalizer():
 
         obs_dnf = DNFTransformer()
 
-        _pattern_canonicalizer = ChainTransformer(
+        _pattern_normalizer = ChainTransformer(
-            canonicalize_comp_expr,
+            normalize_comp_expr,
             obs_settle_simplify, obs_dnf, obs_settle_simplify,
         )
 
-    return _pattern_canonicalizer
+    return _pattern_normalizer
 
 
 def equivalent_patterns(pattern1, pattern2, stix_version=DEFAULT_VERSION):
@@ -77,11 +77,11 @@ def equivalent_patterns(pattern1, pattern2, stix_version=DEFAULT_VERSION):
         pattern2, version=stix_version,
     )
 
-    pattern_canonicalizer = _get_pattern_canonicalizer()
+    pattern_normalizer = _get_pattern_normalizer()
-    canon_patt1, _ = pattern_canonicalizer.transform(patt_ast1)
+    norm_patt1, _ = pattern_normalizer.transform(patt_ast1)
-    canon_patt2, _ = pattern_canonicalizer.transform(patt_ast2)
+    norm_patt2, _ = pattern_normalizer.transform(patt_ast2)
 
-    result = observation_expression_cmp(canon_patt1, canon_patt2)
+    result = observation_expression_cmp(norm_patt1, norm_patt2)
 
     return result == 0
 
@@ -92,7 +92,7 @@ def find_equivalent_patterns(
     """
     Find patterns from a sequence which are equivalent to a given pattern.
     This is more efficient than using equivalent_patterns() in a loop, because
-    it doesn't re-canonicalize the search pattern over and over.  This works
+    it doesn't re-normalize the search pattern over and over.  This works
     on an input iterable and is implemented as a generator of matches.  So you
     can "stream" patterns in and matching patterns will be streamed out.
 
@@ -109,8 +109,8 @@ def find_equivalent_patterns(
         search_pattern, version=stix_version,
     )
 
-    pattern_canonicalizer = _get_pattern_canonicalizer()
+    pattern_normalizer = _get_pattern_normalizer()
-    canon_search_pattern_ast, _ = pattern_canonicalizer.transform(
+    norm_search_pattern_ast, _ = pattern_normalizer.transform(
         search_pattern_ast,
     )
 
@@ -118,10 +118,10 @@ def find_equivalent_patterns(
         pattern_ast = pattern_visitor.create_pattern_object(
             pattern, version=stix_version,
         )
-        canon_pattern_ast, _ = pattern_canonicalizer.transform(pattern_ast)
+        norm_pattern_ast, _ = pattern_normalizer.transform(pattern_ast)
 
         result = observation_expression_cmp(
-            canon_search_pattern_ast, canon_pattern_ast,
+            norm_search_pattern_ast, norm_pattern_ast,
         )
 
         if result == 0:

stix2/equivalence/pattern/compare/comparison.py

@@ -346,7 +346,7 @@ def comparison_expression_cmp(expr1, expr2):
     """
     Compare two comparison expressions.  This is sensitive to the order of the
     expressions' sub-components.  To achieve an order-insensitive comparison,
-    the ASTs must be canonically ordered first.
+    the sub-component ASTs must be ordered first.
 
     Args:
         expr1: The first comparison expression

stix2/equivalence/pattern/compare/observation.py

@@ -62,7 +62,7 @@ def observation_expression_cmp(expr1, expr2):
     """
     Compare two observation expression ASTs.  This is sensitive to the order of
     the expressions' sub-components.  To achieve an order-insensitive
-    comparison, the ASTs must be canonically ordered first.
+    comparison, the sub-component ASTs must be ordered first.
 
     Args:
         expr1: The first observation expression

stix2/equivalence/pattern/transform/comparison.py

@@ -46,7 +46,7 @@ def _dupe_ast(ast):
 
     elif isinstance(ast, _ComparisonExpression):
         # Change this to create a dupe, if we ever need to change simple
-        # comparison expressions as part of canonicalization.
+        # comparison expressions as part of normalization.
         result = ast
 
     else:

stix2/equivalence/pattern/transform/observation.py

@@ -489,11 +489,11 @@ class DNFTransformer(ObservationExpressionTransformer):
         return self.__transform(ast)
 
 
-class CanonicalizeComparisonExpressionsTransformer(
+class NormalizeComparisonExpressionsTransformer(
     ObservationExpressionTransformer,
 ):
     """
-    Canonicalize all comparison expressions.
+    Normalize all comparison expressions.
     """
     def __init__(self):
         comp_flatten = CFlattenTransformer()
@@ -504,13 +504,13 @@ class CanonicalizeComparisonExpressionsTransformer(
 
         comp_special = SpecialValueCanonicalization()
         comp_dnf = CDNFTransformer()
-        self.__comp_canonicalize = ChainTransformer(
+        self.__comp_normalize = ChainTransformer(
             comp_special, settle_simplify, comp_dnf, settle_simplify,
         )
 
     def transform_observation(self, ast):
         comp_expr = ast.operand
-        canon_comp_expr, changed = self.__comp_canonicalize.transform(comp_expr)
+        norm_comp_expr, changed = self.__comp_normalize.transform(comp_expr)
-        ast.operand = canon_comp_expr
+        ast.operand = norm_comp_expr
 
         return ast, changed

stix2/equivalence/pattern/transform/specials.py

@@ -1,5 +1,5 @@
 """
-Some simple comparison expression canonicalization functions.
+Some simple comparison expression normalization functions.
 """
 import socket