Merging upstream version 18.11.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/sqlglot/dialects/dialect.py b/sqlglot/dialects/dialect.py
index ccf04da..bd839af 100644
--- a/sqlglot/dialects/dialect.py
+++ b/sqlglot/dialects/dialect.py
@@ -81,6 +81,8 @@ class _Dialect(type):
         klass.INVERSE_TIME_MAPPING = {v: k for k, v in klass.TIME_MAPPING.items()}
         klass.INVERSE_TIME_TRIE = new_trie(klass.INVERSE_TIME_MAPPING)
 
+        klass.INVERSE_ESCAPE_SEQUENCES = {v: k for k, v in klass.ESCAPE_SEQUENCES.items()}
+
         klass.tokenizer_class = getattr(klass, "Tokenizer", Tokenizer)
         klass.parser_class = getattr(klass, "Parser", Parser)
         klass.generator_class = getattr(klass, "Generator", Generator)
@@ -188,6 +190,9 @@ class Dialect(metaclass=_Dialect):
     # special syntax cast(x as date format 'yyyy') defaults to time_mapping
     FORMAT_MAPPING: t.Dict[str, str] = {}
 
+    # Mapping of an unescaped escape sequence to the corresponding character
+    ESCAPE_SEQUENCES: t.Dict[str, str] = {}
+
     # Columns that are auto-generated by the engine corresponding to this dialect
     # Such columns may be excluded from SELECT * queries, for example
     PSEUDOCOLUMNS: t.Set[str] = set()
@@ -204,6 +209,8 @@ class Dialect(metaclass=_Dialect):
     INVERSE_TIME_MAPPING: t.Dict[str, str] = {}
     INVERSE_TIME_TRIE: t.Dict = {}
 
+    INVERSE_ESCAPE_SEQUENCES: t.Dict[str, str] = {}
+
     def __eq__(self, other: t.Any) -> bool:
         return type(self) == other
 
@@ -245,7 +252,7 @@ class Dialect(metaclass=_Dialect):
         """
         Normalizes an unquoted identifier to either lower or upper case, thus essentially
         making it case-insensitive. If a dialect treats all identifiers as case-insensitive,
-        they will be normalized regardless of being quoted or not.
+        they will be normalized to lowercase regardless of being quoted or not.
         """
         if isinstance(expression, exp.Identifier) and (
             not expression.quoted or cls.RESOLVES_IDENTIFIERS_AS_UPPERCASE is None