chore: rewrite sqlite parse

ibis/backends/base/sql/glot/datatypes.py

@@ -340,3 +340,7 @@ class OracleType(SqlglotType):
 
 class SnowflakeType(SqlglotType):
     dialect = "snowflake"
+
+
+class SQLiteType(SqlglotType):
+    dialect = "sqlite"

ibis/backends/sqlite/__init__.py

@@ -30,7 +30,7 @@
 from ibis.backends.base.sql.alchemy import BaseAlchemyBackend
 from ibis.backends.sqlite import udf
 from ibis.backends.sqlite.compiler import SQLiteCompiler
-from ibis.backends.sqlite.datatypes import ISODATETIME, SqliteType, parse
+from ibis.backends.sqlite.datatypes import ISODATETIME, SqliteType
 
 if TYPE_CHECKING:
     from collections.abc import Iterator
@@ -204,7 +204,7 @@ def _metadata(self, query: str) -> Iterator[tuple[str, dt.DataType]]:
             for name, notnull, raw_typ, typ in zip(
                 names, notnulls, raw_types, single_row_types
             ):
-                ibis_type = parse(raw_typ or typ)
+                ibis_type = SqliteType.from_string(raw_typ or typ)
                 yield name, ibis_type(nullable=not notnull)
 
             # drop the view when we're done with it

ibis/backends/sqlite/datatypes.py

@@ -9,39 +9,7 @@
 
 import ibis.expr.datatypes as dt
 from ibis.backends.base.sql.alchemy.datatypes import AlchemyType
-
-
-def parse(text: str) -> dt.DataType:
-    """Parse `text` into an ibis data type."""
-    text = text.strip().upper()
-
-    # SQLite affinity rules
-    # (see https://www.sqlite.org/datatype3.html).
-
-    # 1. If the declared type contains the string "INT" then it is
-    # assigned INTEGER affinity.
-    if "INT" in text:
-        return dt.int64
-
-    # 2. If the declared type of the column contains any of the
-    # strings "CHAR", "CLOB", or "TEXT" then that column has TEXT
-    # affinity. Notice that the type VARCHAR contains the string
-    # "CHAR" and is thus assigned TEXT affinity.
-    if "CHAR" in text or "CLOB" in text or "TEXT" in text:
-        return dt.string
-
-    # 3. If the declared type for a column contains the string "BLOB"
-    # or if no type is specified then the column has affinity BLOB.
-    if not text or "BLOB" in text:
-        return dt.binary
-
-    # 4. If the declared type for a column contains any of the strings
-    # "REAL", "FLOA", or "DOUB" then the column has REAL affinity.
-    if "REAL" in text or "FLOA" in text or "DOUB" in text:
-        return dt.float64
-
-    # 5. Otherwise, the affinity is NUMERIC.
-    return dt.decimal
+from ibis.backends.base.sql.glot.datatypes import SQLiteType as SqlglotSQLiteType
 
 
 class SqliteType(AlchemyType):
@@ -63,6 +31,10 @@ def to_ibis(cls, typ: sat.TypeEngine, nullable: bool = True) -> dt.DataType:
         else:
             return super().to_ibis(typ, nullable=nullable)
 
+    @classmethod
+    def from_string(cls, type_string, nullable=True):
+        return SqlglotSQLiteType.from_string(type_string, nullable=nullable)
+
 
 class ISODATETIME(sqlite.DATETIME):
     """A thin `datetime` type to override sqlalchemy's datetime parsing.