Merge pull request #713 from datafold/simplify-ast-compilation

Compile all AST elements always via dialects, never directly

Author: nolar

data_diff/__init__.py

@@ -1,6 +1,7 @@
 from typing import Sequence, Tuple, Iterator, Optional, Union
 
 from data_diff.abcs.database_types import DbTime, DbPath
+from data_diff.databases import Database
 from data_diff.tracking import disable_tracking
 from data_diff.databases._connect import connect
 from data_diff.diff_tables import Algorithm
@@ -31,10 +32,10 @@ def connect_to_table(
     if isinstance(key_columns, str):
         key_columns = (key_columns,)
 
-    db = connect(db_info, thread_count=thread_count)
+    db: Database = connect(db_info, thread_count=thread_count)
 
     if isinstance(table_name, str):
-        table_name = db.parse_table_name(table_name)
+        table_name = db.dialect.parse_table_name(table_name)
 
     return TableSegment(db, table_name, key_columns, **kwargs)
 
@@ -161,7 +162,8 @@ def diff_tables(
         )
     elif algorithm == Algorithm.JOINDIFF:
         if isinstance(materialize_to_table, str):
-            materialize_to_table = table1.database.parse_table_name(eval_name_template(materialize_to_table))
+            table_name = eval_name_template(materialize_to_table)
+            materialize_to_table = table1.database.dialect.parse_table_name(table_name)
         differ = JoinDiffer(
             threaded=threaded,
             max_threadpool_size=max_threadpool_size,

data_diff/__main__.py

@@ -6,12 +6,13 @@
 import json
 import logging
 from itertools import islice
-from typing import Dict, Optional
+from typing import Dict, Optional, Tuple
 
 import rich
 from rich.logging import RichHandler
 import click
 
+from data_diff import Database
 from data_diff.schema import create_schema
 from data_diff.queries.api import current_timestamp
 
@@ -425,7 +426,7 @@ def _data_diff(
             logging.error(f"Error while parsing age expression: {e}")
             return
 
-    dbs = db1, db2
+    dbs: Tuple[Database, Database] = db1, db2
 
     if interactive:
         for db in dbs:
@@ -444,7 +445,7 @@ def _data_diff(
             materialize_all_rows=materialize_all_rows,
             table_write_limit=table_write_limit,
             materialize_to_table=materialize_to_table
-            and db1.parse_table_name(eval_name_template(materialize_to_table)),
+            and db1.dialect.parse_table_name(eval_name_template(materialize_to_table)),
         )
     else:
         assert algorithm == Algorithm.HASHDIFF
@@ -456,7 +457,7 @@ def _data_diff(
         )
 
     table_names = table1, table2
-    table_paths = [db.parse_table_name(t) for db, t in safezip(dbs, table_names)]
+    table_paths = [db.dialect.parse_table_name(t) for db, t in safezip(dbs, table_names)]
 
     schemas = list(differ._thread_map(_get_schema, safezip(dbs, table_paths)))
     schema1, schema2 = schemas = [

data_diff/abcs/compiler.py

@@ -1,15 +1,9 @@
-from typing import Any, Dict
-from abc import ABC, abstractmethod
+from abc import ABC
 
 
 class AbstractCompiler(ABC):
-    @abstractmethod
-    def compile(self, elem: Any, params: Dict[str, Any] = None) -> str:
-        ...
+    pass
 
 
 class Compilable(ABC):
-    # TODO generic syntax, so we can write Compilable[T] for expressions returning a value of type T
-    @abstractmethod
-    def compile(self, c: AbstractCompiler) -> str:
-        ...
+    pass

data_diff/abcs/database_types.py

@@ -1,11 +1,12 @@
 import decimal
 from abc import ABC, abstractmethod
-from typing import Sequence, Optional, Tuple, Type, Union, Dict, List
+from typing import Sequence, Optional, Tuple, Union, Dict, List
 from datetime import datetime
 
 from runtype import dataclass
 from typing_extensions import Self
 
+from data_diff.abcs.compiler import AbstractCompiler
 from data_diff.utils import ArithAlphanumeric, ArithUUID, Unknown
 
 
@@ -176,6 +177,14 @@ class UnknownColType(ColType):
 class AbstractDialect(ABC):
     """Dialect-dependent query expressions"""
 
+    @abstractmethod
+    def compile(self, compiler: AbstractCompiler, elem, params=None) -> str:
+        raise NotImplementedError
+
+    @abstractmethod
+    def parse_table_name(self, name: str) -> DbPath:
+        "Parse the given table name into a DbPath"
+
     @property
     @abstractmethod
     def name(self) -> str:
@@ -319,10 +328,6 @@ def _process_table_schema(
 
         """
 
-    @abstractmethod
-    def parse_table_name(self, name: str) -> DbPath:
-        "Parse the given table name into a DbPath"
-
     @abstractmethod
     def close(self):
         "Close connection(s) to the database instance. Querying will stop functioning."

data_diff/bound_exprs.py

@@ -8,7 +8,6 @@
 from typing_extensions import Self
 
 from data_diff.abcs.database_types import AbstractDatabase
-from data_diff.abcs.compiler import AbstractCompiler
 from data_diff.queries.ast_classes import ExprNode, TablePath, Compilable
 from data_diff.queries.api import table
 from data_diff.schema import create_schema
@@ -37,10 +36,6 @@ def query(self, res_type=list):
     def type(self):
         return self.node.type
 
-    def compile(self, c: AbstractCompiler) -> str:
-        assert c.database is self.database
-        return self.node.compile(c)
-
 
 def bind_node(node, database):
     return BoundNode(database, node)