refactor: add ops.clip_op to the sqlglot compiler

Author: chelsea-lin

bigframes/core/compile/sqlglot/expressions/generic_ops.py

@@ -67,6 +67,18 @@ def _(expr: TypedExpr, op: ops.AsTypeOp) -> sge.Expression:
     return _cast(sg_expr, sg_to_type, op.safe)
 
 
+@register_ternary_op(ops.clip_op)
+def _(
+    original: TypedExpr,
+    lower: TypedExpr,
+    upper: TypedExpr,
+) -> sge.Expression:
+    return sge.Greatest(
+        this=sge.Least(this=original.expr, expressions=[upper.expr]),
+        expressions=[lower.expr],
+    )
+
+
 @register_unary_op(ops.hash_op)
 def _(expr: TypedExpr) -> sge.Expression:
     return sge.func("FARM_FINGERPRINT", expr.expr)

tests/unit/core/compile/sqlglot/expressions/snapshots/test_generic_ops/test_clip/out.sql

@@ -0,0 +1,15 @@
+WITH `bfcte_0` AS (
+  SELECT
+    `int64_col` AS `bfcol_0`,
+    `int64_too` AS `bfcol_1`,
+    `rowindex` AS `bfcol_2`
+  FROM `bigframes-dev`.`sqlglot_test`.`scalar_types`
+), `bfcte_1` AS (
+  SELECT
+    *,
+    GREATEST(LEAST(`bfcol_2`, `bfcol_1`), `bfcol_0`) AS `bfcol_3`
+  FROM `bfcte_0`
+)
+SELECT
+  `bfcol_3` AS `result_col`
+FROM `bfcte_1`

tests/unit/core/compile/sqlglot/expressions/test_generic_ops.py

@@ -168,6 +168,22 @@ def test_astype_json_invalid(
         )
 
 
+def test_clip(scalar_types_df: bpd.DataFrame, snapshot):
+    op_expr = ops.clip_op.as_expr("rowindex", "int64_col", "int64_too")
+
+    array_value = scalar_types_df._block.expr
+    result, col_ids = array_value.compute_values([op_expr])
+
+    # Rename columns for deterministic golden SQL results.
+    assert len(col_ids) == 1
+    result = result.rename_columns({col_ids[0]: "result_col"}).select_columns(
+        ["result_col"]
+    )
+
+    sql = result.session._executor.to_sql(result, enable_cache=False)
+    snapshot.assert_match(sql, "out.sql")
+
+
 def test_hash(scalar_types_df: bpd.DataFrame, snapshot):
     col_name = "string_col"
     bf_df = scalar_types_df[[col_name]]