ARROW-2159: [JS] Support custom predicates
Adds support for defining a custom predicate with callback functions, like so:
```js
table.filter(predicate.custom(
(idx) => {...},
(batch) => {...}
));
```
Author: Brian Hulette <brian.hulette@ccri.com>
Closes #1616 from TheNeuralBit/custom-predicate and squashes the following commits:
77f5441 [Brian Hulette] Add test, squash bug
29ecc80 [Brian Hulette] Add CustomPredicate
diff --git a/js/src/Arrow.externs.js b/js/src/Arrow.externs.js
index 21dca8b..de1e653 100644
--- a/js/src/Arrow.externs.js
+++ b/js/src/Arrow.externs.js
@@ -70,6 +70,7 @@
var col = function () {};
var lit = function () {};
+var custom = function () {};
var Value = function() {};
/** @type {?} */
@@ -738,4 +739,4 @@
/** @type {?} */
VectorVisitor.prototype.visitFixedSizeList;
/** @type {?} */
-VectorVisitor.prototype.visitMap;
\ No newline at end of file
+VectorVisitor.prototype.visitMap;
diff --git a/js/src/Arrow.ts b/js/src/Arrow.ts
index df37a8f..4a0a2ac 100644
--- a/js/src/Arrow.ts
+++ b/js/src/Arrow.ts
@@ -168,6 +168,7 @@
export namespace predicate {
export import col = predicate_.col;
export import lit = predicate_.lit;
+ export import custom = predicate_.custom;
export import Or = predicate_.Or;
export import Col = predicate_.Col;
diff --git a/js/src/predicate.ts b/js/src/predicate.ts
index 981ffb1..b177b4f 100644
--- a/js/src/predicate.ts
+++ b/js/src/predicate.ts
@@ -222,5 +222,19 @@
}
}
+export class CustomPredicate extends Predicate {
+ constructor(private next: PredicateFunc, private bind_: (batch: RecordBatch) => void) {
+ super();
+ }
+
+ bind(batch: RecordBatch) {
+ this.bind_(batch);
+ return this.next;
+ }
+}
+
export function lit(v: any): Value<any> { return new Literal(v); }
export function col(n: string): Col<any> { return new Col(n); }
+export function custom(next: PredicateFunc, bind: (batch: RecordBatch) => void) {
+ return new CustomPredicate(next, bind);
+}
diff --git a/js/test/unit/table-tests.ts b/js/test/unit/table-tests.ts
index ffcc8f4..8a43381 100644
--- a/js/test/unit/table-tests.ts
+++ b/js/test/unit/table-tests.ts
@@ -15,11 +15,11 @@
// specific language governing permissions and limitations
// under the License.
-import Arrow from '../Arrow';
+import Arrow, { RecordBatch } from '../Arrow';
const { predicate, Table } = Arrow;
-const { col, lit } = predicate;
+const { col, lit, custom } = predicate;
const F32 = 0, I32 = 1, DICT = 2;
const test_data = [
@@ -323,6 +323,7 @@
expect(table.getColumnIndex('f32')).toEqual(F32);
expect(table.getColumnIndex('dictionary')).toEqual(DICT);
});
+ let get_i32: (idx: number) => number, get_f32: (idx: number) => number;
const filter_tests = [
{
name: `filter on f32 >= 0`,
@@ -364,6 +365,15 @@
name: `filter on f32 <= i32`,
filtered: table.filter(col('f32').lteq(col('i32'))),
expected: values.filter((row) => row[F32] <= row[I32])
+ }, {
+ name: `filter on f32*i32 > 0 (custom predicate)`,
+ filtered: table.filter(custom(
+ (idx: number) => (get_f32(idx) * get_i32(idx) > 0),
+ (batch: RecordBatch) => {
+ get_f32 = col('f32').bind(batch);
+ get_i32 = col('i32').bind(batch);
+ })),
+ expected: values.filter((row) => (row[F32] as number) * (row[I32] as number) > 0)
}
];
for (let this_test of filter_tests) {
