Binary column windows, make all column functions closures

src/reader/cif/binary/field.ts

@@ -8,12 +8,13 @@ import * as Column from '../../common/column'
 import * as Data from '../data-model'
 import { EncodedColumn } from './encoding'
 import decode from './decoder'
+import { isTypedArray, typedArrayWindow } from '../../common/binary/column'
 import { parseInt as fastParseInt, parseFloat as fastParseFloat } from '../../common/text/number-parser'
 
 export default function Field(column: EncodedColumn): Data.Field {
     const mask = column.mask ? decode(column.mask) as number[] : void 0;
     const data = decode(column.data);
-    const isNumeric = (data as any).buffer && (data as any).byteLength && (data as any).BYTES_PER_ELEMENT;
+    const isNumeric = isTypedArray(data);
 
     const str: Data.Field['str'] = isNumeric
         ? mask
@@ -45,9 +46,13 @@ export default function Field(column: EncodedColumn): Data.Field {
         float,
         presence,
         areValuesEqual: (rowA, rowB) => data[rowA] === data[rowB],
-        stringEquals(row, v) { return str(row) === v; },
-        toStringArray(params) { return Column.createAndFillArray(rowCount, str, params); },
-        toIntArray(params) { return Column.createAndFillArray(rowCount, int, params); },
-        toFloatArray(params)  { return Column.createAndFillArray(rowCount, float, params); }
+        stringEquals: (row, v) => str(row) === v,
+        toStringArray: params => Column.createAndFillArray(rowCount, str, params),
+        toIntArray: isNumeric
+            ? params => typedArrayWindow(data, params)
+            : params => Column.createAndFillArray(rowCount, int, params),
+        toFloatArray: isNumeric
+            ? params => typedArrayWindow(data, params)
+            : params => Column.createAndFillArray(rowCount, float, params)
     };
 }

src/reader/cif/text/field.ts

@@ -44,7 +44,7 @@ export default function CifTextField(tokens: Tokens, rowCount: number): Data.Fie
         float,
         presence,
         areValuesEqual: TokenColumn.areValuesEqualProvider(tokens),
-        stringEquals(row, v) {
+        stringEquals: (row, v) => {
             const s = indices[2 * row];
             const value = v || '';
             if (!value && presence(row) !== Data.ValuePresence.Present) return true;
@@ -55,8 +55,8 @@ export default function CifTextField(tokens: Tokens, rowCount: number): Data.Fie
             }
             return true;
         },
-        toStringArray(params) { return Column.createAndFillArray(rowCount, str, params); },
-        toIntArray(params) { return Column.createAndFillArray(rowCount, int, params); },
-        toFloatArray(params)  { return Column.createAndFillArray(rowCount, float, params); }
+        toStringArray: params => Column.createAndFillArray(rowCount, str, params),
+        toIntArray: params => Column.createAndFillArray(rowCount, int, params),
+        toFloatArray: params => Column.createAndFillArray(rowCount, float, params)
     }
 }

src/reader/common/binary/column.ts

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) 2017 molio contributors, licensed under MIT, See LICENSE file for more info.
+ *
+ * @author David Sehnal <david.sehnal@gmail.com>
+ */
+
+import { getArrayBounds, ToArrayParams } from '../column'
+
+export function isTypedArray(data: any) {
+    return data.buffer && typeof data.byteLength === 'number' && data.BYTES_PER_ELEMENT;
+}
+
+export function typedArrayWindow(data: any, params?: ToArrayParams): ArrayLike<number> {
+    const { constructor, buffer, length, byteOffset, BYTES_PER_ELEMENT } = data;
+    const { start, end } = getArrayBounds(length, params);
+    if (start === 0 && end === length) return data;
+    return new constructor(buffer, byteOffset + BYTES_PER_ELEMENT * start, Math.min(length, end - start));
+}

src/reader/common/column.ts

@@ -48,13 +48,18 @@ export function UndefinedColumn<T extends ColumnType>(rowCount: number, type: T)
     }
 }
 
+/** A helped function for Column.toArray */
+export function getArrayBounds(rowCount: number, params?: ToArrayParams) {
+    const start = params && typeof params.start !== 'undefined' ? Math.max(Math.min(params.start, rowCount - 1), 0) : 0;
+    const end = params && typeof params.end !== 'undefined' ? Math.min(params.end, rowCount) : rowCount;
+    return { start, end };
+}
+
 /** A helped function for Column.toArray */
 export function createArray(rowCount: number, params?: ToArrayParams) {
-    const { array, start, end } = params || ({} as ToArrayParams);
-    const c = typeof array !== 'undefined' ? array : Array;
-    const s = typeof start !== 'undefined' ? Math.max(Math.min(start, rowCount - 1), 0) : 0;
-    const e = typeof end !== 'undefined' ? Math.min(end, rowCount) : rowCount;
-    return { array: new c(e - s) as any[], start: s, end: e };
+    const c = params && typeof params.array !== 'undefined' ? params.array : Array;
+    const { start, end } = getArrayBounds(rowCount, params);
+    return { array: new c(end - start) as any[], start, end };
 }
 
 /** A helped function for Column.toArray */

src/reader/common/text/column/fixed.ts

@@ -45,11 +45,9 @@ export function FixedColumn<T extends ColumnType>(lines: Tokens, offset: number,
         isDefined: true,
         rowCount,
         value,
-        isValueDefined(row) { return true; },
-        toArray(params) { return createAndFillArray(rowCount, value, params); },
-        stringEquals(row, v) { return value(row) === v; },
-        areValuesEqual(rowA, rowB) {
-            return value(rowA) === value(rowB);
-        }
+        isValueDefined: row => true,
+        toArray: params => createAndFillArray(rowCount, value, params),
+        stringEquals: (row, v) => value(row) === v,
+        areValuesEqual: (rowA, rowB) => value(rowA) === value(rowB)
     };
 }

src/reader/common/text/column/token.ts

@@ -33,9 +33,9 @@ export function TokenColumn<T extends ColumnType>(tokens: Tokens, type: T): Colu
         isDefined: true,
         rowCount,
         value,
-        isValueDefined(row) { return true; },
-        toArray(params) { return createAndFillArray(rowCount, value, params); },
-        stringEquals(row, v) {
+        isValueDefined: row => true,
+        toArray: params => createAndFillArray(rowCount, value, params),
+        stringEquals: (row, v) => {
             const s = indices[2 * row];
             const value = v || '';
             const len = value.length;

src/reader/spec/text-column.spec.ts → src/reader/spec/column.spec.ts

@@ -5,6 +5,7 @@
  * @author David Sehnal <david.sehnal@gmail.com>
  */
 
+import * as BinaryColumn from '../common/binary/column'
 import FixedColumn from '../common/text/column/fixed'
 import TokenColumn from '../common/text/column/token'
 import { ColumnType } from '../common/column'
@@ -60,3 +61,17 @@ describe('token text column', () => {
         expect(col1.value(2)).toBe(1);
     })
 });
+
+describe('binary column', () => {
+    it('window works', () => {
+        const xs = new Float64Array([1, 2, 3, 4]);
+        const w1 = BinaryColumn.typedArrayWindow(xs, { start: 1 });
+        const w2 = BinaryColumn.typedArrayWindow(xs, { start: 2, end: 4 });
+
+        expect(w1.length).toBe(3);
+        for (let i = 0; i < w1.length; i++) expect(w1[i]).toBe(xs[i + 1]);
+
+        expect(w2.length).toBe(2);
+        for (let i = 0; i < w2.length; i++) expect(w2[i]).toBe(xs[i + 2]);
+    });
+})