Array based column

src/reader/cif/binary/field.ts

@@ -8,13 +8,12 @@ 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 = isTypedArray(data);
+    const isNumeric = Column.isTypedArray(data);
 
     const str: Data.Field['str'] = isNumeric
         ? mask
@@ -49,10 +48,10 @@ export default function Field(column: EncodedColumn): Data.Field {
         stringEquals: (row, v) => str(row) === v,
         toStringArray: params => Column.createAndFillArray(rowCount, str, params),
         toIntArray: isNumeric
-            ? params => typedArrayWindow(data, params)
+            ? params => Column.typedArrayWindow(data, params)
             : params => Column.createAndFillArray(rowCount, int, params),
         toFloatArray: isNumeric
-            ? params => typedArrayWindow(data, params)
+            ? params => Column.typedArrayWindow(data, params)
             : params => Column.createAndFillArray(rowCount, float, params)
     };
 }
\ No newline at end of file

src/reader/common/binary/column.ts

@@ -3,16 +3,3 @@
  *
  * @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): ReadonlyArray<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));
-}
\ No newline at end of file

src/reader/common/column.ts

@@ -37,14 +37,42 @@ export function UndefinedColumn<T extends ColumnType>(rowCount: number, type: T)
         isDefined: false,
         rowCount,
         value,
-        isValueDefined(row) { return false; },
-        toArray(params) {
+        isValueDefined: row => false,
+        toArray: params => {
             const { array } = createArray(rowCount, params);
             for (let i = 0, _i = array.length; i < _i; i++) array[i] = value(0)
             return array;
         },
-        stringEquals(row, value) { return !value; },
-        areValuesEqual(rowA, rowB) { return true; }
+        stringEquals: (row, value) => !value,
+        areValuesEqual: (rowA, rowB) => true
+    }
+}
+
+export function ArrayColumn<T>(array: ArrayLike<T>): Column<T> {
+    const rowCount = array.length;
+    const value: Column<T>['value'] = row => array[row];
+    const isTyped = isTypedArray(array);
+    return {
+        isDefined: false,
+        rowCount,
+        value,
+        isValueDefined: row => true,
+        toArray: isTyped
+            ? params => typedArrayWindow(array, params) as any as ReadonlyArray<T>
+            : params => {
+                const { start, end } = getArrayBounds(rowCount, params);
+                const ret = new Array(end - start);
+                for (let i = 0, _i = end - start; i < _i; i++) ret[i] = array[start + i];
+                return ret;
+            },
+        stringEquals: isTyped
+            ? (row, value) => (array as any)[row] === +value
+            : (row, value) => {
+                const v = array[row];
+                if (typeof v !== 'string') return '' + v === value;
+                return v === value;
+            },
+        areValuesEqual: (rowA, rowB) => array[rowA] === array[rowB]
     }
 }
 
@@ -74,4 +102,13 @@ export function createAndFillArray(rowCount: number, value: (row: number) => any
     return fillArrayValues(value, array, start);
 }
 
+export function isTypedArray(data: any) {
+    return data.buffer && typeof data.byteLength === 'number' && data.BYTES_PER_ELEMENT;
+}
 
+export function typedArrayWindow(data: any, params?: ToArrayParams): ReadonlyArray<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));
+}
\ No newline at end of file

src/reader/spec/column.spec.ts

@@ -5,10 +5,9 @@
  * @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'
+import { ColumnType, typedArrayWindow } from '../common/column'
 
 const lines = [
     '1.123 abc',
@@ -65,8 +64,8 @@ describe('token text column', () => {
 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 });
+        const w1 = typedArrayWindow(xs, { start: 1 });
+        const w2 = 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]);