New segmentEach & segmentReduce (@turf/meta)

packages/turf-line-distance/bench.js

@@ -1,7 +1,7 @@
+const fs = require('fs');
 const path = require('path');
 const load = require('load-json-file');
 const Benchmark = require('benchmark');
-const fs = require('fs');
 const lineDistance = require('./');
 
 // Define fixtures
@@ -17,12 +17,12 @@ const fixtures = fs.readdirSync(directory).map(filename => {
 /**
  * Benmark Results
  *
- * feature-collection x 274,292 ops/sec ±6.58% (75 runs sampled)
- * multi-linestring x 606,888 ops/sec ±1.65% (87 runs sampled)
- * multi-polygon x 425,090 ops/sec ±4.51% (80 runs sampled)
- * polygon x 617,824 ops/sec ±4.31% (76 runs sampled)
- * route1 x 1,234 ops/sec ±0.89% (87 runs sampled)
- * route2 x 1,356 ops/sec ±0.89% (90 runs sampled)
+ * feature-collection x 240,519 ops/sec ±2.55% (83 runs sampled)
+ * multi-linestring x 352,542 ops/sec ±8.44% (76 runs sampled)
+ * multi-polygon x 308,500 ops/sec ±3.92% (83 runs sampled)
+ * polygon x 534,768 ops/sec ±1.29% (84 runs sampled)
+ * route1 x 1,280 ops/sec ±1.23% (89 runs sampled)
+ * route2 x 1,452 ops/sec ±1.57% (87 runs sampled)
  */
 
 // Define benchmark

packages/turf-line-distance/index.d.ts

@@ -1,12 +1,11 @@
 /// <reference types="geojson" />
 
-type Geometry = GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon
-type Feature = GeoJSON.Feature<GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon>
-type Features = GeoJSON.FeatureCollection<GeoJSON.Polygon | GeoJSON.LineString | GeoJSON.MultiLineString | GeoJSON.MultiPolygon>
+import {Units} from '@turf/helpers'
+type Input = GeoJSON.Feature<any> | GeoJSON.FeatureCollection<any> | GeoJSON.GeometryObject | GeoJSON.GeometryCollection
 
 /**
  * http://turfjs.org/docs/#linedistance
  */
-declare function lineDistance(features: Geometry | Feature | Features, units?: string): number;
+declare function lineDistance(geojson: Input, units?: Units): number;
 declare namespace lineDistance { }
 export = lineDistance;

packages/turf-line-distance/index.js

@@ -1,30 +1,15 @@
-var flatten = require('@turf/flatten');
 var distance = require('@turf/distance');
-var meta = require('@turf/meta');
-var geomEach = meta.geomEach;
-var featureEach = meta.featureEach;
-var coordReduce = meta.coordReduce;
-var helpers = require('@turf/helpers');
-var point = helpers.point;
-var lineString = helpers.lineString;
+var segmentReduce = require('@turf/meta').segmentReduce;
 
 /**
- * Takes a {@link LineString} or {@link Polygon} and measures its length in the specified units.
+ * Takes a {@link GeoJSON} and measures its length in the specified units, {@link (Multi)Point|Point}'s distance are ignored.
  *
  * @name lineDistance
- * @param {Feature<(LineString|Polygon)>|FeatureCollection<(LineString|Polygon)>} geojson feature to measure
+ * @param {FeatureCollection|Feature|Geometry} geojson GeoJSON to measure
  * @param {string} [units=kilometers] can be degrees, radians, miles, or kilometers
- * @returns {number} length feature
+ * @returns {number} length of GeoJSON
  * @example
- * var line = turf.lineString([
- *     [-77.031669, 38.878605],
- *     [-77.029609, 38.881946],
- *     [-77.020339, 38.884084],
- *     [-77.025661, 38.885821],
- *     [-77.021884, 38.889563],
- *     [-77.019824, 38.892368]
- * ]);
- *
+ * var line = turf.lineString([[115, -32], [131, -22], [143, -25], [150, -34]]);
  * var length = turf.lineDistance(line, 'miles');
  *
  * //addToMap
@@ -34,71 +19,10 @@ var lineString = helpers.lineString;
 module.exports = function lineDistance(geojson, units) {
     // Input Validation
     if (!geojson) throw new Error('geojson is required');
-    geomEach(geojson, function (geometry) {
-        if (geometry.type === 'Point') throw new Error('geojson cannot be a Point');
-        if (geometry.type === 'MultiPoint') throw new Error('geojson cannot be a MultiPoint');
-    });
 
     // Calculate distance from 2-vertex line segements
     return segmentReduce(geojson, function (previousValue, segment) {
         var coords = segment.geometry.coordinates;
-        var start = point(coords[0]);
-        var end = point(coords[1]);
-        return previousValue + distance(start, end, units);
+        return previousValue + distance(coords[0], coords[1], units);
     }, 0);
 };
-
-/**
- * Iterate over 2-vertex line segment in any GeoJSON object, similar to Array.forEach()
- *
- * @private
- * @param {FeatureCollection|Feature<any>} geojson any GeoJSON
- * @param {Function} callback a method that takes (currentSegment, currentIndex)
- * @returns {void}
- * @example
- * var polygon = {
- *   "type": "Feature",
- *   "properties": {},
- *   "geometry": {
- *     "type": "Polygon",
- *     "coordinates": [[[-50, 5], [-40, -10], [-50, -10], [-40, 5], [-50, 5]]]
- *   }
- * }
- * turf.segmentEach(polygon, function (segment) {
- *   //= segment
- * });
- */
-function segmentEach(geojson, callback) {
-    var count = 0;
-    featureEach(geojson, function (multiFeature) {
-        featureEach(flatten(multiFeature), function (feature) {
-            coordReduce(feature, function (previousCoords, currentCoords) {
-                var line = lineString([previousCoords, currentCoords], feature.properties);
-                callback(line, count);
-                count++;
-                return currentCoords;
-            });
-        });
-    });
-}
-
-/**
- * Reduce 2-vertex line segment in any GeoJSON object, similar to Array.reduce()
- *
- * @private
- * @param {FeatureCollection|Feature<any>} geojson any GeoJSON
- * @param {Function} callback a method that takes (previousValue, currentSegment, currentIndex)
- * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
- * @returns {void}
- */
-function segmentReduce(geojson, callback, initialValue) {
-    var previousValue = initialValue;
-    segmentEach(geojson, function (currentSegment, currentIndex) {
-        if (currentIndex === 0 && initialValue === undefined) {
-            previousValue = currentSegment;
-        } else {
-            previousValue = callback(previousValue, currentSegment, currentIndex);
-        }
-    });
-    return previousValue;
-}

packages/turf-line-distance/package.json

@@ -25,6 +25,10 @@
     "gis"
   ],
   "author": "Turf Authors",
+  "contributors": [
+    "Denis Carriere <@DenisCarriere>",
+    "Tom MacWright <@tmcw>"
+  ],
   "license": "MIT",
   "bugs": {
     "url": "https://github.com/Turfjs/turf/issues"
@@ -38,7 +42,6 @@
   },
   "dependencies": {
     "@turf/distance": "^4.5.2",
-    "@turf/flatten": "^4.5.2",
     "@turf/helpers": "^4.5.2",
     "@turf/meta": "^4.5.2"
   }

packages/turf-line-distance/test.js

@@ -1,9 +1,8 @@
-const test = require('tape');
 const fs = require('fs');
+const test = require('tape');
 const path = require('path');
 const load = require('load-json-file');
 const write = require('write-json-file');
-const {point, multiPoint} = require('@turf/helpers');
 const lineDistance = require('./');
 
 const directories = {
@@ -27,9 +26,3 @@ test('turf-line-distance', t => {
     }
     t.end();
 });
-
-test('turf-line-distance -- throws', t => {
-    t.throws(() => lineDistance(point([110, 60])), 'point');
-    t.throws(() => lineDistance(multiPoint([[-120, 40], [110, 60]])), 'multiPoint');
-    t.end();
-});

packages/turf-line-distance/types.ts

@@ -0,0 +1,8 @@
+import {lineString} from '@turf/helpers'
+import * as lineDistance from './'
+
+var line = lineString([[115, -32], [131, -22], [143, -25], [150, -34]]);
+var length = lineDistance(line, 'miles');
+
+lineDistance(line, 'kilometers');
+lineDistance(line);