| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401 | 
							- import { feature, lineString, isObject, point } from '@turf/helpers';
 
- /**
 
-  * Callback for coordEach
 
-  *
 
-  * @callback coordEachCallback
 
-  * @param {Array<number>} currentCoord The current coordinate being processed.
 
-  * @param {number} coordIndex The current index of the coordinate being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  * @param {number} geometryIndex The current index of the Geometry being processed.
 
-  */
 
- /**
 
-  * Iterate over coordinates in any GeoJSON object, similar to Array.forEach()
 
-  *
 
-  * @name coordEach
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (currentCoord, coordIndex, featureIndex, multiFeatureIndex)
 
-  * @param {boolean} [excludeWrapCoord=false] whether or not to include the final coordinate of LinearRings that wraps the ring in its iteration.
 
-  * @returns {void}
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *   turf.point([26, 37], {"foo": "bar"}),
 
-  *   turf.point([36, 53], {"hello": "world"})
 
-  * ]);
 
-  *
 
-  * turf.coordEach(features, function (currentCoord, coordIndex, featureIndex, multiFeatureIndex, geometryIndex) {
 
-  *   //=currentCoord
 
-  *   //=coordIndex
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   //=geometryIndex
 
-  * });
 
-  */
 
- function coordEach(geojson, callback, excludeWrapCoord) {
 
-   // Handles null Geometry -- Skips this GeoJSON
 
-   if (geojson === null) return;
 
-   var j,
 
-     k,
 
-     l,
 
-     geometry,
 
-     stopG,
 
-     coords,
 
-     geometryMaybeCollection,
 
-     wrapShrink = 0,
 
-     coordIndex = 0,
 
-     isGeometryCollection,
 
-     type = geojson.type,
 
-     isFeatureCollection = type === "FeatureCollection",
 
-     isFeature = type === "Feature",
 
-     stop = isFeatureCollection ? geojson.features.length : 1;
 
-   // This logic may look a little weird. The reason why it is that way
 
-   // is because it's trying to be fast. GeoJSON supports multiple kinds
 
-   // of objects at its root: FeatureCollection, Features, Geometries.
 
-   // This function has the responsibility of handling all of them, and that
 
-   // means that some of the `for` loops you see below actually just don't apply
 
-   // to certain inputs. For instance, if you give this just a
 
-   // Point geometry, then both loops are short-circuited and all we do
 
-   // is gradually rename the input until it's called 'geometry'.
 
-   //
 
-   // This also aims to allocate as few resources as possible: just a
 
-   // few numbers and booleans, rather than any temporary arrays as would
 
-   // be required with the normalization approach.
 
-   for (var featureIndex = 0; featureIndex < stop; featureIndex++) {
 
-     geometryMaybeCollection = isFeatureCollection
 
-       ? geojson.features[featureIndex].geometry
 
-       : isFeature
 
-       ? geojson.geometry
 
-       : geojson;
 
-     isGeometryCollection = geometryMaybeCollection
 
-       ? geometryMaybeCollection.type === "GeometryCollection"
 
-       : false;
 
-     stopG = isGeometryCollection
 
-       ? geometryMaybeCollection.geometries.length
 
-       : 1;
 
-     for (var geomIndex = 0; geomIndex < stopG; geomIndex++) {
 
-       var multiFeatureIndex = 0;
 
-       var geometryIndex = 0;
 
-       geometry = isGeometryCollection
 
-         ? geometryMaybeCollection.geometries[geomIndex]
 
-         : geometryMaybeCollection;
 
-       // Handles null Geometry -- Skips this geometry
 
-       if (geometry === null) continue;
 
-       coords = geometry.coordinates;
 
-       var geomType = geometry.type;
 
-       wrapShrink =
 
-         excludeWrapCoord &&
 
-         (geomType === "Polygon" || geomType === "MultiPolygon")
 
-           ? 1
 
-           : 0;
 
-       switch (geomType) {
 
-         case null:
 
-           break;
 
-         case "Point":
 
-           if (
 
-             callback(
 
-               coords,
 
-               coordIndex,
 
-               featureIndex,
 
-               multiFeatureIndex,
 
-               geometryIndex
 
-             ) === false
 
-           )
 
-             return false;
 
-           coordIndex++;
 
-           multiFeatureIndex++;
 
-           break;
 
-         case "LineString":
 
-         case "MultiPoint":
 
-           for (j = 0; j < coords.length; j++) {
 
-             if (
 
-               callback(
 
-                 coords[j],
 
-                 coordIndex,
 
-                 featureIndex,
 
-                 multiFeatureIndex,
 
-                 geometryIndex
 
-               ) === false
 
-             )
 
-               return false;
 
-             coordIndex++;
 
-             if (geomType === "MultiPoint") multiFeatureIndex++;
 
-           }
 
-           if (geomType === "LineString") multiFeatureIndex++;
 
-           break;
 
-         case "Polygon":
 
-         case "MultiLineString":
 
-           for (j = 0; j < coords.length; j++) {
 
-             for (k = 0; k < coords[j].length - wrapShrink; k++) {
 
-               if (
 
-                 callback(
 
-                   coords[j][k],
 
-                   coordIndex,
 
-                   featureIndex,
 
-                   multiFeatureIndex,
 
-                   geometryIndex
 
-                 ) === false
 
-               )
 
-                 return false;
 
-               coordIndex++;
 
-             }
 
-             if (geomType === "MultiLineString") multiFeatureIndex++;
 
-             if (geomType === "Polygon") geometryIndex++;
 
-           }
 
-           if (geomType === "Polygon") multiFeatureIndex++;
 
-           break;
 
-         case "MultiPolygon":
 
-           for (j = 0; j < coords.length; j++) {
 
-             geometryIndex = 0;
 
-             for (k = 0; k < coords[j].length; k++) {
 
-               for (l = 0; l < coords[j][k].length - wrapShrink; l++) {
 
-                 if (
 
-                   callback(
 
-                     coords[j][k][l],
 
-                     coordIndex,
 
-                     featureIndex,
 
-                     multiFeatureIndex,
 
-                     geometryIndex
 
-                   ) === false
 
-                 )
 
-                   return false;
 
-                 coordIndex++;
 
-               }
 
-               geometryIndex++;
 
-             }
 
-             multiFeatureIndex++;
 
-           }
 
-           break;
 
-         case "GeometryCollection":
 
-           for (j = 0; j < geometry.geometries.length; j++)
 
-             if (
 
-               coordEach(geometry.geometries[j], callback, excludeWrapCoord) ===
 
-               false
 
-             )
 
-               return false;
 
-           break;
 
-         default:
 
-           throw new Error("Unknown Geometry Type");
 
-       }
 
-     }
 
-   }
 
- }
 
- /**
 
-  * Callback for coordReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback coordReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Array<number>} currentCoord The current coordinate being processed.
 
-  * @param {number} coordIndex The current index of the coordinate being processed.
 
-  * Starts at index 0, if an initialValue is provided, and at index 1 otherwise.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  * @param {number} geometryIndex The current index of the Geometry being processed.
 
-  */
 
- /**
 
-  * Reduce coordinates in any GeoJSON object, similar to Array.reduce()
 
-  *
 
-  * @name coordReduce
 
-  * @param {FeatureCollection|Geometry|Feature} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (previousValue, currentCoord, coordIndex)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @param {boolean} [excludeWrapCoord=false] whether or not to include the final coordinate of LinearRings that wraps the ring in its iteration.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *   turf.point([26, 37], {"foo": "bar"}),
 
-  *   turf.point([36, 53], {"hello": "world"})
 
-  * ]);
 
-  *
 
-  * turf.coordReduce(features, function (previousValue, currentCoord, coordIndex, featureIndex, multiFeatureIndex, geometryIndex) {
 
-  *   //=previousValue
 
-  *   //=currentCoord
 
-  *   //=coordIndex
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   //=geometryIndex
 
-  *   return currentCoord;
 
-  * });
 
-  */
 
- function coordReduce(geojson, callback, initialValue, excludeWrapCoord) {
 
-   var previousValue = initialValue;
 
-   coordEach(
 
-     geojson,
 
-     function (
 
-       currentCoord,
 
-       coordIndex,
 
-       featureIndex,
 
-       multiFeatureIndex,
 
-       geometryIndex
 
-     ) {
 
-       if (coordIndex === 0 && initialValue === undefined)
 
-         previousValue = currentCoord;
 
-       else
 
-         previousValue = callback(
 
-           previousValue,
 
-           currentCoord,
 
-           coordIndex,
 
-           featureIndex,
 
-           multiFeatureIndex,
 
-           geometryIndex
 
-         );
 
-     },
 
-     excludeWrapCoord
 
-   );
 
-   return previousValue;
 
- }
 
- /**
 
-  * Callback for propEach
 
-  *
 
-  * @callback propEachCallback
 
-  * @param {Object} currentProperties The current Properties being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  */
 
- /**
 
-  * Iterate over properties in any GeoJSON object, similar to Array.forEach()
 
-  *
 
-  * @name propEach
 
-  * @param {FeatureCollection|Feature} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (currentProperties, featureIndex)
 
-  * @returns {void}
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.propEach(features, function (currentProperties, featureIndex) {
 
-  *   //=currentProperties
 
-  *   //=featureIndex
 
-  * });
 
-  */
 
- function propEach(geojson, callback) {
 
-   var i;
 
-   switch (geojson.type) {
 
-     case "FeatureCollection":
 
-       for (i = 0; i < geojson.features.length; i++) {
 
-         if (callback(geojson.features[i].properties, i) === false) break;
 
-       }
 
-       break;
 
-     case "Feature":
 
-       callback(geojson.properties, 0);
 
-       break;
 
-   }
 
- }
 
- /**
 
-  * Callback for propReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback propReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {*} currentProperties The current Properties being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  */
 
- /**
 
-  * Reduce properties in any GeoJSON object into a single value,
 
-  * similar to how Array.reduce works. However, in this case we lazily run
 
-  * the reduction, so an array of all properties is unnecessary.
 
-  *
 
-  * @name propReduce
 
-  * @param {FeatureCollection|Feature} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (previousValue, currentProperties, featureIndex)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.propReduce(features, function (previousValue, currentProperties, featureIndex) {
 
-  *   //=previousValue
 
-  *   //=currentProperties
 
-  *   //=featureIndex
 
-  *   return currentProperties
 
-  * });
 
-  */
 
- function propReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   propEach(geojson, function (currentProperties, featureIndex) {
 
-     if (featureIndex === 0 && initialValue === undefined)
 
-       previousValue = currentProperties;
 
-     else
 
-       previousValue = callback(previousValue, currentProperties, featureIndex);
 
-   });
 
-   return previousValue;
 
- }
 
- /**
 
-  * Callback for featureEach
 
-  *
 
-  * @callback featureEachCallback
 
-  * @param {Feature<any>} currentFeature The current Feature being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  */
 
- /**
 
-  * Iterate over features in any GeoJSON object, similar to
 
-  * Array.forEach.
 
-  *
 
-  * @name featureEach
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (currentFeature, featureIndex)
 
-  * @returns {void}
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *   turf.point([26, 37], {foo: 'bar'}),
 
-  *   turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.featureEach(features, function (currentFeature, featureIndex) {
 
-  *   //=currentFeature
 
-  *   //=featureIndex
 
-  * });
 
-  */
 
- function featureEach(geojson, callback) {
 
-   if (geojson.type === "Feature") {
 
-     callback(geojson, 0);
 
-   } else if (geojson.type === "FeatureCollection") {
 
-     for (var i = 0; i < geojson.features.length; i++) {
 
-       if (callback(geojson.features[i], i) === false) break;
 
-     }
 
-   }
 
- }
 
- /**
 
-  * Callback for featureReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback featureReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Feature} currentFeature The current Feature being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  */
 
- /**
 
-  * Reduce features in any GeoJSON object, similar to Array.reduce().
 
-  *
 
-  * @name featureReduce
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (previousValue, currentFeature, featureIndex)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *   turf.point([26, 37], {"foo": "bar"}),
 
-  *   turf.point([36, 53], {"hello": "world"})
 
-  * ]);
 
-  *
 
-  * turf.featureReduce(features, function (previousValue, currentFeature, featureIndex) {
 
-  *   //=previousValue
 
-  *   //=currentFeature
 
-  *   //=featureIndex
 
-  *   return currentFeature
 
-  * });
 
-  */
 
- function featureReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   featureEach(geojson, function (currentFeature, featureIndex) {
 
-     if (featureIndex === 0 && initialValue === undefined)
 
-       previousValue = currentFeature;
 
-     else previousValue = callback(previousValue, currentFeature, featureIndex);
 
-   });
 
-   return previousValue;
 
- }
 
- /**
 
-  * Get all coordinates from any GeoJSON object.
 
-  *
 
-  * @name coordAll
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @returns {Array<Array<number>>} coordinate position array
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *   turf.point([26, 37], {foo: 'bar'}),
 
-  *   turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * var coords = turf.coordAll(features);
 
-  * //= [[26, 37], [36, 53]]
 
-  */
 
- function coordAll(geojson) {
 
-   var coords = [];
 
-   coordEach(geojson, function (coord) {
 
-     coords.push(coord);
 
-   });
 
-   return coords;
 
- }
 
- /**
 
-  * Callback for geomEach
 
-  *
 
-  * @callback geomEachCallback
 
-  * @param {Geometry} currentGeometry The current Geometry being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {Object} featureProperties The current Feature Properties being processed.
 
-  * @param {Array<number>} featureBBox The current Feature BBox being processed.
 
-  * @param {number|string} featureId The current Feature Id being processed.
 
-  */
 
- /**
 
-  * Iterate over each geometry in any GeoJSON object, similar to Array.forEach()
 
-  *
 
-  * @name geomEach
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (currentGeometry, featureIndex, featureProperties, featureBBox, featureId)
 
-  * @returns {void}
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.geomEach(features, function (currentGeometry, featureIndex, featureProperties, featureBBox, featureId) {
 
-  *   //=currentGeometry
 
-  *   //=featureIndex
 
-  *   //=featureProperties
 
-  *   //=featureBBox
 
-  *   //=featureId
 
-  * });
 
-  */
 
- function geomEach(geojson, callback) {
 
-   var i,
 
-     j,
 
-     g,
 
-     geometry,
 
-     stopG,
 
-     geometryMaybeCollection,
 
-     isGeometryCollection,
 
-     featureProperties,
 
-     featureBBox,
 
-     featureId,
 
-     featureIndex = 0,
 
-     isFeatureCollection = geojson.type === "FeatureCollection",
 
-     isFeature = geojson.type === "Feature",
 
-     stop = isFeatureCollection ? geojson.features.length : 1;
 
-   // This logic may look a little weird. The reason why it is that way
 
-   // is because it's trying to be fast. GeoJSON supports multiple kinds
 
-   // of objects at its root: FeatureCollection, Features, Geometries.
 
-   // This function has the responsibility of handling all of them, and that
 
-   // means that some of the `for` loops you see below actually just don't apply
 
-   // to certain inputs. For instance, if you give this just a
 
-   // Point geometry, then both loops are short-circuited and all we do
 
-   // is gradually rename the input until it's called 'geometry'.
 
-   //
 
-   // This also aims to allocate as few resources as possible: just a
 
-   // few numbers and booleans, rather than any temporary arrays as would
 
-   // be required with the normalization approach.
 
-   for (i = 0; i < stop; i++) {
 
-     geometryMaybeCollection = isFeatureCollection
 
-       ? geojson.features[i].geometry
 
-       : isFeature
 
-       ? geojson.geometry
 
-       : geojson;
 
-     featureProperties = isFeatureCollection
 
-       ? geojson.features[i].properties
 
-       : isFeature
 
-       ? geojson.properties
 
-       : {};
 
-     featureBBox = isFeatureCollection
 
-       ? geojson.features[i].bbox
 
-       : isFeature
 
-       ? geojson.bbox
 
-       : undefined;
 
-     featureId = isFeatureCollection
 
-       ? geojson.features[i].id
 
-       : isFeature
 
-       ? geojson.id
 
-       : undefined;
 
-     isGeometryCollection = geometryMaybeCollection
 
-       ? geometryMaybeCollection.type === "GeometryCollection"
 
-       : false;
 
-     stopG = isGeometryCollection
 
-       ? geometryMaybeCollection.geometries.length
 
-       : 1;
 
-     for (g = 0; g < stopG; g++) {
 
-       geometry = isGeometryCollection
 
-         ? geometryMaybeCollection.geometries[g]
 
-         : geometryMaybeCollection;
 
-       // Handle null Geometry
 
-       if (geometry === null) {
 
-         if (
 
-           callback(
 
-             null,
 
-             featureIndex,
 
-             featureProperties,
 
-             featureBBox,
 
-             featureId
 
-           ) === false
 
-         )
 
-           return false;
 
-         continue;
 
-       }
 
-       switch (geometry.type) {
 
-         case "Point":
 
-         case "LineString":
 
-         case "MultiPoint":
 
-         case "Polygon":
 
-         case "MultiLineString":
 
-         case "MultiPolygon": {
 
-           if (
 
-             callback(
 
-               geometry,
 
-               featureIndex,
 
-               featureProperties,
 
-               featureBBox,
 
-               featureId
 
-             ) === false
 
-           )
 
-             return false;
 
-           break;
 
-         }
 
-         case "GeometryCollection": {
 
-           for (j = 0; j < geometry.geometries.length; j++) {
 
-             if (
 
-               callback(
 
-                 geometry.geometries[j],
 
-                 featureIndex,
 
-                 featureProperties,
 
-                 featureBBox,
 
-                 featureId
 
-               ) === false
 
-             )
 
-               return false;
 
-           }
 
-           break;
 
-         }
 
-         default:
 
-           throw new Error("Unknown Geometry Type");
 
-       }
 
-     }
 
-     // Only increase `featureIndex` per each feature
 
-     featureIndex++;
 
-   }
 
- }
 
- /**
 
-  * Callback for geomReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback geomReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Geometry} currentGeometry The current Geometry being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {Object} featureProperties The current Feature Properties being processed.
 
-  * @param {Array<number>} featureBBox The current Feature BBox being processed.
 
-  * @param {number|string} featureId The current Feature Id being processed.
 
-  */
 
- /**
 
-  * Reduce geometry in any GeoJSON object, similar to Array.reduce().
 
-  *
 
-  * @name geomReduce
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (previousValue, currentGeometry, featureIndex, featureProperties, featureBBox, featureId)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.point([36, 53], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.geomReduce(features, function (previousValue, currentGeometry, featureIndex, featureProperties, featureBBox, featureId) {
 
-  *   //=previousValue
 
-  *   //=currentGeometry
 
-  *   //=featureIndex
 
-  *   //=featureProperties
 
-  *   //=featureBBox
 
-  *   //=featureId
 
-  *   return currentGeometry
 
-  * });
 
-  */
 
- function geomReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   geomEach(
 
-     geojson,
 
-     function (
 
-       currentGeometry,
 
-       featureIndex,
 
-       featureProperties,
 
-       featureBBox,
 
-       featureId
 
-     ) {
 
-       if (featureIndex === 0 && initialValue === undefined)
 
-         previousValue = currentGeometry;
 
-       else
 
-         previousValue = callback(
 
-           previousValue,
 
-           currentGeometry,
 
-           featureIndex,
 
-           featureProperties,
 
-           featureBBox,
 
-           featureId
 
-         );
 
-     }
 
-   );
 
-   return previousValue;
 
- }
 
- /**
 
-  * Callback for flattenEach
 
-  *
 
-  * @callback flattenEachCallback
 
-  * @param {Feature} currentFeature The current flattened feature being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  */
 
- /**
 
-  * Iterate over flattened features in any GeoJSON object, similar to
 
-  * Array.forEach.
 
-  *
 
-  * @name flattenEach
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (currentFeature, featureIndex, multiFeatureIndex)
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.multiPoint([[40, 30], [36, 53]], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.flattenEach(features, function (currentFeature, featureIndex, multiFeatureIndex) {
 
-  *   //=currentFeature
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  * });
 
-  */
 
- function flattenEach(geojson, callback) {
 
-   geomEach(geojson, function (geometry, featureIndex, properties, bbox, id) {
 
-     // Callback for single geometry
 
-     var type = geometry === null ? null : geometry.type;
 
-     switch (type) {
 
-       case null:
 
-       case "Point":
 
-       case "LineString":
 
-       case "Polygon":
 
-         if (
 
-           callback(
 
-             feature(geometry, properties, { bbox: bbox, id: id }),
 
-             featureIndex,
 
-             0
 
-           ) === false
 
-         )
 
-           return false;
 
-         return;
 
-     }
 
-     var geomType;
 
-     // Callback for multi-geometry
 
-     switch (type) {
 
-       case "MultiPoint":
 
-         geomType = "Point";
 
-         break;
 
-       case "MultiLineString":
 
-         geomType = "LineString";
 
-         break;
 
-       case "MultiPolygon":
 
-         geomType = "Polygon";
 
-         break;
 
-     }
 
-     for (
 
-       var multiFeatureIndex = 0;
 
-       multiFeatureIndex < geometry.coordinates.length;
 
-       multiFeatureIndex++
 
-     ) {
 
-       var coordinate = geometry.coordinates[multiFeatureIndex];
 
-       var geom = {
 
-         type: geomType,
 
-         coordinates: coordinate,
 
-       };
 
-       if (
 
-         callback(feature(geom, properties), featureIndex, multiFeatureIndex) ===
 
-         false
 
-       )
 
-         return false;
 
-     }
 
-   });
 
- }
 
- /**
 
-  * Callback for flattenReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback flattenReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Feature} currentFeature The current Feature being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  */
 
- /**
 
-  * Reduce flattened features in any GeoJSON object, similar to Array.reduce().
 
-  *
 
-  * @name flattenReduce
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON object
 
-  * @param {Function} callback a method that takes (previousValue, currentFeature, featureIndex, multiFeatureIndex)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var features = turf.featureCollection([
 
-  *     turf.point([26, 37], {foo: 'bar'}),
 
-  *     turf.multiPoint([[40, 30], [36, 53]], {hello: 'world'})
 
-  * ]);
 
-  *
 
-  * turf.flattenReduce(features, function (previousValue, currentFeature, featureIndex, multiFeatureIndex) {
 
-  *   //=previousValue
 
-  *   //=currentFeature
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   return currentFeature
 
-  * });
 
-  */
 
- function flattenReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   flattenEach(
 
-     geojson,
 
-     function (currentFeature, featureIndex, multiFeatureIndex) {
 
-       if (
 
-         featureIndex === 0 &&
 
-         multiFeatureIndex === 0 &&
 
-         initialValue === undefined
 
-       )
 
-         previousValue = currentFeature;
 
-       else
 
-         previousValue = callback(
 
-           previousValue,
 
-           currentFeature,
 
-           featureIndex,
 
-           multiFeatureIndex
 
-         );
 
-     }
 
-   );
 
-   return previousValue;
 
- }
 
- /**
 
-  * Callback for segmentEach
 
-  *
 
-  * @callback segmentEachCallback
 
-  * @param {Feature<LineString>} currentSegment The current Segment being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  * @param {number} geometryIndex The current index of the Geometry being processed.
 
-  * @param {number} segmentIndex The current index of the Segment being processed.
 
-  * @returns {void}
 
-  */
 
- /**
 
-  * Iterate over 2-vertex line segment in any GeoJSON object, similar to Array.forEach()
 
-  * (Multi)Point geometries do not contain segments therefore they are ignored during this operation.
 
-  *
 
-  * @param {FeatureCollection|Feature|Geometry} geojson any GeoJSON
 
-  * @param {Function} callback a method that takes (currentSegment, featureIndex, multiFeatureIndex, geometryIndex, segmentIndex)
 
-  * @returns {void}
 
-  * @example
 
-  * var polygon = turf.polygon([[[-50, 5], [-40, -10], [-50, -10], [-40, 5], [-50, 5]]]);
 
-  *
 
-  * // Iterate over GeoJSON by 2-vertex segments
 
-  * turf.segmentEach(polygon, function (currentSegment, featureIndex, multiFeatureIndex, geometryIndex, segmentIndex) {
 
-  *   //=currentSegment
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   //=geometryIndex
 
-  *   //=segmentIndex
 
-  * });
 
-  *
 
-  * // Calculate the total number of segments
 
-  * var total = 0;
 
-  * turf.segmentEach(polygon, function () {
 
-  *     total++;
 
-  * });
 
-  */
 
- function segmentEach(geojson, callback) {
 
-   flattenEach(geojson, function (feature, featureIndex, multiFeatureIndex) {
 
-     var segmentIndex = 0;
 
-     // Exclude null Geometries
 
-     if (!feature.geometry) return;
 
-     // (Multi)Point geometries do not contain segments therefore they are ignored during this operation.
 
-     var type = feature.geometry.type;
 
-     if (type === "Point" || type === "MultiPoint") return;
 
-     // Generate 2-vertex line segments
 
-     var previousCoords;
 
-     var previousFeatureIndex = 0;
 
-     var previousMultiIndex = 0;
 
-     var prevGeomIndex = 0;
 
-     if (
 
-       coordEach(
 
-         feature,
 
-         function (
 
-           currentCoord,
 
-           coordIndex,
 
-           featureIndexCoord,
 
-           multiPartIndexCoord,
 
-           geometryIndex
 
-         ) {
 
-           // Simulating a meta.coordReduce() since `reduce` operations cannot be stopped by returning `false`
 
-           if (
 
-             previousCoords === undefined ||
 
-             featureIndex > previousFeatureIndex ||
 
-             multiPartIndexCoord > previousMultiIndex ||
 
-             geometryIndex > prevGeomIndex
 
-           ) {
 
-             previousCoords = currentCoord;
 
-             previousFeatureIndex = featureIndex;
 
-             previousMultiIndex = multiPartIndexCoord;
 
-             prevGeomIndex = geometryIndex;
 
-             segmentIndex = 0;
 
-             return;
 
-           }
 
-           var currentSegment = lineString(
 
-             [previousCoords, currentCoord],
 
-             feature.properties
 
-           );
 
-           if (
 
-             callback(
 
-               currentSegment,
 
-               featureIndex,
 
-               multiFeatureIndex,
 
-               geometryIndex,
 
-               segmentIndex
 
-             ) === false
 
-           )
 
-             return false;
 
-           segmentIndex++;
 
-           previousCoords = currentCoord;
 
-         }
 
-       ) === false
 
-     )
 
-       return false;
 
-   });
 
- }
 
- /**
 
-  * Callback for segmentReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback segmentReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Feature<LineString>} currentSegment The current Segment being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed.
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed.
 
-  * @param {number} geometryIndex The current index of the Geometry being processed.
 
-  * @param {number} segmentIndex The current index of the Segment being processed.
 
-  */
 
- /**
 
-  * Reduce 2-vertex line segment in any GeoJSON object, similar to Array.reduce()
 
-  * (Multi)Point geometries do not contain segments therefore they are ignored during this operation.
 
-  *
 
-  * @param {FeatureCollection|Feature|Geometry} 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}
 
-  * @example
 
-  * var polygon = turf.polygon([[[-50, 5], [-40, -10], [-50, -10], [-40, 5], [-50, 5]]]);
 
-  *
 
-  * // Iterate over GeoJSON by 2-vertex segments
 
-  * turf.segmentReduce(polygon, function (previousSegment, currentSegment, featureIndex, multiFeatureIndex, geometryIndex, segmentIndex) {
 
-  *   //= previousSegment
 
-  *   //= currentSegment
 
-  *   //= featureIndex
 
-  *   //= multiFeatureIndex
 
-  *   //= geometryIndex
 
-  *   //= segmentIndex
 
-  *   return currentSegment
 
-  * });
 
-  *
 
-  * // Calculate the total number of segments
 
-  * var initialValue = 0
 
-  * var total = turf.segmentReduce(polygon, function (previousValue) {
 
-  *     previousValue++;
 
-  *     return previousValue;
 
-  * }, initialValue);
 
-  */
 
- function segmentReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   var started = false;
 
-   segmentEach(
 
-     geojson,
 
-     function (
 
-       currentSegment,
 
-       featureIndex,
 
-       multiFeatureIndex,
 
-       geometryIndex,
 
-       segmentIndex
 
-     ) {
 
-       if (started === false && initialValue === undefined)
 
-         previousValue = currentSegment;
 
-       else
 
-         previousValue = callback(
 
-           previousValue,
 
-           currentSegment,
 
-           featureIndex,
 
-           multiFeatureIndex,
 
-           geometryIndex,
 
-           segmentIndex
 
-         );
 
-       started = true;
 
-     }
 
-   );
 
-   return previousValue;
 
- }
 
- /**
 
-  * Callback for lineEach
 
-  *
 
-  * @callback lineEachCallback
 
-  * @param {Feature<LineString>} currentLine The current LineString|LinearRing being processed
 
-  * @param {number} featureIndex The current index of the Feature being processed
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed
 
-  * @param {number} geometryIndex The current index of the Geometry being processed
 
-  */
 
- /**
 
-  * Iterate over line or ring coordinates in LineString, Polygon, MultiLineString, MultiPolygon Features or Geometries,
 
-  * similar to Array.forEach.
 
-  *
 
-  * @name lineEach
 
-  * @param {Geometry|Feature<LineString|Polygon|MultiLineString|MultiPolygon>} geojson object
 
-  * @param {Function} callback a method that takes (currentLine, featureIndex, multiFeatureIndex, geometryIndex)
 
-  * @example
 
-  * var multiLine = turf.multiLineString([
 
-  *   [[26, 37], [35, 45]],
 
-  *   [[36, 53], [38, 50], [41, 55]]
 
-  * ]);
 
-  *
 
-  * turf.lineEach(multiLine, function (currentLine, featureIndex, multiFeatureIndex, geometryIndex) {
 
-  *   //=currentLine
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   //=geometryIndex
 
-  * });
 
-  */
 
- function lineEach(geojson, callback) {
 
-   // validation
 
-   if (!geojson) throw new Error("geojson is required");
 
-   flattenEach(geojson, function (feature, featureIndex, multiFeatureIndex) {
 
-     if (feature.geometry === null) return;
 
-     var type = feature.geometry.type;
 
-     var coords = feature.geometry.coordinates;
 
-     switch (type) {
 
-       case "LineString":
 
-         if (callback(feature, featureIndex, multiFeatureIndex, 0, 0) === false)
 
-           return false;
 
-         break;
 
-       case "Polygon":
 
-         for (
 
-           var geometryIndex = 0;
 
-           geometryIndex < coords.length;
 
-           geometryIndex++
 
-         ) {
 
-           if (
 
-             callback(
 
-               lineString(coords[geometryIndex], feature.properties),
 
-               featureIndex,
 
-               multiFeatureIndex,
 
-               geometryIndex
 
-             ) === false
 
-           )
 
-             return false;
 
-         }
 
-         break;
 
-     }
 
-   });
 
- }
 
- /**
 
-  * Callback for lineReduce
 
-  *
 
-  * The first time the callback function is called, the values provided as arguments depend
 
-  * on whether the reduce method has an initialValue argument.
 
-  *
 
-  * If an initialValue is provided to the reduce method:
 
-  *  - The previousValue argument is initialValue.
 
-  *  - The currentValue argument is the value of the first element present in the array.
 
-  *
 
-  * If an initialValue is not provided:
 
-  *  - The previousValue argument is the value of the first element present in the array.
 
-  *  - The currentValue argument is the value of the second element present in the array.
 
-  *
 
-  * @callback lineReduceCallback
 
-  * @param {*} previousValue The accumulated value previously returned in the last invocation
 
-  * of the callback, or initialValue, if supplied.
 
-  * @param {Feature<LineString>} currentLine The current LineString|LinearRing being processed.
 
-  * @param {number} featureIndex The current index of the Feature being processed
 
-  * @param {number} multiFeatureIndex The current index of the Multi-Feature being processed
 
-  * @param {number} geometryIndex The current index of the Geometry being processed
 
-  */
 
- /**
 
-  * Reduce features in any GeoJSON object, similar to Array.reduce().
 
-  *
 
-  * @name lineReduce
 
-  * @param {Geometry|Feature<LineString|Polygon|MultiLineString|MultiPolygon>} geojson object
 
-  * @param {Function} callback a method that takes (previousValue, currentLine, featureIndex, multiFeatureIndex, geometryIndex)
 
-  * @param {*} [initialValue] Value to use as the first argument to the first call of the callback.
 
-  * @returns {*} The value that results from the reduction.
 
-  * @example
 
-  * var multiPoly = turf.multiPolygon([
 
-  *   turf.polygon([[[12,48],[2,41],[24,38],[12,48]], [[9,44],[13,41],[13,45],[9,44]]]),
 
-  *   turf.polygon([[[5, 5], [0, 0], [2, 2], [4, 4], [5, 5]]])
 
-  * ]);
 
-  *
 
-  * turf.lineReduce(multiPoly, function (previousValue, currentLine, featureIndex, multiFeatureIndex, geometryIndex) {
 
-  *   //=previousValue
 
-  *   //=currentLine
 
-  *   //=featureIndex
 
-  *   //=multiFeatureIndex
 
-  *   //=geometryIndex
 
-  *   return currentLine
 
-  * });
 
-  */
 
- function lineReduce(geojson, callback, initialValue) {
 
-   var previousValue = initialValue;
 
-   lineEach(
 
-     geojson,
 
-     function (currentLine, featureIndex, multiFeatureIndex, geometryIndex) {
 
-       if (featureIndex === 0 && initialValue === undefined)
 
-         previousValue = currentLine;
 
-       else
 
-         previousValue = callback(
 
-           previousValue,
 
-           currentLine,
 
-           featureIndex,
 
-           multiFeatureIndex,
 
-           geometryIndex
 
-         );
 
-     }
 
-   );
 
-   return previousValue;
 
- }
 
- /**
 
-  * Finds a particular 2-vertex LineString Segment from a GeoJSON using `@turf/meta` indexes.
 
-  *
 
-  * Negative indexes are permitted.
 
-  * Point & MultiPoint will always return null.
 
-  *
 
-  * @param {FeatureCollection|Feature|Geometry} geojson Any GeoJSON Feature or Geometry
 
-  * @param {Object} [options={}] Optional parameters
 
-  * @param {number} [options.featureIndex=0] Feature Index
 
-  * @param {number} [options.multiFeatureIndex=0] Multi-Feature Index
 
-  * @param {number} [options.geometryIndex=0] Geometry Index
 
-  * @param {number} [options.segmentIndex=0] Segment Index
 
-  * @param {Object} [options.properties={}] Translate Properties to output LineString
 
-  * @param {BBox} [options.bbox={}] Translate BBox to output LineString
 
-  * @param {number|string} [options.id={}] Translate Id to output LineString
 
-  * @returns {Feature<LineString>} 2-vertex GeoJSON Feature LineString
 
-  * @example
 
-  * var multiLine = turf.multiLineString([
 
-  *     [[10, 10], [50, 30], [30, 40]],
 
-  *     [[-10, -10], [-50, -30], [-30, -40]]
 
-  * ]);
 
-  *
 
-  * // First Segment (defaults are 0)
 
-  * turf.findSegment(multiLine);
 
-  * // => Feature<LineString<[[10, 10], [50, 30]]>>
 
-  *
 
-  * // First Segment of 2nd Multi Feature
 
-  * turf.findSegment(multiLine, {multiFeatureIndex: 1});
 
-  * // => Feature<LineString<[[-10, -10], [-50, -30]]>>
 
-  *
 
-  * // Last Segment of Last Multi Feature
 
-  * turf.findSegment(multiLine, {multiFeatureIndex: -1, segmentIndex: -1});
 
-  * // => Feature<LineString<[[-50, -30], [-30, -40]]>>
 
-  */
 
- function findSegment(geojson, options) {
 
-   // Optional Parameters
 
-   options = options || {};
 
-   if (!isObject(options)) throw new Error("options is invalid");
 
-   var featureIndex = options.featureIndex || 0;
 
-   var multiFeatureIndex = options.multiFeatureIndex || 0;
 
-   var geometryIndex = options.geometryIndex || 0;
 
-   var segmentIndex = options.segmentIndex || 0;
 
-   // Find FeatureIndex
 
-   var properties = options.properties;
 
-   var geometry;
 
-   switch (geojson.type) {
 
-     case "FeatureCollection":
 
-       if (featureIndex < 0)
 
-         featureIndex = geojson.features.length + featureIndex;
 
-       properties = properties || geojson.features[featureIndex].properties;
 
-       geometry = geojson.features[featureIndex].geometry;
 
-       break;
 
-     case "Feature":
 
-       properties = properties || geojson.properties;
 
-       geometry = geojson.geometry;
 
-       break;
 
-     case "Point":
 
-     case "MultiPoint":
 
-       return null;
 
-     case "LineString":
 
-     case "Polygon":
 
-     case "MultiLineString":
 
-     case "MultiPolygon":
 
-       geometry = geojson;
 
-       break;
 
-     default:
 
-       throw new Error("geojson is invalid");
 
-   }
 
-   // Find SegmentIndex
 
-   if (geometry === null) return null;
 
-   var coords = geometry.coordinates;
 
-   switch (geometry.type) {
 
-     case "Point":
 
-     case "MultiPoint":
 
-       return null;
 
-     case "LineString":
 
-       if (segmentIndex < 0) segmentIndex = coords.length + segmentIndex - 1;
 
-       return lineString(
 
-         [coords[segmentIndex], coords[segmentIndex + 1]],
 
-         properties,
 
-         options
 
-       );
 
-     case "Polygon":
 
-       if (geometryIndex < 0) geometryIndex = coords.length + geometryIndex;
 
-       if (segmentIndex < 0)
 
-         segmentIndex = coords[geometryIndex].length + segmentIndex - 1;
 
-       return lineString(
 
-         [
 
-           coords[geometryIndex][segmentIndex],
 
-           coords[geometryIndex][segmentIndex + 1],
 
-         ],
 
-         properties,
 
-         options
 
-       );
 
-     case "MultiLineString":
 
-       if (multiFeatureIndex < 0)
 
-         multiFeatureIndex = coords.length + multiFeatureIndex;
 
-       if (segmentIndex < 0)
 
-         segmentIndex = coords[multiFeatureIndex].length + segmentIndex - 1;
 
-       return lineString(
 
-         [
 
-           coords[multiFeatureIndex][segmentIndex],
 
-           coords[multiFeatureIndex][segmentIndex + 1],
 
-         ],
 
-         properties,
 
-         options
 
-       );
 
-     case "MultiPolygon":
 
-       if (multiFeatureIndex < 0)
 
-         multiFeatureIndex = coords.length + multiFeatureIndex;
 
-       if (geometryIndex < 0)
 
-         geometryIndex = coords[multiFeatureIndex].length + geometryIndex;
 
-       if (segmentIndex < 0)
 
-         segmentIndex =
 
-           coords[multiFeatureIndex][geometryIndex].length - segmentIndex - 1;
 
-       return lineString(
 
-         [
 
-           coords[multiFeatureIndex][geometryIndex][segmentIndex],
 
-           coords[multiFeatureIndex][geometryIndex][segmentIndex + 1],
 
-         ],
 
-         properties,
 
-         options
 
-       );
 
-   }
 
-   throw new Error("geojson is invalid");
 
- }
 
- /**
 
-  * Finds a particular Point from a GeoJSON using `@turf/meta` indexes.
 
-  *
 
-  * Negative indexes are permitted.
 
-  *
 
-  * @param {FeatureCollection|Feature|Geometry} geojson Any GeoJSON Feature or Geometry
 
-  * @param {Object} [options={}] Optional parameters
 
-  * @param {number} [options.featureIndex=0] Feature Index
 
-  * @param {number} [options.multiFeatureIndex=0] Multi-Feature Index
 
-  * @param {number} [options.geometryIndex=0] Geometry Index
 
-  * @param {number} [options.coordIndex=0] Coord Index
 
-  * @param {Object} [options.properties={}] Translate Properties to output Point
 
-  * @param {BBox} [options.bbox={}] Translate BBox to output Point
 
-  * @param {number|string} [options.id={}] Translate Id to output Point
 
-  * @returns {Feature<Point>} 2-vertex GeoJSON Feature Point
 
-  * @example
 
-  * var multiLine = turf.multiLineString([
 
-  *     [[10, 10], [50, 30], [30, 40]],
 
-  *     [[-10, -10], [-50, -30], [-30, -40]]
 
-  * ]);
 
-  *
 
-  * // First Segment (defaults are 0)
 
-  * turf.findPoint(multiLine);
 
-  * // => Feature<Point<[10, 10]>>
 
-  *
 
-  * // First Segment of the 2nd Multi-Feature
 
-  * turf.findPoint(multiLine, {multiFeatureIndex: 1});
 
-  * // => Feature<Point<[-10, -10]>>
 
-  *
 
-  * // Last Segment of last Multi-Feature
 
-  * turf.findPoint(multiLine, {multiFeatureIndex: -1, coordIndex: -1});
 
-  * // => Feature<Point<[-30, -40]>>
 
-  */
 
- function findPoint(geojson, options) {
 
-   // Optional Parameters
 
-   options = options || {};
 
-   if (!isObject(options)) throw new Error("options is invalid");
 
-   var featureIndex = options.featureIndex || 0;
 
-   var multiFeatureIndex = options.multiFeatureIndex || 0;
 
-   var geometryIndex = options.geometryIndex || 0;
 
-   var coordIndex = options.coordIndex || 0;
 
-   // Find FeatureIndex
 
-   var properties = options.properties;
 
-   var geometry;
 
-   switch (geojson.type) {
 
-     case "FeatureCollection":
 
-       if (featureIndex < 0)
 
-         featureIndex = geojson.features.length + featureIndex;
 
-       properties = properties || geojson.features[featureIndex].properties;
 
-       geometry = geojson.features[featureIndex].geometry;
 
-       break;
 
-     case "Feature":
 
-       properties = properties || geojson.properties;
 
-       geometry = geojson.geometry;
 
-       break;
 
-     case "Point":
 
-     case "MultiPoint":
 
-       return null;
 
-     case "LineString":
 
-     case "Polygon":
 
-     case "MultiLineString":
 
-     case "MultiPolygon":
 
-       geometry = geojson;
 
-       break;
 
-     default:
 
-       throw new Error("geojson is invalid");
 
-   }
 
-   // Find Coord Index
 
-   if (geometry === null) return null;
 
-   var coords = geometry.coordinates;
 
-   switch (geometry.type) {
 
-     case "Point":
 
-       return point(coords, properties, options);
 
-     case "MultiPoint":
 
-       if (multiFeatureIndex < 0)
 
-         multiFeatureIndex = coords.length + multiFeatureIndex;
 
-       return point(coords[multiFeatureIndex], properties, options);
 
-     case "LineString":
 
-       if (coordIndex < 0) coordIndex = coords.length + coordIndex;
 
-       return point(coords[coordIndex], properties, options);
 
-     case "Polygon":
 
-       if (geometryIndex < 0) geometryIndex = coords.length + geometryIndex;
 
-       if (coordIndex < 0)
 
-         coordIndex = coords[geometryIndex].length + coordIndex;
 
-       return point(coords[geometryIndex][coordIndex], properties, options);
 
-     case "MultiLineString":
 
-       if (multiFeatureIndex < 0)
 
-         multiFeatureIndex = coords.length + multiFeatureIndex;
 
-       if (coordIndex < 0)
 
-         coordIndex = coords[multiFeatureIndex].length + coordIndex;
 
-       return point(coords[multiFeatureIndex][coordIndex], properties, options);
 
-     case "MultiPolygon":
 
-       if (multiFeatureIndex < 0)
 
-         multiFeatureIndex = coords.length + multiFeatureIndex;
 
-       if (geometryIndex < 0)
 
-         geometryIndex = coords[multiFeatureIndex].length + geometryIndex;
 
-       if (coordIndex < 0)
 
-         coordIndex =
 
-           coords[multiFeatureIndex][geometryIndex].length - coordIndex;
 
-       return point(
 
-         coords[multiFeatureIndex][geometryIndex][coordIndex],
 
-         properties,
 
-         options
 
-       );
 
-   }
 
-   throw new Error("geojson is invalid");
 
- }
 
- export { coordAll, coordEach, coordReduce, featureEach, featureReduce, findPoint, findSegment, flattenEach, flattenReduce, geomEach, geomReduce, lineEach, lineReduce, propEach, propReduce, segmentEach, segmentReduce };
 
 
  |