Add -calc + and -info + options

src/cli/mapshaper-command-utils.mjs

@@ -6,7 +6,7 @@ import { dissolveArcs } from '../paths/mapshaper-arc-dissolve';
 // Apply a command to an array of target layers
 export function applyCommandToEachLayer(func, targetLayers) {
   var args = utils.toArray(arguments).slice(2);
-  return targetLayers.reduce(function(memo, lyr) {
+  var output = targetLayers.reduce(function(memo, lyr) {
     var result = func.apply(null, [lyr].concat(args));
     if (utils.isArray(result)) { // some commands return an array of layers
       memo = memo.concat(result);
@@ -15,6 +15,7 @@ export function applyCommandToEachLayer(func, targetLayers) {
     }
     return memo;
   }, []);
+  return output.length > 0 ? output : null;
 }
 
 export function applyCommandToEachTarget(func, targets) {

src/cli/mapshaper-options.mjs

@@ -14,9 +14,17 @@ export function getOptionParser() {
         alias: '+',
         type: 'flag',
         label: '+, no-replace', // show alias as primary option
-        // describe: 'retain the original layer(s) instead of replacing'
         describe: 'retain both input and output layer(s)'
       },
+      nameOpt2 = { // for -calc and -info
+        describe: 'name the output layer'
+      },
+      noReplaceOpt2 = { // for -calc and -info
+        alias: '+',
+        type: 'flag',
+        label: '+',
+        describe: 'save output to a new layer'
+      },
       noSnapOpt = {
         // describe: 'don't snap points before applying command'
         type: 'flag'
@@ -1911,8 +1919,8 @@ export function getOptionParser() {
       type: 'flag'
     })
     .option('calc', calcOpt)
-    .option('name', nameOpt)
     .option('target', targetOpt)
+    .option('name', nameOpt)
     .option('no-replace', noReplaceOpt);
 
   parser.command('require')
@@ -2072,7 +2080,9 @@ export function getOptionParser() {
       describe: 'functions: sum() average() median() max() min() count()'
     })
     .option('where', whereOpt)
-    .option('target', targetOpt);
+    .option('target', targetOpt)
+    .option('to-layer', noReplaceOpt2)
+    .option('name', nameOpt2);
 
   parser.command('colors')
     .describe('print list of color scheme names');
@@ -2102,7 +2112,9 @@ export function getOptionParser() {
     .option('save-to', {
       describe: 'name of file to save info in JSON format'
     })
-    .option('target', targetOpt);
+    .option('target', targetOpt)
+    .option('to-layer', noReplaceOpt2)
+    .option('name', nameOpt2);
 
   parser.command('inspect')
     .describe('print information about a feature')

src/cli/mapshaper-run-command.mjs

@@ -203,7 +203,7 @@ export async function runCommand(command, job) {
       applyCommandToEachLayer(cmd.cluster, targetLayers, arcs, opts);
 
     } else if (name == 'calc') {
-      applyCommandToEachLayer(cmd.calc, targetLayers, arcs, opts);
+      outputDataset = cmd.calc(targetLayers, arcs, opts);
 
     } else if (name == 'classify') {
       applyCommandToEachLayer(cmd.classify, targetLayers, targetDataset, opts);
@@ -317,7 +317,7 @@ export async function runCommand(command, job) {
       cmd.include(opts);
 
     } else if (name == 'info') {
-      cmd.info(targets, opts);
+      outputDataset = cmd.info(targets, opts);
 
     } else if (name == 'inlay') {
       outputLayers = cmd.inlay(targetLayers, source, targetDataset, opts);

src/commands/mapshaper-calc.mjs

@@ -6,6 +6,20 @@ import cmd from '../mapshaper-cmd';
 import utils from '../utils/mapshaper-utils';
 import { getStashedVar } from '../mapshaper-stash';
 import { message, error, stop } from '../utils/mapshaper-logging';
+import { DataTable } from '../datatable/mapshaper-data-table';
+
+
+cmd.calc = function(layers, arcs, opts) {
+  var arr = layers.map(lyr => applyCalcExpression(lyr, arcs, opts));
+  if (!opts.to_layer) return null;
+  return {
+    info: {},
+    layers: [{
+      name: opts.name || 'info',
+      data: new DataTable(arr)
+    }]
+  };
+};
 
 // Calculate an expression across a group of features, print and return the result
 // Supported functions include sum(), average(), max(), min(), median(), count()
@@ -14,9 +28,9 @@ import { message, error, stop } from '../utils/mapshaper-logging';
 // opts.expression  Expression to evaluate
 // opts.where  Optional filter expression (see -filter command)
 //
-cmd.calc = function(lyr, arcs, opts) {
+export function applyCalcExpression(lyr, arcs, opts) {
   var msg = opts.expression,
-      result, compiled, defs;
+      result, compiled, defs, d;
   if (opts.where) {
     // TODO: implement no_replace option for filter() instead of this
     lyr = getLayerSelection(lyr, arcs, opts);
@@ -27,9 +41,17 @@ cmd.calc = function(lyr, arcs, opts) {
   defs = getStashedVar('defs');
   compiled = compileCalcExpression(lyr, arcs, opts.expression);
   result = compiled(null, defs);
-  message(msg + ":  " + result);
-  return result;
-};
+  if (!opts.to_layer) {
+    message(msg + ":  " + result);
+  }
+  d = {
+    expression: opts.expression,
+    value: result
+  };
+  if (opts.where) d.where = opts.where;
+  if (lyr.name) d.layer_name = lyr.name;
+  return d;
+}
 
 export function evalCalcExpression(lyr, arcs, exp) {
   return compileCalcExpression(lyr, arcs, exp)();

src/commands/mapshaper-info.mjs

@@ -9,6 +9,7 @@ import geom from '../geom/mapshaper-geom';
 import { message } from '../utils/mapshaper-logging';
 import { NodeCollection } from '../topology/mapshaper-nodes';
 import cmd from '../mapshaper-cmd';
+import { DataTable } from '../datatable/mapshaper-data-table';
 
 var MAX_RULE_LEN = 50;
 
@@ -17,14 +18,24 @@ cmd.info = function(targets, opts) {
   var arr = layers.map(function(o) {
     return getLayerInfo(o.layer, o.dataset);
   });
-  message(formatInfo(arr));
+
   if (opts.save_to) {
     var output = [{
       filename: opts.save_to + (opts.save_to.endsWith('.json') ? '' : '.json'),
       content: JSON.stringify(arr, null, 2)
     }];
     writeFiles(output, opts);
   }
+  if (opts.to_layer) {
+    return {
+      info: {},
+      layers: [{
+        name: opts.name || 'info',
+        data: new DataTable(arr)
+      }]
+    };
+  }
+  message(formatInfo(arr));
 };
 
 cmd.printInfo = cmd.info; // old name

test/calc-test.mjs

@@ -16,8 +16,14 @@ describe('mapshaper-calc.js', function () {
         done();
       });
     })
-  });
 
+    it('+ option creates a new layer', async function() {
+      var data = [{a: 1}, {a: 3}];
+      var cmd = 'data.json -calc + "sum(a)" -o out.csv';
+      var out = await api.applyCommands(cmd, {'data.json': data});
+      assert.equal(out['out.csv'], 'expression,value,layer_name\nsum(a),4,data')
+    })
+  });
 
   describe('evalCalcExpression()', function () {
     var data1 = [{foo: -1}, {foo: 3}, {foo: 4}],
@@ -178,9 +184,9 @@ describe('mapshaper-calc.js', function () {
             data: new api.internal.DataTable(data2)
           };
 
-      var result = api.cmd.calc(lyr2, null,
-          {no_replace: true, expression: 'average(foo)', where: '!!bar'});
-      assert.deepEqual(result.data.getRecords(), [{
+      var result = api.cmd.calc([lyr2], null,
+          {to_layer: true, expression: 'average(foo)', where: '!!bar'});
+      assert.deepEqual(result.layers[0].data.getRecords(), [{
         value: 1,
         where: '!!bar',
         expression: 'average(foo)'

test/info-test.mjs

@@ -3,6 +3,17 @@ import api from '../mapshaper.js';
 
 
 describe('mapshaper-info.js', function () {
+  describe('+ option', function() {
+    it('simple table', async function() {
+      var data = [{foo: 'bar'}, {foo: 'baz'}];
+      var cmd = 'data.json -info + -o format=json';
+      var out = await api.applyCommands(cmd, {'data.json': data});
+      var d = JSON.parse(out['info.json'])[0];
+      assert.equal(d.layer_name, 'data');
+      assert.equal(d.feature_count, 2);
+    });
+
+  })
 
   describe('save-to option', function() {