Introduce "analyze" verb and framework.

Introduce a new "analyze" command and start setting up the inspector /
analyzer pipeline with a simple "gap analysis" inspector using a
reference-counted gap detection approach.

src/inspectors/gap-inspector.js

@@ -0,0 +1,86 @@
+/**
+Employment gap analysis for HackMyResume.
+@license MIT. See LICENSE.md for details.
+@module gap-analyzer.js
+*/
+
+
+
+(function() {
+
+
+
+  var _ = require('underscore');
+  var FluentDate = require('../core/fluent-date');
+
+
+
+  /**
+  Identify gaps in the candidate's employment history.
+  @class gapInspector
+  */
+  var gapInspector = module.exports = {
+
+
+
+    moniker: 'gap-inspector',
+
+    /**
+    Run the Gap Analyzer on a resume.
+    @method run
+    @return An array of object representing gaps in the candidate's employment
+    history. Each object provides the start, end, and duration of the gap:
+        { <-- gap
+          start: // A Moment.js date
+          end: // A Moment.js date
+          duration: // Gap length
+        }
+    */
+    run: function( rez ) {
+
+      // Convert the candidate's employment history to an array of dates,
+      // where each element in the array is a start date or an end date of a
+      // job -- it doesn't matter which.
+      var new_e = rez.employment.history.map( function( job ){
+        var obj = _.pairs( _.pick( job, ['start', 'end'] ) );
+        obj[0][1] = FluentDate.fmt( obj[0][1] );
+        if( obj.length > 1 )
+          obj[1][1] = FluentDate.fmt( obj[1][1] );
+        return obj;
+      });
+
+      // Flatten the array.
+      new_e = _.flatten( new_e, true );
+
+      // Sort the array, mixing start dates and end dates together
+      new_e = _.sortBy( new_e, function( elem ) { return elem[1].unix(); });
+
+      // Iterative over elements in the array. Each time a start date is found,
+      // increment a reference count. Each time an end date is found, decrement
+      // the reference count. When the reference count reaches 0, we have a gap.
+      // When the reference count is > 0, the candidate is employed.
+      var num_gaps = 0, ref_count = 0, gap_start,gaps = [];
+      new_e.forEach( function(point) {
+        var inc = point[0] === 'start' ? 1 : -1;
+        ref_count += inc;
+        if( ref_count === 0 ) {
+          gaps.push( { start: point[1], end: null });
+        }
+        else if( ref_count === 1 && inc === 1 ) {
+          var lastGap = _.last( gaps );
+          if( lastGap ) {
+            lastGap.end = point[1];
+            lastGap.duration = lastGap.end.diff( lastGap.start, 'days' );
+          }
+        }
+      });
+
+      return gaps;
+    }
+
+
+  };
+
+
+
+}());