mock census parser for cs 142

mock-census/README.md

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+CS 142 Mid-Term 2 (Fall 2010)
+====
+
+**Mock Census Parser**
+
+Must read a file via HTTP or on the local filesystem.
+
+(The file has ostensibly just passed validation and needs no further error-checking)
+
+The file contains three newline-delimited directives per block and one EOF directive.
+
+Each directive has a number of space-delimited attributes.
+
+The directives appear in this order:
+
+ * `Head` - this must be the start of the block. Represents the head of household
+   * name - first name of the individual
+   * gender
+   * eye_color
+   * hair_color
+   * height - feet as a float
+
+ * `Depedent` - 0 or many may exist. Represents children, spouse, etc
+   * name
+   * gender
+   * age - 'minor' or 'adult'
+   * height
+
+ * `End` - must close the block before the next 'Head'
+
+ * `SUPER-END` - a special end-of-file (EOF) marker
+   * `end` MUST precede `SUPER-END`
+
+Example Data File
+====
+
+    Head Kevin M brown brown 6.15
+    Dependent Dagmar F adult 5.9
+    Dependent Dorkus M minor 5.7
+    End
+    Head Eve F blue brown 5.5
+    Dependent Adam M adult 6.2
+    Dependent Fred M minor 6.1
+    Dependent Fredwenda F adult 5.3
+    End
+    Head Pentultimus M brown brown 6
+    End
+    Head Beautisha F green red 5.7
+    Dependent Bodacious M minor 4.0
+    End
+    SUPER-END
+
+Variations from the Spec
+====
+
+My implementation is written in JavaScript (which is like LISP, not at all like Java).
+I take advantage of some JavaScript-isms.
+
+In my implementation I also handle `#` comments as well as some extremely minimalistic error-checking.

mock-census/mock-census-test.sh

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+# invalid
+node mock-census.js
+node mock-census.js files:///path/to/file
+node mock-census.js httpss://domain.tld/resource
+# valid
+node mock-census.js /path/to/file
+node mock-census.js file:///path/to/file
+node mock-census.js http://domain.tld/resource
+node mock-census.js https://domain.tld/resource

mock-census/mock-census.js

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+// TODO parse streaming
+"use strict";
+(function (undefined) {
+  var fs = require('fs'),
+    url = require('url'),
+    ahr = require('ahr'),
+    stream,
+    node = process.argv[0],
+    self = process.argv[1],
+    fulluri = process.argv[2],
+    uri;
+
+  self = self.substr(self.lastIndexOf('/') + 1);
+
+  require('remedial');
+
+  function usage() {
+    console.log("Usage: node {self}".supplant({self: self}) + 
+      " file:///path/to/file | http://path/to/file");
+  }
+
+
+  // Head, and Dependent "Classes"
+  function Comment(lines) {
+    while (true) {
+      line = lines.shift();
+      if (undefined === line || null === line) {
+        throw new Error("Expected 'Dependent' or 'end' but reach end-of-file");
+      }
+      if (!line.match(/\s*#/)){
+        break;
+      }
+    }
+    return line;
+  }
+
+  function Dependent(lines) {
+    var line, dep;
+    line = Comment(lines);
+    
+    if (line.match(/^Dependent\s*/)) {
+      parts = line.split(/\s+/);
+      dep = {
+        // no error checking in spec
+        name: parts[1],
+        gender: parts[2],
+        age: parts[3],
+        height: parseInt(parts[4], 10),
+      };
+    } else if (line.match(/^End\s*/)) {
+      return false;
+    } else {
+      throw new Error("Expected 'Dependent' or 'End' but saw\n    " + line.substr(0,20));
+    }
+    return dep;
+  }
+
+  function Head(lines) {
+    var line, head, parts, dep;
+    line = Comment(lines);
+
+    if (line.match(/^Head\s*/)) {
+      parts = line.split(/\s+/);
+      head = {
+        // no error checking in spec
+        name: parts[1],
+        gender: parts[2],
+        eye_color: parts[3],
+        hair_color: parts[4],
+        height: parseInt(parts[5], 10),
+        deps: []
+      };
+      while (dep = Dependent(lines)) {
+        head.deps.push(dep);
+      }
+    } else if (line.match(/^SUPER-END\s*/)) {
+      return false;
+    } else {
+        throw new Error("Expected 'Head' or 'SUPER-END' but saw\n    " + line.substr(0,20));
+    }
+    return head;
+  }
+
+  function readFile(file) {
+    var promise = require('futures').promise(),
+      stream,
+      data = new Buffer('');
+
+    stream = fs.createReadStream(file, { flags: 'r' });
+    stream.on('error', function (err) {
+      promise.fulfill(err, stream, data);
+    });
+    stream.on('data', function (chunk) {
+      data += chunk;
+    });
+    stream.on('end', function () {
+      promise.fulfill(undefined, stream, data);
+    });
+    return promise;
+  }
+
+  // Queries
+
+  // Average height of Heads of Household
+  function query1(heads) {
+    var heights = 0.0;
+    heads.forEach(function (head) {
+      heights += head.height;
+    });
+    console.log("Average Height of Heads of Household: " + (heights / heads.length));
+  }
+
+  // What is the height of the tallest of all dependents?
+  function query2(heads) {
+    var max = 0.0;
+    heads.forEach(function (head) {
+      head.deps.forEach(function (dep) {
+        max = Math.max(max, dep.height);
+      });
+    });
+    console.log("Height of tallest Dependent: " + max);
+  }
+
+  // The height of the shortest Dependent of a female Head of Household
+  function query3(heads) {
+    var min = Infinity;
+    heads.forEach(function (head) {
+      if ('F' !== head.gender) {
+        return;
+      }
+      head.deps.forEach(function (dep) {
+        min = Math.min(min, dep.height);
+      });
+    });
+    console.log("Height of shortest Dependent of a Female-Headed Household: " + min);
+  }
+
+  // Average height of male dependents of brown-haired male heads of houshold
+  function query4(heads) {
+    var heights = 0.0, count = 0;
+    heads.forEach(function (head) {
+      if ('m' !== head.gender && 'brown' !== head.hair_color) {
+        return;
+      }
+      head.deps.forEach(function (dep) {
+        count += 1;
+        heights += dep.height;
+      });
+    });
+    console.log("Average height of male dependent of brown-haired male Heads of Household: " + (heights / count));
+  }
+
+  function parseData(err, x, data) {
+    var lines = data.split('\n'),
+      heads = [],
+      curHead;
+
+    while (curHead = Head(lines)) {
+      heads.push(curHead);
+    }
+    console.log(JSON.stringify(heads, null, '  '));
+    query1(heads);
+    query2(heads);
+    query3(heads);
+    query4(heads);
+    return heads;
+  }
+
+  function main() {
+    if (!fulluri) {
+      usage();
+      return;
+    }
+      
+    uri = url.parse(fulluri, true);
+    if (!uri.protocol) {
+      uri.protocol = '';
+    }
+    if ('file:' === uri.protocol || '' === uri.protocol) {
+      readFile(uri.pathname).when(parseData);
+    } else if (uri.protocol.match(/^http[s]?:$/)) {
+      ahr.get(fulluri).when(parseData);
+    } else {
+      usage();
+      return;
+    }
+  }
+
+  main();
+
+}());

mock-census/mock-census.txt

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+#Head First Gender Eye-color Hair-color Height (exactly one per block)
+Head Kevin M brown brown 6.15
+#Dependent First Gender Age Height (0 or more per block)
+Dependent Dagmar F adult 5.9
+Dependent Dorkus M minor 5.7
+#End end-of-block
+End
+Head Eve F blue brown 5.5
+Dependent Adam M adult 6.2
+Dependent Fred M minor 6.1
+Dependent Fredwenda F adult 5.3
+End
+Head Pentultimus M brown brown 6
+End
+Head Beautisha F green red 5.7
+Dependent Bodacious M minor 4.0
+End
+#SUPER-END end-of-file
+SUPER-END