fizzbuzz/mock-census/mock-census.js

187 lines
4.3 KiB
JavaScript

// TODO beef up AHR to allow streamed parsing
"use strict";
(function (undefined) {
var fs = require('fs'),
request = require('ahr'),
stream,
node = process.argv[0],
self = process.argv[1],
fulluri = process.argv[2];
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;
}
// 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 parseChunk(chunk) {
/*
// TODO be more memory efficient
// by seeking into the buffer
data += chunk
while (true) {
index = data.indexOf('\n')
if (-1 === index) {
break;
}
line = data.substr(0, index);
data = data.substr(index + 1);
parseLine(line);
}
*/
}
var data = '';
function parseData(err, x, chunk, end) {
if (err) {
usage();
throw err;
}
if (!end) {
data += chunk.toString();
return;
}
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;
}
request.get(fulluri, undefined, { stream: true }).when(parseData);
}
main();
}());