Skip to content

Commit eda7132

Browse files
author
Ryan
committed
food-chain
1 parent 62c7a3f commit eda7132

File tree

3 files changed

+272
-0
lines changed

3 files changed

+272
-0
lines changed

‎food-chain/README.md

+92
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,92 @@
1+
# Food Chain
2+
3+
Write a program that generates the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'
4+
5+
Write a program that generates the lyrics to the song
6+
"I know an old lady who swallowed a fly". While you could
7+
copy/paste the lyrics, or read them from a file, this
8+
problem is much more interesting if you approach it
9+
algorithmically.
10+
11+
This is a [cumulative song](http://en.wikipedia.org/wiki/Cumulative_song) of unknown origin.
12+
13+
This is one of many common variants.
14+
15+
```plain
16+
I know an old lady who swallowed a fly.
17+
I don't know why she swallowed the fly. Perhaps she'll die.
18+
19+
I know an old lady who swallowed a spider.
20+
It wriggled and jiggled and tickled inside her.
21+
She swallowed the spider to catch the fly.
22+
I don't know why she swallowed the fly. Perhaps she'll die.
23+
24+
I know an old lady who swallowed a bird.
25+
How absurd to swallow a bird!
26+
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
27+
She swallowed the spider to catch the fly.
28+
I don't know why she swallowed the fly. Perhaps she'll die.
29+
30+
I know an old lady who swallowed a cat.
31+
Imagine that, to swallow a cat!
32+
She swallowed the cat to catch the bird.
33+
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
34+
She swallowed the spider to catch the fly.
35+
I don't know why she swallowed the fly. Perhaps she'll die.
36+
37+
I know an old lady who swallowed a dog.
38+
What a hog, to swallow a dog!
39+
She swallowed the dog to catch the cat.
40+
She swallowed the cat to catch the bird.
41+
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
42+
She swallowed the spider to catch the fly.
43+
I don't know why she swallowed the fly. Perhaps she'll die.
44+
45+
I know an old lady who swallowed a goat.
46+
Just opened her throat and swallowed a goat!
47+
She swallowed the goat to catch the dog.
48+
She swallowed the dog to catch the cat.
49+
She swallowed the cat to catch the bird.
50+
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
51+
She swallowed the spider to catch the fly.
52+
I don't know why she swallowed the fly. Perhaps she'll die.
53+
54+
I know an old lady who swallowed a cow.
55+
I don't know how she swallowed a cow!
56+
She swallowed the cow to catch the goat.
57+
She swallowed the goat to catch the dog.
58+
She swallowed the dog to catch the cat.
59+
She swallowed the cat to catch the bird.
60+
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
61+
She swallowed the spider to catch the fly.
62+
I don't know why she swallowed the fly. Perhaps she'll die.
63+
64+
I know an old lady who swallowed a horse.
65+
She's dead, of course!
66+
```
67+
68+
## Setup
69+
70+
Go through the setup instructions for JavaScript to
71+
install the necessary dependencies:
72+
73+
http://exercism.io/languages/javascript
74+
75+
## Making the Test Suite Pass
76+
77+
Execute the tests with:
78+
79+
jasmine-node .
80+
81+
In many test suites all but the first test have been skipped.
82+
83+
Once you get a test passing, you can unskip the next one by
84+
changing `xit` to `it`.
85+
86+
## Source
87+
88+
Wikipedia [http://en.wikipedia.org/wiki/There_Was_an_Old_Lady_Who_Swallowed_a_Fly](http://en.wikipedia.org/wiki/There_Was_an_Old_Lady_Who_Swallowed_a_Fly)
89+
90+
## Submitting Incomplete Problems
91+
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
92+

‎food-chain/food-chain.js

+29
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,29 @@
1+
const song = [
2+
['fly', 'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n'],
3+
['spider', 'It wriggled and jiggled and tickled inside her.\n'],
4+
['bird', 'How absurd to swallow a bird!\n'],
5+
['cat', 'Imagine that, to swallow a cat!\n'],
6+
['dog', 'What a hog, to swallow a dog!\n'],
7+
['goat', 'Just opened her throat and swallowed a goat!\n'],
8+
['cow', 'I don\'t know how she swallowed a cow!\n'],
9+
['horse', 'She\'s dead, of course!\n']
10+
]
11+
12+
module.exports = class {
13+
next(i) {
14+
const next = i > 0 ? this.next(i - 1) : song[0][1]
15+
const ifSpider = i === 1 ? ' that wriggled and jiggled and tickled inside her.' : '.'
16+
return `She swallowed the ${song[i + 1][0]} to catch the ${song[i][0]}${ifSpider}\n` + next
17+
}
18+
19+
verse(verse) {
20+
const i = verse - 1
21+
const next = i > 0 && i < 7 ? this.next(i - 1) : ''
22+
return `I know an old lady who swallowed a ${song[i][0]}.\n${song[i][1]}` + next
23+
}
24+
25+
verses(from, to) {
26+
const next = from < to ? this.verses(from + 1, to) : ''
27+
return this.verse(from) + `\n${next}`
28+
}
29+
}

‎food-chain/food-chain.spec.js

+151
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,151 @@
1+
var FoodChain = require('./food-chain');
2+
3+
describe('Food Chain', function () {
4+
var song = new FoodChain();
5+
6+
it('fly', function () {
7+
var expected = 'I know an old lady who swallowed a fly.\nI don\'t know why she swallowed the fly. Perhaps she\'ll die.\n';
8+
9+
expect(song.verse(1)).toEqual(expected);
10+
});
11+
12+
it('spider', function () {
13+
var expected = 'I know an old lady who swallowed a spider.\nIt wriggled and jiggled and tickled inside her.\n' +
14+
'She swallowed the spider to catch the fly.\n' + 'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n';
15+
16+
expect(song.verse(2)).toEqual(expected);
17+
});
18+
19+
it('bird', function () {
20+
var expected = 'I know an old lady who swallowed a bird.\n' +
21+
'How absurd to swallow a bird!\n' +
22+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
23+
'She swallowed the spider to catch the fly.\n' +
24+
'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n';
25+
26+
expect(song.verse(3)).toEqual(expected);
27+
});
28+
29+
it('cat', function () {
30+
var expected = 'I know an old lady who swallowed a cat.\n' +
31+
'Imagine that, to swallow a cat!\n' +
32+
'She swallowed the cat to catch the bird.\n' +
33+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
34+
'She swallowed the spider to catch the fly.\n' +
35+
'I don\'t know why she swallowed the fly. ' +
36+
'Perhaps she\'ll die.\n';
37+
38+
expect(song.verse(4)).toEqual(expected);
39+
});
40+
41+
it('dog', function () {
42+
var expected = 'I know an old lady who swallowed a dog.\n' +
43+
'What a hog, to swallow a dog!\n' +
44+
'She swallowed the dog to catch the cat.\n' +
45+
'She swallowed the cat to catch the bird.\n' +
46+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
47+
'She swallowed the spider to catch the fly.\n' +
48+
'I don\'t know why she swallowed the fly. ' +
49+
'Perhaps she\'ll die.\n';
50+
51+
expect(song.verse(5)).toEqual(expected);
52+
});
53+
54+
it('goat', function () {
55+
var expected = 'I know an old lady who swallowed a goat.\n' +
56+
'Just opened her throat and swallowed a goat!\n' +
57+
'She swallowed the goat to catch the dog.\n' +
58+
'She swallowed the dog to catch the cat.\n' +
59+
'She swallowed the cat to catch the bird.\n' +
60+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
61+
'She swallowed the spider to catch the fly.\n' +
62+
'I don\'t know why she swallowed the fly. ' +
63+
'Perhaps she\'ll die.\n';
64+
65+
expect(song.verse(6)).toEqual(expected);
66+
});
67+
68+
it('cow', function () {
69+
var expected = 'I know an old lady who swallowed a cow.\n' +
70+
'I don\'t know how she swallowed a cow!\n' +
71+
'She swallowed the cow to catch the goat.\n' +
72+
'She swallowed the goat to catch the dog.\n' +
73+
'She swallowed the dog to catch the cat.\n' +
74+
'She swallowed the cat to catch the bird.\n' +
75+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
76+
'She swallowed the spider to catch the fly.\n' +
77+
'I don\'t know why she swallowed the fly. ' +
78+
'Perhaps she\'ll die.\n';
79+
80+
expect(song.verse(7)).toEqual(expected);
81+
});
82+
83+
it('horse', function () {
84+
var expected = 'I know an old lady who swallowed a horse.\n' + 'She\'s dead, of course!\n';
85+
86+
expect(song.verse(8)).toEqual(expected);
87+
});
88+
89+
it('multiple verses', function () {
90+
var expected = '';
91+
92+
expected += 'I know an old lady who swallowed a fly.\nI don\'t know why she swallowed the fly. Perhaps she\'ll die.\n\n';
93+
expected += 'I know an old lady who swallowed a spider.\nIt wriggled and jiggled and tickled inside her.\n' +
94+
'She swallowed the spider to catch the fly.\n' +
95+
'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n\n';
96+
97+
expect(song.verses(1, 2)).toEqual(expected);
98+
});
99+
100+
it('the whole song', function () {
101+
var expected = '';
102+
103+
expected += 'I know an old lady who swallowed a fly.\nI don\'t know why she swallowed the fly. Perhaps she\'ll die.\n\n';
104+
expected += 'I know an old lady who swallowed a spider.\nIt wriggled and jiggled and tickled inside her.\n' +
105+
'She swallowed the spider to catch the fly.\n' +
106+
'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n\n';
107+
expected += 'I know an old lady who swallowed a bird.\n' +
108+
'How absurd to swallow a bird!\n' +
109+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
110+
'She swallowed the spider to catch the fly.\n' +
111+
'I don\'t know why she swallowed the fly. Perhaps she\'ll die.\n\n';
112+
expected += 'I know an old lady who swallowed a cat.\n' +
113+
'Imagine that, to swallow a cat!\n' +
114+
'She swallowed the cat to catch the bird.\n' +
115+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
116+
'She swallowed the spider to catch the fly.\n' +
117+
'I don\'t know why she swallowed the fly. ' +
118+
'Perhaps she\'ll die.\n\n';
119+
expected += 'I know an old lady who swallowed a dog.\n' +
120+
'What a hog, to swallow a dog!\n' +
121+
'She swallowed the dog to catch the cat.\n' +
122+
'She swallowed the cat to catch the bird.\n' +
123+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
124+
'She swallowed the spider to catch the fly.\n' +
125+
'I don\'t know why she swallowed the fly. ' +
126+
'Perhaps she\'ll die.\n\n';
127+
expected += 'I know an old lady who swallowed a goat.\n' +
128+
'Just opened her throat and swallowed a goat!\n' +
129+
'She swallowed the goat to catch the dog.\n' +
130+
'She swallowed the dog to catch the cat.\n' +
131+
'She swallowed the cat to catch the bird.\n' +
132+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
133+
'She swallowed the spider to catch the fly.\n' +
134+
'I don\'t know why she swallowed the fly. ' +
135+
'Perhaps she\'ll die.\n\n';
136+
expected += 'I know an old lady who swallowed a cow.\n' +
137+
'I don\'t know how she swallowed a cow!\n' +
138+
'She swallowed the cow to catch the goat.\n' +
139+
'She swallowed the goat to catch the dog.\n' +
140+
'She swallowed the dog to catch the cat.\n' +
141+
'She swallowed the cat to catch the bird.\n' +
142+
'She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n' +
143+
'She swallowed the spider to catch the fly.\n' +
144+
'I don\'t know why she swallowed the fly. ' +
145+
'Perhaps she\'ll die.\n\n';
146+
expected += 'I know an old lady who swallowed a horse.\n' + 'She\'s dead, of course!\n\n';
147+
148+
expect(song.verses(1, 8)).toEqual(expected);
149+
});
150+
151+
});

0 commit comments

Comments
 (0)