1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
|
=========================
Pesto specification draft
=========================
Pesto is a text-based human-editable and machine-transformable cooking recipe
interchange format.
.. warning::
This specification is work-in-progress and thus neither stable, consistent or
complete.
.. class:: nodoc
> module Codec.Pesto where
About this document
-------------------
This section contains various information about this document. The `second
section`__ motivates why inventing another file format is necessary, followed
by the goals__ of Pesto. After a short Pesto primer__ intended for the casual
user the language’s syntax__ and semantics__ are presented. The `linting
section`__ limits the language to useful cooking recipes. Examples for user
presentation of recipes and serialization follow.
__ #motivation
__ #goals
__ #introduction-by-example
__ #language-syntax
__ #language-semantics
__ #linting
Being a literate program this document is specification and reference
implementation at the same time. The code is written in Haskell_ and uses the
parsec_ parser combinator library, as well as HUnit_ for unit tests. Even
without knowing Haskell’s syntax you should be able to understand this
specification. There’s a description above every code snippet explaining what
is going on.
.. _Haskell: http://learnyouahaskell.com/
.. _HUnit: http://hackage.haskell.org/package/HUnit
.. _parsec: http://hackage.haskell.org/package/parsec
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,
“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be
interpreted as described in `RFC 2119`_.
.. _RFC 2119: http://tools.ietf.org/html/rfc2119
:Version: 1-draft
:License: CC0_
:Website: https://6xq.net/pesto/
:Discussion: https://github.com/PromyLOPh/pesto
:Contributors:
- `Lars-Dominik Braun <mailto:lars+pesto@6xq.net>`_
.. _CC0: https://creativecommons.org/publicdomain/zero/1.0/
.. _motivation:
Motivation
----------
The landscape of recipe interchange formats is quite fragmented. First of all
there’s HTML microdata. `Google rich snippets`_, which are equivalent to the
schema.org_ microdata vocabulary, are widely used by commercial recipe sites.
Although the main objective of microdata is to make content machine-readable
most sites will probably use it, because it is considered a search-engine
optimization (SEO). Additionally parsing HTML pulled from the web is a
nightmare and thus not a real option for sharing recipes. h-recipe_ provides a
second vocabulary that has not been adopted widely yet.
.. _Google rich snippets: https://developers.google.com/structured-data/rich-snippets/recipes
.. _schema.org: http://schema.org/Recipe
.. _h-recipe: http://microformats.org/wiki/h-recipe
.. _formats-by-software:
Most cooking-related software comes with its own recipe file format. Some of
them, due to their age, can be imported by other programs.
Meal-Master_ is one of these widely supported formats. A huge trove of recipe files
is `available in this format <http://www.ffts.com/recipes.htm>`_. There does
not seem to be any official documentation for the format, but inofficial
`ABNF grammar`_ and `format description <http://www.ffts.com/mmformat.txt>`_
exist. A Meal-Master recipe template might look like this:
.. _MasterCook: http://mastercook.com/
.. _MXP: http://www.oocities.org/heartland/woods/2073/Appendix.htm
.. _ABNF grammar: http://web.archive.org/web/20161002135718/http://www.wedesoft.de/anymeal-api/mealmaster.html
.. code:: mealmaster
---------- Recipe via Meal-Master (tm)
Title: <Title>
Categories: <Categories>
Yield: <N servings>
<N> <unit> <ingredient>
…
-------------------------------<Section name>-----------------------------
<More ingredients>
<Instructions>
-----
Rezkonv_ aims to improve the Mealmaster format by lifting some of its character
limits, adding new syntax and translating it to german. However the
specification is available on request only.
A second format some programs can import is MasterCook_’s MXP_ file format, as
well as its XML-based successor MX2. And then there’s a whole bunch of
more-or-less proprietary formats:
`Living Cookbook`_
Uses a XML-based format called fdx version 1.1. There’s no specification to
be found, but a few
`examples <http://livingcookbook.com/Resource/DownloadableRecipes>`_
are available and those are dated 2006.
`My CookBook`_
Uses the file extension .mcb. A specification `is available
<http://mycookbook-android.com/site/my-cookbook-xml-schema/>`_.
KRecipes_
Uses its own export format. However there is no documentation whatsoever.
Gourmet_
The program’s export format suffers from the same problem. The only
document available is the `DTD
<https://github.com/thinkle/gourmet/blob/7715c6ef87ee8c106f0a021972cd70d61d83cadb/data/recipe.dtd>`_.
CookML_
Last updated in 2006 (version 1.0.4) for the german-language shareware
program Kalorio has a custom and restrictive licence that requires
attribution and forbids derivate works.
Paprika_
Cross-platform application, supports its own “emailed recipe format” and a
simple YAML-based format.
.. _Paprika: https://paprikaapp.com/help/android/#importrecipes
.. _xml-formats:
Between 2002 and 2005 a bunch of XML-based exchange formats were created. They
are not tied to a specific software, so none of them seems to be actively used
nowadays:
RecipeML_
Formerly known as DESSERT and released in 2002 (version 0.5). The
license requires attribution and – at the same time – forbids using the name
RecipeML for promotion without written permission.
eatdrinkfeelgood_
Version 1.1 was released in 2002 as well, but the site is not online
anymore. The DTD is licensed under the `CC by-sa`_ license.
REML_
Released in 2005 (version 0.5), aims to improve support for commercial uses
(restaurant menus and cookbooks). The XSD’s license permits free use and
redistribution, but the reference implementation has no licensing
information.
`RecipeBook XML`_
Released 2005 as well and shared unter the terms of `CC by-sa`_ is not
available on the web any more.
.. _CC by-sa: https://creativecommons.org/licenses/by-sa/2.5/
.. _obscure-formats:
Finally, a few non-XML or obscure exchange formats have been created in the past:
YumML_ is an approach similar to those listed above, but based on YAML instead
of XML. The specification has been removed from the web and is available
through the Web Archive only.
`Cordon Bleu`_ (1999) encodes recipes as programs for a cooking machine and
defines a Pascal-like language. Being so close to real programming languages
Cordon Bleu is barely useable by anyone except programmers. Additionally the
language is poorly-designed, since its syntax is inconsistent and the user is
limited to a set of predefined functions.
Finally there is RxOL_, created in 1985. It constructs a graph from recipes
written down with a few operators and postfix notation. It does not separate
ingredients and cooking instructions like every other syntax introduced before.
Although Pesto is not a direct descendant of RxOL both share many ideas.
microformats.org_ has a similar list of recipe interchange formats.
.. _REML: http://reml.sourceforge.net/
.. _eatdrinkfeelgood: https://web.archive.org/web/20070109085643/http://eatdrinkfeelgood.org/1.1/
.. _RecipeML: http://www.formatdata.com/recipeml/index.html
.. _CookML: http://www.kalorio.de/index.php?Mod=Ac&Cap=CE&SCa=../cml/CookML_EN
.. _Meal-Master: http://web.archive.org/web/20151029032924/http://episoft.home.comcast.net:80/~episoft/
.. _RecipeBook XML: http://web.archive.org/web/20141101132332/http://www.happy-monkey.net/recipebook/
.. _YumML: http://web.archive.org/web/20140703234140/http://vikingco.de/yumml.html
.. _Rezkonv: http://www.rezkonv.de/software/rksuite/rkformat.html
.. _RxOL: http://web.archive.org/web/20150814041516/www.dodomagnifico.com/641/Recipes/CompCook.html
.. _Gourmet: http://thinkle.github.io/gourmet/
.. _KRecipes: http://krecipes.sourceforge.net/
.. _Cordon Bleu: http://web.archive.org/web/20090115210732/http://www.inf.unideb.hu/~bognar/ps_ek/cb_lang.ps
.. _microformats.org: http://microformats.org/wiki/recipe-formats
.. _Living Cookbook: http://livingcookbook.com/
.. _My CookBook: http://mycookbook-android.com/
.. There is a copy at http://diyhpl.us/~bryan/papers2/CompCook.html as well
.. More interesting stuff:
.. - http://blog.moertel.com/posts/2010-01-08-a-formal-language-for-recipes-brain-dump.html
.. - http://www.dangermouse.net/esoteric/chef.html
.. _goals:
Goals
-----
First of all recipes are written *by* humans *for* humans. Thus a
human-readable recipe interchange format is not enough. The recipes need to be
human-editable without guidance like a GUI or assistant. That’s why, for
instance, XML is not suitable and the interchange formats listed `above
<xml-formats_>`_ have largely failed to gain traction. XML, even though simple
itself, is still too complicated for the ordinary user. Instead a format needs
to be as simple as possible, with as little markup as possible. A human editor
must be able to remember the entire syntax. This works best if the file
contents “make sense”. A good example for this is Markdown_.
.. _Markdown: https://daringfireball.net/projects/markdown/syntax
We also have to acknowledge that machines play an important role in our daily
life. They can help us, the users, accomplish our goals if they are able to
understand the recipes as well. Thus they too need to be able to read and write
recipes. Again, designing a machine-readable format is not enough. Recipes must
be machine-transformable. A computer program should be able to create a new
recipe from two existing ones, look up the ingredients and tell us how many
joules one piece of that cake will have. And so on.
That being said, Pesto does not aim to carry additional information about
ingredients or recipes itself. Nutrition data for each ingredient should be
maintained in a separate database. Due to its minimal syntax Pesto is also not
suitable for extensive guides on cooking or the usual chitchat found in cooking
books.
.. _introduction-by-example:
Introduction by example
-----------------------
.. code::
So let’s start by introducing Pesto by example. This text does not belong
to the recipe and is ignored by any software. The following line starts the
recipe:
%pesto
&pot
+1 l water
+salt
[boil]
+100 g penne
&10 min
[cook]
>1 serving pasta
(language: en)
And that’s how you make pasta: Boil one liter of water in a pot with a little
bit of salt. Then add 100 g penne, cook them for ten minutes and you get one
serving pasta. That’s all.
There’s more syntax available to express alternatives (either penne or
tagliatelle), ranges (1–2 l water or approximately 1 liter water) and metadata.
But now you can have a first peek at `my own recipe collection`_.
.. _my own recipe collection: https://github.com/PromyLOPh/rezepte
.. include:: Pesto/Parse.lhs
.. include:: Pesto/Graph.lhs
.. include:: Pesto/Lint.lhs
.. include:: Pesto/Serialize.lhs
Using this project
------------------
This project uses cabal. It provides the Codec.Pesto library that implements
the Pesto language as described in the previous sections. It also comes with
three binaries.
.. include:: ../../exe/Main.lhs
.. include:: ../../exe/Test.lhs
.. include:: ../../exe/Doc.lhs
|