README.md 8.66 KB
Newer Older
1
2
DHParser
========
Eckhart Arnold's avatar
Eckhart Arnold committed
3

4
A parser-combinator-based parsing and compiling infrastructure for domain
5
specific languages (DSL) in Digital Humanities projects.
Eckhart Arnold's avatar
Eckhart Arnold committed
6
7
8
9
10
11
12
13

Author: Eckhart Arnold, Bavarian Academy of Sciences
Email:  arnold@badw.de


License
-------

14
DHParser is open source software under the [Apache 2.0 License](https://www.apache.org/licenses/LICENSE-2.0)
15

Eckhart Arnold's avatar
Eckhart Arnold committed
16
17
Copyright 2016-2017  Eckhart Arnold, Bavarian Academy of Sciences and Humanities

18
19
20
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
Eckhart Arnold's avatar
Eckhart Arnold committed
21

22
    https://www.apache.org/licenses/LICENSE-2.0
Eckhart Arnold's avatar
Eckhart Arnold committed
23

24
25
26
27
28
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Eckhart Arnold's avatar
Eckhart Arnold committed
29

30
**Exception**: The module ``DHParser/foreign_typing.py`` was directly taken from the
Eckhart Arnold's avatar
Eckhart Arnold committed
31
Python 3.5 source code in order for DHParser to be backwards compatible
32
with Python 3.4. The module ``DHParser/foreign_typing.py`` is licensed under the
Eckhart Arnold's avatar
Eckhart Arnold committed
33
34
35
36
37
38
[Python Software Foundation License Version 2](https://docs.python.org/3.5/license.html)


Sources
-------

39
Find the sources on [gitlab.lrz.de/badw-it/DHParser](https://gitlab.lrz.de/badw-it/DHParser) . 
Eckhart Arnold's avatar
Eckhart Arnold committed
40
41
42
Get them with:
    
    git clone https://gitlab.lrz.de/badw-it/DHParser
43

Eckhart Arnold's avatar
Eckhart Arnold committed
44
45
46
47
48
49
50
51
52
53
54
55
56
57
Please contact me, if you are intested in contributing to the
development or just using DHParser.  


Disclaimer
----------

DHParser is still in an early development stage. While it is definitaly
usable, features may be dropped or added without notice and class or
function names changed in future versions. The API is NOT YET STABLE!

Use it for testing an evaluation, but not in an production environment
or contact me first, if you intend to do so.

58
59
60
61

Purpose
-------

62
63
64
65
66
67
DHParser leverages the power of Domain specific languages for the 
Digital Humanities.

Domain specific languages are widespread in 
computer sciences, but seem to be underused in the Digital Humanities.
While DSLs are sometimes introduced to Digital-Humanities-projects as
68
69
70
71
72
73
74
75
76
77
78
[practical adhoc-solution][Müller_2016], these solutions are often
somewhat "quick and dirty". In other words they are more of a hack
than a technology. The purpose of DHParser is to introduce
[DSLs as a technology][Arnold_2016] to the Digital Humanities. It is
based on the well known technology of [EBNF][ISO_IEC_14977]-based
parser generators, but employs the more modern form called
"[parsing expression grammar][Ford_2004]" and
[parser combinators][Ford_20XX] as a variant of the classical
recursive descent parser.

Why another parser generator? There are plenty of good parser
79
80
generators out there, e.g. [Añez's grako parser generator][Añez_2017], 
[Eclipse XText][XText_Website]. However, DHParser is
81
82
intended as a tool that is specifically geared towards digital
humanities applications, while most existing parser generators come
83
84
85
86
87
88
89
90
91
from compiler construction toolkits for programming languages. 
While I expect DSLs in computer science and DSLs in the Digital 
Humanities to be quite similar as far as the technological realization
is concerned, the use cases, requirements and challenges are somewhat 
different. For example, in the humanities annotating text is a central 
use case, which is mostly absent in computer science treatments. 
These differences might sooner or later require to develop the 
DSL-construction toolkits in a different direction. Also,
DHParser shall (in the future) serve as a teaching tool, which
92
93
influences some of its design decisions such as, for example, clearly
separating the parsing, syntax-tree-transformation and compilation
94
stages. Finally, DHParser is intended as a tool to experiment with.  One
95
96
97
98
99
100
101
102
103
104
possible research area is, how non
[context-free grammars](https://en.wikipedia.org/wiki/Context-free_grammar)
such as the grammars of [TeX][tex_stackexchange_no_bnf] or
[CommonMark][MacFarlane_et_al_2017] can be described with declarative
langauges in the spirit of but beyond EBNF, and what extensions of the
parsing technology are necessary to capture such languages.

Primary use case at the Bavarian Academy of Sciences and Humanities
(for the time being): A DSL for the
"[Mittellateinische Wörterbuch](http://www.mlw.badw.de/)"!
105
106
107

Further (intended) use cases are:

108
109
110
111
112
113
114
* LaTeX -> XML/HTML conversion. See this
  [discussion on why an EBNF-parser for the complete TeX/LaTeX-grammar][tex_stackexchange_no_bnf]
  is not possible.
* [CommonMark][MacFarlane_et_al_2017] and other DSLs for cross media
  publishing of scientific literature, e.g. journal articles.  (Common
  Mark and Markdown also go beyond what is feasible with pure
  EBNF-based-parsers.)
115
116
117
* EBNF itself. DHParser is already self-hosting ;-)
* Digital and cross-media editions 
* Digital dictionaries
Eckhart Arnold's avatar
Eckhart Arnold committed
118

119
120
121
122
For a simple self-test run `dhparser.py` from the command line. This
compiles the EBNF-Grammer in `examples/EBNF/EBNF.ebnf` and outputs the
Python-based parser class representing that grammar. The concrete and
abstract syntax tree as well as a full and abbreviated log of the
123
124
125
126
127
128
parsing process will be stored in a sub-directory named "LOG".


Introduction
------------

Eckhart Arnold's avatar
Eckhart Arnold committed
129
see [Introduction.md](https://gitlab.lrz.de/badw-it/DHParser/blob/master/Introduction.md)
Eckhart Arnold's avatar
Eckhart Arnold committed
130

di68kap's avatar
di68kap committed
131

132
133
134
References
----------

135
136
Juancarlo Añez: grako, a PEG parser generator in Python, 2017. URL:
[bitbucket.org/apalala/grako][Añez_2017]
137

di68kap's avatar
di68kap committed
138
[Añez_2017]: https://bitbucket.org/apalala/grako
139
140


141
142
143
144
Eckhart Arnold: Domänenspezifische Notationen. Eine (noch)
unterschätzte Technologie in den Digitalen Geisteswissenschaften,
Präsentation auf dem
[dhmuc-Workshop: Digitale Editionen und Auszeichnungssprachen](https://dhmuc.hypotheses.org/workshop-digitale-editionen-und-auszeichnungssprachen),
di68kap's avatar
di68kap committed
145
München 2016. Short-URL: [tiny.badw.de/2JVT][Arnold_2016]
146

di68kap's avatar
di68kap committed
147
[Arnold_2016]: https://f.hypotheses.org/wp-content/blogs.dir/1856/files/2016/12/EA_Pr%C3%A4sentation_Auszeichnungssprachen.pdf
148
149


150
151
152
Brian Ford: Parsing Expression Grammars: A Recognition-Based Syntactic
Foundation, Cambridge
Massachusetts, 2004. Short-URL:[http://t1p.de/jihs][Ford_2004]
153
154
155
156
157
158
159
160
161
162
163
164
165
166

[Ford_2004]: https://pdos.csail.mit.edu/~baford/packrat/popl04/peg-popl04.pdf
  
[Ford_20XX]: http://bford.info/packrat/ 


Richard A. Frost, Rahmatullah Hafiz and Paul Callaghan: Parser
Combinators for Ambiguous Left-Recursive Grammars, in: P. Hudak and
D.S. Warren (Eds.): PADL 2008, LNCS 4902, pp. 167–181, Springer-Verlag
Berlin Heidelberg 2008.


Dominikus Herzberg: Objekt-orientierte Parser-Kombinatoren in Python,
Blog-Post, September, 18th 2008 on denkspuren. gedanken, ideen,
167
168
anregungen und links rund um informatik-themen, short-URL:
[http://t1p.de/bm3k][Herzberg_2008a]
169
170
171
172
173
174

[Herzberg_2008a]: http://denkspuren.blogspot.de/2008/09/objekt-orientierte-parser-kombinatoren.html


Dominikus Herzberg: Eine einfache Grammatik für LaTeX, Blog-Post,
September, 18th 2008 on denkspuren. gedanken, ideen, anregungen und
175
176
links rund um informatik-themen, short-URL:
[http://t1p.de/7jzh][Herzberg_2008b]
177
178
179
180
181
182

[Herzberg_2008b]: http://denkspuren.blogspot.de/2008/09/eine-einfache-grammatik-fr-latex.html


Dominikus Herzberg: Uniform Syntax, Blog-Post, February, 27th 2007 on
denkspuren. gedanken, ideen, anregungen und links rund um
di68kap's avatar
di68kap committed
183
informatik-themen, short-URL: [http://t1p.de/s0zk][Herzberg_2007]
184
185
186
187
188
189
190

[Herzberg_2007]: http://denkspuren.blogspot.de/2007/02/uniform-syntax.html


[ISO_IEC_14977]: http://www.cl.cam.ac.uk/~mgk25/iso-14977.pdf


191
192
193
194
John MacFarlane, David Greenspan, Vicent Marti, Neil Williams,
Benjamin Dumke-von der Ehe, Jeff Atwood: CommonMark. A strongly
defined, highly compatible specification of
Markdown, 2017. [commonmark.org][MacFarlane_et_al_2017]
195
196
197
198

[MacFarlane_et_al_2017]: http://commonmark.org/


199
200
201
202
Stefan Müller: DSLs in den digitalen Geisteswissenschaften,
Präsentation auf dem
[dhmuc-Workshop: Digitale Editionen und Auszeichnungssprachen](https://dhmuc.hypotheses.org/workshop-digitale-editionen-und-auszeichnungssprachen),
München 2016. Short-URL: [tiny.badw.de/2JVy][Müller_2016]
203
204
205

[Müller_2016]: https://f.hypotheses.org/wp-content/blogs.dir/1856/files/2016/12/Mueller_Anzeichnung_10_Vortrag_M%C3%BCnchen.pdf

206
207
208
209
210
211
Markus Voelter, Sbastian Benz, Christian Dietrich, Birgit Engelmann, 
Mats Helander, Lennart Kats, Eelco Visser, Guido Wachsmuth: 
DSL Engineering. Designing, Implementing and Using Domain-Specific Languages, 2013.
[http://dslbook.org/][Voelter_2013]  

[voelter_2013]: http://dslbook.org/
212
213
214

[tex_stackexchange_no_bnf]: http://tex.stackexchange.com/questions/4201/is-there-a-bnf-grammar-of-the-tex-language
 
di68kap's avatar
di68kap committed
215
[tex_stackexchange_latex_parsers]: http://tex.stackexchange.com/questions/4223/what-parsers-for-latex-mathematics-exist-outside-of-the-tex-engines 
216
217

[XText_website]: https://www.eclipse.org/Xtext/