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
|
Basic Usage
===========
Baron provides two main functions:
* :file:`parse` to transform a string into Baron's FST;
* :file:`dumps` to transform the FST back into a string.
.. ipython:: python
:suppress:
import sys
sys.path.append("..")
.. ipython:: python
from baron import parse, dumps
source_code = "def f(x = 1):\n return x\n"
fst = parse(source_code)
generated_source_code = dumps(fst)
generated_source_code
source_code == generated_source_code
Like said in the introduction, the FST keeps the formatting unlike ASTs.
Here the following 3 codes are equivalent but their formatting is
different. Baron keeps the difference so when dumping back the FST, all
the formatting is respected:
.. ipython:: python
dumps(parse("a = 1"))
dumps(parse("a=1"))
dumps(parse("a = 1"))
Helpers
-------
Baron also provides 3 helper functions `show`, `show_file` and
`show_node` to explore the FST (in iPython for example). Those functions
will print a formatted version of the FST so you can play with it to
explore the FST and have an idea of what you are playing with.
Show
~~~~
:file:`show` is used directly on a string:
.. ipython:: python
from baron.helpers import show
show("a = 1")
show("a += b")
Show_file
~~~~~~~~~
:file:`show_file` is used on a file path:
::
from baron.helpers import show_file
show_file("/path/to/a/file")
Show_node
~~~~~~~~~
:file:`show_node` is used on an already parsed string:
.. ipython:: python
from baron.helpers import show_node
fst = parse("a = 1")
show_node(fst)
Under the hood, the FST is serialized into JSON so the helpers are
simply encapsulating JSON pretty printers.
|
