README.md
1edn-cpp
2=======
3
4edn lib for c++.
5
6##intro
7Useful for parsing [edn](http://github.com/edn-format/edn). read returns an `edn::EdnNode`. There are three cases to consider:
8
9* If it is an atom (nil, symbol, keyword, bool, int, float, string, char) it will have a `value` property which is a string you can then cast/coerce how you please.
10
11* If it is a collection (list, map, vector, set) it will have a `values` property which is itself a list of `edn::EdnNode` items which you can then walk via what ever mechanism and do with them what you will.
12
13* If it is a tagged item you will have the raw tagname in the `value` property and then the `values` property will be a list containing the `edn::EdnNode` representing the tagname and another `edn::EdnNode` containing the value for the tag.
14
15In general `edn-cpp` makes no assumptions about how you want to reify the data - it just guarantees you have well formed edn node(s) which you can handle how ever you like.
16
17
18##using
19
20 #//define DEBUG
21 #include "edn.hpp"
22 #include <iostream>
23
24 using edn::EdnNode;
25 using edn::read;
26 using edn::pprint;
27
28 int main() {
29 try {
30 EdnNode someMap = read("{:some :map :with [a vector of symbols]}");
31 std::cout << pprint(someMap) << std::endl;
32 } catch (const char* e) {
33 std::cout << "Error parsing: " << e << std::endl;
34 }
35 }
36
37will output:
38
39 {:some :map :with [a vector of symbols]}
40
41And with debug uncommented:
42
43 <EdnMap {<EdnKeyword :some> <EdnKeyword :map>
44 <EdnKeyword :with> <EdnVector [<EdnSymbol a>
45 <EdnSymbol vector>
46 <EdnSymbol of>
47 <EdnSymbol symbols>]>}>
48
49##debug
50If you define DEBUG you will see debug output when using pprint. This looks like:
51
52 <EdnMap {
53 <EdnKeyword :x> <EdnKeyword :y>
54 <EdnKeyword :z> <EdnVector [<EdnInt 1>
55 <EdnInt 2>
56 <EdnInt 3>
57 <EdnTagged #<EdnSymbol tagged/item>
58 <EdnString "cats-rabbits-bears">>]>}>
59
60Which is nice when proving things are parsing as you expect.
61
62##api
63
64 list<EdnToken> lex(string ednString)
65
66 EdnNode read(string ednString)
67
68 string pprint(EdnNode node)
69
70 bool validSymbol(string value)
71
72 bool validKeyword(string value)
73
74 bool validNil(string value)
75
76 bool validBool(string value)
77
78 bool validInt(string value)
79
80 bool validFloat(string value)
81
82 bool validChar(string value)
83
84 EdnNode handleAtom(EdnToken token)
85
86 EdnNode handleCollection(EdnToken token, list<EdnNode> values)
87
88 EdnNode handleTagged(EdnToken token, EdnNode value)
89
90##structs
91
92 EdnToken
93 TokenType type
94 int line
95 string value
96
97 EdnNode
98 EdnToken type
99 int line
100 string value #used for atoms
101 list<EdnNode> values #used for collections
102
103##enums
104
105 TokenType
106 TokenString
107 TokenAtom
108 TokenParen
109
110 NodeType
111 EdnNil
112 EdnSymbol
113 EdnKeyword
114 EdnBool
115 EdnInt
116 EdnFloat
117 EdnString
118 EdnChar
119 EdnList
120 EdnVector
121 EdnMap
122 EdnSet
123 EdnDiscard
124 EdnTagged
125
126
127##todo
128make pprint actually format as demonstrated above. Right now it is just a single string with out the indentation.
129