diff options
Diffstat (limited to 'vendor/github.com/zclconf/go-cty/cty/json/type_implied.go')
-rw-r--r-- | vendor/github.com/zclconf/go-cty/cty/json/type_implied.go | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/vendor/github.com/zclconf/go-cty/cty/json/type_implied.go b/vendor/github.com/zclconf/go-cty/cty/json/type_implied.go new file mode 100644 index 0000000..1a97306 --- /dev/null +++ b/vendor/github.com/zclconf/go-cty/cty/json/type_implied.go | |||
@@ -0,0 +1,171 @@ | |||
1 | package json | ||
2 | |||
3 | import ( | ||
4 | "bytes" | ||
5 | "encoding/json" | ||
6 | "fmt" | ||
7 | |||
8 | "github.com/zclconf/go-cty/cty" | ||
9 | ) | ||
10 | |||
11 | // ImpliedType returns the cty Type implied by the structure of the given | ||
12 | // JSON-compliant buffer. This function implements the default type mapping | ||
13 | // behavior used when decoding arbitrary JSON without explicit cty Type | ||
14 | // information. | ||
15 | // | ||
16 | // The rules are as follows: | ||
17 | // | ||
18 | // JSON strings, numbers and bools map to their equivalent primitive type in | ||
19 | // cty. | ||
20 | // | ||
21 | // JSON objects map to cty object types, with the attributes defined by the | ||
22 | // object keys and the types of their values. | ||
23 | // | ||
24 | // JSON arrays map to cty tuple types, with the elements defined by the | ||
25 | // types of the array members. | ||
26 | // | ||
27 | // Any nulls are typed as DynamicPseudoType, so callers of this function | ||
28 | // must be prepared to deal with this. Callers that do not wish to deal with | ||
29 | // dynamic typing should not use this function and should instead describe | ||
30 | // their required types explicitly with a cty.Type instance when decoding. | ||
31 | // | ||
32 | // Any JSON syntax errors will be returned as an error, and the type will | ||
33 | // be the invalid value cty.NilType. | ||
34 | func ImpliedType(buf []byte) (cty.Type, error) { | ||
35 | r := bytes.NewReader(buf) | ||
36 | dec := json.NewDecoder(r) | ||
37 | dec.UseNumber() | ||
38 | |||
39 | ty, err := impliedType(dec) | ||
40 | if err != nil { | ||
41 | return cty.NilType, err | ||
42 | } | ||
43 | |||
44 | if dec.More() { | ||
45 | return cty.NilType, fmt.Errorf("extraneous data after JSON object") | ||
46 | } | ||
47 | |||
48 | return ty, nil | ||
49 | } | ||
50 | |||
51 | func impliedType(dec *json.Decoder) (cty.Type, error) { | ||
52 | tok, err := dec.Token() | ||
53 | if err != nil { | ||
54 | return cty.NilType, err | ||
55 | } | ||
56 | |||
57 | return impliedTypeForTok(tok, dec) | ||
58 | } | ||
59 | |||
60 | func impliedTypeForTok(tok json.Token, dec *json.Decoder) (cty.Type, error) { | ||
61 | if tok == nil { | ||
62 | return cty.DynamicPseudoType, nil | ||
63 | } | ||
64 | |||
65 | switch ttok := tok.(type) { | ||
66 | case bool: | ||
67 | return cty.Bool, nil | ||
68 | |||
69 | case json.Number: | ||
70 | return cty.Number, nil | ||
71 | |||
72 | case string: | ||
73 | return cty.String, nil | ||
74 | |||
75 | case json.Delim: | ||
76 | |||
77 | switch rune(ttok) { | ||
78 | case '{': | ||
79 | return impliedObjectType(dec) | ||
80 | case '[': | ||
81 | return impliedTupleType(dec) | ||
82 | default: | ||
83 | return cty.NilType, fmt.Errorf("unexpected token %q", ttok) | ||
84 | } | ||
85 | |||
86 | default: | ||
87 | return cty.NilType, fmt.Errorf("unsupported JSON token %#v", tok) | ||
88 | } | ||
89 | } | ||
90 | |||
91 | func impliedObjectType(dec *json.Decoder) (cty.Type, error) { | ||
92 | // By the time we get in here, we've already consumed the { delimiter | ||
93 | // and so our next token should be the first object key. | ||
94 | |||
95 | var atys map[string]cty.Type | ||
96 | |||
97 | for { | ||
98 | // Read the object key first | ||
99 | tok, err := dec.Token() | ||
100 | if err != nil { | ||
101 | return cty.NilType, err | ||
102 | } | ||
103 | |||
104 | if ttok, ok := tok.(json.Delim); ok { | ||
105 | if rune(ttok) != '}' { | ||
106 | return cty.NilType, fmt.Errorf("unexpected delimiter %q", ttok) | ||
107 | } | ||
108 | break | ||
109 | } | ||
110 | |||
111 | key, ok := tok.(string) | ||
112 | if !ok { | ||
113 | return cty.NilType, fmt.Errorf("expected string but found %T", tok) | ||
114 | } | ||
115 | |||
116 | // Now read the value | ||
117 | tok, err = dec.Token() | ||
118 | if err != nil { | ||
119 | return cty.NilType, err | ||
120 | } | ||
121 | |||
122 | aty, err := impliedTypeForTok(tok, dec) | ||
123 | if err != nil { | ||
124 | return cty.NilType, err | ||
125 | } | ||
126 | |||
127 | if atys == nil { | ||
128 | atys = make(map[string]cty.Type) | ||
129 | } | ||
130 | atys[key] = aty | ||
131 | } | ||
132 | |||
133 | if len(atys) == 0 { | ||
134 | return cty.EmptyObject, nil | ||
135 | } | ||
136 | |||
137 | return cty.Object(atys), nil | ||
138 | } | ||
139 | |||
140 | func impliedTupleType(dec *json.Decoder) (cty.Type, error) { | ||
141 | // By the time we get in here, we've already consumed the { delimiter | ||
142 | // and so our next token should be the first value. | ||
143 | |||
144 | var etys []cty.Type | ||
145 | |||
146 | for { | ||
147 | tok, err := dec.Token() | ||
148 | if err != nil { | ||
149 | return cty.NilType, err | ||
150 | } | ||
151 | |||
152 | if ttok, ok := tok.(json.Delim); ok { | ||
153 | if rune(ttok) != ']' { | ||
154 | return cty.NilType, fmt.Errorf("unexpected delimiter %q", ttok) | ||
155 | } | ||
156 | break | ||
157 | } | ||
158 | |||
159 | ety, err := impliedTypeForTok(tok, dec) | ||
160 | if err != nil { | ||
161 | return cty.NilType, err | ||
162 | } | ||
163 | etys = append(etys, ety) | ||
164 | } | ||
165 | |||
166 | if len(etys) == 0 { | ||
167 | return cty.EmptyTuple, nil | ||
168 | } | ||
169 | |||
170 | return cty.Tuple(etys), nil | ||
171 | } | ||