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util-jsn.lua /size: 15 Kb last modification: 2020-07-01 14:35
1if
 not
 modules
 then
 modules
 =
 {
 }
 end
 modules
 [
'
util-jsn
'
]
 =
 {
2    version
   =
 1
.
001
,
3    comment
   =
 "
companion to m-json.mkiv
"
,
4    author
    =
 "
Hans Hagen, PRAGMA-ADE, Hasselt NL
"
,
5    copyright
 =
 "
PRAGMA ADE / ConTeXt Development Team
"
,
6    license
   =
 "
see context related readme files
"
7}
8
9-- Of course we could make a nice complete parser with proper error messages but
10-- as json is generated programmatically errors are systematic and we can assume
11-- a correct stream. If not, we have some fatal error anyway. So, we can just rely
12-- on strings being strings (apart from the unicode escape which is not in 5.1) and
13-- as we first catch known types we just assume that anything else is a number.
14--
15-- Reminder for me: check usage in framework and extend when needed. Also document
16-- it in the cld lib documentation.
17--
18-- Upgraded for handling the somewhat more fax server templates.
19
20local
 P
,
 V
,
 R
,
 S
,
 C
,
 Cc
,
 Cs
,
 Ct
,
 Cf
,
 Cg
 =
 lpeg
.
P
,
 lpeg
.
V
,
 lpeg
.
R
,
 lpeg
.
S
,
 lpeg
.
C
,
 lpeg
.
Cc
,
 lpeg
.
Cs
,
 lpeg
.
Ct
,
 lpeg
.
Cf
,
 lpeg
.
Cg
21local
 lpegmatch
 =
 lpeg
.
match
22local
 format
,
 gsub
 =
 string
.
format
,
 string
.
gsub
23local
 formatters
 =
 string
.
formatters
24local
 utfchar
 =
 utf
.
char
25local
 concat
,
 sortedkeys
 =
 table
.
concat
,
 table
.
sortedkeys
26
27local
 tonumber
,
 tostring
,
 rawset
,
 type
,
 next
 =
 tonumber
,
 tostring
,
 rawset
,
 type
,
 next
28
29local
 json
      =
 utilities
.
json
 or
 {
 }
30utilities
.
json
  =
 json
31
32do
33
34    -- \\ \/ \b \f \n \r \t \uHHHH
35
36    local
 lbrace
     =
 P
(
"
{
"
)
37    local
 rbrace
     =
 P
(
"
}
"
)
38    local
 lparent
    =
 P
(
"
[
"
)
39    local
 rparent
    =
 P
(
"
]
"
)
40    local
 comma
      =
 P
(
"
,
"
)
41    local
 colon
      =
 P
(
"
:
"
)
42    local
 dquote
     =
 P
(
'
"
'
)
43
44    local
 whitespace
 =
 lpeg
.
patterns
.
whitespace
45    local
 optionalws
 =
 whitespace
^
0
46
47    local
 escapes
    =
 {
48        [
"
b
"
]
 =
 "
\010
"
,
49        [
"
f
"
]
 =
 "
\014
"
,
50        [
"
n
"
]
 =
 "
\n
"
,
51        [
"
r
"
]
 =
 "
\r
"
,
52        [
"
t
"
]
 =
 "
\t
"
,
53    }
54
55    -- todo: also handle larger utf16
56
57    local
 escape_un
  =
 P
(
"
\\u
"
)
/
"
"
 *
 (
C
(
R
(
"
09
"
,
"
AF
"
,
"
af
"
)
^
-4
)
 /
 function
(
s
)
58        return
 utfchar
(
tonumber
(
s
,
16
)
)
59    end
)
60
61    local
 escape_bs
  =
 P
(
[[
\
]]
)
 /
 "
"
 *
 (
P
(
1
)
 /
 escapes
)
 -- if not found then P(1) is returned i.e. the to be escaped char
62
63    local
 jstring
    =
 dquote
 *
 Cs
(
(
escape_un
 +
 escape_bs
 +
 (
1
-
dquote
)
)
^
0
)
 *
 dquote
64    local
 jtrue
      =
 P
(
"
true
"
)
  *
 Cc
(
true
)
65    local
 jfalse
     =
 P
(
"
false
"
)
 *
 Cc
(
false
)
66    local
 jnull
      =
 P
(
"
null
"
)
  *
 Cc
(
nil
)
67    local
 jnumber
    =
 (
1
-
whitespace
-
rparent
-
rbrace
-
comma
)
^
1
 /
 tonumber
68
69    local
 key
        =
 jstring
70
71    local
 jsonconverter
 =
 {
 "
value
"
,
72        hash
  =
 lbrace
 *
 Cf
(
Ct
(
"
"
)
 *
 (
V
(
"
pair
"
)
 *
 (
comma
 *
 V
(
"
pair
"
)
)
^
0
 +
 optionalws
)
,
rawset
)
 *
 rbrace
,
73        pair
  =
 Cg
(
optionalws
 *
 key
 *
 optionalws
 *
 colon
 *
 V
(
"
value
"
)
)
,
74        array
 =
 Ct
(
lparent
 *
 (
V
(
"
value
"
)
 *
 (
comma
 *
 V
(
"
value
"
)
)
^
0
 +
 optionalws
)
 *
 rparent
)
,
75    --  value = optionalws * (jstring + V("hash") + V("array") + jtrue + jfalse + jnull + jnumber + #rparent) * optionalws,
76        value
 =
 optionalws
 *
 (
jstring
 +
 V
(
"
hash
"
)
 +
 V
(
"
array
"
)
 +
 jtrue
 +
 jfalse
 +
 jnull
 +
 jnumber
)
 *
 optionalws
,
77    }
78
79    -- local jsonconverter = { "value",
80    --     hash   = lbrace * Cf(Ct("") * (V("pair") * (comma * V("pair"))^0 + optionalws),rawset) * rbrace,
81    --     pair   = Cg(optionalws * V("string") * optionalws * colon * V("value")),
82    --     array  = Ct(lparent * (V("value") * (comma * V("value"))^0 + optionalws) * rparent),
83    --     string = jstring,
84    --     value  = optionalws * (V("string") + V("hash") + V("array") + jtrue + jfalse + jnull + jnumber) * optionalws,
85    -- }
86
87    -- lpeg.print(jsonconverter) -- size 181
88
89    function
 json
.
tolua
(
str
)
90        return
 lpegmatch
(
jsonconverter
,
str
)
91    end
92
93    function
 json
.
load
(
filename
)
94        local
 data
 =
 io
.
loaddata
(
filename
)
95        if
 data
 then
96            return
 lpegmatch
(
jsonconverter
,
data
)
97        end
98    end
99
100end
101
102do
103
104    -- It's pretty bad that JSON doesn't allow the trailing comma ... it's a
105    -- typical example of a spec that then forces all generators to check for
106    -- this. It's a way to make sure programmers keep jobs.
107
108    local
 escaper
109
110    local
 f_start_hash
      =
 formatters
[
         '
%w{
'
 ]
111    local
 f_start_array
     =
 formatters
[
         '
%w[
'
 ]
112    local
 f_start_hash_new
  =
 formatters
[
 "
\n
"
 .
.
 '
%w{
'
 ]
113    local
 f_start_array_new
 =
 formatters
[
 "
\n
"
 .
.
 '
%w[
'
 ]
114    local
 f_start_hash_key
  =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : {
'
 ]
115    local
 f_start_array_key
 =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : [
'
 ]
116
117    local
 f_stop_hash
       =
 formatters
[
 "
\n
"
 .
.
 '
%w}
'
 ]
118    local
 f_stop_array
      =
 formatters
[
 "
\n
"
 .
.
 '
%w]
'
 ]
119
120    local
 f_key_val_seq
     =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : %s
'
    ]
121    local
 f_key_val_str
     =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : "%s"
'
  ]
122    local
 f_key_val_num
     =
 f_key_val_seq
123    local
 f_key_val_yes
     =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : true
'
  ]
124    local
 f_key_val_nop
     =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : false
'
 ]
125    local
 f_key_val_null
    =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s" : null
'
  ]
126
127    local
 f_val_num
         =
 formatters
[
 "
\n
"
 .
.
 '
%w%s
'
    ]
128    local
 f_val_str
         =
 formatters
[
 "
\n
"
 .
.
 '
%w"%s"
'
  ]
129    local
 f_val_yes
         =
 formatters
[
 "
\n
"
 .
.
 '
%wtrue
'
  ]
130    local
 f_val_nop
         =
 formatters
[
 "
\n
"
 .
.
 '
%wfalse
'
 ]
131    local
 f_val_null
        =
 formatters
[
 "
\n
"
 .
.
 '
%wnull
'
  ]
132    local
 f_val_empty
       =
 formatters
[
 "
\n
"
 .
.
 '
%w{ }
'
  ]
133    local
 f_val_seq
         =
 f_val_num
134
135    -- no empty tables because unknown if table or hash
136
137    local
 t
 =
 {
 }
138    local
 n
 =
 0
139
140    local
 function
 is_simple_table
(
tt
)
 -- also used in util-tab so maybe public
141        local
 l
 =
 #
tt
142        if
 l
 >
 0
 then
143            for
 i
=
1
,
l
 do
144                if
 type
(
tt
[
i
]
)
 =
=
 "
table
"
 then
145                    return
 false
146                end
147            end
148            local
 nn
 =
 n
149            n
 =
 n
 +
 1
 t
[
n
]
 =
 "
[ 
"
150            for
 i
=
1
,
l
 do
151                if
 i
 >
 1
 then
152                    n
 =
 n
 +
 1
 t
[
n
]
 =
 "
, 
"
153                end
154                local
 v
 =
 tt
[
i
]
155                local
 tv
 =
 type
(
v
)
156                if
 tv
 =
=
 "
number
"
 then
157                    n
 =
 n
 +
 1
 t
[
n
]
 =
 v
158                elseif
 tv
 =
=
 "
string
"
 then
159                    n
 =
 n
 +
 1
 t
[
n
]
 =
 '
"
'
160                    n
 =
 n
 +
 1
 t
[
n
]
 =
 lpegmatch
(
escaper
,
v
)
 or
 v
161                    n
 =
 n
 +
 1
 t
[
n
]
 =
 '
"
'
162                elseif
 tv
 =
=
 "
boolean
"
 then
163                    n
 =
 n
 +
 1
 t
[
n
]
 =
 v
 and
 "
true
"
 or
 "
false
"
164                elseif
 v
 then
165                    n
 =
 n
 +
 1
 t
[
n
]
 =
 tostring
(
v
)
166                else
167                    n
 =
 n
 +
 1
 t
[
n
]
 =
 "
null
"
168                end
169            end
170            n
 =
 n
 +
 1
 t
[
n
]
 =
 "
 ]
"
171            local
 s
 =
 concat
(
t
,
"
"
,
nn
+
1
,
n
)
172            n
 =
 nn
173            return
 s
174        end
175        return
 false
176    end
177
178    local
 function
 tojsonpp
(
root
,
name
,
depth
,
level
,
size
)
179        if
 root
 then
180            local
 indexed
 =
 size
 >
 0
181            n
 =
 n
 +
 1
182            if
 level
 =
=
 0
 then
183                if
 indexed
 then
184                    t
[
n
]
 =
 f_start_array
(
depth
)
185                else
186                    t
[
n
]
 =
 f_start_hash
(
depth
)
187                end
188            elseif
 name
 then
189                if
 tn
 =
=
 "
string
"
 then
190                    name
 =
 lpegmatch
(
escaper
,
name
)
 or
 name
191                elseif
 tn
 ~
=
 "
number
"
 then
192                    name
 =
 tostring
(
name
)
193                end
194                if
 indexed
 then
195                    t
[
n
]
 =
 f_start_array_key
(
depth
,
name
)
196                else
197                    t
[
n
]
 =
 f_start_hash_key
(
depth
,
name
)
198                end
199            else
200                if
 indexed
 then
201                    t
[
n
]
 =
 f_start_array_new
(
depth
)
202                else
203                    t
[
n
]
 =
 f_start_hash_new
(
depth
)
204                end
205            end
206            depth
 =
 depth
 +
 1
207            if
 indexed
 then
 -- indexed
208                for
 i
=
1
,
size
 do
209                    if
 i
 >
 1
 then
210                        n
 =
 n
 +
 1
 t
[
n
]
 =
 "
,
"
211                    end
212                    local
 v
  =
 root
[
i
]
213                    local
 tv
 =
 type
(
v
)
214                    if
 tv
 =
=
 "
number
"
 then
215                        n
 =
 n
 +
 1
 t
[
n
]
 =
 f_val_num
(
depth
,
v
)
216                    elseif
 tv
 =
=
 "
string
"
 then
217                        v
 =
 lpegmatch
(
escaper
,
v
)
 or
 v
218                        n
 =
 n
 +
 1
 t
[
n
]
 =
 f_val_str
(
depth
,
v
)
219                    elseif
 tv
 =
=
 "
table
"
 then
220                        if
 next
(
v
)
 then
221                            local
 st
 =
 is_simple_table
(
v
)
222                            if
 st
 then
223                                n
 =
 n
 +
 1
 t
[
n
]
 =
 f_val_seq
(
depth
,
st
)
224                            else
225                                tojsonpp
(
v
,
nil
,
depth
,
level
+
1
,
#
v
)
226                            end
227                        else
228                            n
 =
 n
 +
 1
229                            t
[
n
]
 =
 f_val_empty
(
depth
)
230                        end
231                    elseif
 tv
 =
=
 "
boolean
"
 then
232                        n
 =
 n
 +
 1
233                        if
 v
 then
234                            t
[
n
]
 =
 f_val_yes
(
depth
,
v
)
235                        else
236                            t
[
n
]
 =
 f_val_nop
(
depth
,
v
)
237                        end
238                    else
239                        n
 =
 n
 +
 1
240                        t
[
n
]
 =
 f_val_null
(
depth
)
241                    end
242                end
243            elseif
 next
(
root
)
 then
244                local
 sk
 =
 sortedkeys
(
root
)
245                for
 i
=
1
,
#
sk
 do
246                    if
 i
 >
 1
 then
247                        n
 =
 n
 +
 1
 t
[
n
]
 =
 "
,
"
248                    end
249                    local
 k
  =
 sk
[
i
]
250                    local
 v
  =
 root
[
k
]
251                    local
 tv
 =
 type
(
v
)
252                    local
 tk
 =
 type
(
k
)
253                    if
 tv
 =
=
 "
number
"
 then
254                        if
 tk
 =
=
 "
number
"
 then
255                            n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_num
(
depth
,
k
,
v
)
256                        elseif
 tk
 =
=
 "
string
"
 then
257                            k
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
258                            n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_num
(
depth
,
k
,
v
)
259                        end
260                    elseif
 tv
 =
=
 "
string
"
 then
261                        if
 tk
 =
=
 "
number
"
 then
262                            v
 =
 lpegmatch
(
escaper
,
v
)
 or
 v
263                            n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_str
(
depth
,
k
,
v
)
264                        elseif
 tk
 =
=
 "
string
"
 then
265                            k
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
266                            v
 =
 lpegmatch
(
escaper
,
v
)
 or
 v
267                            n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_str
(
depth
,
k
,
v
)
268                        end
269                    elseif
 tv
 =
=
 "
table
"
 then
270                        local
 l
 =
 #
v
271                        if
 l
 >
 0
 then
272                            local
 st
 =
 is_simple_table
(
v
)
273                            if
 not
 st
 then
274                                tojsonpp
(
v
,
k
,
depth
,
level
+
1
,
l
)
275                            elseif
 tk
 =
=
 "
number
"
 then
276                                n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_seq
(
depth
,
k
,
st
)
277                            elseif
 tk
 =
=
 "
string
"
 then
278                                k
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
279                                n
 =
 n
 +
 1
 t
[
n
]
 =
 f_key_val_seq
(
depth
,
k
,
st
)
280                            end
281                        elseif
 next
(
v
)
 then
282                            tojsonpp
(
v
,
k
,
depth
,
level
+
1
,
0
)
283                        end
284                    elseif
 tv
 =
=
 "
boolean
"
 then
285                        if
 tk
 =
=
 "
number
"
 then
286                            n
 =
 n
 +
 1
287                            if
 v
 then
288                                t
[
n
]
 =
 f_key_val_yes
(
depth
,
k
)
289                            else
290                                t
[
n
]
 =
 f_key_val_nop
(
depth
,
k
)
291                            end
292                        elseif
 tk
 =
=
 "
string
"
 then
293                            k
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
294                            n
 =
 n
 +
 1
295                            if
 v
 then
296                                t
[
n
]
 =
 f_key_val_yes
(
depth
,
k
)
297                            else
298                                t
[
n
]
 =
 f_key_val_nop
(
depth
,
k
)
299                            end
300                        end
301                    else
302                        if
 tk
 =
=
 "
number
"
 then
303                            n
 =
 n
 +
 1
304                            t
[
n
]
 =
 f_key_val_null
(
depth
,
k
)
305                        elseif
 tk
 =
=
 "
string
"
 then
306                            k
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
307                            n
 =
 n
 +
 1
308                            t
[
n
]
 =
 f_key_val_null
(
depth
,
k
)
309                        end
310                    end
311                end
312            end
313            n
 =
 n
 +
 1
314            if
 indexed
 then
315                t
[
n
]
 =
 f_stop_array
(
depth
-1
)
316            else
317                t
[
n
]
 =
 f_stop_hash
(
depth
-1
)
318            end
319        end
320    end
321
322    local
 function
 tojson
(
value
,
n
)
323        local
 kind
 =
 type
(
value
)
324        if
 kind
 =
=
 "
table
"
 then
325            local
 done
 =
 false
326            local
 size
 =
 #
value
327            if
 size
 =
=
 0
 then
328                for
 k
,
 v
 in
 next
,
 value
 do
329                    if
 done
 then
330                     -- n = n + 1 ; t[n] = ","
331                        n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 '
,"
'
332                    else
333                     -- n = n + 1 ; t[n] = "{"
334                        n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 '
{"
'
335                        done
 =
 true
336                    end
337                    n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 lpegmatch
(
escaper
,
k
)
 or
 k
338                    n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 '
":
'
339                    t
,
 n
 =
 tojson
(
v
,
n
)
340                end
341                if
 done
 then
342                    n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
}
"
343                else
344                    n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
{}
"
345                end
346            elseif
 size
 =
=
 1
 then
347                -- we can optimize for non tables
348                n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
[
"
349                t
,
 n
 =
 tojson
(
value
[
1
]
,
n
)
350                n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
]
"
351            else
352                for
 i
=
1
,
size
 do
353                    if
 done
 then
354                        n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
,
"
355                    else
356                        n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
[
"
357                        done
 =
 true
358                    end
359                    t
,
 n
 =
 tojson
(
value
[
i
]
,
n
)
360                end
361                n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
]
"
362            end
363        elseif
 kind
 =
=
 "
string
"
  then
364            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 '
"
'
365            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 lpegmatch
(
escaper
,
value
)
 or
 value
366            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 '
"
'
367        elseif
 kind
 =
=
 "
number
"
 then
368            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 value
369        elseif
 kind
 =
=
 "
boolean
"
 then
370            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 tostring
(
value
)
371        else
372            n
 =
 n
 +
 1
 ;
 t
[
n
]
 =
 "
null
"
373        end
374        return
 t
,
 n
375    end
376
377    -- escaping keys can become an option
378
379    local
 function
 jsontostring
(
value
,
pretty
)
380        -- todo optimize for non table
381        local
 kind
 =
 type
(
value
)
382        if
 kind
 =
=
 "
table
"
 then
383            if
 not
 escaper
 then
384                local
 escapes
 =
 {
385                    [
"
\\
"
]
 =
 "
\\u005C
"
,
386                    [
"
\"
"
]
 =
 "
\\u0022
"
,
387                }
388                for
 i
=
0
,
0x1F
 do
389                    escapes
[
utfchar
(
i
)
]
 =
 format
(
"
\\u%04X
"
,
i
)
390                end
391                escaper
 =
 Cs
(
 (
392                    (
R
(
'
\0\x20
'
)
 +
 S
(
'
\"\\
'
)
)
 /
 escapes
393                  +
 P
(
1
)
394                )
^
1
 )
395
396            end
397            -- local to the closure (saves wrapping and local functions)
398            t
 =
 {
 }
399            n
 =
 0
400            if
 pretty
 then
401                tojsonpp
(
value
,
name
,
0
,
0
,
#
value
)
402                value
 =
 concat
(
t
,
"
"
,
1
,
n
)
403            else
404                t
,
 n
 =
 tojson
(
value
,
0
)
405                value
 =
 concat
(
t
,
"
"
,
1
,
n
)
406            end
407            t
 =
 nil
408            n
 =
 0
409            return
 value
410        elseif
 kind
 =
=
 "
string
"
 or
 kind
 =
=
 "
number
"
 then
411            return
 lpegmatch
(
escaper
,
value
)
 or
 value
412        else
413            return
 tostring
(
value
)
414        end
415    end
416
417    json
.
tostring
 =
 jsontostring
418
419    function
 json
.
tojson
(
value
)
420        return
 jsontostring
(
value
,
true
)
421    end
422
423end
424
425-- local tmp = [[ { "t\nt t" : "foo bar", "a" : true, "b" : [ 123 , 456E-10, { "a" : true, "b" : [ 123 , 456 ] } ] } ]]
426-- tmp = json.tolua(tmp)
427-- inspect(tmp)
428-- tmp = json.tostring(tmp,true)
429-- inspect(tmp)
430-- tmp = json.tolua(tmp)
431-- inspect(tmp)
432-- tmp = json.tostring(tmp)
433-- inspect(tmp)
434-- inspect(json.tostring(true))
435
436-- local s = [[\foo"bar"]]
437-- local j = json.tostring { s = s }
438-- local l = json.tolua(j)
439-- inspect(j)
440-- inspect(l)
441-- print(s==l.s)
442
443return
 json
444
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