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if not modules then modules = { } end modules ['util-jsn'] = {
version = 1.001,
comment = "companion to m-json.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- Of course we could make a nice complete parser with proper error messages but
-- as json is generated programmatically errors are systematic and we can assume
-- a correct stream. If not, we have some fatal error anyway. So, we can just rely
-- on strings being strings (apart from the unicode escape which is not in 5.1) and
-- as we first catch known types we just assume that anything else is a number.
--
-- Reminder for me: check usage in framework and extend when needed. Also document
-- it in the cld lib documentation.
--
-- Upgraded for handling the somewhat more fax server templates.
local 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
local lpegmatch = lpeg.match
local format, gsub = string.format, string.gsub
local utfchar = utf.char
local concat = table.concat
local tonumber, tostring, rawset, type, next = tonumber, tostring, rawset, type, next
local json = utilities.json or { }
utilities.json = json
-- \\ \/ \b \f \n \r \t \uHHHH
local lbrace = P("{")
local rbrace = P("}")
local lparent = P("[")
local rparent = P("]")
local comma = P(",")
local colon = P(":")
local dquote = P('"')
local whitespace = lpeg.patterns.whitespace
local optionalws = whitespace^0
local escapes = {
["b"] = "\010",
["f"] = "\014",
["n"] = "\n",
["r"] = "\r",
["t"] = "\t",
}
-- todo: also handle larger utf16
local escape_un = P("\\u")/"" * (C(R("09","AF","af")^-4) / function(s)
return utfchar(tonumber(s,16))
end)
local escape_bs = P([[\]]) / "" * (P(1) / escapes) -- if not found then P(1) is returned i.e. the to be escaped char
local jstring = dquote * Cs((escape_un + escape_bs + (1-dquote))^0) * dquote
local jtrue = P("true") * Cc(true)
local jfalse = P("false") * Cc(false)
local jnull = P("null") * Cc(nil)
local jnumber = (1-whitespace-rparent-rbrace-comma)^1 / tonumber
local key = jstring
local jsonconverter = { "value",
hash = lbrace * Cf(Ct("") * (V("pair") * (comma * V("pair"))^0 + optionalws),rawset) * rbrace,
pair = Cg(optionalws * key * optionalws * colon * V("value")),
array = Ct(lparent * (V("value") * (comma * V("value"))^0 + optionalws) * rparent),
-- value = optionalws * (jstring + V("hash") + V("array") + jtrue + jfalse + jnull + jnumber + #rparent) * optionalws,
value = optionalws * (jstring + V("hash") + V("array") + jtrue + jfalse + jnull + jnumber) * optionalws,
}
-- local jsonconverter = { "value",
-- hash = lbrace * Cf(Ct("") * (V("pair") * (comma * V("pair"))^0 + optionalws),rawset) * rbrace,
-- pair = Cg(optionalws * V("string") * optionalws * colon * V("value")),
-- array = Ct(lparent * (V("value") * (comma * V("value"))^0 + optionalws) * rparent),
-- string = jstring,
-- value = optionalws * (V("string") + V("hash") + V("array") + jtrue + jfalse + jnull + jnumber) * optionalws,
-- }
-- lpeg.print(jsonconverter) -- size 181
function json.tolua(str)
return lpegmatch(jsonconverter,str)
end
local escaper
local function tojson(value,t,n) -- we could optimize #t
local kind = type(value)
if kind == "table" then
local done = false
local size = #value
if size == 0 then
for k, v in next, value do
if done then
n = n + 1 ; t[n] = ","
else
n = n + 1 ; t[n] = "{"
done = true
end
n = n + 1 ; t[n] = format("%q:",k)
t, n = tojson(v,t,n)
end
if done then
n = n + 1 ; t[n] = "}"
else
n = n + 1 ; t[n] = "{}"
end
elseif size == 1 then
-- we can optimize for non tables
n = n + 1 ; t[n] = "["
t, n = tojson(value[1],t,n)
n = n + 1 ; t[n] = "]"
else
for i=1,size do
if done then
n = n + 1 ; t[n] = ","
else
n = n + 1 ; t[n] = "["
done = true
end
t, n = tojson(value[i],t,n)
end
n = n + 1 ; t[n] = "]"
end
elseif kind == "string" then
n = n + 1 ; t[n] = '"'
n = n + 1 ; t[n] = lpegmatch(escaper,value) or value
n = n + 1 ; t[n] = '"'
elseif kind == "number" then
n = n + 1 ; t[n] = value
elseif kind == "boolean" then
n = n + 1 ; t[n] = tostring(value)
end
return t, n
end
function json.tostring(value)
-- todo optimize for non table
local kind = type(value)
if kind == "table" then
if not escaper then
local escapes = {
["\\"] = "\\u005C",
["\""] = "\\u0022",
}
for i=0,0x20 do
escapes[utfchar(i)] = format("\\u%04X",i)
end
escaper = Cs( (
(R('\0\x20') + S('\"\\')) / escapes
+ P(1)
)^1 )
end
return concat((tojson(value,{},0)))
elseif kind == "string" or kind == "number" then
return lpegmatch(escaper,value) or value
else
return tostring(value)
end
end
-- local tmp = [[ { "t" : "foobar", "a" : true, "b" : [ 123 , 456E-10, { "a" : true, "b" : [ 123 , 456 ] } ] } ]]
-- tmp = json.tolua(tmp)
-- inspect(tmp)
-- tmp = json.tostring(tmp)
-- inspect(tmp)
-- tmp = json.tolua(tmp)
-- inspect(tmp)
-- tmp = json.tostring(tmp)
-- inspect(tmp)
-- inspect(json.tostring(true))
function json.load(filename)
local data = io.loaddata(filename)
if data then
return lpegmatch(jsonconverter,data)
end
end
-- local s = [[\foo"bar"]]
-- local j = json.tostring { s = s }
-- local l = json.tolua(j)
-- inspect(j)
-- inspect(l)
-- print(s==l.s)
return json
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