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 formatters = string.formatters
local utfchar = utf.char
local concat, sortedkeys = table.concat, table.sortedkeys
local tonumber, tostring, rawset, type, next = tonumber, tostring, rawset, type, next
local json = utilities.json or { }
utilities.json = json
do
-- \\ \/ \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
function json.load(filename)
local data = io.loaddata(filename)
if data then
return lpegmatch(jsonconverter,data)
end
end
end
do
-- It's pretty bad that JSON doesn't allow the trailing comma ... it's a
-- typical example of a spec that then forces all generators to check for
-- this. It's a way to make sure programmers keep jobs.
local escaper
local f_start_hash = formatters[ '%w{' ]
local f_start_array = formatters[ '%w[' ]
local f_start_hash_new = formatters[ "\n" .. '%w{' ]
local f_start_array_new = formatters[ "\n" .. '%w[' ]
local f_start_hash_key = formatters[ "\n" .. '%w"%s" : {' ]
local f_start_array_key = formatters[ "\n" .. '%w"%s" : [' ]
local f_stop_hash = formatters[ "\n" .. '%w}' ]
local f_stop_array = formatters[ "\n" .. '%w]' ]
local f_key_val_seq = formatters[ "\n" .. '%w"%s" : %s' ]
local f_key_val_str = formatters[ "\n" .. '%w"%s" : "%s"' ]
local f_key_val_num = f_key_val_seq
local f_key_val_yes = formatters[ "\n" .. '%w"%s" : true' ]
local f_key_val_nop = formatters[ "\n" .. '%w"%s" : false' ]
local f_key_val_null = formatters[ "\n" .. '%w"%s" : null' ]
local f_val_num = formatters[ "\n" .. '%w%s' ]
local f_val_str = formatters[ "\n" .. '%w"%s"' ]
local f_val_yes = formatters[ "\n" .. '%wtrue' ]
local f_val_nop = formatters[ "\n" .. '%wfalse' ]
local f_val_null = formatters[ "\n" .. '%wnull' ]
local f_val_empty = formatters[ "\n" .. '%w{ }' ]
local f_val_seq = f_val_num
-- no empty tables because unknown if table or hash
local t = { }
local n = 0
local function is_simple_table(tt) -- also used in util-tab so maybe public
local l = #tt
if l > 0 then
for i=1,l do
if type(tt[i]) == "table" then
return false
end
end
local nn = n
n = n + 1 t[n] = "[ "
for i=1,l do
if i > 1 then
n = n + 1 t[n] = ", "
end
local v = tt[i]
local tv = type(v)
if tv == "number" then
n = n + 1 t[n] = v
elseif tv == "string" then
n = n + 1 t[n] = '"'
n = n + 1 t[n] = lpegmatch(escaper,v) or v
n = n + 1 t[n] = '"'
elseif tv == "boolean" then
n = n + 1 t[n] = v and "true" or "false"
elseif v then
n = n + 1 t[n] = tostring(v)
else
n = n + 1 t[n] = "null"
end
end
n = n + 1 t[n] = " ]"
local s = concat(t,"",nn+1,n)
n = nn
return s
end
return false
end
local function tojsonpp(root,name,depth,level,size)
if root then
local indexed = size > 0
n = n + 1
if level == 0 then
if indexed then
t[n] = f_start_array(depth)
else
t[n] = f_start_hash(depth)
end
elseif name then
if tn == "string" then
name = lpegmatch(escaper,name) or name
elseif tn ~= "number" then
name = tostring(name)
end
if indexed then
t[n] = f_start_array_key(depth,name)
else
t[n] = f_start_hash_key(depth,name)
end
else
if indexed then
t[n] = f_start_array_new(depth)
else
t[n] = f_start_hash_new(depth)
end
end
depth = depth + 1
if indexed then -- indexed
for i=1,size do
if i > 1 then
n = n + 1 t[n] = ","
end
local v = root[i]
local tv = type(v)
if tv == "number" then
n = n + 1 t[n] = f_val_num(depth,v)
elseif tv == "string" then
v = lpegmatch(escaper,v) or v
n = n + 1 t[n] = f_val_str(depth,v)
elseif tv == "table" then
if next(v) then
local st = is_simple_table(v)
if st then
n = n + 1 t[n] = f_val_seq(depth,st)
else
tojsonpp(v,nil,depth,level+1,#v)
end
else
n = n + 1
t[n] = f_val_empty(depth)
end
elseif tv == "boolean" then
n = n + 1
if v then
t[n] = f_val_yes(depth,v)
else
t[n] = f_val_nop(depth,v)
end
else
n = n + 1
t[n] = f_val_null(depth)
end
end
elseif next(root) then
local sk = sortedkeys(root)
for i=1,#sk do
if i > 1 then
n = n + 1 t[n] = ","
end
local k = sk[i]
local v = root[k]
local tv = type(v)
local tk = type(k)
if tv == "number" then
if tk == "number" then
n = n + 1 t[n] = f_key_val_num(depth,k,v)
elseif tk == "string" then
k = lpegmatch(escaper,k) or k
n = n + 1 t[n] = f_key_val_num(depth,k,v)
end
elseif tv == "string" then
if tk == "number" then
v = lpegmatch(escaper,v) or v
n = n + 1 t[n] = f_key_val_str(depth,k,v)
elseif tk == "string" then
k = lpegmatch(escaper,k) or k
v = lpegmatch(escaper,v) or v
n = n + 1 t[n] = f_key_val_str(depth,k,v)
end
elseif tv == "table" then
local l = #v
if l > 0 then
local st = is_simple_table(v)
if not st then
tojsonpp(v,k,depth,level+1,l)
elseif tk == "number" then
n = n + 1 t[n] = f_key_val_seq(depth,k,st)
elseif tk == "string" then
k = lpegmatch(escaper,k) or k
n = n + 1 t[n] = f_key_val_seq(depth,k,st)
end
elseif next(v) then
tojsonpp(v,k,depth,level+1,0)
end
elseif tv == "boolean" then
if tk == "number" then
n = n + 1
if v then
t[n] = f_key_val_yes(depth,k)
else
t[n] = f_key_val_nop(depth,k)
end
elseif tk == "string" then
k = lpegmatch(escaper,k) or k
n = n + 1
if v then
t[n] = f_key_val_yes(depth,k)
else
t[n] = f_key_val_nop(depth,k)
end
end
else
if tk == "number" then
n = n + 1
t[n] = f_key_val_null(depth,k)
elseif tk == "string" then
k = lpegmatch(escaper,k) or k
n = n + 1
t[n] = f_key_val_null(depth,k)
end
end
end
end
n = n + 1
if indexed then
t[n] = f_stop_array(depth-1)
else
t[n] = f_stop_hash(depth-1)
end
end
end
local function tojson(value,n)
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] = ","
n = n + 1 ; t[n] = ',"'
else
-- n = n + 1 ; t[n] = "{"
n = n + 1 ; t[n] = '{"'
done = true
end
n = n + 1 ; t[n] = lpegmatch(escaper,k) or k
n = n + 1 ; t[n] = '":'
t, n = tojson(v,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],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],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)
else
n = n + 1 ; t[n] = "null"
end
return t, n
end
-- escaping keys can become an option
local function jsontostring(value,pretty)
-- todo optimize for non table
local kind = type(value)
if kind == "table" then
if not escaper then
local escapes = {
["\\"] = "\\u005C",
["\""] = "\\u0022",
}
for i=0,0x1F do
escapes[utfchar(i)] = format("\\u%04X",i)
end
escaper = Cs( (
(R('\0\x20') + S('\"\\')) / escapes
+ P(1)
)^1 )
end
-- local to the closure (saves wrapping and local functions)
t = { }
n = 0
if pretty then
tojsonpp(value,name,0,0,#value)
value = concat(t,"",1,n)
else
t, n = tojson(value,0)
value = concat(t,"",1,n)
end
t = nil
n = 0
return value
elseif kind == "string" or kind == "number" then
return lpegmatch(escaper,value) or value
else
return tostring(value)
end
end
json.tostring = jsontostring
function json.tojson(value)
return jsontostring(value,true)
end
end
-- local tmp = [[ { "t\nt t" : "foo bar", "a" : true, "b" : [ 123 , 456E-10, { "a" : true, "b" : [ 123 , 456 ] } ] } ]]
-- tmp = json.tolua(tmp)
-- inspect(tmp)
-- tmp = json.tostring(tmp,true)
-- inspect(tmp)
-- tmp = json.tolua(tmp)
-- inspect(tmp)
-- tmp = json.tostring(tmp)
-- inspect(tmp)
-- inspect(json.tostring(true))
-- 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
