diff options
Diffstat (limited to 'Data/BuiltIn/Libraries/lua-addons/addons/libs/json.lua')
| -rw-r--r-- | Data/BuiltIn/Libraries/lua-addons/addons/libs/json.lua | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/Data/BuiltIn/Libraries/lua-addons/addons/libs/json.lua b/Data/BuiltIn/Libraries/lua-addons/addons/libs/json.lua new file mode 100644 index 0000000..ff8e314 --- /dev/null +++ b/Data/BuiltIn/Libraries/lua-addons/addons/libs/json.lua @@ -0,0 +1,297 @@ +--[[ +Small implementation of a JSON file reader. +]] + +_libs = _libs or {} + +require('tables') +require('lists') +require('sets') +require('strings') + +local table, list, set, string = _libs.tables, _libs.lists, _libs.sets, _libs.strings +local files = require('files') + +local json = {} + +_libs.json = json + +-- Define singleton JSON characters that can delimit strings. +local singletons = '{}[],:' +local key_types = S{'string', 'number'} +local value_types = S{'boolean', 'number', 'string', 'nil'} + +-- Takes a filename and tries to parse the JSON in it, after a validity check. +function json.read(file) + if type(file) == 'string' then + file = files.new(file) + end + + if not file:exists() then + return json.error('File not found: \''..file.path..'\'') + end + + return json.parse(file:read()) +end + +-- Returns nil as the parsed table and an additional error message with an optional line number. +function json.error(message, line) + if line == nil then + return nil, 'JSON error: '..message + end + return nil, 'JSON error, line '..line..': '..message +end + +-- Returns a Lua value based on a string. +-- Recognizes all valid atomic JSON values: booleans, numbers, strings and null. +-- Object and error groupings will be eliminated during the classifying process. +-- If stripquotes is set to true, quote characters delimiting strings will be stripped. +function json.make_val(str, stripquotes) + stripquotes = true and (stripquotes ~= false) + + str = str:trim() + if str == '' then + return nil + elseif str == 'true' then + return true + elseif str == 'false' then + return false + elseif str == 'null' then + return nil + elseif stripquotes and (str:enclosed('\'') or str:enclosed('"')) then + return str:slice(2, -2) + end + + str = str:gsub('\\x([%w%d][%w%d])', string.char..tonumber-{16}) + + return tonumber(str) or str +end + +-- Parsing function. Gets a string representation of a JSON object and outputs a Lua table or an error message. +function json.parse(content) + return json.classify(json.tokenize(content)) +end + +-- Tokenizer. Reads a string and returns an array of lines, each line with a number of valid JSON tokens. Valid tokens include: +-- * \w+ Keys or values +-- * : Key indexer +-- * , Value separator +-- * \{\} Dictionary start/end +-- * \[\] List start/end +function json.tokenize(content) + -- Tokenizer. Reads the string by characters and finds word boundaries, returning an array of tokens to be interpreted. + local current = nil + local tokens = L{L{}} + local quote = nil + local comment = false + local line = 1 + + content = content:trim() + local length = #content + if content:sub(length, length) == ',' then + content = content:sub(1, length - 1) + length = length - 1 + end + + local first = content:sub(1, 1) + local last = content:sub(length, length) + if first ~= '[' and first ~= '{' then + return json.error('Invalid JSON format. Document needs to start with \'{\' (object) or \'[\' (array).') + end + + if not (first == '[' and last == ']' or first == '{' and last == '}') then + return json.error('Invalid JSON format. Document starts with \''..first..'\' but ends with \''..last..'\'.') + end + + local root + if first == '[' then + root = 'array' + else + root = 'object' + end + + content = content:sub(2, length - 1) + + for c in content:it() do + -- Only useful for a line count, to produce more accurate debug messages. + if c == '\n' then + line = line + 1 + comment = false + tokens:append(L{}) + end + + -- If the quote character is set, don't parse but syntax, but instead just append to the string until the same quote character is encountered. + if quote ~= nil then + current = current..c + -- If the quote character is found, append the parsed string and reset the parsing values. + if quote == c then + tokens[line]:append(json.make_val(current)) + current = nil + quote = nil + end + elseif not comment then + -- If the character is a singleton character, append the previous token and this one, reset the parsing values. + if singletons:contains(c) then + if current ~= nil then + tokens[line]:append(json.make_val(current)) + current = nil + end + tokens[line]:append(c) + -- If a quote character is found, start a quoting session, see alternative condition. + elseif c == '"' or c == '\'' and current == nil then + quote = c + current = c + -- Otherwise, just append + elseif not c:match('%s') or current ~= nil then + -- Ignore comments. Not JSON conformant. + if c == '/' and current ~= nil and current:last() == '/' then + current = current:slice(1, -2) + if current == '' then + current = nil + end + comment = true + else + current = current or '' + current = current..c + end + end + end + end + + return tokens, root +end + +-- Takes a list of tokens and analyzes it to construct a valid Lua object from it. +function json.classify(tokens, root) + if tokens == nil then + return tokens, root + end + + local scopes = L{root} + + -- Scopes and their domains: + -- * 'object': Object scope, delimited by '{' and '}' as well as global scope + -- * 'array': Array scope, delimited by '[' and ']' + -- Possible modes and triggers: + -- * 'new': After an opening brace, bracket, comma or at the start, expecting a new element + -- * 'key': After reading a key + -- * 'colon': After reading a colon + -- * 'value': After reading or having scoped a value (either an object, or an array for the latter) + local modes = L{'new'} + + local parsed + if root == 'object' then + parsed = L{T{}} + else + parsed = L{L{}} + end + + local keys = L{} + -- Classifier. Iterates through the tokens and assigns meaning to them. Determines scoping and creates objects and arrays. + for array, line in tokens:it() do + for token, pos in array:it() do + if token == '{' then + if modes:last() == 'colon' or modes:last() == 'new' and scopes:last() == 'array' then + parsed:append(T{}) + scopes:append('object') + modes:append('new') + else + return json.error('Unexpected token \'{\'.', line) + end + elseif token == '}' then + if modes:last() == 'value' or modes:last() == 'new' then + modes:remove() + scopes:remove() + if modes:last() == 'colon' then + parsed:last(2)[keys:remove()] = parsed:remove() + elseif modes:last() == 'new' and scopes:last() == 'array' then + parsed:last():append(parsed:remove()) + else + return json.error('Unexpected token \'}\'.', line) + end + modes[#modes] = 'value' + else + return json.error('Unexpected token \'}\'.', line) + end + elseif token == '[' then + if modes:last() == 'colon' or modes:last() == 'new' and scopes:last() == 'array' then + parsed:append(T{}) + scopes:append('array') + modes:append('new') + else + return json.error('Unexpected token \'{\'.', line) + end + elseif token == ']' then + if modes:last() == 'value' or modes:last() == 'new' then + modes:remove() + scopes:remove() + if modes:last() == 'colon' then + parsed[#parsed-1][keys:remove()] = parsed:remove() + elseif modes:last() == 'new' and scopes:last() == 'array' then + parsed:last():append(parsed:remove()) + else + return json.error('Unexpected token \'}\'.', line) + end + modes[#modes] = 'value' + else + return json.error('Unexpected token \'}\'.', line) + end + elseif token == ':' then + if modes:last() == 'key' then + modes[#modes] = 'colon' + else + return json.error('Unexpected token \':\'.', line) + end + elseif token == ',' then + if modes:last() == 'value' then + modes[#modes] = 'new' + else + return json.error('Unexpected token \',\'.', line) + end + elseif key_types:contains(type(token)) and modes:last() == 'new' and scopes:last() == 'object' then + keys:append(token) + modes[#modes] = 'key' + elseif value_types:contains(type(token)) then + if modes:last() == 'colon' then + parsed:last()[keys:remove()] = token + modes[#modes] = 'value' + elseif modes:last() == 'new' then + if scopes:last() == 'array' then + parsed:last():append(token) + modes[#modes] = 'value' + else + return json.error('Unexpected token \''..token..'\'.', line) + end + else + return json.error('Unexpected token \''..token..'\'.', line) + end + else + return json.error('Unkown token parsed. You should never see this. Token type: '..type(token), line) + end + end + end + + if parsed:empty() then + return json.error('No JSON found.') + end + if #parsed > 1 then + return json.error('Invalid nesting, missing closing tags.') + end + + return parsed:remove() +end + +return json + +--[[ +Copyright (c) 2013, Windower +All rights reserved. + +Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. + * Neither the name of Windower nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Windower BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +]] |