basic_functions/functions.lua

basic_functions.has_value = function(tab, val)
-- test if val is in tab
    for index, value in ipairs(tab) do
        if value == val then
            return true
        end
    end
    return false
end

local has_value=basic_functions.has_value

-- read table "infile" where in "def" is defined, which cols are numbers and which belongs to a group
-- First line has to be the header.
-- def.as_numeric: all values not stated in col_num, col_tab or with name "name" are interpreted as numeric
-- def.seperator: character to use as field delimiter
-- def.col_num: turn this elements to numbers
-- def.groups_num: put this elements as numbers into matrix groups
basic_functions.import_csv = function(infile,def)
	local file = io.open(infile, "r")
	local outdata = {}
	-- reading header with column names
	local splitchar=","
	if def.seperator then
		splitchar=def.seperator
	end
	local as_numeric=false
	if def.as_numeric then
		as_numeric = true
	end
	local header = file:read():gsub("\r",""):split(splitchar,true)
	-- read each line, split in separat fields and stores in array
	-- by header the value is stored as numeric, in the group environment or as text
	for line in file:lines() do
		if line:sub(1,1) ~= "#" then -- lines starting with # are handled as comment
			local attribs = line:gsub("\r",""):split(splitchar,true)
			local nrow={groups={}}
			for i,d in ipairs(attribs) do
				if d ~= "" then
					local th=header[i]
					local dsaved = false
					if def.col_num then
						if has_value(def.col_num,th) then
							nrow[th] = tonumber(d)
							dsaved = true
						end
					end
					if def.groups_num then
						if has_value(def.groups_num,th) then
							nrow.groups[th]=tonumber(d)
							dsaved = true
						end
					end
					if th == "name" then
						nrow[th] = d
					else
						if not dsaved then
							if as_numeric then
								nrow[th] = tonumber(d)
							else
								nrow[th]=d
							end
						end
					end
				end
			end
			if nrow.name then
				outdata[nrow.name] = nrow
			else
				outdata[#outdata+1] = nrow
			end
		end
	end
	file:close()

	return outdata
end

-- split name of value (ind) by "_" and store content in nested matrix
-- inside "mat" 
basic_functions.parse_tree=function(mat,ind,val)
	if string.find(ind,"_") == nil then
		if tonumber(ind) ~= nil then
			mat[tonumber(ind)] = {}
			mat[tonumber(ind)] = tonumber(val)
		else
			mat[ind] = {}
			mat[ind] = tonumber(val)
		end
	else
		local ind_split=string.split(ind,"_")
		local first=ind_split[1]
		local second=string.split(ind,"_")[2]
		if #ind_split > 2 then
			for n=3,#ind_split do
				second = second.."_"..ind_split[n]
			end
		end
		if mat[first] == nil then
			mat[first]={}
		end
		mat[first]=basic_functions.parse_tree(mat[first],second,val)
	end
	return(mat)
end

-- function to read settingtypes.txt and insert values into minetest.setting
basic_functions.import_settingtype = function(infile)
	local file = io.open(infile, "r")
	local outdata = {}
	-- reading header with column names
	local splitchar=" "
	local setname=minetest.settings:get_names()
	for line in file:lines() do
		if line:sub(1,1) ~= "#" then -- lines starting with # are handled as comment
			local attrib = line:gsub("\"",""):gsub("%(.*%) ",""):gsub("\r",""):split(splitchar,true)
			if(#attrib >= 3) then -- there should be at least 3 fields in a row (without the description)
				if has_value(setname,attrib[1]) == false then
					if attrib[2] == "bool" then
						minetest.settings:set_bool(attrib[1],attrib[3] == "true")
					else
						minetest.settings:set(attrib[1],attrib[3])
					end
				end
			end
		end
	end
end

basic_functions.read_file=function(filename)
	local file=io.open(filename,"r")
	local out=""
	if file then
		for line in file:lines() do
			out=out..line
		end
		file:close()
	end
	return(out)
end