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nmap/nselib/strbuf.lua
batrick 670792a4a6 Updated all libraries documentation.
packet and url both need more work.
2008-08-18 04:03:45 +00:00

114 lines
3.1 KiB
Lua

--- String Buffer Facilities
--@copyright See nmaps COPYING for license
-- DEPENDENCIES --
local getmetatable = getmetatable;
local setmetatable = setmetatable;
local type = type;
local error = error;
local ipairs = ipairs;
local pairs = pairs;
local concat = table.concat;
module(... or "strbuf");
-- String buffer functions. Concatenation is not efficient in
-- lua as strings are immutable. If a large amount of '..' sequential
-- operations are needed a string buffer should be used instead
-- e.g. for i = 1, 10 do s = s..i end
--[[
local buf = strbuf.new()
-- from here buf may be used like a string for concatenation operations
-- (the lefthand-operand has to be a strbuf, the righthand-operand may be
-- a string or a strbuf)
-- alternativly you can assign a value (which will become the first string
-- inside the buffer) with new
local buf2 = strbuf.new('hello')
buf = buf .. 'string'
buf = buf .. 'data'
print(buf) -- default seperator is a new line
print(strbuf.dump(buf)) -- no seperator
print(strbuf.dump(buf, ' ')) -- seperated by spaces
strbuf.clear(buf)
--]]
--- Dumps the string buffer as a string.
--@name dump
--@class function
--@param sbuf String buffer to dump.
--@param delimiter String to separate the buffer's contents.
--@return Concatenated string result.
dump = concat;
--- Appends the string s to the buffer, sbuf.
--@param sbuf String buffer.
--@param s String to append.
function concatbuf(sbuf, s)
if type(s) == "string" then
sbuf[#sbuf+1] = s;
elseif getmetatable(s) == getmetatable(sbuf) then
for _,v in ipairs(s) do
sbuf[#sbuf+1] = v;
end
else
error("bad #2 operand to strbuf concat operation", 2);
end
return sbuf;
end
--- Determines if the two buffers are equal. Two buffers are equal
-- if they are the same or if they have equivalent contents.
--@param sbuf1 String buffer one.
--@param sbuf2 String buffer two.
--@return boolean true if equal, false otherwise.
function eqbuf(sbuf1, sbuf2)
if getmetatable(sbuf1) ~= getmetatable(sbuf2) then
error("one or more operands is not a string buffer", 2);
elseif #sbuf1 ~= #sbuf2 then
return false;
else
for i = 1, #sbuf1 do
if sbuf1[i] ~= sbuf2[i] then
return false;
end
end
return true;
end
end
--- Clears the string buffer.
--@param sbuf String buffer.
function clear(sbuf)
for k in pairs(sbuf) do
sbuf[k] = nil;
end
end
--- Returns the result of the buffer as a string. The delimiter used
-- is a newline.
--@param sbuf String buffer.
--@return String made from concatenating the buffer.
function tostring(sbuf)
return concat(sbuf, "\n");
end
local mt = {
__concat = concatbuf,
__tostring = tostring,
__eq = eqbuf,
__index = _M,
};
--- Create a new string buffer. The equals and tostring operators for String
-- buffers are overloaded to be strbuf.eqbuf and strbuf.tostring respectively.
-- All functions in strbuf can be accessed by a String buffer using the self
-- calling mechanism in Lua (e.g. strbuf:dump(...)).
--@param ... Strings to add to the buffer initially.
--@return String buffer.
function new(...)
return setmetatable({...}, mt);
end