💾 Archived View for gemini.conman.org › extensions › port70 › handlers › blog › url-util.lua captured on 2020-11-01 at 00:00:23.
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-- ***************************************************************
--
-- Copyright 2019 by Sean Conner. All Rights Reserved.
--
-- This library is free software; you can redistribute it and/or modify it
-- under the terms of the GNU Lesser General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or (at your
-- option) any later version.
--
-- This library is distributed in the hope that it will be useful, but
-- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
-- License for more details.
--
-- You should have received a copy of the GNU Lesser General Public License
-- along with this library; if not, see <http://www.gnu.org/licenses/>.
--
-- Comments, questions and criticisms can be sent to: sean@conman.org
--
-- ********************************************************************
-- luacheck: globals rm_dot_segs merge toa query toq
-- luacheck: globals esc_auth esc_path esc_query esc_frag
-- luacheck: ignore 611
local lpeg = require "lpeg"
local string = require "string"
local table = require "table"
local tonumber = tonumber
local tostring = tostring
local type = type
local pairs = pairs
_ENV = {}
local Cc = lpeg.Cc
local Cf = lpeg.Cf
local Cg = lpeg.Cg
local Cs = lpeg.Cs
local C = lpeg.C
local P = lpeg.P
local R = lpeg.R
-- ********************************************************************
-- Note: The commented letters A, B, C, etc., reference RFC-3986 5.2.4.
-- ********************************************************************
local segment = P'../' * Cc'' * Cc(false) -- A
+ P'./' * Cc'' * Cc(false)
+ P'/.' * #P'/' * Cc'' * Cc(false) -- B
+ P'/.' * P(-1) * Cc'/' * Cc(false)
+ P'/..' * #P'/' * Cc'' * Cc(true) -- C
+ P'/..' * P(-1) * Cc'/' * Cc(true)
+ P'..' * P(-1) * Cc'' * Cc(false) -- D
+ P'.' * P(-1) * Cc'' * Cc(false)
+ C(P'/'^-1 * (R"!~" - P'/')^1) * Cc(false) -- E
+ C'/' * Cc(false)
rm_dot_segs = Cf(Cc"" * (Cg(segment))^1,function(acc,capture,trim)
if trim then
for i = -2,-#acc,-1 do
if acc:sub(i,i) == '/' then
return acc:sub(1,i-1) .. capture
end
end
return capture
else
return acc .. capture
end
end) + Cc''
-- ********************************************************************
-- Usage: u = merge(Base,R)
-- Desc: Merge a URL with a base URL
-- Input: Base (table) a URL from url2:match()
-- R (table) a URL from url2:match()
-- Return: u (table) A merged URL
--
-- Note: Implements the algorithm from RFC-3986 5.2.2, with the
-- "authority" portion being .host, .port and .user.
-- ********************************************************************
function merge(Base,Ru)
local function mergepath()
if Base.host and Base.path == "" then
return "/" .. Ru.path
else
for i = -1 , -#Base.path , -1 do
if Base.path:sub(i,i) == '/' then
return Base.path:sub(1,i) .. Ru.path
end
end
end
end
local T = {}
if Ru.scheme then
T.scheme = Ru.scheme
T.host = Ru.host -- authority
T.port = Ru.port
T.user = Ru.user
T.path = Ru.path
T.path = rm_dot_segs:match(T.path)
T.query = Ru.query
else
if Ru.host then
T.host = Ru.host
T.port = Ru.port
T.user = Ru.user
T.path = rm_dot_segs:match(Ru.path)
T.query = Ru.query
else
if Ru.path == "" then
T.path = Base.path
if Ru.query then
T.query = Ru.query
else
T.query = Base.query
end
else
if Ru.path:match "^/" then
T.path = rm_dot_segs:match(Ru.path)
else
T.path = mergepath()
T.path = rm_dot_segs:match(T.path)
end
T.query = Ru.query
end
T.host = Base.host
T.port = Base.port
T.user = Base.user
end
T.scheme = Base.scheme
end
T.fragment = Ru.fragment
return T
end
-- ********************************************************************
local unsafe = P" " / "%%20"
+ P"#" / "%%23"
+ P"%" / "%%25"
+ P"<" / "%%3C"
+ P">" / "%%3E"
+ P"[" / "%%5B"
+ P"\\" / "%%5C"
+ P"]" / "%%5D"
+ P"^" / "%%5E"
+ P"{" / "%%7B"
+ P"|" / "%%7C"
+ P"}" / "%%7D"
+ P'"' / "%%22"
local char_auth = P"?" / "%%3F"
+ P"@" / "%%40"
+ unsafe
+ P(1)
local char_path = P"?" / "%%3F"
+ unsafe
+ P(1)
local char_query = P"=" / "%%3D"
+ P"&" / "%%26"
+ unsafe
+ P(1)
local char_frag = unsafe
+ P(1)
esc_auth = Cs(char_auth^0)
esc_path = Cs(char_path^0)
esc_query = Cs(char_query^0)
esc_frag = Cs(char_frag^0)
-- ********************************************************************
local xdigit = lpeg.locale().xdigit
local char = lpeg.P"%" * lpeg.C(xdigit * xdigit)
/ function(c)
return string.char(tonumber(c,16))
end
+ lpeg.R"!~"
local name = lpeg.Cs((char - (lpeg.P"=" + lpeg.P"&"))^1)
local value = lpeg.P"=" * lpeg.Cs((char - lpeg.P"&")^1)
+ lpeg.Cc(true)
query = lpeg.Cf(
lpeg.Ct"" * lpeg.Cg(name * value * lpeg.P"&"^-1)^0,
function(result,n,v)
if result and not result[n] then
result[n] = v
return result
else
return false
end
end
)
-- ********************************************************************
function toq(q)
local res = {}
for n,v in pairs(q) do
if v == true then
table.insert(res,esc_query:match(n))
else
table.insert(res,string.format("%s=%s",
esc_query:match(tostring(n)),
esc_query:match(tostring(v))
))
end
end
return table.concat(res,"&")
end
-- ********************************************************************
-- Note: From RFC-3986 5.3
-- ********************************************************************
local SCHEMES =
{
http = 80,
https = 443,
ftp = 21,
gemini = 1965,
}
function toa(u)
local authority
if u.host then
authority = ""
if u.user then authority = esc_auth:match(u.user) .. "@" end
if u.host:match"%:" then
authority = authority .. "[" .. esc_auth:match(u.host) .. "]"
else
authority = authority .. esc_auth:match(u.host)
end
if u.port and u.port ~= SCHEMES[u.scheme] then
authority = authority .. ':' .. tostring(u.port)
end
end
local result = ""
if u.scheme then result = result .. u.scheme .. ':' end
if authority then result = result .. "//" .. authority end
result = result .. esc_path:match(u.path)
if u.query then
if type(u.query) == 'table' then
result = result .. "?" .. toq(u.query)
else
result = result .. "?" .. u.query
end
end
if u.fragment then result = result .. "#" .. esc_frag:match(u.fragment) end
return result
end
-- ********************************************************************
return _ENV