teliva/gemini.tlv

536 lines
16 KiB
Lua

# .tlv file generated by https://github.com/akkartik/teliva
# You may edit it if you are careful; however, you may see cryptic errors if you
# violate Teliva's assumptions.
#
# .tlv files are representations of Teliva programs. Teliva programs consist of
# sequences of definitions. Each definition is a table of key/value pairs. Keys
# and values are both strings.
#
# Lines in .tlv files always follow exactly one of the following forms:
# - comment lines at the top of the file starting with '#' at column 0
# - beginnings of definitions starting with '- ' at column 0, followed by a
# key/value pair
# - key/value pairs consisting of ' ' at column 0, containing either a
# spaceless value on the same line, or a multi-line value
# - multiline values indented by more than 2 spaces, starting with a '>'
#
# If these constraints are violated, Teliva may unceremoniously crash. Please
# report bugs at http://akkartik.name/contact
- __teliva_timestamp: original
str_helpers:
>-- some string helpers from http://lua-users.org/wiki/StringIndexing
>
>-- index characters using []
>getmetatable('').__index = function(str,i)
> if type(i) == 'number' then
> return str:sub(i,i)
> else
> return string[i]
> end
>end
>
>-- ranges using (), selected bytes using {}
>getmetatable('').__call = function(str,i,j)
> if type(i)~='table' then
> return str:sub(i,j)
> else
> local t={}
> for k,v in ipairs(i) do
> t[k]=str:sub(v,v)
> end
> return table.concat(t)
> end
>end
>
>-- iterate over an ordered sequence
>function q(x)
> if type(x) == 'string' then
> return x:gmatch('.')
> else
> return ipairs(x)
> end
>end
>
>-- insert within string
>function string.insert(str1, str2, pos)
> return str1:sub(1,pos)..str2..str1:sub(pos+1)
>end
>
>function string.remove(s, pos)
> return s:sub(1,pos-1)..s:sub(pos+1)
>end
>
>function string.pos(s, sub)
> return string.find(s, sub, 1, true) -- plain=true to disable regular expressions
>end
>
>-- TODO: backport utf-8 support from Lua 5.3
- __teliva_timestamp: original
debugy:
>debugy = 5
- __teliva_timestamp: original
dbg:
>-- helper for debug by print; overlay debug information towards the right
>-- reset debugy every time you refresh screen
>function dbg(window, s)
> local oldy = 0
> local oldx = 0
> oldy, oldx = window:getyx()
> window:mvaddstr(debugy, 60, s)
> debugy = debugy+1
> window:mvaddstr(oldy, oldx, '')
>end
- __teliva_timestamp: original
check:
>function check(x, msg)
> if x then
> Window:addch('.')
> else
> print('F - '..msg)
> print(' '..str(x)..' is false/nil')
> teliva_num_test_failures = teliva_num_test_failures + 1
> -- overlay first test failure on editors
> if teliva_first_failure == nil then
> teliva_first_failure = msg
> end
> end
>end
- __teliva_timestamp: original
check_eq:
>function check_eq(x, expected, msg)
> if eq(x, expected) then
> Window:addch('.')
> else
> print('F - '..msg)
> print(' expected '..str(expected)..' but got '..str(x))
> teliva_num_test_failures = teliva_num_test_failures + 1
> -- overlay first test failure on editors
> if teliva_first_failure == nil then
> teliva_first_failure = msg
> end
> end
>end
- __teliva_timestamp: original
eq:
>function eq(a, b)
> if type(a) ~= type(b) then return false end
> if type(a) == 'table' then
> if #a ~= #b then return false end
> for k, v in pairs(a) do
> if b[k] ~= v then
> return false
> end
> end
> for k, v in pairs(b) do
> if a[k] ~= v then
> return false
> end
> end
> return true
> end
> return a == b
>end
- __teliva_timestamp: original
str:
>-- smarter tostring
>-- slow; used only for debugging
>function str(x)
> if type(x) == 'table' then
> local result = ''
> result = result..#x..'{'
> for k, v in pairs(x) do
> result = result..str(k)..'='..str(v)..', '
> end
> result = result..'}'
> return result
> elseif type(x) == 'string' then
> return '"'..x..'"'
> end
> return tostring(x)
>end
- __teliva_timestamp: original
find_index:
>function find_index(arr, x)
> for n, y in ipairs(arr) do
> if x == y then
> return n
> end
> end
>end
- __teliva_timestamp: original
trim:
>function trim(s)
> return s:gsub('^%s*', ''):gsub('%s*$', '')
>end
- __teliva_timestamp: original
split:
>function split(s, d)
> result = {}
> for match in (s..d):gmatch("(.-)"..d) do
> table.insert(result, match);
> end
> return result
>end
- __teliva_timestamp: original
clear:
>function clear(lines)
> while #lines > 0 do
> table.remove(lines)
> end
>end
- __teliva_timestamp: original
Window:
>Window = curses.stdscr()
- __teliva_timestamp: original
render_line:
>function render_line(window, y, line)
> window:mvaddstr(y, 0, '')
> for i=1,line:len() do
> window:addstr(line[i])
> end
>end
- __teliva_timestamp: original
render_link:
>function render_link(window, y, line)
> local rendered_line = line:gsub('=>%s*%S*%s*', '')
> if trim(rendered_line) == '' then
> rendered_line = line
> end
> render_line(window, y, rendered_line)
>end
- __teliva_timestamp: original
state:
>state = {
> lines={},
> history={},
> highlight_index=0,
> source=false, -- show source (link urls, etc.)
>}
- __teliva_timestamp: original
render_page:
>function render_page(window)
> local y = 0
> window:attron(curses.color_pair(6))
> print(state.url)
> window:attroff(curses.color_pair(6))
> y = y+2
>--? dbg(window, state.highlight_index)
> for i, line in pairs(state.lines) do
> if not state.source and line:find('=> ') == 1 then
> if state.highlight_index == 0 or i == state.highlight_index then
> -- highlighted link
> state.highlight_index = i -- TODO: ugly state update while rendering, just for first render after gemini_get
> window:attron(curses.A_REVERSE)
> render_link(window, y, line)
> window:attroff(curses.A_REVERSE)
> else
> -- link
> window:attron(curses.A_BOLD)
> render_link(window, y, line)
> window:attroff(curses.A_BOLD)
> end
> else
> -- non-link
> render_line(window, y, line)
> end
> y = y+1
> end
>end
- __teliva_timestamp: original
render:
>function render(window, lines)
> window:clear()
> render_page(window, lines)
> curses.curs_set(0)
> window:refresh()
>end
- __teliva_timestamp: original
menu:
>menu = {
> {'Enter', 'go to highlight'},
> {'<-', 'back'},
> {'^g', 'enter url'},
> {'^u', 'view source'},
>}
- __teliva_timestamp: original
edit_line:
>function edit_line(window)
> local result = ''
> local cursor = 1
> local screen_rows, screen_cols = window:getmaxyx()
> menu = {
> {'enter', 'submit'},
> {'^g', 'cancel'},
> {'^u', 'clear'},
> }
> while true do
> window:mvaddstr(screen_rows-1, 9, '')
> window:clrtoeol()
> window:mvaddstr(screen_rows-1, 9, result)
> window:attron(curses.A_REVERSE)
> -- window:refresh()
> local key = window:getch()
> window:attrset(curses.A_NORMAL)
> if key >= 32 and key < 127 then
> local screen_rows, screen_cols = window:getmaxyx()
> if #result < screen_cols then
> result = result:insert(string.char(key), cursor-1)
> cursor = cursor+1
> end
> elseif key == curses.KEY_LEFT then
> if cursor > 1 then
> cursor = cursor-1
> end
> elseif key == curses.KEY_RIGHT then
> if cursor <= #result then
> cursor = cursor+1
> end
> elseif key == curses.KEY_BACKSPACE then
> if cursor > 1 then
> cursor = cursor-1
> result = result:remove(cursor)
> end
> elseif key == 21 then -- ctrl-u
> result = ''
> cursor = 1
> elseif key == 10 then -- enter
> return result
> elseif key == 7 then -- ctrl-g
> return nil
> end
> end
>end
- __teliva_timestamp: original
is_link:
>function is_link(line)
> return line:find('=>%s*%S*%s*') == 1
>end
- __teliva_timestamp: original
next_link:
>function next_link()
> local new_index = state.highlight_index
> while true do
> new_index = new_index+1
> if new_index > #state.lines then return end
> if is_link(state.lines[new_index]) then break end
> end
> state.highlight_index = new_index
>end
- __teliva_timestamp: original
previous_link:
>function previous_link()
> local new_index = state.highlight_index
> while true do
> new_index = new_index - 1
> if new_index < 1 then return end
> if is_link(state.lines[new_index]) then break end
> end
> state.highlight_index = new_index
>end
- __teliva_timestamp: original
update:
>function update(window)
> local key = window:getch()
> local screen_rows, screen_cols = window:getmaxyx()
> if key == curses.KEY_DOWN then
> next_link()
> elseif key == curses.KEY_UP then
> previous_link()
> elseif key == curses.KEY_LEFT then
> if #state.history > 1 then
> table.remove(state.history)
> gemini_get(table.remove(state.history))
> end
> elseif key == 21 then -- ctrl-u
> state.source = not state.source
> elseif key == 10 then -- enter
> local s, e, new_url = string.find(state.lines[state.highlight_index], '=>%s*(%S*)')
> gemini_get(url.absolute(state.url, new_url))
> elseif key == 7 then -- ctrl-g
> window:mvaddstr(screen_rows-2, 0, '')
> window:clrtoeol()
> window:mvaddstr(screen_rows-1, 0, '')
> window:clrtoeol()
> window:mvaddstr(screen_rows-1, 5, 'go: ')
> curses.curs_set(2)
> local old_menu = menu
> local new_url = edit_line(window)
> menu = old_menu
> if new_url then
> state.url = new_url
> gemini_get(new_url)
> end
> curses.curs_set(0)
> end
>end
- __teliva_timestamp: original
init_colors:
>function init_colors()
> for i=0,7 do
> curses.init_pair(i, i, -1)
> end
> curses.init_pair(8, 7, 0)
> curses.init_pair(9, 7, 1)
> curses.init_pair(10, 7, 2)
> curses.init_pair(11, 7, 3)
> curses.init_pair(12, 7, 4)
> curses.init_pair(13, 7, 5)
> curses.init_pair(14, 7, 6)
> curses.init_pair(15, -1, 15)
>end
- __teliva_timestamp: original
main:
>function main()
> Window:clear()
> Window:refresh()
> init_colors()
> local lines = {}
> local url = ''
> if #arg > 0 then
> state.url = arg[1]
> lines = gemini_get(state.url)
> end
> while true do
> render(Window, lines)
> update(Window, lines)
> end
>end
- __teliva_timestamp: original
http_get:
>function http_get(url)
> -- https://stackoverflow.com/questions/42445423/luasocket-serveraccept-timeout-tcp
> local parsed_url = socket.url.parse(url)
> local tcp = socket.tcp()
> tcp:connect(parsed_url.host, 80)
> tcp:send('GET / HTTP/1.1\r\n')
> -- http requires the Host header
> tcp:send(string.format('Host: %s\r\n', parsed_url.host))
> tcp:send('\r\n')
> -- tcp:receive('*a') doesn't seem to detect when a request is done
> -- so we have to manage the size of the expected response
> headers = {}
> while true do
> local s, status = tcp:receive()
> if s == nil then break end
> if s == '' then break end
> local header, value = s:match('(.-): (.*)')
> if header == nil then
> print(s)
> else
> headers[header:lower()] = value
> print(header, value)
> end
> end
> local bytes_remaining = tonumber(headers['content-length'])
> body = ''
> while true do
> local s, status = tcp:receive(bytes_remaining)
> if s == nil then break end
> body = body .. s
> bytes_remaining = bytes_remaining - s:len()
> if bytes_remaining <= 0 then break end
> end
> return body
>end
- __teliva_timestamp: original
https_get:
>-- http://notebook.kulchenko.com/programming/https-ssl-calls-with-lua-and-luasec
>function https_get(url)
> local parsed_url = socket.url.parse(url)
> local params = {
> mode = 'client',
> protocol = 'any',
> verify = 'none', -- I don't know what I'm doing
> options = 'all',
> }
> local conn = socket.tcp()
> conn:connect(parsed_url.host, parsed_url.port or 443)
> conn, err = ssl.wrap(conn, params)
> if conn == nil then
> io.write(err)
> os.exit(1)
> end
> conn:dohandshake()
>
> conn:send(url .. "\r\n")
> local line, err = conn:receive()
> return line or err
>end
- __teliva_timestamp: original
parse_gemini_body:
>function parse_gemini_body(conn, type)
> if type == 'text/gemini' then
> while true do
> local line, err = conn:receive()
> if line == nil then break end
> table.insert(state.lines, line)
> end
> elseif type:sub(1, 5) == 'text/' then
> while true do
> local line, err = conn:receive()
> if line == nil then break end
> table.insert(state.lines, line)
> end
> end
>end
- __teliva_timestamp: original
gemini_get:
>-- http://notebook.kulchenko.com/programming/https-ssl-calls-with-lua-and-luasec
>-- https://tildegit.org/solderpunk/gemini-demo-2
>-- returns an array of lines, containing either the body or just an error
>function gemini_get(url)
> if url:find("://") == nil then
> url = "gemini://" .. url
> end
> local parsed_url = socket.url.parse(url)
> local params = {
> mode = 'client',
> protocol = 'any',
> verify = 'none', -- I don't know what I'm doing
> options = 'all',
> }
> local conn = socket.tcp()
> local conn2, err = conn:connect(parsed_url.host, parsed_url.port or 1965)
> clear(state.lines)
> state.highlight_index = 0 -- highlighted link not computed yet
> if conn2 == nil then
> table.insert(state.lines, err)
> return
> end
> conn, err = ssl.wrap(conn, params)
> if conn == nil then
> table.insert(state.lines, err)
> return
> end
> conn:dohandshake()
> conn:send(url .. "\r\n")
> local line, err = conn:receive()
> if line == nil then
> table.insert(state.lines, err)
> return
> end
> local status, meta = line:match("(%S+) (%S+)")
> if status[1] == '2' then
> parse_gemini_body(conn, meta)
> state.url = url
> table.insert(state.history, url)
> elseif status[1] == '3' then
> gemini_get(socket.url.absolute(url, meta))
> elseif status[1] == '4' or line[1] == '5' then
> table.insert(state.lines, 'Error: '..meta)
> else
> table.insert(state.lines, 'invalid response from server: '..line)
> end
>end
- __teliva_timestamp:
>Thu Feb 17 20:04:42 2022
doc:blurb:
>A bare-bones browser for the Gemini protocol
>
>https://gemini.circumlunar.space
>
>A couple of good pages to try it out with:
> $ src/teliva gemini.tlv gemini.circumlunar.space
> $ src/teliva gemini.tlv gemini.conman.org
> $ src/teliva gemini.tlv gemini.susa.net/cgi-bin/links.lua # shows 20 random links from Gemini space