Updated builtins/__modules.lua

Added modules@hyperlink. A new presser tool which will convert text to a
hyperlink in markdown format.
	- Firstly the function identifies the mode. If visual-mode, the text
	  selected is used. If normal-mode, the text used is whatever is
	  identified under the cursor.
	- Secondly, if the text is identified to be a valid URI schema, then
	  hyperlink will automatically make the conversion.
	- If the text isn't a URI schema, then a new steamer is created to
	  allow for the user to enter a URI.

lua/presser/builtins/__modules.lua

@@ -1,6 +1,7 @@
 local gcm = require 'presser.context_manager'
 local steamers = require 'presser.steamers'
 local actions = require 'presser.actions'
+local utils   = require 'presser.utils'
 
 local a = vim.api
 
@@ -80,4 +81,130 @@ modules.find_replace = function ()
   a.nvim_feedkeys('A', 'n', false)
 end
 
+
+modules.hyperlink = function ()
+  local check_url = function ( text )
+    local text = string.lower( text )
+
+    -- string list of all possible URI schemes which have RFC specification and identified with permanent status
+    local patterns = "aaa|aaas|about|acap|acct|afs|cap|cid|coap|coap+tcp|coap+ws|coaps|coaps+tcp|coaps+ws|crid|data" ..
+      "|dav|dict|dns|dtn|example|fax|file|ftp|geo|go|gopher|h323|ham|http|https|iax|icap|im|imap|info|ipn|ipp|ipps" ..
+      "|iris|iris.beep|iris.lwz|iris.xpc|iris.xpcs|jms|ldap|leaptofrogans|mailserver|mailto|mid|modem|msrp|msrps" ..
+      "|mtqp|mupdate|news|nfs|ni|nih|nntp|opaquelocktoken|payto|pkcs11|pop|pres|prospero|reload|rsync|rtmfp|rtsp" ..
+      "|rtsps|rtspu|secret-token|service|session|sieve|sip|sips|sms|snews|snmp|soap.beep|soap.beeps|stun|stuns|tag" ..
+      "|tel|telnet|tftp|thismessage|tip|tn3270|turn|turns|tv|urn|vemmi|videotex|vnc|wais|ws|wss|xcon|xcon-userid" ..
+      "|xmlrpc.beep|xmlrpc.beeps|xmpp|z39.50|z39.50r|z39.50s|"
+
+    -- check if text is a type of URI
+    -- @Dev: TODO, consider option of logarithmic matching (patterns already in alphabetical order)
+    for proto in string.gmatch( patterns, "([^|]+)" ) do
+      -- if so, text can be converted directly to hyperlink (return true)
+      if string.find( text, proto ) then
+        return true
+      end
+    end
+
+    return false
+  end
+
+
+  local link_txt = nil
+  local row, col = unpack(a.nvim_win_get_cursor(0))
+  local h,j,_,l = utils.get_selection()
+  local line = a.nvim_get_current_line()
+  if vim.api.nvim_get_mode()["mode"] == "n" then
+    if (row-1) == h and (col == j or col == l) then
+      print("visual mode selection")
+      link_txt = string.sub(line, j, l)
+    else
+      link_txt = string.sub(line, unpack(utils.subslice(line, col)))
+    end
+  else
+    link_txt = vim.fn.expand "<cexpr>"
+  end
+
+  link_txt = utils.clean_buf(link_txt)
+  if link_txt == "" then
+    print("Presser.hyperlink: No text selected to convert.")
+    return
+  end
+
+  if check_url( link_txt ) then
+    print("Identified URI scheme under cursor, generating hyperlink for: " .. link_txt)
+    if not ( col == j or col == l ) then
+      j, l = unpack(utils.subslice( line .. " ", col ))
+    end
+
+    print(j,l)
+    actions.suburl( line, row, link_txt, j, l )
+    return nil
+  end
+
+  print("Cursor is not over an identified URI scheme: " .. link_txt .. ". Constructing UI...")
+
+  -- define the context which these windows will belong to in the context manager.
+  local ctx = "hyperlink"
+  gcm.create( ctx )
+
+  local keymap = {
+    n = {
+      ["<esc>"] = "<cmd>lua require'presser.actions'.close()<CR>",
+      ["<A-a>"] = "<cmd>lua require'presser.actions'.hyperlink_exec()<CR>",
+    },
+    i = {
+      ["<A-a>"] = "<cmd>lua require'presser.actions'.hyperlink_exec()<CR>",
+    }
+  }
+
+  -- get the centre of the current buffer
+  local c_lines = math.floor( a.nvim_win_get_height(0) / 2 )
+
+  -- create a title buffer for the steamer
+  steamers
+    .new( ctx, {
+      label = "presser_title",
+      steamer = {
+        placeholder = "Hyperlink",
+        allowed = false,
+        window = {
+          line = c_lines - 2,
+          border = false,
+          minwidth = 82,
+          padding = { 0, 1, 1, 1 }
+        }
+      }
+    } )
+
+  steamers
+    .new( ctx, {
+      label = "selected_text",
+      steamer = {
+        placeholder = "Selected text: " .. link_txt,
+        allowed = false,
+        window = {
+          line = c_lines,
+          border = false,
+          minwidth = 82,
+          padding = { 0, 1, 1, 1 }
+        }
+      }
+    } )
+
+  -- create a new buffer for replace pattern
+  steamers
+    .new( ctx, {
+      label = "hyperlink_buf",
+      steamer = {
+        window = {
+          line = c_lines + 3,
+          title = "Hyperlink",
+        },
+        keybinds = keymap,
+      }
+    } )
+
+  local result = actions.buf_put_curser_at( "hyperlink_buf" )
+  a.nvim_feedkeys('A', 'n', false)
+end
+
 return modules