lua/vis.lua

   1 ---
   2 -- Vis Lua plugin API standard library
   3 -- @module vis
   4
   5 ---
   6 -- @type Vis
   7
   8 --- Map a new operator.
   9 --
  10 -- Sets up a mapping in normal, visual and operator pending mode.
  11 -- The operator function will receive the @{File}, @{Range} and position
  12 -- to operate on and is expected to return the new cursor position.
  13 --
  14 -- @tparam string key the key to associate with the new operator
  15 -- @tparam function operator the operator logic implemented as Lua function
  16 -- @tparam[opt] string help the single line help text as displayed in `:help`
  17 -- @treturn bool whether the new operator could be installed
  18 -- @usage
  19 -- vis:operator_new("gq", function(file, range, pos)
  20 --      local status, out, err = vis:pipe(file, range, "fmt")
  21 --      if not status then
  22 --              vis:info(err)
  23 --      else
  24 --              file:delete(range)
  25 --              file:insert(range.start, out)
  26 --      end
  27 --      return range.start -- new cursor location
  28 -- end, "Formating operator, filter range through fmt(1)")
  29 --
  30 vis.operator_new = function(vis, key, operator, help)
  31         local id = vis:operator_register(operator)
  32         if id < 0 then
  33                 return false
  34         end
  35         local binding = function()
  36                 vis:operator(id)
  37         end
  38         vis:map(vis.modes.NORMAL, key, binding, help)
  39         vis:map(vis.modes.VISUAL, key, binding, help)
  40         vis:map(vis.modes.OPERATOR_PENDING, key, binding, help)
  41         return true
  42 end
  43
  44 --- Map a new motion.
  45 --
  46 -- Sets up a mapping in normal, visual and operator pending mode.
  47 -- The motion function will receive the @{Window} and an initial position
  48 -- (in bytes from the start of the file) as argument and is expected to
  49 -- return the resulting position.
  50 -- @tparam string key the key to associate with the new mption
  51 -- @tparam function motion the motion logic implemented as Lua function
  52 -- @tparam[opt] string help the single line help text as displayed in `:help`
  53 -- @treturn bool whether the new motion could be installed
  54 -- @usage
  55 -- vis:motion_new("<C-l>", function(win, pos)
  56 --      return pos+1
  57 -- end, "Advance to next byte")
  58 --
  59 vis.motion_new = function(vis, key, motion, help)
  60         local id = vis:motion_register(motion)
  61         if id < 0 then
  62                 return false
  63         end
  64         local binding = function()
  65                 vis:motion(id)
  66         end
  67         vis:map(vis.modes.NORMAL, key, binding, help)
  68         vis:map(vis.modes.VISUAL, key, binding, help)
  69         vis:map(vis.modes.OPERATOR_PENDING, key, binding, help)
  70         return true
  71 end
  72
  73 --- Map a new text object.
  74 --
  75 -- Sets up a mapping in visual and operator pending mode.
  76 -- The text object function will receive the @{Window} and an initial
  77 -- position(in bytes from the start of the file) as argument and is
  78 -- expected to return the resulting range or `nil`.
  79 -- @tparam string key the key associated with the new text object
  80 -- @tparam function textobject the text object logic implemented as Lua function
  81 -- @tparam[opt] string help the single line help text as displayed in `:help`
  82 -- @treturn bool whether the new text object could be installed
  83 -- @usage
  84 -- vis:textobject_new("<C-l>", function(win, pos)
  85 --      return pos, pos+1
  86 -- end, "Single byte text object")
  87 --
  88 vis.textobject_new = function(vis, key, textobject, help)
  89         local id = vis:textobject_register(textobject)
  90         if id < 0 then
  91                 return false
  92         end
  93         local binding = function()
  94                 vis:textobject(id)
  95         end
  96         vis:map(vis.modes.VISUAL, key, binding, help)
  97         vis:map(vis.modes.OPERATOR_PENDING, key, binding, help)
  98         return true
  99 end
 100
 101 --- Check whether a Lua module exists
 102 --
 103 -- Checks whether a subsequent @{require} call will succeed.
 104 -- @tparam string name the module name to check
 105 -- @treturn bool whether the module was found
 106 vis.module_exist = function(vis, name)
 107         for _, searcher in ipairs(package.searchers or package.loaders) do
 108                 local loader = searcher(name)
 109                 if type(loader) == 'function' then
 110                         return true
 111                 end
 112         end
 113         return false
 114 end
 115
 116 vis.lexers = {}
 117
 118 if not vis:module_exist('lpeg') then
 119         vis:info('WARNING: could not find lpeg module')
 120 elseif not vis:module_exist('lexer') then
 121         vis:info('WARNING: could not find lexer module')
 122 else
 123         vis.lexers = require('lexer')
 124         vis.lpeg = require('lpeg')
 125 end
 126
 127 --- Events.
 128 --
 129 -- User scripts can subscribe Lua functions to certain events. Multiple functions
 130 -- can be associated with the same event. They will be called in the order they were
 131 -- registered. The first function which returns a non `nil` value terminates event
 132 -- propagation. The remaining event handler will not be called.
 133 --
 134 -- Keep in mind that the editor is blocked while the event handlers
 135 -- are being executed, avoid long running tasks.
 136 --
 137 -- @section Events
 138
 139 --- Event names.
 140 --- @table events
 141 local events = {
 142         FILE_CLOSE = "Event::FILE_CLOSE", -- see @{file_close}
 143         FILE_OPEN = "Event::FILE_OPEN", -- see @{file_open}
 144         FILE_SAVE_POST = "Event::FILE_SAVE_POST", -- see @{file_save_post}
 145         FILE_SAVE_PRE = "Event::FILE_SAVE_PRE", -- see @{file_save_pre}
 146         INIT = "Event::INIT", -- see @{init}
 147         INPUT = "Event::INPUT", -- see @{input}
 148         QUIT = "Event::QUIT", -- see @{quit}
 149         START = "Event::START", -- see @{start}
 150         WIN_CLOSE = "Event::WIN_CLOSE", -- see @{win_close}
 151         WIN_HIGHLIGHT = "Event::WIN_HIGHLIGHT", -- see @{win_highlight}
 152         WIN_OPEN = "Event::WIN_OPEN", -- see @{win_open}
 153         WIN_STATUS = "Event::WIN_STATUS", -- see @{win_status}
 154         TERM_CSI = "Event::TERM_CSI", -- see @{term_csi}
 155 }
 156
 157 events.file_close = function(...) events.emit(events.FILE_CLOSE, ...) end
 158 events.file_open = function(...) events.emit(events.FILE_OPEN, ...) end
 159 events.file_save_post = function(...) events.emit(events.FILE_SAVE_POST, ...) end
 160 events.file_save_pre = function(...) return events.emit(events.FILE_SAVE_PRE, ...) end
 161 events.init = function(...) events.emit(events.INIT, ...) end
 162 events.input = function(...) return events.emit(events.INPUT, ...) end
 163 events.quit = function(...) events.emit(events.QUIT, ...) end
 164 events.start = function(...) events.emit(events.START, ...) end
 165 events.win_close = function(...) events.emit(events.WIN_CLOSE, ...) end
 166 events.win_highlight = function(...) events.emit(events.WIN_HIGHLIGHT, ...) end
 167 events.win_open = function(...) events.emit(events.WIN_OPEN, ...) end
 168 events.win_status = function(...) events.emit(events.WIN_STATUS, ...) end
 169 events.term_csi = function(...) events.emit(events.TERM_CSI, ...) end
 170
 171 local handlers = {}
 172
 173 --- Subscribe to an event.
 174 --
 175 -- Register an event handler.
 176 -- @tparam string event the event name
 177 -- @tparam function handler the event handler
 178 -- @tparam[opt] int index the index at which to insert the handler (1 is the highest priority)
 179 -- @usage
 180 -- vis.events.subscribe(vis.events.FILE_SAVE_PRE, function(file, path)
 181 --      -- do something useful
 182 --      return true
 183 -- end)
 184 events.subscribe = function(event, handler, index)
 185         if not event then error("Invalid event name") end
 186         if type(handler) ~= 'function' then error("Invalid event handler") end
 187         if not handlers[event] then handlers[event] = {} end
 188         events.unsubscribe(event, handler)
 189         table.insert(handlers[event], index or #handlers[event]+1, handler)
 190 end
 191
 192 --- Unsubscribe from an event.
 193 --
 194 -- Remove a registered event handler.
 195 -- @tparam string event the event name
 196 -- @tparam function handler the event handler to unsubscribe
 197 -- @treturn bool whether the handler was successfully removed
 198 events.unsubscribe = function(event, handler)
 199         local h = handlers[event]
 200         if not h then return end
 201         for i = 1, #h do
 202                 if h[i] == handler then
 203                         table.remove(h, i)
 204                         return true
 205                 end
 206         end
 207         return false
 208 end
 209
 210 --- Generate event.
 211 --
 212 -- Invokes all event handlers in the order they were registered.
 213 -- Passes all arguments to the handler. The first handler which returns a non `nil`
 214 -- value terminates the event propagation. The other handlers will not be called.
 215 --
 216 -- @tparam string event the event name
 217 -- @tparam ... ... the remaining paramters are passed on to the handler
 218 events.emit = function(event, ...)
 219         local h = handlers[event]
 220         if not h then return end
 221         for i = 1, #h do
 222                 local ret = h[i](...)
 223                 if type(ret) ~= 'nil' then return ret end
 224         end
 225 end
 226
 227 vis.events = events
 228
 229 ---
 230 -- @type Window
 231
 232 --- The file type associated with this window.
 233 -- @tfield string syntax the syntax lexer name or `nil` if unset
 234
 235 --- Change syntax lexer to use for this window
 236 -- @function set_syntax
 237 -- @tparam string syntax the syntax lexer name or `nil` to disable syntax highlighting
 238 -- @treturn bool whether the lexer could be changed
 239 vis.types.window.set_syntax = function(win, syntax)
 240
 241         local lexers = vis.lexers
 242
 243         win:style_define(win.STYLE_DEFAULT, lexers.STYLE_DEFAULT or '')
 244         win:style_define(win.STYLE_CURSOR, lexers.STYLE_CURSOR or '')
 245         win:style_define(win.STYLE_CURSOR_PRIMARY, lexers.STYLE_CURSOR_PRIMARY or '')
 246         win:style_define(win.STYLE_CURSOR_LINE, lexers.STYLE_CURSOR_LINE or '')
 247         win:style_define(win.STYLE_SELECTION, lexers.STYLE_SELECTION or '')
 248         win:style_define(win.STYLE_LINENUMBER, lexers.STYLE_LINENUMBER or '')
 249         win:style_define(win.STYLE_LINENUMBER_CURSOR, lexers.STYLE_LINENUMBER_CURSOR or '')
 250         win:style_define(win.STYLE_COLOR_COLUMN, lexers.STYLE_COLOR_COLUMN or '')
 251         win:style_define(win.STYLE_STATUS, lexers.STYLE_STATUS or '')
 252         win:style_define(win.STYLE_STATUS_FOCUSED, lexers.STYLE_STATUS_FOCUSED or '')
 253         win:style_define(win.STYLE_SEPARATOR, lexers.STYLE_SEPARATOR or '')
 254         win:style_define(win.STYLE_INFO, lexers.STYLE_INFO or '')
 255         win:style_define(win.STYLE_EOF, lexers.STYLE_EOF or '')
 256
 257         if syntax == nil or syntax == 'off' then
 258                 win.syntax = nil
 259                 return true
 260         end
 261
 262         if not lexers.load then return false end
 263         local lexer = lexers.load(syntax)
 264         if not lexer then return false end
 265
 266         for token_name, id in pairs(lexer._TOKENSTYLES) do
 267                 local style = lexers['STYLE_'..string.upper(token_name)] or lexer._EXTRASTYLES[token_name]
 268                 win:style_define(id, style)
 269         end
 270
 271         win.syntax = syntax
 272         return true
 273 end
 274
 275 ---
 276 -- @type File
 277
 278 --- Check whether LPeg pattern matches at a given file position.
 279 -- @function match_at
 280 -- @param pattern the LPeg pattern
 281 -- @tparam int pos the absolute file position which should be tested for a match
 282 -- @tparam[opt] int horizon the number of bytes around `pos` to consider (defaults to 1K)
 283 -- @treturn int start,end the range of the matched region or `nil`
 284 vis.types.file.match_at = function(file, pattern, pos, horizon)
 285         horizon = horizon or 1024
 286         local lpeg = vis.lpeg
 287         if not lpeg then return nil end
 288         local before, after = pos - horizon, pos + horizon
 289         if before < 0 then before = 0 end
 290         local data = file:content(before, after - before)
 291         local string_pos = pos - before + 1
 292
 293         local I = lpeg.Cp()
 294         local p = lpeg.P{ I * pattern * I + 1 * lpeg.V(1) }
 295         local s, e = 1
 296         while true do
 297                 s, e = p:match(data, s)
 298                 if not s then return nil end
 299                 if s <= string_pos and string_pos < e then
 300                         return before + s - 1, before + e - 1
 301                 end
 302                 s = e
 303         end
 304 end
 305
 306 require('vis-std')