Save implementation of other layers

doc/libmodal-lua.txt

@@ -707,10 +707,10 @@ FUNCTIONS                                         *libmodal-lua-Layer-functions*
 		layer:enter()
 
 		-- Start a timer for five seconds.
-		vim.loop.new_timer():start(5000, 0, vim.schedule_wrap(
+		vim.loop.new_timer():start(5000, 0,
 			-- Exit the layer. `gg` should return to normal.
-			function() layer:exit() end
-		))
+			vim.schedule_wrap(layer:exit())
+		)
 
 <
 

doc/libmodal.txt

@@ -456,9 +456,9 @@ LAYERS                                              *libmodal-examples-layers*
 	local exitFunc = libmodal.layer.exit()
 
 	-- exit the mode in five seconds
-	vim.loop.new_timer():start(5000, 0, vim.schedule_wrap(
-		function() exitFunc() end
-	))
+	vim.loop.new_timer():start(5000, 0,
+		vim.schedule_wrap(exitFunc)
+	)
 <
 ------------------------------------------------------------------------------
 PROMPTS                                            *libmodal-examples-prompts*

examples/lua/layer-simple.lua

@@ -0,0 +1,19 @@
+local libmodal = require('libmodal')
+
+-- create a new layer.
+local exitFunc = libmodal.layer.enter('FOO', {
+	['n'] = { -- normal mode mappings
+		['gg'] = { -- remap `gg`
+			['rhs'] = 'G', -- map it to `G`
+			['noremap'] = true, -- don't recursively map.
+		},
+		['G'] = { -- remap `G`
+			['rhs'] = 'gg', -- map it to `gg`
+			['noremap'] = true -- don't recursively map.
+		}
+	}
+})
+
+vim.loop.new_timer():start(5000, 0, vim.schedule_wrap(
+	function() exitFunc(); print('EXITED.') end
+))

lua/libmodal/src/Layer.lua

@@ -16,6 +16,7 @@ local Layer = {['TYPE'] = 'libmodal-layer'}
 
 local _BUFFER_CURRENT = 0
 local _RESTORED       = nil
+local _ERR_NO_MAP = 'E5555: API call: E31: No such mapping'
 
 local function convertKeymap(keymapEntry)
 	local lhs = keymapEntry.lhs
@@ -76,7 +77,6 @@ function _metaLayer:enter()
 		end
 	end
 
-	print(vim.inspect(priorKeymap))
 	self._priorKeymap = priorKeymap
 end
 
@@ -139,7 +139,6 @@ function _metaLayer:map(mode, lhs, rhs, options)
 	self._keymap[mode][lhs] = vim.tbl_extend('force',
 		options, {['rhs'] = rhs}
 	)
-	print(vim.inspect(self._priorKeymap))
 end
 
 ----------------------------------------------
@@ -155,8 +154,6 @@ function _metaLayer:_unmapFromBuffer(mode, lhs)
 	local priorKeymap  = self._priorKeymap
 	local priorMapping = self._priorKeymap[mode][lhs]
 
-	print('unmapping ' .. mode .. ':' .. lhs)
-
 	if not priorKeymap then error(
 		"You can't undo a map from a buffer without activating the layer first."
 	) end
@@ -168,14 +165,13 @@ function _metaLayer:_unmapFromBuffer(mode, lhs)
 
 		-- set the prior mapping as restored.
 		priorKeymap[mode][lhs] = _RESTORED
-
-		print('reverted mapping')
 	else
 		-- just delete the buffer mapping.
 		local noErrors, err = pcall(api.nvim_buf_del_keymap, _BUFFER_CURRENT, mode, lhs)
 
-		if not noErrors then print(err) end
-		print('deleted mapping')
+		if not noErrors and err ~= _ERR_NO_MAP then
+			print(err)
+		end
 	end
 end
 

lua/libmodal/src/ModeLayer.lua

@@ -14,6 +14,40 @@ local ModeLayer = {['TYPE'] = 'libmodal-mode-layer'}
 
 local _metaModeLayer = require('libmodal/src/classes').new(ModeLayer.TYPE)
 
+function _metaModeLayer:map(keys, mapping)
+	local priorInstruction = self._priorInstruction
+	local layerInstruction = self._instruction
+
+	if priorInstruction then
+		local modeInstruction = self._mode._instruction
+
+		-- only save the value from `mode` when adding a new mapping.
+		if not layerInstruction[keys] then
+			priorInstruction[keys] = modeInstruction:parseGet(keys)
+		end
+
+		-- map the keys to mode.
+		modeInstruction:parsePut(keys, mapping)
+	end
+
+	-- add the keys to the instruction.
+	layerInstruction[keys] = mapping
+end
+
+function _metaModeLayer:unmap(keys)
+	local priorInstruction = self._priorInstruction or {}
+	local layerInstruction = self._instruction
+
+	if priorInstruction[keys] then
+		self._mode._instruction:parsePut(keys, priorInstruction[keys])
+		priorInstruction[keys] = nil
+	end
+
+	-- remove `keys` from the instruction.
+	layerInstruction[keys] = nil
+end
+
+
 -------------------------------
 --[[ SUMMARY:
 	* Enter the `ModeLayer`, replacing any conflicting mappings.