Initial commit

1 files changed, 95 insertions, 0 deletions

diff --git a/toggler.lua b/toggler.lua
new file mode 100644
index 0000000..4b643af
--- /dev/null
+++ b/toggler.lua
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+-- Author: Georgi Kirilov
+--
+-- You can contact me via email to the posteo.net domain.
+-- The local-part is the Z code for "Place a competent operator on this circuit."
+
+require("vis")
+local vis = vis
+
+local M = {}
+local lookup = {}
+local count
+
+local inner_word = 0
+local char_next = 17
+
+local function toggle(func, motion)
+	return function(file, range, pos)
+		local word = file:content(range)
+		local toggled = func(word, count)
+		if toggled then
+			file:delete(range)
+			file:insert(range.start, toggled)
+			return motion and range.finish or range.start
+		end
+		return pos
+	end
+end
+
+local function make_shift(shift)
+	return function(word, delta)
+		local number = tonumber(word)
+		local iter = number and {number} or lookup[word]
+		if not iter then return end
+		local binary = iter[2] and #iter[2] == 2
+		local neighbor, rotate = shift(iter[1], iter[2], delta)
+		return number and neighbor or iter[2][neighbor] or binary and iter[2][rotate]
+	end
+end
+
+local increment = make_shift(function(i, _, delta) return i + (delta or 1), 1 end)
+local decrement = make_shift(function(i, options, delta) return i - (delta or 1), options and #options end)
+
+local function case(str)
+	return str:gsub("[%l%u]", function(char)
+		local lower = char:lower()
+		return char == lower and char:upper() or lower
+	end)
+end
+
+local function operator_new(key, handler, object, motion, help)
+	local id = vis:operator_register(handler)
+	if id < 0 then
+		return false
+	end
+	local function binding()
+		vis:operator(id)
+		if vis.mode == vis.modes.OPERATOR_PENDING then
+			if object then
+				count = vis.count
+				vis.count = nil
+				vis:textobject(object)
+			elseif motion then
+				vis:motion(motion)
+			end
+		end
+	end
+	vis:map(vis.modes.NORMAL, key, binding, help)
+	vis:map(vis.modes.VISUAL, key, binding, help)
+end
+
+local function preprocess(tbl)
+	local cfg = {}
+	for _, options in ipairs(tbl) do
+		for i, key in ipairs(options) do
+			cfg[key] = {i, options}
+		end
+	end
+	return cfg
+end
+
+vis.events.subscribe(vis.events.INIT, function()
+	operator_new("<C-a>", toggle(increment),    inner_word, nil,       "Toggle/increment word or selection")
+	operator_new("<C-x>", toggle(decrement),    inner_word, nil,       "Toggle/decrement word or selection")
+	operator_new("~",     toggle(case, true),   nil,        char_next, "Toggle case of character or selection")
+	operator_new("g~",    toggle(case),         nil,        nil,       "Toggle-case operator")
+	operator_new("gu",    toggle(string.lower), nil,        nil,       "Lower-case operator")
+	operator_new("gU",    toggle(string.upper), nil,        nil,       "Upper-case operator")
+	lookup = preprocess(M)
+end)
+
+return function(config)
+	local ext_config = require(config)
+	M = ext_config or M
+	return M
+end