Few minor optimizations

Misc. fixes and refactors

README.md

@@ -1,23 +1,29 @@
-## ![Preview1](http://i.imgur.com/fIPNYkb.png) Crafting Guide ##
+# ![Preview1](http://i.imgur.com/fIPNYkb.png) Crafting Guide
 
-#### `craftguide` is the most comprehensive crafting guide on Minetest. ####
-#### Consult the [Minetest Wiki](http://wiki.minetest.net/Crafting_guide) for more details. ####
+#### `craftguide` is the most comprehensive crafting guide on Minetest.
+#### Consult the [Minetest Wiki](http://wiki.minetest.net/Crafting_guide) for more details.
 
 This crafting guide is a blue book named *"Crafting Guide"* or a wooden sign.
 
 This crafting guide features a **progressive mode**.
-The progressive mode is a Terraria-like system that only shows recipes you can craft from items in inventory.
-The progressive mode can be enabled with `craftguide_progressive_mode = true` in `minetest.conf`.
+The progressive mode is a Terraria-like system that only shows recipes you can craft
+from items you ever had in your inventory. To enable it: `craftguide_progressive_mode = true` in `minetest.conf`.
 
-`craftguide` is also integrated in `sfinv` (Minetest Game inventory) when you enable it with
+`craftguide` is also integrated in `sfinv` (Minetest Game inventory). To enable it:
 `craftguide_sfinv_only = true` in `minetest.conf`.
 
 Use the command `/craft` to show the recipe(s) of the pointed node.
 
+![Preview2](https://i.imgur.com/bToFH38.png)
+
 ---
 
-`craftguide` has an API to register **custom recipes**. Demos:
-#### Registering a custom crafting type ####
+## API
+
+### Custom recipes
+
+#### Registering a custom crafting type
+
 ```Lua
 craftguide.register_craft_type("digging", {
 	description = "Digging",
@@ -25,7 +31,8 @@ craftguide.register_craft_type("digging", {
 })
 ```
 
-#### Registering a custom crafting recipe ####
+#### Registering a custom crafting recipe
+
 ```Lua
 craftguide.register_craft({
 	type   = "digging",
@@ -35,4 +42,41 @@ craftguide.register_craft({
 })
 ```
 
-![Preview2](https://i.imgur.com/bToFH38.png)
+### Recipe filters
+
+Recipe filters can be used to filter the recipes shown to players. Progressive
+mode is implemented as a recipe filter.
+
+#### `craftguide.add_recipe_filter(name, function(recipes, player))`
+
+Adds a recipe filter with the given name. The filter function should return the
+recipes to be displayed, given the available recipes and an `ObjectRef` to the
+user. Each recipe is a table of the form returned by
+`minetest.get_craft_recipe`.
+
+Example function to hide recipes for items from a mod called "secretstuff":
+
+```lua
+craftguide.add_recipe_filter("Hide secretstuff", function(recipes)
+	local filtered = {}
+	for _, recipe in ipairs(recipes) do
+		if recipe.output:sub(1,12) ~= "secretstuff:" then
+			filtered[#filtered + 1] = recipe
+		end
+	end
+
+	return filtered
+end)
+```
+
+#### `craftguide.remove_recipe_filter(name)`
+
+Removes the recipe filter with the given name.
+
+#### `craftguide.set_recipe_filter(name, function(recipe, player))`
+
+Removes all recipe filters and adds a new one.
+
+#### `craftguide.get_recipe_filters()`
+
+Returns a map of recipe filters, indexed by name.

depends.txt

@@ -1,3 +1,3 @@
 sfinv?
 sfinv_buttons?
-intllib?
+intllib?

license.txt

@@ -1,15 +1,28 @@
 License of source code
 ----------------------
 
-« Copyright © 2015-2018, Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
+The MIT License (MIT)
 
-Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+Copyright (c) 2015-2019 Jean-Patrick Guerrero and contributors.
 
-The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
 
-The Software is provided “as is”, without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders X be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the Software.
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
 
-Except as contained in this notice, the name of the <copyright holders> shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the <copyright holders>. »
 
 Licenses of media (textures)
 ----------------------------