Add relative numbers for commands by prepending ~ (#9588)

* Add relative numbers for commands by prepending ~

* Some builtin code cleanup

* Disallow nan and inf in minetest.string_to_area

* Remove unused local variable teleportee (makes Luacheck happy)

* Clean up core.string_to_pos

* Make area parsing less permissive

* Rewrite tests as busted tests

* /time: Fix negative minutes not working

Co-authored-by: Lars Mueller <appgurulars@gmx.de>

1 files changed, 9 insertions, 1 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 6046a5902..96b1cc469 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -3550,8 +3550,16 @@ Helper functions
 * `minetest.string_to_pos(string)`: returns a position or `nil`
     * Same but in reverse.
     * If the string can't be parsed to a position, nothing is returned.
-* `minetest.string_to_area("(X1, Y1, Z1) (X2, Y2, Z2)")`: returns two positions
+* `minetest.string_to_area("(X1, Y1, Z1) (X2, Y2, Z2)", relative_to)`:
+    * returns two positions
     * Converts a string representing an area box into two positions
+    * X1, Y1, ... Z2 are coordinates
+    * `relative_to`: Optional. If set to a position, each coordinate
+      can use the tilde notation for relative positions
+    * Tilde notation: "~": Relative coordinate
+                      "~<number>": Relative coordinate plus <number>
+    * Example: `minetest.string_to_area("(1,2,3) (~5,~-5,~)", {x=10,y=10,z=10})`
+      returns `{x=1,y=2,z=3}, {x=15,y=5,z=10}`
 * `minetest.formspec_escape(string)`: returns a string
     * escapes the characters "[", "]", "\", "," and ";", which can not be used
       in formspecs.