Configurable auto pairs (#1624)

* impl auto pairs config

Implements configuration for which pairs of tokens get auto completed.

In order to help with this, the logic for when *not* to auto complete
has been generalized from a specific hardcoded list of characters to
simply testing if the next/prev char is alphanumeric.

It is possible to configure a global list of pairs as well as at the
language level. The language config will take precedence over the
global config.

* rename AutoPair -> Pair

* clean up insert_char command

* remove Rc

* remove some explicit cloning with another impl

* fix lint

* review comments

* global auto-pairs = false takes precedence over language settings

* make clippy happy

* print out editor config on startup

* move auto pairs accessor into Document

* rearrange auto pair doc comment

* use pattern in Froms

1 files changed, 7 insertions, 0 deletions

diff --git a/languages.toml b/languages.toml
index 9876bcf1..33906e4b 100644
--- a/languages.toml
+++ b/languages.toml
@@ -9,6 +9,13 @@ comment-token = "//"
 language-server = { command = "rust-analyzer" }
 indent = { tab-width = 4, unit = "    " }
 
+[language.auto-pairs]
+'(' = ')'
+'{' = '}'
+'[' = ']'
+'"' = '"'
+'`' = '`'
+
 [language.debugger]
 name = "lldb-vscode"
 transport = "stdio"