feature: add a toggle-option command

This commands allows to toggle boolean options.
It does not support other enumerated types.

book/src/generated/typable-cmd.md

@@ -60,6 +60,7 @@
 | `:goto`, `:g` | Goto line number. |
 | `:set-language`, `:lang` | Set the language of current buffer. |
 | `:set-option`, `:set` | Set a config option at runtime.<br>For example to disable smart case search, use `:set search.smart-case false`. |
+| `:toggle-option`, `:toggle` | Toggle a config option at runtime.<br>For example to toggle smart case search, use `:toggle search.smart-case`. |
 | `:get-option`, `:get` | Get the current value of a config option. |
 | `:sort` | Sort ranges in selection. |
 | `:rsort` | Sort ranges in selection in reverse order. |

helix-term/src/commands/typed.rs

@@ -1479,6 +1479,42 @@ fn get_option(
     Ok(())
 }
 
+/// Change config at runtime. Access nested values by dot syntax, for
+/// example to toggle smart case search, use `:toggle search.smart-case`.
+fn toggle_option(
+    cx: &mut compositor::Context,
+    args: &[Cow<str>],
+    event: PromptEvent,
+) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    if args.len() != 1 {
+        anyhow::bail!("Bad arguments. Usage: `:toggle key`");
+    }
+
+    let key = &args[0].to_lowercase();
+
+    let key_error = || anyhow!("Unknown key `{}`", key);
+
+    let mut config = serde_json::json!(&cx.editor.config().deref());
+    let pointer = format!("/{}", key.replace('.', "/"));
+    let value = config.pointer_mut(&pointer).ok_or_else(key_error)?;
+
+    *value = match value {
+        serde_json::Value::Bool(v) => serde_json::Value::Bool(!*v),
+        _ => anyhow::bail!("key {} must be a bool to be toggled", key),
+    };
+    let config = serde_json::from_value(config)?;
+
+    cx.editor
+        .config_events
+        .0
+        .send(ConfigEvent::Update(config))?;
+    Ok(())
+}
+
 /// Change config at runtime. Access nested values by dot syntax, for
 /// example to disable smart case search, use `:set search.smart-case false`.
 fn set_option(
@@ -2246,6 +2282,13 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
             fun: set_option,
             completer: Some(completers::setting),
         },
+        TypableCommand {
+            name: "toggle-option",
+            aliases: &["toggle"],
+            doc: "Toggle a config option at runtime.\nFor example to toggle smart case search, use `:toggle search.smart-case`.",
+            fun: toggle_option,
+            completer: Some(completers::setting),
+        },
         TypableCommand {
             name: "get-option",
             aliases: &["get"],