Allow LSP settings to be set independently (#913)

* clarify the readme

There is no longer a .envrc file, so `direnv allow` does not work, and
`nix develop` (if you use Nix) is required.

* allow LSP settings to be set individually

Previously, all four settings needed to be provided for any to have an
effect. Now, missing settings are filled in with defaults.

* chore: simplify logic

Author: prsteele

readme.md

@@ -48,8 +48,7 @@ This requires [Rust](https://www.rust-lang.org/tools/install) (>=1.75) to be ins
   cargo build    # to build latest debug version of uiua
   cargo run repl # to get uiua repl
   ```
-  `nix develop` is not necessary if you have direnv active, in that case `direnv allow` will activate the flake devshell.
-  
+
   *Note:* If you encounter errors such as rustc or any other package
   version mismatch, it is most likely that flake.lock file needs to be
   updated to pull in updated dependencies for nix shell.

src/lsp.rs

@@ -2210,22 +2210,30 @@ mod server {
                 )
                 .await
                 .unwrap_or_default();
-            let (binding_sigs, inline_sigs, min_length, show_values) = if let [
-                serde_json::Value::Bool(binding_sigs),
-                serde_json::Value::Bool(inline_sigs),
-                serde_json::Value::Number(min_length),
-                serde_json::Value::Bool(show_values),
-            ] = config.as_slice()
-            {
-                (
-                    *binding_sigs,
-                    *inline_sigs,
-                    min_length.as_u64().unwrap_or(1) as usize,
-                    *show_values,
-                )
-            } else {
-                (true, true, 3, true)
-            };
+            let default_binding_sigs = true;
+            let default_inline_sigs = true;
+            let default_min_length = 3;
+            let default_show_values = true;
+            let (binding_sigs, inline_sigs, min_length, show_values) =
+                if let [m_binding_sigs, m_inline_sigs, m_min_length, m_show_values] =
+                    config.as_slice()
+                {
+                    (
+                        m_binding_sigs.as_bool().unwrap_or(default_binding_sigs),
+                        m_inline_sigs.as_bool().unwrap_or(default_inline_sigs),
+                        m_min_length
+                            .as_u64()
+                            .map_or(default_min_length, |u| u as usize),
+                        m_show_values.as_bool().unwrap_or(default_show_values),
+                    )
+                } else {
+                    (
+                        default_binding_sigs,
+                        default_inline_sigs,
+                        default_min_length,
+                        default_show_values,
+                    )
+                };
             let path = uri_path(&params.text_document.uri);
             // Signature hints
             let mut hints = Vec::new();