double prompt (#686)

* double prompt

* prompt env var name

Cargo.lock

@@ -2777,7 +2777,7 @@ dependencies = [
 [[package]]
 name = "reedline"
 version = "0.2.0"
-source = "git+https://github.com/nushell/reedline?branch=main#811dde6d03ff3059a6cdb9c0c05a2564258098da"
+source = "git+https://github.com/nushell/reedline?branch=main#373c76a383b9cde471671047f739e65477b80481"
 dependencies = [
  "chrono",
  "crossterm",

crates/nu-cli/src/prompt.rs

@@ -10,7 +10,8 @@ use {
 /// Nushell prompt definition
 #[derive(Clone)]
 pub struct NushellPrompt {
-    prompt_string: Option<String>,
+    left_prompt_string: Option<String>,
+    right_prompt_string: Option<String>,
     default_prompt_indicator: String,
     default_vi_insert_prompt_indicator: String,
     default_vi_visual_prompt_indicator: String,
@@ -26,7 +27,8 @@ impl Default for NushellPrompt {
 impl NushellPrompt {
     pub fn new() -> NushellPrompt {
         NushellPrompt {
-            prompt_string: None,
+            left_prompt_string: None,
+            right_prompt_string: None,
             default_prompt_indicator: "〉".to_string(),
             default_vi_insert_prompt_indicator: ": ".to_string(),
             default_vi_visual_prompt_indicator: "v ".to_string(),
@@ -34,8 +36,12 @@ impl NushellPrompt {
         }
     }
 
-    pub fn update_prompt(&mut self, prompt_string: Option<String>) {
-        self.prompt_string = prompt_string;
+    pub fn update_prompt_left(&mut self, prompt_string: Option<String>) {
+        self.left_prompt_string = prompt_string;
+    }
+
+    pub fn update_prompt_right(&mut self, prompt_string: Option<String>) {
+        self.right_prompt_string = prompt_string;
     }
 
     pub fn update_prompt_indicator(&mut self, prompt_indicator_string: String) {
@@ -56,13 +62,15 @@ impl NushellPrompt {
 
     pub fn update_all_prompt_strings(
         &mut self,
-        prompt_string: Option<String>,
+        left_prompt_string: Option<String>,
+        right_prompt_string: Option<String>,
         prompt_indicator_string: String,
         prompt_vi_insert_string: String,
         prompt_vi_visual_string: String,
         prompt_multiline_indicator_string: String,
     ) {
-        self.prompt_string = prompt_string;
+        self.left_prompt_string = left_prompt_string;
+        self.right_prompt_string = right_prompt_string;
         self.default_prompt_indicator = prompt_indicator_string;
         self.default_vi_insert_prompt_indicator = prompt_vi_insert_string;
         self.default_vi_visual_prompt_indicator = prompt_vi_visual_string;
@@ -75,12 +83,21 @@ impl NushellPrompt {
 }
 
 impl Prompt for NushellPrompt {
-    fn render_prompt(&self, width: usize) -> Cow<str> {
-        if let Some(prompt_string) = &self.prompt_string {
+    fn render_prompt_left(&self) -> Cow<str> {
+        if let Some(prompt_string) = &self.left_prompt_string {
             prompt_string.into()
         } else {
-            let default = DefaultPrompt::new(1);
-            default.render_prompt(width).to_string().into()
+            let default = DefaultPrompt::new();
+            default.render_prompt_left().to_string().into()
+        }
+    }
+
+    fn render_prompt_right(&self) -> Cow<str> {
+        if let Some(prompt_string) = &self.right_prompt_string {
+            prompt_string.into()
+        } else {
+            let default = DefaultPrompt::new();
+            default.render_prompt_right().to_string().into()
         }
     }
 

src/main.rs

@@ -34,6 +34,7 @@ mod logger;
 
 // Name of environment variable where the prompt could be stored
 const PROMPT_COMMAND: &str = "PROMPT_COMMAND";
+const PROMPT_COMMAND_RIGHT: &str = "PROMPT_COMMAND_RIGHT";
 const PROMPT_INDICATOR: &str = "PROMPT_INDICATOR";
 const PROMPT_INDICATOR_VI_INSERT: &str = "PROMPT_INDICATOR_VI_INSERT";
 const PROMPT_INDICATOR_VI_VISUAL: &str = "PROMPT_INDICATOR_VI_VISUAL";
@@ -851,84 +852,43 @@ fn update_prompt<'prompt>(
         prompt_multiline_string,
     ) = get_prompt_indicators(config, engine_state, stack);
 
-    let prompt_command_block_id = match stack.get_env_var(engine_state, PROMPT_COMMAND) {
-        Some(v) => match v.as_block() {
-            Ok(b) => b,
-            Err(_) => {
-                // apply the other indicators
-                nu_prompt.update_all_prompt_strings(
-                    None,
-                    prompt_indicator_string,
-                    prompt_vi_insert_string,
-                    prompt_vi_visual_string,
-                    prompt_multiline_string,
-                );
-                return nu_prompt as &dyn Prompt;
-            }
-        },
-        None => {
-            // apply the other indicators
-            nu_prompt.update_all_prompt_strings(
-                None,
-                prompt_indicator_string,
-                prompt_vi_insert_string,
-                prompt_vi_visual_string,
-                prompt_multiline_string,
-            );
-            return nu_prompt as &dyn Prompt;
-        }
-    };
-
-    let block = engine_state.get_block(prompt_command_block_id);
-
     let mut stack = stack.clone();
 
-    let evaluated_prompt = match eval_block(
-        engine_state,
-        &mut stack,
-        block,
-        PipelineData::new(Span::new(0, 0)), // Don't try this at home, 0 span is ignored
-    ) {
-        Ok(pipeline_data) => {
-            // let config = stack.get_config().unwrap_or_default();
-            pipeline_data.collect_string("", config)
-        }
-        Err(..) => {
-            // If we can't run the custom prompt, give them the default
     // apply the other indicators
     nu_prompt.update_all_prompt_strings(
-                None,
+        get_prompt_string(PROMPT_COMMAND, config, engine_state, &mut stack),
+        get_prompt_string(PROMPT_COMMAND_RIGHT, config, engine_state, &mut stack),
         prompt_indicator_string,
         prompt_vi_insert_string,
         prompt_vi_visual_string,
         prompt_multiline_string,
     );
-            return nu_prompt as &dyn Prompt;
-        }
-    };
-
-    match evaluated_prompt {
-        Ok(evaluated_prompt) => {
-            nu_prompt.update_all_prompt_strings(
-                Some(evaluated_prompt),
-                prompt_indicator_string,
-                prompt_vi_insert_string,
-                prompt_vi_visual_string,
-                prompt_multiline_string,
-            );
-        }
-        _ => nu_prompt.update_all_prompt_strings(
-            None,
-            prompt_indicator_string,
-            prompt_vi_insert_string,
-            prompt_vi_visual_string,
-            prompt_multiline_string,
-        ),
-    }
 
     nu_prompt as &dyn Prompt
 }
 
+fn get_prompt_string(
+    prompt: &str,
+    config: &Config,
+    engine_state: &EngineState,
+    stack: &mut Stack,
+) -> Option<String> {
+    stack
+        .get_env_var(engine_state, prompt)
+        .and_then(|v| v.as_block().ok())
+        .and_then(|block_id| {
+            let block = engine_state.get_block(block_id);
+            eval_block(
+                engine_state,
+                stack,
+                block,
+                PipelineData::new(Span::new(0, 0)), // Don't try this at home, 0 span is ignored
+            )
+            .ok()
+        })
+        .and_then(|pipeline_data| pipeline_data.collect_string("", config).ok())
+}
+
 fn eval_source(
     engine_state: &mut EngineState,
     stack: &mut Stack,