shell fully configurable

Readme.org

@@ -395,8 +395,12 @@ Errors during configuration are non-terminal. In such a case any defaults which
 *** Configuration Values
 - CFG_RELISH_POSIX (default false): when true, enables POSIX style job control.
 - CFG_RELISH_ENV (default true): when true, interpreter's variable table and environment variable table are kept in sync.
-- CFG_RELISH_PROMPT (default (echo "λ ")): A *function* definition which is called in order to output the prompt for each loop of the REPL.
-  This function will be reloaded each REPL loop and will be called by the interpreter with no arguments.
+- CFG_RELISH_L_PROMPT (default 'λ'): a function that is called with no arguments to output the left hand of the prompt
+- CFG_RELISH_R_PROMPT (default ''): a function that is called with no arguments to output the right hand of the prompt
+- CFG_RELISH_PROMPT_DELIMITER (default '>'): a function that is called with no arguments to output the delimiter separating prompt from user input
+
+*** Prompt design
+For an example of prompt design see file:snippets/mood-prompt.rls
 
 *** Further configuration
 Further configuration can be done by loading scripts that contain more functions and data to evaluate.
@@ -477,12 +481,16 @@ Note: this section will not show the status of each item unless you are viewing
 Note: this section only tracks the state of incomplete TODO items. Having everything on here would be cluttered.
 
 ** TODO Pre-alpha tasks
-- Shell prompt is fully configurable (History, L, R, and Delim)
+- paths function
+- add-path function
 - Shell module
   - Only loadable via POSIX config var
   - Overload Load function to hook into this lib
   - arg processor because these are control flow
   - Process launching with environment variables
+  - "flag" function
+  - "switch" function
+  - "with" function (load with)
   - Optional form of process which allows fd redirecting
   - Background processes (bg function)
   - Foreground process TTY (fg function)
@@ -492,6 +500,9 @@ Note: this section only tracks the state of incomplete TODO items. Having everyt
 - make const all the error messages
 
 ** TODO alpha tasks
+- History length configurable
+- Search delim configurable
+- Escape sequences in strings
 - Rename to Flesh
 - master branch -> main branch
 - Create a dedicated community channel on matrix.sunnypup.io

snippets/mood-prompt.rls

@@ -0,0 +1,15 @@
+#!/bin/relish
+
+(def __mood 'current mood' ':3')
+
+(def CFG_RELISH_L_PROMPT 'mood left prompt'
+() (concat "(" __mood ")" ))
+
+(def CFG_RELISH_R_PROMPT 'mood right prompt'
+() 'call set-mood to change prompt')
+
+(def CFG_RELISH_PROMPT_DELIMITER 'mood prompt delim'
+() '>')
+
+(def set-mood 'set the little ascii face in your prompt'
+(mood) (set (q __mood) mood))

src/bin/main.rs

@@ -28,22 +28,22 @@ use std::borrow::Cow;
 use std::env;
 
 #[derive(Clone)]
-pub struct CustomPrompt<'a>(&'a str);
-impl Prompt for CustomPrompt<'_> {
+pub struct CustomPrompt(String, String, String);
+impl Prompt for CustomPrompt {
     fn render_prompt_left(&self) -> Cow<str> {
         {
-            Cow::Owned(self.0.to_string())
+            Cow::Owned(self.0.to_owned())
         }
     }
 
     fn render_prompt_right(&self) -> Cow<str> {
         {
-            Cow::Owned(format!(""))
+            Cow::Owned(self.1.to_owned())
         }
     }
 
     fn render_prompt_indicator(&self, _edit_mode: PromptEditMode) -> Cow<str> {
-        Cow::Owned("> ".to_string())
+        Cow::Owned(self.2.to_owned())
     }
 
     fn render_prompt_multiline_indicator(&self) -> Cow<str> {
@@ -117,20 +117,7 @@ fn main() {
 
     // repl :)
     loop {
-        let s = *syms
-            .call_symbol(&"CFG_RELISH_PROMPT".to_string(), &Seg::new(), true)
-            .unwrap_or_else(|err: String| {
-                eprintln!("{}", err);
-                Box::new(Ctr::String("<prompt broken!>".to_string()))
-            });
-        let p_str: String;
-        if let Ctr::String(s) = s {
-            p_str = s;
-        } else {
-            p_str = s.to_string();
-        }
-        let readline_prompt = CustomPrompt(p_str.as_str());
-
+        let readline_prompt = make_prompt(&mut syms);
         let user_doc = rl.read_line(&readline_prompt).unwrap();
         match user_doc {
             Signal::Success(line) => {
@@ -156,3 +143,45 @@ fn main() {
         }
     }
 }
+
+fn make_prompt(syms: &mut SymTable) -> CustomPrompt {
+    let l_ctr = *syms
+        .call_symbol(&"CFG_RELISH_L_PROMPT".to_string(), &Seg::new(), true)
+        .unwrap_or_else(|err: String| {
+            eprintln!("{}", err);
+            Box::new(Ctr::String("<prompt broken!>".to_string()))
+        });
+    let r_ctr = *syms
+        .call_symbol(&"CFG_RELISH_R_PROMPT".to_string(), &Seg::new(), true)
+        .unwrap_or_else(|err: String| {
+            eprintln!("{}", err);
+            Box::new(Ctr::String("<prompt broken!>".to_string()))
+        });
+    let d_ctr = *syms
+        .call_symbol(&"CFG_RELISH_PROMPT_DELIMITER".to_string(), &Seg::new(), true)
+        .unwrap_or_else(|err: String| {
+            eprintln!("{}", err);
+            Box::new(Ctr::String("<prompt broken!>".to_string()))
+        });
+
+    let l_str: String;
+    let r_str: String;
+    let d_str: String;
+    if let Ctr::String(s) = l_ctr {
+        l_str = s;
+    } else {
+        l_str = l_ctr.to_string();
+    }
+    if let Ctr::String(s) = r_ctr {
+        r_str = s;
+    } else {
+        r_str = r_ctr.to_string();
+    }
+    if let Ctr::String(s) = d_ctr {
+        d_str = s;
+    } else {
+        d_str = d_ctr.to_string();
+    }
+
+    CustomPrompt(l_str, r_str, d_str)
+}

src/run.rs

@@ -25,8 +25,16 @@ use std::iter::FromIterator;
 use std::env::{vars, var, current_dir};
 use std::rc::Rc;
 
-fn prompt_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
-    Ok(Ctr::Symbol("λ".to_string()))
+fn l_prompt_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
+    Ok(Ctr::String("λ".to_string()))
+}
+
+fn r_prompt_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
+    Ok(Ctr::String(String::new()))
+}
+
+fn prompt_delimiter_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, String> {
+    Ok(Ctr::String(">".to_string()))
 }
 
 fn get_paths() -> Vec<String> {
@@ -70,15 +78,40 @@ default value: 1 (set)
     );
 
     syms.insert(
-        "CFG_RELISH_PROMPT".to_string(),
+        "CFG_RELISH_L_PROMPT".to_string(),
         Symbol {
-            name: String::from("default relish prompt"),
+            name: String::from("default relish left prompt"),
             args: Args::None,
             conditional_branches: false,
-            docs: "function called to output prompt. this function is called with no arguments.
-default value (<lambda>)"
+            docs: "function called to output prompt on left hand. this function is called with no arguments."
                 .to_string(),
-            value: ValueType::Internal(Rc::new(prompt_default_callback)),
+            value: ValueType::Internal(Rc::new(l_prompt_default_callback)),
+            ..Default::default()
+        },
+    );
+
+    syms.insert(
+        "CFG_RELISH_R_PROMPT".to_string(),
+        Symbol {
+            name: String::from("default relish right prompt"),
+            args: Args::None,
+            conditional_branches: false,
+            docs: "function called to output prompt on right hand. this function is called with no arguments."
+                .to_string(),
+            value: ValueType::Internal(Rc::new(r_prompt_default_callback)),
+            ..Default::default()
+        },
+    );
+
+    syms.insert(
+        "CFG_RELISH_PROMPT_DELIMITER".to_string(),
+        Symbol {
+            name: String::from("default relish prompt delimiter"),
+            args: Args::None,
+            conditional_branches: false,
+            docs: "function called to output prompt delimiter. this function is called with no arguments."
+                .to_string(),
+            value: ValueType::Internal(Rc::new(prompt_delimiter_default_callback)),
             ..Default::default()
         },
     );