Implement basic input/output TUI

Cargo.lock

@@ -331,6 +331,7 @@ dependencies = [
  "serde_json",
  "toml",
  "tree-sitter",
+ "tui-textarea",
 ]
 
 [[package]]
@@ -1465,6 +1466,17 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3528ecfd12c466c6f163363caf2d02a71161dd5e1cc6ae7b34207ea2d42d81ed"
 
+[[package]]
+name = "tui-textarea"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3e38ced1f941a9cfc923fbf2fe6858443c42cc5220bfd35bdd3648371e7bd8e"
+dependencies = [
+ "crossterm",
+ "ratatui",
+ "unicode-width",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.13"

Cargo.toml

@@ -28,6 +28,7 @@ serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0.107"
 toml = "0.8.8"
 tree-sitter = "0.20.10"
+tui-textarea = "0.4.0"
 
 [build-dependencies]
 cc = "1.0"

src/error.rs

@@ -20,6 +20,8 @@ pub type Result<T> = std::result::Result<T, Error>;
 
 #[derive(Clone, PartialEq)]
 pub enum Error {
+    NoUserInput,
+
     WithContext {
         error: Box<Error>,
         location: Point,
@@ -412,6 +414,7 @@ impl fmt::Display for Error {
                 source,
             } => write!(f, "{error} Occured at {location}: \"{source}\""),
             SerdeJson(message) => write!(f, "JSON processing error: {message}"),
+            NoUserInput => write!(f, "No input was provided."),
         }
     }
 }

src/evaluate.rs

@@ -2,9 +2,11 @@
 //!
 //! You can use this library externally by calling either of the "eval"
 //! functions or by constructing your own Evaluator.
+use std::cell::RefCell;
+
 use tree_sitter::{Parser, Tree as TSTree};
 
-use crate::{language, AbstractTree, Map, Result, Root, Value};
+use crate::{language, AbstractTree, Error, Map, Result, Root, Value};
 
 /// Evaluate the given source code.
 ///
@@ -43,28 +45,37 @@ pub fn evaluate(source: &str) -> Result<Value> {
 /// );
 /// ```
 pub fn evaluate_with_context(source: &str, context: &mut Map) -> Result<Value> {
-    let mut parser = Parser::new();
-    parser.set_language(language()).unwrap();
-
-    Interpreter::parse(parser, context, source)?.run()
+    Interpreter::parse(context, &RefCell::new(source.to_string()))?.run()
 }
 
 /// A source code interpreter for the Dust language.
 pub struct Interpreter<'c, 's> {
-    _parser: Parser,
+    parser: Parser,
     context: &'c mut Map,
-    source: &'s str,
-    syntax_tree: TSTree,
-    abstract_tree: Root,
+    source: &'s RefCell<String>,
+    syntax_tree: Option<TSTree>,
+    abstract_tree: Option<Root>,
 }
 
 impl<'c, 's> Interpreter<'c, 's> {
-    pub fn parse(mut parser: Parser, context: &'c mut Map, source: &'s str) -> Result<Self> {
-        let syntax_tree = parser.parse(source, None).unwrap();
-        let abstract_tree = Root::from_syntax_node(source, syntax_tree.root_node(), context)?;
+    pub fn parse(context: &'c mut Map, source: &'s RefCell<String>) -> Result<Self> {
+        let mut parser = Parser::new();
+
+        parser.set_language(language()).unwrap();
+
+        let syntax_tree = parser.parse(source.borrow().as_str(), None);
+        let abstract_tree = if let Some(syntax_tree) = &syntax_tree {
+            Some(Root::from_syntax_node(
+                source.borrow().as_str(),
+                syntax_tree.root_node(),
+                context,
+            )?)
+        } else {
+            panic!()
+        };
 
         Ok(Interpreter {
-            _parser: parser,
+            parser,
             context,
             source,
             syntax_tree,
@@ -72,11 +83,38 @@ impl<'c, 's> Interpreter<'c, 's> {
         })
     }
 
+    pub fn update(&mut self) -> Result<()> {
+        let source = self.source.borrow();
+        let syntax_tree = self.parser.parse(source.as_str(), None);
+        let abstract_tree = if let Some(syntax_tree) = &syntax_tree {
+            Some(Root::from_syntax_node(
+                source.as_str(),
+                syntax_tree.root_node(),
+                self.context,
+            )?)
+        } else {
+            None
+        };
+
+        self.syntax_tree = syntax_tree;
+        self.abstract_tree = abstract_tree;
+
+        Ok(())
+    }
+
     pub fn run(&mut self) -> Result<Value> {
-        self.abstract_tree.run(self.source, self.context)
+        if let Some(abstract_tree) = &self.abstract_tree {
+            abstract_tree.run(self.source.borrow().as_ref(), self.context)
+        } else {
+            Err(Error::NoUserInput)
+        }
     }
 
     pub fn syntax_tree(&self) -> String {
-        self.syntax_tree.root_node().to_sexp()
+        if let Some(syntax_tree) = &self.syntax_tree {
+            syntax_tree.root_node().to_sexp()
+        } else {
+            "".to_string()
+        }
     }
 }

src/main.rs

@@ -1,16 +1,19 @@
 //! Command line interface for the dust programming language.
 use clap::Parser;
 use crossterm::{
-    event::{self, KeyCode, KeyEventKind},
+    event::{poll, read, Event, KeyCode},
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
     ExecutableCommand,
 };
-use ratatui::{prelude::CrosstermBackend, style::Stylize, widgets::Paragraph, Terminal};
-use tree_sitter::Parser as TSParser;
+use ratatui::{
+    prelude::{CrosstermBackend, Rect},
+    widgets::Paragraph,
+    Terminal,
+};
+use std::{cell::RefCell, fs::read_to_string, io::stdout, time::Duration};
+use tui_textarea::TextArea;
 
-use std::{fs::read_to_string, io::stdout};
-
-use dust_lang::{language, Interpreter, Map, Result, Value};
+use dust_lang::{Interpreter, Map, Result, Value};
 
 /// Command-line arguments to be parsed.
 #[derive(Parser, Debug)]
@@ -44,16 +47,19 @@ fn main() {
     let args = Args::parse();
 
     if args.path.is_none() && args.command.is_none() {
-        return run_cli_shell().unwrap();
+        run_tui().unwrap();
+
+        return;
     }
 
-    let source = if let Some(path) = &args.path {
+    let source_input = if let Some(path) = &args.path {
         read_to_string(path).unwrap()
     } else if let Some(command) = &args.command {
         command.clone()
     } else {
-        "".to_string()
+        "(output 'Hello dust!')".to_string()
     };
+    let source = RefCell::new(source_input);
 
     let mut context = Map::new();
 
@@ -71,10 +77,7 @@ fn main() {
             .unwrap();
     }
 
-    let mut parser = TSParser::new();
-    parser.set_language(language()).unwrap();
-
-    let mut interpreter = Interpreter::parse(parser, &mut context, &source).unwrap();
+    let mut interpreter = Interpreter::parse(&mut context, &source).unwrap();
 
     if args.interactive {
         loop {
@@ -100,30 +103,59 @@ fn main() {
     }
 }
 
-fn run_cli_shell() -> Result<()> {
-    let mut _context = Map::new();
+fn run_tui() -> Result<()> {
+    let user_input = RefCell::new("(output 'Hello dust!')".to_string());
+    let mut context = Map::new();
+    let mut interpreter = Interpreter::parse(&mut context, &user_input)?;
+
+    interpreter.update()?;
+
+    let mut interpreter_output = interpreter.run();
 
     stdout().execute(EnterAlternateScreen)?;
     enable_raw_mode()?;
 
     let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
+    let mut textarea = TextArea::default();
 
     loop {
         terminal.draw(|frame| {
-            let area = frame.size();
-            frame.render_widget(
-                Paragraph::new("Hello Ratatui! (press 'q' to quit)")
-                    .white()
-                    .on_blue(),
-                area,
-            );
+            let input_area = Rect {
+                x: 0,
+                y: 0,
+                width: frame.size().width,
+                height: frame.size().height / 2,
+            };
+
+            frame.render_widget(textarea.widget(), input_area);
+
+            let output_area = Rect {
+                x: input_area.left(),
+                y: input_area.bottom(),
+                width: frame.size().width,
+                height: frame.size().height / 2,
+            };
+
+            match &interpreter_output {
+                Ok(value) => frame.render_widget(Paragraph::new(value.to_string()), output_area),
+                Err(error) => frame.render_widget(Paragraph::new(error.to_string()), output_area),
+            }
         })?;
 
-        if event::poll(std::time::Duration::from_millis(16))? {
-            if let event::Event::Key(key) = event::read()? {
-                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
+        if poll(Duration::from_millis(16))? {
+            if let Event::Key(key) = read()? {
+                if key.code == KeyCode::Esc {
                     break;
                 }
+                if key.code == KeyCode::Enter {
+                    let input = textarea.lines().join("\n");
+
+                    user_input.replace(input);
+                    interpreter.update()?;
+                    interpreter_output = interpreter.run();
+                }
+
+                textarea.input(key);
             }
         }
     }