Commands in repl for debugging

crates/saft-eval/src/interpreter.rs

@@ -5,6 +5,7 @@ use saft_ast::{Block, Expr, Ident, Item, Module, Statement};
 use saft_common::span::{Span, Spanned};
 use std::borrow::Borrow;
 use std::collections::HashMap;
+use std::fmt::Write;
 use std::rc::Rc;
 
 #[macro_export]
@@ -627,6 +628,29 @@ impl Interpreter {
             }
         })
     }
+
+    pub fn print_env(&self) {
+        let mut lines = Vec::new();
+        for scope in self.env.scopes.iter() {
+            let mut line = Vec::<String>::new();
+
+            for (k, v) in scope.iter() {
+                line.push(format!("{}: {}", k, v.repr()));
+            }
+
+            lines.push(line);
+        }
+
+        println!(
+            "{}",
+            lines
+                .iter()
+                .enumerate()
+                .map(|(i, line)| format!("{}: {}", i, &line.join(", ")))
+                .collect::<Vec<_>>()
+                .join("\n")
+        );
+    }
 }
 
 impl Default for Interpreter {

crates/saft/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 clap = { version = "4.4.11", features = ["derive"] }
 codespan-reporting = "0.11.1"
+indoc = "2.0.4"
 platform-dirs = "0.3.0"
 rustyline = "13.0.0"
 saft-ast = { version = "0.1.0", path = "../saft-ast" }

crates/saft/src/main.rs

@@ -11,6 +11,7 @@ use codespan_reporting::{
         termcolor::{ColorChoice, StandardStream},
     },
 };
+use indoc::indoc;
 use platform_dirs::AppDirs;
 use rustyline::{error::ReadlineError, DefaultEditor};
 use saft_eval::interpreter::Interpreter;
@@ -67,7 +68,17 @@ fn repl() {
         match readline {
             Ok(line) => {
                 rl.add_history_entry(&line).unwrap();
-                interpret_stmt(&mut interpreter, &line);
+                if line.starts_with(':') {
+                    match line.as_str() {
+                        ":h" => println!(indoc! {"
+                            :h   - print help
+                            :env - print env"}),
+                        ":env" => interpreter.print_env(),
+                        _ => println!("Unknown command, :h for help"),
+                    }
+                } else {
+                    interpret_stmt(&mut interpreter, &line);
+                }
             }
             Err(ReadlineError::Interrupted | ReadlineError::Eof) => {
                 break;