environ changes

src/lib/environ.rs

@@ -63,6 +63,32 @@ pub fn default_env<'a>() -> Environ<'a> {
         }),
     );
 
+    data.insert(
+        "+".to_string(),
+        Expr::Func(|args: &[Expr]| -> Result<Expr, RispError> {
+            let sum = parse_list_of_floats(args)?
+                .iter()
+                .fold(0.0, |sum, a| sum + a);
+
+            Ok(Expr::Number(sum))
+        }),
+    );
+
+    data.insert(
+        "*".to_string(),
+        Expr::Func(|args: &[Expr]| -> Result<Expr, RispError> {
+            let floats = parse_list_of_floats(args)?;
+            let first = *floats.first().ok_or(RispError::Reason(
+                "expected at least one number".to_string(),
+            ))?;
+            let sum_of_rest = floats[1..].iter().fold(0.0, |sum, a| sum + a);
+
+            Ok(Expr::Number(first * sum_of_rest))
+        }),
+    );
+
+
+
     data.insert("=".to_string(), Expr::Func(ensure_tonicity!(|a, b| a == b)));
     data.insert(">".to_string(), Expr::Func(ensure_tonicity!(|a, b| a > b)));
     data.insert(

src/lib/mod.rs

@@ -1,4 +1,4 @@
-use core::fmt;
+use std::fmt;
 use core::num::ParseFloatError;
 
 pub use std::collections::HashMap;
@@ -21,7 +21,7 @@ mod evaluate;
 pub enum RispError {
     Reason(String),
 }
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum Expr {
     Bool(bool),
     Symbol(String),
@@ -31,7 +31,7 @@ pub enum Expr {
     Func(fn(&[Expr]) -> Result<Expr, RispError>),
     Lambda(RLambda),
 }
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct RLambda {
     params_exp: Rc<Expr>,
     body_exp: Rc<Expr>,
@@ -47,10 +47,14 @@ impl fmt::Display for Expr {
             Str(s) => format!("\"{}\"", s),
             List(list) => {
                 let xs: Vec<String> = list.iter().map(|x| x.to_string()).collect();
-                format!("({})", xs.join(","))
+                format!("({})", xs.join(" "))
+            }
+            Func(func) => {
+                format!("({:?})", func)
+            }
+            Lambda(lambda) => {
+                format!("(fn {} {})", lambda.params_exp, lambda.body_exp)   
             }
-            Func(_) => "Function {}".to_string(),
-            Lambda(_) => "Lambda {}".to_string(),
         };
 
         write!(f, "{}", str)

src/lib/parser.rs

@@ -44,7 +44,7 @@ fn parse_atom(token: &str) -> Expr {
             let potential_float: Result<f64, ParseFloatError> = token.parse();
             match potential_float {
                 Ok(v) => Number(v),
-                Err(er) => {
+                Err(_er) => {
                     if token.to_string().starts_with("\"") && token.to_string().ends_with("\""){
                         let mut stri = token.to_string().clone();
                         stri.remove(0);

src/main.rs

@@ -1,5 +1,4 @@
-use std::collections::HashMap;
-use std::fmt;
+#![allow(special_module_name)]
 use std::io;
 use std::io::Write;
 
@@ -20,29 +19,44 @@ fn slurp_expr() -> String {
 fn extend_environ<'a>(mut env: Environ<'a>) -> Environ<'a> {
      env.data.insert(
         "quit".to_string(),
-        Expr::Func(|args: &[Expr]| -> Result<Expr, RispError> {
+        Expr::Func(|_args: &[Expr]| -> Result<Expr, RispError> {
             // TODO: let this function take in arguments
             println!("Exiting.");
             std::process::exit(0);
+            #[allow(unreachable_code)]
             Err(RispError::Reason("Cannot exit process".to_string()))
         }),
     );
 
    env.data.insert(
         "prompt".to_string(),
-        Expr::Symbol("risp => ".to_string()),
+        Expr::Symbol("rlisp => ".to_string()),
     );
 
-env
+
+    env.data.insert(
+        "print".to_string(),
+        Expr::Func(|args: &[Expr]| -> Result<Expr, RispError> {
+            let mut stri = String::new();
+            for arg in args {
+                let fmted = format!("{}", arg);
+                stri.push_str(&fmted);
+                stri.push_str(" ")
+            }
+            
+            Ok(Expr::Symbol(stri.to_string()))
+        }),
+    );
+    env
 }
 
 
 
 fn main() {
-    let mut env = &mut default_env();
-    let mut env = &mut extend_environ(env.clone());
+    let env = &mut default_env();
+    let env = &mut extend_environ(env.clone());
     loop {
-        let prompt = env_get("prompt", env).unwrap_or(lib::Expr::Symbol("risp => ".to_string()));
+        let prompt = env_get("prompt", env).unwrap_or(lib::Expr::Symbol("rlisp => ".to_string()));
         print!("{}", prompt);
         let _ = std::io::stdout().flush();
         let expr = slurp_expr();