Fully fledged lambdas, along with efficiency tweaks across the ast

src/eval.rs

@@ -16,13 +16,14 @@
  */
 
 use crate::segment::{Ctr, Seg};
-use crate::sym::SymTable;
+use crate::sym::{SymTable, call_lambda};
 
 /* iterates over a syntax tree
  * returns a NEW LIST of values
  * representing the simplest possible form of the input
  */
 pub fn eval(ast: &Seg, syms: &mut SymTable) -> Result<Box<Ctr>, String> {
+    println!("E: {}", ast);
     // data to return
     let mut ret = Box::from(Ctr::None);
     let mut first = true;
@@ -39,7 +40,17 @@ pub fn eval(ast: &Seg, syms: &mut SymTable) -> Result<Box<Ctr>, String> {
     let mut none = false;
     while !none {
         match &**arg_car {
-            Ctr::Seg(ref inner) => car = eval(inner, syms)?,
+            Ctr::Seg(ref inner) => {
+                let interm = eval(inner, syms)?;
+                if let Ctr::Lambda(ref l) = *interm {
+                    match call_lambda(l, arg_cdr, syms) {
+                        Ok(s) => return Ok(s.clone()),
+                        Err(s) => return Err(format!("err in call to lambda: {}", s)),
+                    }
+                } else {
+                    car = interm;
+                }
+            },
 
             Ctr::Symbol(ref tok) => {
                 let outer_scope_seg_holder: Seg;