added env function and test

src/stl.rs

@@ -172,6 +172,17 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
         },
     );
 
+    syms.insert(
+        "env".to_string(),
+        Symbol {
+            name: String::from("env"),
+            args: Args::None,
+            conditional_branches: false,
+            docs: decl::ENV_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(decl::env_callback)),
+        },
+    );
+
     Ok(())
 }
 

src/stl/decl.rs

@@ -189,3 +189,24 @@ pub fn isset_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
         }
     }
 }
+
+pub const ENV_DOCSTRING: &str = "takes no arguments
+prints out all available symbols and their associated values";
+
+pub fn env_callback(_ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
+    let mut functions = vec![];
+    println!("VARIABLES:");
+    for (name, val) in syms.iter() {
+        match val.value {
+            ValueType::VarForm(_) => {
+                println!("  {}: {}", &name, val.value);
+            },
+            _ => functions.push(name.clone()),
+        }
+    }
+    println!("FUNCTIONS:");
+    for func in functions {
+        println!("  {}", func);
+    }
+    Ok(Ctr::None)
+}

src/sym.rs

@@ -87,6 +87,10 @@ impl SymTable {
         self.0.remove(arg)
     }
 
+    pub fn iter(&self) -> std::collections::hash_map::Iter<'_, String, Symbol> {
+        self.0.iter()
+    }
+
     pub fn call_symbol(
         &mut self,
         name: &String,