Added USERLIB with prepend and set.

Added a q shortcut to quote
get-doc and set-doc no longer conditionally evaluate args
Fixed bug in let, documented potential performance improvements
upped default history to 5k lines

src/stl/control.rs

@@ -205,8 +205,13 @@ pub fn let_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
 
     // we need to get any var declared from within the let eval forms
     // those need to exist in the outside context
+    // TODO: make this more optimal
+    //     How can we skip iterations?
+    //     implement a counter for number of calls to def
+    //     store it inside the SymTable and Symbol
+    //     only re-insert into global scope what is most recent
     for i in localsyms.iter() {
-        if !locals.contains(i.0) && !syms.contains_key(i.0) {
+        if !locals.contains(i.0) {
             syms.insert(
                 i.0.clone(),
                 i.1.clone(),

src/stl/decl.rs

@@ -69,7 +69,7 @@ pub fn eval_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
                 }
             },
             _ => Ok(arguments)
-        }*/
+    }*/
     }
 }
 
@@ -195,27 +195,28 @@ pub fn lambda_callback(
 }
 
 pub const GETDOC_DOCSTRING: &str = "accepts an unevaluated symbol, returns the doc string.
-Returns an error if symbol is undefined";
+Returns an error if symbol is undefined.
+
+Note: make sure to quote the input like this:
+    (get-doc (quote symbol-name))";
 
 pub fn getdoc_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
-    if ast.len() != 1 {
-        Err("get-doc only takes a single argument".to_string())
-    } else {
-        if let Ctr::Symbol(ref symbol) = *ast.car {
-            if let Some(sym) = syms.get(symbol) {
-                Ok(Ctr::String(sym.docs.clone()))
-            } else {
-                Err("undefined symbol".to_string())
-            }
-
+    if let Ctr::Symbol(ref symbol) = *ast.car {
+        if let Some(sym) = syms.get(symbol) {
+            Ok(Ctr::String(sym.docs.clone()))
         } else {
-            Err("get-doc should only be called on a symbol".to_string())
+            Err("undefined symbol".to_string())
         }
+    } else {
+        Err("get-doc should only be called on a symbol".to_string())
     }
 }
 
 pub const SETDOC_DOCSTRING: &str = "accepts a symbol and a doc string.
-Returns an error if symbol is undefined, otherwise sets the symbols docstring to the argument.";
+Returns an error if symbol is undefined, otherwise sets the symbols docstring to the argument.
+
+Note: make sure to quote the input like this:
+    (set-doc (quote symbol-name) my-new-docs)";
 
 pub fn setdoc_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, String> {
     if ast.len() != 2 {