diff --git a/core/Cargo.toml b/core/Cargo.toml
index 81e3f4a..8e55239 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["Ava <ava@sunnypup.io>"]
 edition = "2021"
 
 [dependencies]
+libm = "0.2.8"
 # this one provides a global constant lookup table for simple
 # string escaping in the lexer
 phf = { version = "0.11", default-features = false, features = ["macros"] }
@@ -14,4 +15,4 @@ name = "flesh"
 
 # only turn this on if you set POSIX_LOAD_NAME at build time
 [features]
-implicit-load = []
\ No newline at end of file
+implicit-load = []
diff --git a/core/src/error.rs b/core/src/error.rs
index 7df44c3..8c9609f 100644
--- a/core/src/error.rs
+++ b/core/src/error.rs
@@ -15,7 +15,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-use std::fmt;
+use alloc::vec::Vec;
+use alloc::string::String;
+use core::fmt;
+use core::convert;
 
 #[derive(Debug, Clone)]
 pub struct TraceItem {
@@ -32,7 +35,7 @@ pub fn start_trace(item: TraceItem) -> Traceback {
 
 impl Traceback {
     pub fn new() -> Traceback {
-        Traceback(vec![])
+        Traceback(Vec::new())
     }
 
     pub fn with_trace(mut self, item: TraceItem) -> Traceback {
@@ -56,13 +59,13 @@ impl fmt::Display for Traceback {
 }
 
 
-impl std::convert::From<Traceback> for String {
+impl convert::From<Traceback> for String {
     fn from(arg: Traceback) -> Self {
         format!("{}", arg)
     }
 }
 
-impl std::convert::From<(&String, &str)> for TraceItem {
+impl convert::From<(&String, &str)> for TraceItem {
     fn from(value: (&String, &str)) -> Self {
         TraceItem {
             caller:  value.0.clone(),
@@ -71,7 +74,7 @@ impl std::convert::From<(&String, &str)> for TraceItem {
     }
 }
 
-impl std::convert::From<(&String, String)> for TraceItem {
+impl convert::From<(&String, String)> for TraceItem {
     fn from(value: (&String, String)) -> Self {
         TraceItem {
             caller: value.0.clone(),
@@ -80,7 +83,7 @@ impl std::convert::From<(&String, String)> for TraceItem {
     }
 }
 
-impl std::convert::From<(&str, String)> for TraceItem {
+impl convert::From<(&str, String)> for TraceItem {
     fn from(value: (&str, String)) -> Self {
         TraceItem {
             caller: String::from(value.0),
@@ -89,7 +92,7 @@ impl std::convert::From<(&str, String)> for TraceItem {
     }
 }
 
-impl std::convert::From<(&str, &str)> for TraceItem {
+impl convert::From<(&str, &str)> for TraceItem {
     fn from(value: (&str, &str)) -> Self {
         TraceItem {
             caller: String::from(value.0),
diff --git a/core/src/eval.rs b/core/src/eval.rs
index 0af5115..eb6890e 100644
--- a/core/src/eval.rs
+++ b/core/src/eval.rs
@@ -15,6 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+use alloc::boxed::Box;
 use crate::segment::{Ctr, Seg};
 use crate::sym::{SymTable, call_lambda};
 use crate::error::Traceback;
diff --git a/core/src/hashmap.rs b/core/src/hashmap.rs
new file mode 100644
index 0000000..b192fa2
--- /dev/null
+++ b/core/src/hashmap.rs
@@ -0,0 +1,159 @@
+/* Flesh: Flexible Shell
+ * Copyright (C) 2021 Ava Affine
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use alloc::slice;
+use alloc::vec::Vec;
+use alloc::boxed::Box;
+use alloc::string::String;
+
+/* Use a prime number so that the modulus operation
+ * provides better avalanche effect
+ */
+const INDEXED_BUCKETS: u8 = 199;
+
+/* This only has to work to make quasi unique indexes from
+ * variable names. Any given program will not have so many
+ * symbols that this becomes a bottleneck in runtime.
+ *
+ * Priorities:
+ *   - SPEED in embedded code
+ *   - avalanche effect
+ *
+ * Not a priority: minimal collisions
+ *
+ * Just to make sure this is not misused I keep it private
+ */
+#[inline]
+fn string_hash(input: &String) -> u8 {
+    input
+        .chars()
+        .map(|c| c.to_digit(10)
+             .or_else(|| Some(0))
+             .unwrap())
+        .reduce(|acc, i| (acc + i) % INDEXED_BUCKETS as u32)
+        .or_else(|| Some(0))
+        .unwrap() as u8
+}
+
+#[derive(Clone)]
+pub struct Bucket<T: Clone>(Vec<(String, T)>);
+#[derive(Clone)]
+pub struct QuickMap<T: Clone>(Box<[Bucket<T>; INDEXED_BUCKETS as usize]>);
+
+impl<'a, T: Clone> QuickMap<T> {
+    const ARRAY_REPEAT_VALUE: Bucket<T> = Bucket(vec![]);
+
+    pub fn new() -> QuickMap<T> {
+        QuickMap(Box::new([QuickMap::ARRAY_REPEAT_VALUE; INDEXED_BUCKETS as usize]))
+    }
+
+    pub fn get(&self, arg: &String) -> Option<&T> {
+        let idx = string_hash(&arg);
+        for kv in self.0[idx as usize].0.iter() {
+            if &kv.0 == arg {
+                return Some(&kv.1);
+            }
+        }
+
+        return None;
+    }
+
+    pub fn remove(&mut self, arg: &String) -> Option<T> {
+        let idx = string_hash(&arg);
+        let len = self.0[idx as usize].0.len();
+        for i in 0..len {
+            if &self
+                .0[idx as usize]
+                .0[i as usize]
+                .0 == arg {
+                    return Some(self.0[idx as usize].0.swap_remove(i).1);
+            }
+        }
+
+        return None;
+    }
+
+    pub fn contains_key(&self, arg: &String) -> bool {
+        let idx = string_hash(arg);
+        for kv in self.0[idx as usize].0.iter() {
+            if &kv.0 == arg {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    pub fn insert(&mut self, k: String, v: T) -> Option<T> {
+        let idx = string_hash(&k);
+        for kv in self.0[idx as usize].0.iter_mut() {
+            if kv.0 == k {
+                let tmp = kv.1.clone();
+                kv.1 = v;
+                return Some(tmp);
+            }
+        }
+
+        self.0[idx as usize].0.push((k, v));
+        return None
+    }
+
+    pub fn iter(&'a self) -> QuickMapIter<'a, T> {
+        QuickMapIter::<'a, T>{
+            buckets: &self.0,
+            bucket_cursor: 0,
+            vec_iter: self.0[0].0.iter(),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct QuickMapIter<'a, T: Clone> {
+    buckets: &'a [Bucket<T>; INDEXED_BUCKETS as usize],
+    bucket_cursor: usize,
+    vec_iter: slice::Iter<'a, (String, T)>,
+}
+
+impl<'a, T: Clone> Iterator for QuickMapIter<'a, T> {
+    type Item = &'a (String, T);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.vec_iter
+            .next()
+            .or_else(|| {
+                self.bucket_cursor += 1;
+                if self.bucket_cursor == INDEXED_BUCKETS as usize{
+                    None
+                } else {
+                    self.vec_iter = self.buckets[self.bucket_cursor].0.iter();
+                    self.next()
+                }
+            })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn add_and_fetch_simple() {
+        let mut q = QuickMap::<u8>::new();
+        q.insert(String::from("test"), 1);
+        assert_eq!(*q.get(&String::from("test")).unwrap(), 1);
+    }
+}
diff --git a/core/src/lex.rs b/core/src/lex.rs
index 4623256..bac40f8 100644
--- a/core/src/lex.rs
+++ b/core/src/lex.rs
@@ -15,6 +15,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 use crate::segment::{Ctr, Seg};
 use crate::error::{Traceback, start_trace};
 use phf::{Map, phf_map};
@@ -67,7 +69,7 @@ fn process(document: &String) -> Result<Box<Seg>, String> {
     let mut is_str = false;
     let mut ign = false;
     let mut token = String::new();
-    let mut delim_stack = Vec::new();
+    let mut delim_stack = vec![];
     let mut ref_stack = vec![];
     let mut cursor = 0;
 
@@ -130,7 +132,6 @@ fn process(document: &String) -> Result<Box<Seg>, String> {
             match c {
                 // add a new Seg reference to the stack
                 '(' if !is_str && token.is_empty() => {
-                    let mut s = Seg::new();
                     ref_stack.push(Seg::new());
                     delim_stack.push(')');
                 }
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 6edb8dc..cf85eea 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -15,7 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-//#![no_std]
+#![cfg_attr(not(test), no_std)]
 
 mod eval;
 mod lex;
@@ -24,6 +24,9 @@ mod stl;
 mod sym;
 mod error;
 
+#[macro_use]
+extern crate alloc;
+
 pub mod ast {
     pub use crate::eval::eval;
     pub use crate::lex::lex;
diff --git a/core/src/segment.rs b/core/src/segment.rs
index 3aea7c8..f4813b7 100644
--- a/core/src/segment.rs
+++ b/core/src/segment.rs
@@ -15,9 +15,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 use crate::sym::UserFn;
-use std::fmt;
-use std::marker::PhantomData;
-use std::ops::{Add, Div, Index, Mul, Sub};
+use alloc::fmt;
+use alloc::string::{String, ToString};
+use alloc::boxed::Box;
+use core::convert;
+use core::marker::PhantomData;
+use core::ops::{Add, Div, Index, Mul, Sub};
 
 // Container
 #[derive(Debug, Default)]
@@ -409,7 +412,7 @@ impl fmt::Display for Type {
     }
 }
 
-impl std::convert::From<String> for Type {
+impl convert::From<String> for Type {
     fn from(value: String) -> Self {
         match value.as_str() {
             "symbol" => Type::Symbol,
diff --git a/core/src/stl.rs b/core/src/stl.rs
index b405842..835a0e9 100644
--- a/core/src/stl.rs
+++ b/core/src/stl.rs
@@ -16,6 +16,7 @@
  */
 
 use crate::sym::SymTable;
+use alloc::string::String;
 
 pub mod append;
 pub mod boolean;
@@ -29,10 +30,10 @@ pub const CFG_FILE_VNAME: &str = "FLESH_CFG_FILE";
 /// static_stdlib
 /// inserts all stdlib functions that can be inserted without
 /// any kind of further configuration data into a symtable
-pub fn static_stdlib(syms: &mut SymTable) {
+pub fn static_stdlib(syms: &mut SymTable, print: fn(&String), read: fn() -> String) {
     append::add_list_lib(syms);
-    strings::add_string_lib(syms);
-    decl::add_decl_lib_static(syms);
+    strings::add_string_lib(syms, print, read);
+    decl::add_decl_lib_static(syms, print);
     control::add_control_lib(syms);
     boolean::add_bool_lib(syms);
     math::add_math_lib(syms);
diff --git a/core/src/stl/append.rs b/core/src/stl/append.rs
index bc9f188..7d79cfd 100644
--- a/core/src/stl/append.rs
+++ b/core/src/stl/append.rs
@@ -18,7 +18,10 @@
 use crate::segment::{Ctr, Seg, Type};
 use crate::sym::{SymTable, Symbol, Args, ValueType};
 use crate::error::{Traceback, start_trace};
-use std::rc::Rc;
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
+
 
 const CONS_DOCSTRING: &str = "traverses any number of arguments collecting them into a list.
 If the first argument is a list, all other arguments are added sequentially to the end of the list contained in the first argument.";
diff --git a/core/src/stl/boolean.rs b/core/src/stl/boolean.rs
index a448f14..93091fa 100644
--- a/core/src/stl/boolean.rs
+++ b/core/src/stl/boolean.rs
@@ -18,7 +18,9 @@
 use crate::segment::{Ctr, Seg, Type};
 use crate::error::{Traceback, start_trace};
 use crate::sym::{SymTable, ValueType, Args, Symbol};
-use std::rc::Rc;
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 
 const AND_DOCSTRING: &str =
     "traverses a list of N arguments, all of which are expected to be boolean.
diff --git a/core/src/stl/control.rs b/core/src/stl/control.rs
index 3db0644..0632bc7 100644
--- a/core/src/stl/control.rs
+++ b/core/src/stl/control.rs
@@ -19,8 +19,9 @@ use crate::eval::eval;
 use crate::error::{Traceback, start_trace};
 use crate::segment::{Ctr, Seg, Type};
 use crate::sym::{SymTable, Symbol, ValueType, Args};
-use std::rc::Rc;
-use std::process;
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 
 const IF_DOCSTRING: &str =
     "accepts three bodies, a condition, an unevaluated consequence, and an alternative consequence.
@@ -397,33 +398,7 @@ fn assert_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
     }
 }
 
-const EXIT_DOCSTRING: &str = "Takes on input: an integer used as an exit code.
-Entire REPL process quits with exit code.";
-fn exit_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
-    if let Ctr::Integer(i) = *ast.car {
-        if i > 2 ^ 32 {
-            panic!("argument to exit too large!")
-        } else {
-            process::exit(i as i32);
-        }
-    } else {
-        panic!("impossible argument to exit")
-    }
-}
-
 pub fn add_control_lib(syms: &mut SymTable) {
-    syms.insert(
-        "exit".to_string(),
-        Symbol {
-            name: String::from("exit"),
-            args: Args::Strict(vec![Type::Integer]),
-            conditional_branches: false,
-            docs: EXIT_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(exit_callback)),
-            ..Default::default()
-        },
-    );
-
     syms.insert(
         "assert".to_string(),
         Symbol {
diff --git a/core/src/stl/decl.rs b/core/src/stl/decl.rs
index 26c020c..81e191b 100644
--- a/core/src/stl/decl.rs
+++ b/core/src/stl/decl.rs
@@ -19,7 +19,9 @@ use crate::eval::eval;
 use crate::error::{Traceback, start_trace};
 use crate::segment::{Ctr, Seg, Type};
 use crate::sym::{SymTable, Symbol, UserFn, ValueType, Args};
-use std::rc::Rc;
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 
 const QUOTE_DOCSTRING: &str = "takes a single unevaluated tree and returns it as it is: unevaluated.";
 fn quote_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
@@ -84,7 +86,7 @@ fn eval_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
 }
 
 const HELP_DOCSTRING: &str = "prints help text for a given symbol. Expects only one argument.";
-fn help_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
+fn help_callback(ast: &Seg, syms: &mut SymTable, print: fn(&String)) -> Result<Ctr, Traceback> {
     if ast.len() != 1 {
         return Err(start_trace(("help", "expected one input").into()));
     }
@@ -96,7 +98,7 @@ fn help_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
             } else {
                 args_str = sym.args.to_string();
             }
-            println!(
+            print(&format!(
                 "NAME: {0}\n
 ARGS: {1}\n
 DOCUMENTATION:\n
@@ -104,7 +106,7 @@ DOCUMENTATION:\n
 CURRENT VALUE AND/OR BODY:
 {3}",
                 sym.name, args_str, sym.docs, sym.value
-            );
+            ));
         } else {
             return Err(start_trace(("help", format!("{symbol} is undefined")).into()));
         }
@@ -129,7 +131,7 @@ fn isset_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
 
 const ENV_DOCSTRING: &str = "takes no arguments
 prints out all available symbols and their associated values";
-fn env_callback(_ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
+fn env_callback(_ast: &Seg, syms: &mut SymTable, print: fn(&String)) -> Result<Ctr, Traceback> {
     let mut functions = vec![];
     let mut variables = vec![];
     for (name, val) in syms.iter() {
@@ -146,13 +148,13 @@ fn env_callback(_ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
         }
     }
 
-    println!("VARIABLES:");
+    print(&String::from("VARIABLES:"));
     for var in variables {
-        println!("{}", var)
+        print(&var)
     }
-    println!("\nFUNCTIONS:");
+    print(&String::from("\nFUNCTIONS:"));
     for func in functions {
-        println!("{}", func);
+        print(&func);
     }
     Ok(Ctr::None)
 }
@@ -414,7 +416,8 @@ pub fn store_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback>
     }
 }
 
-pub fn add_decl_lib_static(syms: &mut SymTable) {
+pub fn add_decl_lib_static(syms: &mut SymTable, print: fn(&String)) {
+    let help_print = print.clone();
     syms.insert(
         "help".to_string(),
         Symbol {
@@ -422,7 +425,11 @@ pub fn add_decl_lib_static(syms: &mut SymTable) {
             args: Args::Strict(vec![Type::Symbol]),
             conditional_branches: true,
             docs: HELP_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(help_callback)),
+            value: ValueType::Internal(Rc::new(
+                move |ast: &Seg, syms: &mut SymTable| -> Result<Ctr, Traceback> {
+                    help_callback(ast, syms, help_print)
+                }
+            )),
             ..Default::default()
         },
     );
@@ -511,6 +518,7 @@ pub fn add_decl_lib_static(syms: &mut SymTable) {
         }
     );
 
+    let env_print = print.clone();
     syms.insert(
         "env".to_string(),
         Symbol {
@@ -518,7 +526,11 @@ pub fn add_decl_lib_static(syms: &mut SymTable) {
             args: Args::None,
             conditional_branches: false,
             docs: ENV_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(env_callback)),
+            value: ValueType::Internal(Rc::new(
+                move |ast: &Seg, syms: &mut SymTable| -> Result<Ctr, Traceback> {
+                    env_callback(ast, syms, env_print)
+                }
+            )),
             ..Default::default()
         },
     );
diff --git a/core/src/stl/math.rs b/core/src/stl/math.rs
index 193d62f..3d0d481 100644
--- a/core/src/stl/math.rs
+++ b/core/src/stl/math.rs
@@ -18,7 +18,12 @@
 use crate::segment::{Ctr, Seg};
 use crate::sym::{SymTable, ValueType, Symbol, Args};
 use crate::error::{Traceback, start_trace};
-use std::rc::Rc;
+
+use libm::pow;
+
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 
 fn isnumeric(arg: &Ctr) -> bool {
     matches!(arg, Ctr::Integer(_) | Ctr::Float(_))
@@ -189,12 +194,7 @@ fn floatcast_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, Traceback> {
 
 const EXP_DOCSTRING: &str = "Takes two args, both expected to be numeric.
 Returns the first arg to the power of the second arg.
-Does not handle overflow or underflow.
-
-PANIC CASES:
-- arg1 is a float and arg2 is greater than an int32
-- an integer exceeding the size of a float64 is raised to a float power
-- an integer is rased to the power of another integer exceeding the max size of an unsigned 32bit integer";
+Does not handle overflow or underflow.";
 fn exp_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, Traceback> {
     let first = *ast.car.clone();
     if !isnumeric(&first) {
@@ -218,15 +218,15 @@ fn exp_callback(ast: &Seg, _: &mut SymTable) -> Result<Ctr, Traceback> {
 
     match first {
         Ctr::Float(lf) => match second {
-            Ctr::Float(rf) => Ok(Ctr::Float(f64::powf(lf, rf))),
-            Ctr::Integer(ri) => Ok(Ctr::Float(f64::powi(lf, ri as i32))),
+            Ctr::Float(rf) => Ok(Ctr::Float(pow(lf, rf))),
+            Ctr::Integer(ri) => Ok(Ctr::Float(pow(lf as f64, ri as f64))),
             _ => Err(start_trace(
                 ("exp", "not implemented for these input types")
                     .into())),
         },
         Ctr::Integer(li) => match second {
-            Ctr::Float(rf) => Ok(Ctr::Float(f64::powf(li as f64, rf))),
-            Ctr::Integer(ri) => Ok(Ctr::Integer(li.pow(ri as u32))),
+            Ctr::Float(rf) => Ok(Ctr::Float(pow(li as f64, rf))),
+            Ctr::Integer(ri) => Ok(Ctr::Float(pow(li as f64, ri as f64))),
             _ => Err(start_trace(
                 ("exp", "not implemented for these input types")
                     .into())),
diff --git a/core/src/stl/strings.rs b/core/src/stl/strings.rs
index fc670fe..6db54a9 100644
--- a/core/src/stl/strings.rs
+++ b/core/src/stl/strings.rs
@@ -18,18 +18,19 @@
 use crate::segment::{Ctr, Seg, Type};
 use crate::sym::{SymTable, Symbol, ValueType, Args};
 use crate::error::{Traceback, start_trace};
-use std::io::Write;
-use std::io;
-use std::rc::Rc;
+use alloc::rc::Rc;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
+
 
 const ECHO_DOCSTRING: &str =
     "traverses any number of arguments. Prints their evaluated values on a new line for each.";
-fn echo_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
+fn echo_callback(ast: &Seg, _syms: &mut SymTable, print_callback: fn(&String)) -> Result<Ctr, Traceback> {
     ast.circuit(&mut |arg: &Ctr| match arg {
-        Ctr::String(s) => print!("{}", s) == (),
-        _ => print!("{}", arg) == (),
+        Ctr::String(s) => print_callback(s) == (),
+        _ => print_callback(&arg.to_string()) == (),
     });
-    println!();
+    print_callback(&String::from("\n"));
     Ok(Ctr::None)
 }
 
@@ -239,13 +240,15 @@ fn split_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
 const INPUT_DOCSTRING: &str = "Takes one argument (string) and prints it.
 Then prompts for user input.
 User input is returned as a string";
-fn input_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
+fn input_callback(
+    ast: &Seg,
+    _syms: &mut SymTable,
+    print_callback: fn(&String),
+    read_callback: fn() -> String,
+) -> Result<Ctr, Traceback> {
     if let Ctr::String(ref s) = *ast.car {
-        print!("{}", s);
-        let _= io::stdout().flush();
-        let mut input = String::new();
-        io::stdin().read_line(&mut input).expect("couldnt read user input");
-        Ok(Ctr::String(input.trim().to_string()))
+        print_callback(s);
+        Ok(Ctr::String(read_callback()))
     } else {
         Err(start_trace(
             ("input", "expected a string input to prompt user with")
@@ -253,7 +256,8 @@ fn input_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
     }
 }
 
-pub fn add_string_lib(syms: &mut SymTable) {
+pub fn add_string_lib(syms: &mut SymTable, print: fn(&String), read: fn() -> String) {
+    let echo_print = print.clone();
     syms.insert(
         "echo".to_string(),
         Symbol {
@@ -261,7 +265,11 @@ pub fn add_string_lib(syms: &mut SymTable) {
             args: Args::Infinite,
             conditional_branches: false,
             docs: ECHO_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(echo_callback)),
+            value: ValueType::Internal(Rc::new(
+                move |ast: &Seg, syms: &mut SymTable| -> Result<Ctr, Traceback> {
+                    echo_callback(ast, syms, echo_print)
+                }
+            )),
             ..Default::default()
         },
     );
@@ -344,6 +352,8 @@ pub fn add_string_lib(syms: &mut SymTable) {
         },
     );
 
+    let input_print = print.clone();
+    let input_read = read.clone();
     syms.insert(
         "input".to_string(),
         Symbol {
@@ -351,7 +361,11 @@ pub fn add_string_lib(syms: &mut SymTable) {
             args: Args::Strict(vec![Type::String]),
             conditional_branches: false,
             docs: INPUT_DOCSTRING.to_string(),
-            value: ValueType::Internal(Rc::new(input_callback)),
+            value: ValueType::Internal(Rc::new(
+                move |ast: &Seg, syms: &mut SymTable| -> Result<Ctr, Traceback> {
+                    input_callback(ast, syms, input_print, input_read)
+                }
+            )),
             ..Default::default()
         }
     );
diff --git a/core/src/sym.rs b/core/src/sym.rs
index 4c480c2..f2925ed 100644
--- a/core/src/sym.rs
+++ b/core/src/sym.rs
@@ -15,15 +15,21 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#[path = "hashmap.rs"]
+mod hashmap;
+use hashmap::{QuickMap, QuickMapIter};
+
 use crate::eval::eval;
 use crate::error::{Traceback, start_trace};
 use crate::segment::{Ctr, Seg, Type};
-use std::collections::HashMap;
-use std::fmt;
-use std::rc::Rc;
+use alloc::fmt;
+use alloc::rc::Rc;
+use alloc::vec::Vec;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
 
 #[derive(Clone)]
-pub struct SymTable(HashMap<String, Symbol>, usize);
+pub struct SymTable(QuickMap<Symbol>, usize);
 
 #[derive(Debug, Clone)]
 pub struct UserFn {
@@ -76,7 +82,7 @@ pub struct Symbol {
 
 impl SymTable {
     pub fn new() -> SymTable {
-        SymTable(HashMap::<String, Symbol>::new(), 0)
+        SymTable(QuickMap::<Symbol>::new(), 0)
     }
 
     pub fn get(&self, arg: &String) -> Option<&Symbol> {
@@ -97,33 +103,30 @@ impl SymTable {
         self.0.remove(arg)
     }
 
-    pub fn iter(&self) -> std::collections::hash_map::Iter<'_, String, Symbol> {
+    pub fn iter(&self) -> QuickMapIter<'_, Symbol>{
         self.0.iter()
     }
 
-    pub fn keys(&self) -> std::collections::hash_map::Keys<String, Symbol> {
-        self.0.keys()
-    }
-
     pub fn update(&mut self, other: &mut SymTable) {
         /* updates self with all syms in other that match the following cases:
          *   * sym is not in self
          *   * sym has a newer generation than the entry in self
+         *
+         *  TODO: Write a method for QuickMap for update in place
+         *  so that none of these need to be reallocated
          */
         let tmp = self.1;
         for i in other.iter() {
-            self.0.entry(i.0.to_string())
-                .and_modify(|inner: &mut Symbol| {
-                    if tmp < i.1.__generation {
-                        inner.__generation = i.1.__generation;
-                        inner.value = i.1.value.clone();
-                        inner.args = i.1.args.clone();
-                        inner.docs = i.1.docs.clone();
-                        inner.conditional_branches = i.1.conditional_branches;
-                        inner.name = i.1.name.clone();
-                    }
-                })
-                .or_insert(i.1.clone());
+            let s = self.0
+                .remove(&i.0)
+                .map_or(
+                    i.1.clone(),
+                    |existing| if tmp < i.1.__generation {
+                        i.1.clone()
+                    } else {
+                        existing
+                    });
+            self.0.insert(i.0.to_string(), s);
         }
     }
 
diff --git a/core/tests/test_eval.rs b/core/tests/test_eval.rs
index 36cc32b..8c449b4 100644
--- a/core/tests/test_eval.rs
+++ b/core/tests/test_eval.rs
@@ -102,7 +102,7 @@ mod eval_tests {
         let rh_doc = "(apply (lambda (x) (car x)) (1 2 3))";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&comparator.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
diff --git a/core/tests/test_lib_append.rs b/core/tests/test_lib_append.rs
index e82471e..10eff02 100644
--- a/core/tests/test_lib_append.rs
+++ b/core/tests/test_lib_append.rs
@@ -7,7 +7,7 @@ mod append_lib_tests {
         let document = "(cons () 1)";
         let result = "(1)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -22,7 +22,7 @@ mod append_lib_tests {
         let result = "(1 \"two\" 3.4)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -37,7 +37,7 @@ mod append_lib_tests {
         let result = "(1 2 3)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -52,7 +52,7 @@ mod append_lib_tests {
         let result = "(<nil>)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -67,7 +67,7 @@ mod append_lib_tests {
         let result = "(\"test\" 1 2 3)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -82,7 +82,7 @@ mod append_lib_tests {
         let result = "0";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -97,7 +97,7 @@ mod append_lib_tests {
         let result = "3";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -111,7 +111,7 @@ mod append_lib_tests {
         let document = "(car ())";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .err()
@@ -130,7 +130,7 @@ mod append_lib_tests {
         let result = "1";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -144,7 +144,7 @@ mod append_lib_tests {
         let document = "(cdr ())";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -164,7 +164,7 @@ mod append_lib_tests {
         let result = "3";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -183,7 +183,7 @@ mod append_lib_tests {
         let result2 = "(2 3)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         let ch1 = lex(&check1.to_string()).unwrap();
@@ -209,7 +209,7 @@ mod append_lib_tests {
         let result2 = "(<nil>)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         let ch1 = lex(&check1.to_string()).unwrap();
@@ -235,7 +235,7 @@ mod append_lib_tests {
         let result2 = "(1 2)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         let ch1 = lex(&check1.to_string()).unwrap();
@@ -261,7 +261,7 @@ mod append_lib_tests {
         let result2 = "(<nil>)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         let ch1 = lex(&check1.to_string()).unwrap();
@@ -284,7 +284,7 @@ mod append_lib_tests {
         let result = "(3 2 1 \"test\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -300,7 +300,7 @@ mod append_lib_tests {
         let result = "(\"test\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -316,7 +316,7 @@ mod append_lib_tests {
         let result = "(<nil>)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -332,7 +332,7 @@ mod append_lib_tests {
         let result = "true";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -348,7 +348,7 @@ mod append_lib_tests {
         let result = "false";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
diff --git a/core/tests/test_lib_bools.rs b/core/tests/test_lib_bools.rs
index c55a4d0..00cdcdd 100644
--- a/core/tests/test_lib_bools.rs
+++ b/core/tests/test_lib_bools.rs
@@ -7,7 +7,7 @@ mod bool_lib_tests {
         let document = "(and true true true true true)";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -21,7 +21,7 @@ mod bool_lib_tests {
         let document = "(and true true false true true)";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -35,7 +35,7 @@ mod bool_lib_tests {
         let document = "(and false false false false false)";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -49,7 +49,7 @@ mod bool_lib_tests {
         let document = "(or true true true true true)";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -63,7 +63,7 @@ mod bool_lib_tests {
         let document = "(or true true false true true)";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -77,7 +77,7 @@ mod bool_lib_tests {
         let document = "(or false false false false false)";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -91,7 +91,7 @@ mod bool_lib_tests {
         let document = "(not true)";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -107,7 +107,7 @@ mod bool_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -145,7 +145,7 @@ mod bool_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -177,7 +177,7 @@ mod bool_lib_tests {
         let check = "(tester \"1\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -206,7 +206,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -221,7 +221,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -236,7 +236,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -251,7 +251,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -266,7 +266,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -281,7 +281,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -296,7 +296,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -311,7 +311,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -326,7 +326,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -341,7 +341,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -356,7 +356,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
@@ -371,7 +371,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(b)
@@ -386,7 +386,7 @@ mod bool_lib_tests {
         let test = lex(&document.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
             assert!(!b)
diff --git a/core/tests/test_lib_control.rs b/core/tests/test_lib_control.rs
index 790466f..6007f93 100644
--- a/core/tests/test_lib_control.rs
+++ b/core/tests/test_lib_control.rs
@@ -6,7 +6,7 @@ mod control_lib_tests {
     fn test_assert_t() {
         let document = "(assert true)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
     }
 
@@ -14,7 +14,7 @@ mod control_lib_tests {
     fn test_assert_f() {
         let document = "(assert false)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert!(eval(&lex(&document.to_string()).unwrap(), &mut syms).is_err())
     }
 
@@ -23,7 +23,7 @@ mod control_lib_tests {
         let document = "(if true 1 2)";
         let result = 1;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -37,7 +37,7 @@ mod control_lib_tests {
         let document = "(if false 1 2)";
         let result = 2;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -51,7 +51,7 @@ mod control_lib_tests {
         let document = "(if true (cons () 1) 2)";
         let result = "(1)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -68,7 +68,7 @@ mod control_lib_tests {
                          temp)";
         let result = "(\"1\" \"2\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -86,7 +86,7 @@ mod control_lib_tests {
         let document2 = "global";
         let result = "(\"hello world\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         eval(&lex(&document1.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
             *eval(&lex(&document2.to_string()).unwrap(), &mut syms)
@@ -101,7 +101,7 @@ mod control_lib_tests {
         let document = "(let ((temp \"1\")) temp (cons () temp \"2\"))";
         let result = "(\"1\" \"2\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -120,7 +120,7 @@ mod control_lib_tests {
 
         let result = "(\"1\" \"2\" \"3\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -148,7 +148,7 @@ mod control_lib_tests {
         let check_tree = lex(&test_check.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&switch_tree, &mut syms).unwrap();
         eval(&while_tree, &mut syms).unwrap();
@@ -174,7 +174,7 @@ mod control_lib_tests {
         let check_tree = lex(&test_check.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&switch_tree, &mut syms).unwrap();
         eval(&while_tree, &mut syms).unwrap();
@@ -200,7 +200,7 @@ mod control_lib_tests {
         let check_tree = lex(&test_check.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&another_tree, &mut syms).unwrap();
         eval(&switch_tree, &mut syms).unwrap();
@@ -217,7 +217,7 @@ mod control_lib_tests {
         let test_tree = lex(&test.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&doc_tree, &mut syms).unwrap();
         let res = eval(&test_tree, &mut syms);
@@ -234,7 +234,7 @@ mod control_lib_tests {
         let test_tree = lex(&test.to_string()).unwrap();
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&doc_tree, &mut syms).unwrap();
         assert_eq!(
diff --git a/core/tests/test_lib_decl.rs b/core/tests/test_lib_decl.rs
index f53051a..f99623c 100644
--- a/core/tests/test_lib_decl.rs
+++ b/core/tests/test_lib_decl.rs
@@ -9,7 +9,7 @@ mod decl_lib_tests {
         let result = "(1)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         let res = *eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -23,7 +23,7 @@ mod decl_lib_tests {
         let result = "((1))";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         let res = *eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -37,7 +37,7 @@ mod decl_lib_tests {
         let result = "1";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         let res = *eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -52,7 +52,7 @@ mod decl_lib_tests {
         let result = "(\"2\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -68,7 +68,7 @@ mod decl_lib_tests {
         let doc3 = "(test)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -95,7 +95,7 @@ mod decl_lib_tests {
         let res2 = "(\"2\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -117,7 +117,7 @@ mod decl_lib_tests {
                            (eq? test \"one\")))";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -135,7 +135,7 @@ mod decl_lib_tests {
         let result = "1";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&doc1.to_string()).unwrap(), &mut syms).unwrap();
         let res = *eval(&lex(&doc2.to_string()).unwrap(), &mut syms).unwrap();
@@ -148,7 +148,7 @@ mod decl_lib_tests {
         let doc2 = "(set? test)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let def_tree = lex(&doc1.to_string()).unwrap();
         let set_tree = lex(&doc2.to_string()).unwrap();
@@ -162,7 +162,7 @@ mod decl_lib_tests {
     fn test_isset_false() {
         let doc = "(set? test)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let set_tree = lex(&doc.to_string()).unwrap();
         if let Ctr::Bool(b) = *eval(&set_tree, &mut syms).unwrap() {
             assert!(!b);
@@ -175,7 +175,7 @@ mod decl_lib_tests {
         let doc2 = "(env)";
         let doc3 = "t";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let set_tree = lex(&doc1.to_string()).unwrap();
         let env_tree = lex(&doc2.to_string()).unwrap();
         let tst_tree = lex(&doc3.to_string()).unwrap();
@@ -189,7 +189,7 @@ mod decl_lib_tests {
         let document = "(quote (add 1 2))";
         let result = "(add 1 2)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -205,7 +205,7 @@ mod decl_lib_tests {
             (eval stored-tree)))";
         let result = "3";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -219,7 +219,7 @@ mod decl_lib_tests {
         let document = "(eval (1 2 3))";
         let result = "(1 2 3)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -232,7 +232,7 @@ mod decl_lib_tests {
     fn test_lambda_str_equivalency_list() {
         let document = "(lambda (x y) (add x y))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -245,7 +245,7 @@ mod decl_lib_tests {
     fn test_lambda_str_equivalency_no_args() {
         let document = "(lambda () (add 1 2))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -258,7 +258,7 @@ mod decl_lib_tests {
     fn test_lambda_inline_call() {
         let document = "((lambda (x y) (add x y)) 1 2)";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let it = *eval(
             &lex(&document.to_string()).unwrap(),
             &mut syms).unwrap();
@@ -274,7 +274,7 @@ mod decl_lib_tests {
         let document = "(let ((adder (lambda (x y) (add x y))))
             (adder 1 2))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
                 let it = *eval(
             &lex(&document.to_string()).unwrap(),
             &mut syms).unwrap();
@@ -291,7 +291,7 @@ mod decl_lib_tests {
             (def adder \"my adder\" (lambda (x y) (add x y)))
             (adder 1 2))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let it = *eval(
             &lex(&document.to_string()).unwrap(),
             &mut syms).unwrap();
@@ -309,7 +309,7 @@ mod decl_lib_tests {
             (def adder \"my adder\" (lambda (x) (add x 1)))
             (appl adder 2))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let it = *eval(
             &lex(&document.to_string()).unwrap(),
             &mut syms).unwrap();
@@ -326,7 +326,7 @@ mod decl_lib_tests {
         let highly_inadvisable = "(set-doc (q help) \"help\")";
         let document = "(get-doc (q help))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let _ = *eval(
             &lex(&highly_inadvisable.to_string()).unwrap(),
             &mut syms).unwrap();
@@ -344,7 +344,7 @@ mod decl_lib_tests {
     fn test_eval_quote() {
         let doc = "(eval (quote (add 1 1)))";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&doc.to_string()).unwrap(), &mut syms).unwrap().to_string(),
             2.to_string()
diff --git a/core/tests/test_lib_math.rs b/core/tests/test_lib_math.rs
index 33e3cba..54dbeff 100644
--- a/core/tests/test_lib_math.rs
+++ b/core/tests/test_lib_math.rs
@@ -1,6 +1,7 @@
 mod math_lib_tests {
     use flesh::ast::{eval, lex, Ctr, SymTable};
     use flesh::stdlib::static_stdlib;
+    use libm::pow;
 
     #[test]
     fn test_add_chain() {
@@ -8,7 +9,7 @@ mod math_lib_tests {
         let result = "10";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -23,7 +24,7 @@ mod math_lib_tests {
         let result = "10.2";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -38,7 +39,7 @@ mod math_lib_tests {
         let result = "24";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -53,7 +54,7 @@ mod math_lib_tests {
         let result = "-8.2";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -68,7 +69,7 @@ mod math_lib_tests {
         let result = "2";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -83,7 +84,7 @@ mod math_lib_tests {
         let result = "10";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -98,7 +99,7 @@ mod math_lib_tests {
         let result = "10";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -113,7 +114,7 @@ mod math_lib_tests {
         let result = "10";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -128,7 +129,7 @@ mod math_lib_tests {
         let result = "10.3";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -140,10 +141,10 @@ mod math_lib_tests {
     #[test]
     fn test_ii_exp() {
         let document = "(exp 7 20)";
-        let result = 7i128.pow(20);
+        let result = pow(7 as f64, 20 as f64);
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -158,7 +159,7 @@ mod math_lib_tests {
         let result = f64::powf(1f64, 10.2);
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -169,26 +170,26 @@ mod math_lib_tests {
 
     #[test]
     fn test_fi_exp() {
-        let document = "(exp 1.2 5)";
-        let result = f64::powf(1.2, 5f64);
+        let document = "(exp 10.2 1)";
+        let result = pow(10.2 as f64, 1 as f64);
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
                 .to_string(),
-            format!("{:.5}", result),
+            result.to_string(),
         );
     }
 
     #[test]
     fn test_ff_exp() {
-        let document = "(exp 1.3 1.5)";
-        let result = f64::powf(1.3, 1.5);
+        let document = "(exp 1.4 1.5)";
+        let result = pow(1.4, 1.5);
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -206,7 +207,7 @@ mod math_lib_tests {
         let result2 = "1";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let _ = *eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
             *eval(&lex(&check1.to_string()).unwrap(), &mut syms)
@@ -229,7 +230,7 @@ mod math_lib_tests {
         let result1 = "2";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let _ = *eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
             *eval(&lex(&check1.to_string()).unwrap(), &mut syms)
@@ -245,7 +246,7 @@ mod math_lib_tests {
         let check1 = "(car test)";
         let result1 = "3";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let _ = *eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
             *eval(&lex(&check1.to_string()).unwrap(), &mut syms)
@@ -262,7 +263,7 @@ mod math_lib_tests {
         let result1 = "2";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let _ = *eval(&lex(&document.to_string()).unwrap(), &mut syms).unwrap();
         assert_eq!(
             *eval(&lex(&check1.to_string()).unwrap(), &mut syms)
@@ -278,7 +279,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -293,7 +294,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -308,7 +309,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -323,7 +324,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -338,7 +339,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -353,7 +354,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -368,7 +369,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -383,7 +384,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -398,7 +399,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -413,7 +414,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -428,7 +429,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -443,7 +444,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -458,7 +459,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -473,7 +474,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -488,7 +489,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -503,7 +504,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -518,7 +519,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -533,7 +534,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -548,7 +549,7 @@ mod math_lib_tests {
         let result = false;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -563,7 +564,7 @@ mod math_lib_tests {
         let result = true;
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -579,7 +580,7 @@ mod math_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -617,7 +618,7 @@ mod math_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -649,7 +650,7 @@ mod math_lib_tests {
         let check = "(tester \"1\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -679,7 +680,7 @@ mod math_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -717,7 +718,7 @@ mod math_lib_tests {
         let check = "(tester)";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
@@ -749,7 +750,7 @@ mod math_lib_tests {
         let check = "(tester \"1\")";
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         let doc_tree = lex(&document.to_string()).unwrap();
         let change_tree = lex(&change.to_string()).unwrap();
diff --git a/core/tests/test_lib_str.rs b/core/tests/test_lib_str.rs
index 98ea328..b8446ba 100644
--- a/core/tests/test_lib_str.rs
+++ b/core/tests/test_lib_str.rs
@@ -7,7 +7,7 @@ mod str_lib_tests {
         let document = "(concat \"test\")";
         let result = "\"test\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -21,7 +21,7 @@ mod str_lib_tests {
         let document = "(concat \"test\" 1 2 3)";
         let result = "\"test123\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -35,7 +35,7 @@ mod str_lib_tests {
         let document = "(concat)";
         let result = "\"\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -49,7 +49,7 @@ mod str_lib_tests {
         let document = "(strlen \"test\")";
         let result = 4;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -63,7 +63,7 @@ mod str_lib_tests {
         let document = "(strlen 1000)";
         let result = 4;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -77,7 +77,7 @@ mod str_lib_tests {
         let document = "(strlen 10.2)";
         let result = 4;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -91,7 +91,7 @@ mod str_lib_tests {
         let document = "(strlen (1 2 3))";
         let result = 7;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -105,7 +105,7 @@ mod str_lib_tests {
         let document = "(strlen true)";
         let result = 4;
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -119,7 +119,7 @@ mod str_lib_tests {
         let document = "(string 4)";
         let result = "\"4\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -133,7 +133,7 @@ mod str_lib_tests {
         let document = "(string (1 2 3))";
         let result = "\"(1 2 3)\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -147,7 +147,7 @@ mod str_lib_tests {
         let document = "(substr? \"bigger\" \"ger\")";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -161,7 +161,7 @@ mod str_lib_tests {
         let document = "(substr? \"smaller\" \"ger\")";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -175,7 +175,7 @@ mod str_lib_tests {
         let document = "(split \"one.two.three\" \".\")";
         let result = "(\"one\" \"two\" \"three\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -189,7 +189,7 @@ mod str_lib_tests {
         let document = "(split \"one:d:two:d:three\" \":d:\")";
         let result = "(\"one\" \"two\" \"three\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -203,7 +203,7 @@ mod str_lib_tests {
         let document = "(split \"one.two.three\" \"-\")";
         let result = "(\"one.two.three\")";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -217,7 +217,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" 0 4)";
         let result = "\"test\"";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
                 .unwrap()
@@ -231,7 +231,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" -1 3)";
         let result = "start index cannot be negative";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let doc_res= eval(&lex(&document.to_string()).unwrap(), &mut syms);
         if let Err(e) = doc_res {
             assert_eq!(
@@ -248,7 +248,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" 1 -3)";
         let result = "end index cannot be negative";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let doc_res= eval(&lex(&document.to_string()).unwrap(), &mut syms);
         if let Err(e) = doc_res {
             assert_eq!(
@@ -265,7 +265,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" 5 3)";
         let result = "start index larger than source string";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let doc_res= eval(&lex(&document.to_string()).unwrap(), &mut syms);
         if let Err(e) = doc_res {
             assert_eq!(
@@ -282,7 +282,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" 1 5)";
         let result = "end index larger than source string";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let doc_res= eval(&lex(&document.to_string()).unwrap(), &mut syms);
         if let Err(e) = doc_res {
             assert_eq!(
@@ -299,7 +299,7 @@ mod str_lib_tests {
         let document = "(substr \"test\" 3 2)";
         let result = "end index must be larger than start index";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         let doc_res= eval(&lex(&document.to_string()).unwrap(), &mut syms);
         if let Err(e) = doc_res {
             assert_eq!(
diff --git a/shell/src/file.rs b/shell/src/file.rs
index 80208db..206d50f 100644
--- a/shell/src/file.rs
+++ b/shell/src/file.rs
@@ -184,7 +184,7 @@ mod tests {
         let document = "(exists? \"/tmp\")";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         static_stdlib_overwrites(&mut syms);
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -199,7 +199,7 @@ mod tests {
         let document = "(exists? \"cargo.timtam\")";
         let result = "false";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         static_stdlib_overwrites(&mut syms);
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -219,7 +219,7 @@ mod tests {
             (eq? (read-file t) s))";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         static_stdlib_overwrites(&mut syms);
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
@@ -240,7 +240,7 @@ mod tests {
                 (concat s s)))";
         let result = "true";
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
         static_stdlib_overwrites(&mut syms);
         assert_eq!(
             *eval(&lex(&document.to_string()).unwrap(), &mut syms)
diff --git a/shell/src/main.rs b/shell/src/main.rs
index 5edc17a..98dd68c 100644
--- a/shell/src/main.rs
+++ b/shell/src/main.rs
@@ -466,11 +466,9 @@ fn make_prompt(syms: &mut SymTable) -> CustomPrompt {
 }
 
 fn make_completer(syms: &mut SymTable) -> CustomCompleter {
-    let mut toks = vec![];
-    for i in syms.keys(){
-        toks.push(i.clone());
-    }
-    CustomCompleter(toks)
+    CustomCompleter(syms.iter()
+        .map(|i| i.0.clone())
+        .collect())
 }
 
 fn get_token_to_complete(line: &str, pos: usize) -> (String, bool, usize) {
diff --git a/shell/src/posix.rs b/shell/src/posix.rs
index c2cd249..a5d022c 100644
--- a/shell/src/posix.rs
+++ b/shell/src/posix.rs
@@ -23,7 +23,7 @@ use {
     },
     crate::run,
     libc::{
-        sigaddset, sigemptyset, sigprocmask, exit,
+        sigaddset, sigemptyset, sigprocmask,
         SIGINT, SIGCHLD, SIGTTOU, SIGTTIN, SIGQUIT, SIGTSTP,
         SIG_BLOCK, SIG_UNBLOCK
     },
@@ -43,6 +43,7 @@ use {
         os::unix::process::CommandExt,
         mem,
         thread,
+        process,
         time::Duration,
     },
     nix::{
@@ -619,19 +620,6 @@ fn q_callback(_ast: &Seg, _syms: &SymTable, state: &mut ShellState) -> Result<Ct
     Ok(Ctr::Integer(state.last_exit_code.into()))
 }
 
-const EXIT_DOCSTRING: &str = "Takes on integer input. calls libc exit() with given argument.";
-fn exit_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
-    let mut ret = -1;
-    if let Ctr::Integer(i) = *ast.car {
-        ret = i;
-    } else {
-        eprintln!("WARNING: input was not an integer. Exiting -1.")
-    }
-    unsafe {
-        exit(ret as i32);
-    }
-}
-
 const BG_DOCSTRING: &str = "Calls a binary off disk with given arguments.
 Arguments may be of any type except lambda. If a symbol is not defined it will be passed as a string.
 first argument (command name) will be found on path (or an error returned).
@@ -780,7 +768,34 @@ fn cd_callback(ast: &Seg, syms: &mut SymTable) -> Result<Ctr, Traceback> {
     }
 }
 
+const EXIT_DOCSTRING: &str = "Takes on input: an integer used as an exit code.
+Entire REPL process quits with exit code.";
+fn exit_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, Traceback> {
+    if let Ctr::Integer(i) = *ast.car {
+        if i > 2 ^ 32 {
+            panic!("argument to exit too large!")
+        } else {
+            process::exit(i as i32);
+        }
+    } else {
+        panic!("impossible argument to exit")
+    }
+}
+
+
 pub fn load_posix_shell(syms: &mut SymTable, shell_state: Rc<RefCell<ShellState>>) {
+    syms.insert(
+        "exit".to_string(),
+        Symbol {
+            name: String::from("exit"),
+            args: Args::Strict(vec![Type::Integer]),
+            conditional_branches: false,
+            docs: EXIT_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(exit_callback)),
+            ..Default::default()
+        },
+    );
+
     let pid = unistd::getpid();
     let pgid_res = unistd::getpgid(Some(pid));
     let sid_res = unistd::getsid(Some(pid));
@@ -986,7 +1001,7 @@ mod tests {
         let result = vec!["binary"];
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ok(ref s) = lex(&document.to_string()) {
             assert_eq!(
@@ -1004,7 +1019,7 @@ mod tests {
         let result = vec!["binary", "--flag=1", "122", "yeet", "true"];
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ok(ref s) = lex(&document.to_string()) {
             assert_eq!(
@@ -1022,7 +1037,7 @@ mod tests {
         let result = vec!["binary", "--flag=1", "122", "yeet", "true", "syms"];
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ok(ref s) = lex(&document.to_string()) {
             assert_eq!(
@@ -1041,7 +1056,7 @@ mod tests {
         let result = vec!["binary", "--flag=1", "122", "yeet", "true", "1"];
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         eval(&lex(&decl.to_string()).unwrap(), &mut syms).unwrap();
 
@@ -1061,7 +1076,7 @@ mod tests {
         let result = vec!["binary", "--flag=1", "122", "yeet", "true", "3"];
 
         let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
+        static_stdlib(&mut syms, |_: &String| (), || String::new());
 
         if let Ok(ref s) = lex(&document.to_string()) {
             assert_eq!(
diff --git a/shell/src/stl.rs b/shell/src/stl.rs
index 8638887..5e83b49 100644
--- a/shell/src/stl.rs
+++ b/shell/src/stl.rs
@@ -25,6 +25,7 @@ use crate::run::{run_callback, RUN_DOCSTRING};
 use std::rc::Rc;
 use std::cell::RefCell;
 use std::env::vars;
+use std::io;
 
 #[cfg(feature = "posix")]
 use crate::posix;
@@ -63,7 +64,16 @@ fn prompt_delimiter_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, T
 /// inserts all stdlib functions that can be inserted without
 /// any kind of further configuration data into a symtable
 pub fn static_stdlib_overwrites(syms: &mut SymTable) {
-    static_stdlib(syms);
+    static_stdlib(
+        syms,
+        |arg: &String| print!("{}", arg),
+        || -> String {
+            let _= io::stdout();
+            let mut input = String::new();
+            io::stdin().read_line(&mut input).expect("couldnt read user input");
+            input.trim().to_string()
+        },
+    );
     window::add_window_lib_funcs(syms);
     file::add_file_lib(syms);