diff --git a/Cargo.toml b/Cargo.toml
index bf5c65e..a659328 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,4 +3,4 @@ resolver = "2"
 members = [
 	"shell",
 	"core"
-]
\ No newline at end of file
+]
diff --git a/core/src/error.rs b/core/src/error.rs
index 8c9609f..02d04be 100644
--- a/core/src/error.rs
+++ b/core/src/error.rs
@@ -29,6 +29,7 @@ pub struct TraceItem {
 #[derive(Debug, Clone)]
 pub struct Traceback(pub Vec<TraceItem>);
 
+#[inline]
 pub fn start_trace(item: TraceItem) -> Traceback {
     Traceback::new().with_trace(item)
 }
diff --git a/core/src/hashmap.rs b/core/src/hashmap.rs
index b192fa2..f88707b 100644
--- a/core/src/hashmap.rs
+++ b/core/src/hashmap.rs
@@ -35,14 +35,15 @@ const INDEXED_BUCKETS: u8 = 199;
  *
  * Not a priority: minimal collisions
  *
- * Just to make sure this is not misused I keep it private
+ * Just to make sure this is not misused I keep it private.
+ * And yes, I am sure a B-Tree would be better.
  */
 #[inline]
 fn string_hash(input: &String) -> u8 {
     input
         .chars()
-        .map(|c| c.to_digit(10)
-             .or_else(|| Some(0))
+        .map(|c| c.to_digit(36) // each letter and number get a digit
+             .or_else(|| Some(0)) // all else is 0
              .unwrap())
         .reduce(|acc, i| (acc + i) % INDEXED_BUCKETS as u32)
         .or_else(|| Some(0))
@@ -151,9 +152,46 @@ mod tests {
     use super::*;
 
     #[test]
-    fn add_and_fetch_simple() {
+    fn add_fetch_and_remove_simple() {
         let mut q = QuickMap::<u8>::new();
+        let key = String::from("test");
         q.insert(String::from("test"), 1);
-        assert_eq!(*q.get(&String::from("test")).unwrap(), 1);
+        assert_eq!(*q.get(&key).unwrap(), 1);
+        assert!(q.contains_key(&key));
+        assert_eq!(
+            q.remove(&key),
+            Some(1),
+        );
+        assert_eq!(q.contains_key(&key), false);
+        assert_eq!(q.get(&key), None);
+    }
+
+    #[test]
+    fn iter_test() {
+        let mut q = QuickMap::<u8>::new();
+        let k1 = String::from("test1");
+        let k2 = String::from("test1@"); // will be in same bucket
+        let k3 = String::from("test2");
+        let k4 = String::from("test2--"); // will be in same bucket
+        q.insert(k1.clone(), 1);
+        q.insert(k2.clone(), 2);
+        q.insert(k3.clone(), 3);
+        q.insert(k4.clone(), 4);
+
+        let mut i = q.iter();
+        let entry1 = i.next().unwrap();
+        let entry2 = i.next().unwrap();
+        let entry3 = i.next().unwrap();
+        let entry4 = i.next().unwrap();
+
+        assert_eq!(i.next(), None);
+        assert_eq!(entry1.0, k1);
+        assert_eq!(entry1.1, 1);
+        assert_eq!(entry2.0, k2);
+        assert_eq!(entry2.1, 2);
+        assert_eq!(entry3.0, k3);
+        assert_eq!(entry3.1, 3);
+        assert_eq!(entry4.0, k4);
+        assert_eq!(entry4.1, 4);
     }
 }
diff --git a/core/src/lex.rs b/core/src/lex.rs
index c8a006b..379e81b 100644
--- a/core/src/lex.rs
+++ b/core/src/lex.rs
@@ -59,6 +59,7 @@ pub fn lex(document: &String) -> Result<Box<Seg>, Traceback> {
  * Returns Ok(Rc<Seg>) if lexing passes
  * Returns Err(String) if an error occurs
  */
+#[inline]
 fn process(document: &String) -> Result<Box<Seg>, String> {
     let doc_len = document.len();
 
@@ -227,6 +228,7 @@ fn process(document: &String) -> Result<Box<Seg>, String> {
  *   - equals is also allowed but only for shell command compatibility
  * else returns false
  */
+#[inline]
 fn tok_is_symbol(token: &str) -> Option<String> {
     for t in token.chars() {
         if !t.is_alphanumeric() &&
diff --git a/core/src/segment.rs b/core/src/segment.rs
index f4813b7..c20360b 100644
--- a/core/src/segment.rs
+++ b/core/src/segment.rs
@@ -185,6 +185,7 @@ impl Seg {
     }
 }
 
+#[inline]
 fn seg_to_string(s: &Seg, parens: bool) -> String {
     let mut string = String::new();
     if parens {
diff --git a/core/src/stl.rs b/core/src/stl.rs
index 835a0e9..60ff67e 100644
--- a/core/src/stl.rs
+++ b/core/src/stl.rs
@@ -30,6 +30,7 @@ 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
+#[inline]
 pub fn static_stdlib(syms: &mut SymTable, print: fn(&String), read: fn() -> String) {
     append::add_list_lib(syms);
     strings::add_string_lib(syms, print, read);