diff --git a/docs/builtins.md b/docs/builtins.md
index 122d9873..ee6f4c17 100644
--- a/docs/builtins.md
+++ b/docs/builtins.md
@@ -190,15 +190,15 @@ def Maybe/unwrap(m: Maybe(T)) -> T:
 ## Map
 
 ```python
-type Map:
-  Node { value ~left ~right }
-  Leaf
+type Map(T):
+  Node { value: Maybe(T), ~left: Map(T), ~right: Map(T) }
+  Leaf  
 ```
 
 **`Map`** represents a tree with values stored in the branches.
 It is meant to be used as an efficient map data structure with integer keys and O(log n) read and write operations.
 
-- **Node { value ~left ~right }**: Represents a map node with a `Maybe` and `left` and `right` subtrees. Empty nodes have `Maybe/None` stored in the `value` field, whislt non-empty nodes have `Maybe/Some` stored in the `value` field.
+- **Node { value: Maybe(T), ~left: Map(T), ~right: Map(T) }**: Represents a map node with a `Maybe` and `left` and `right` subtrees. Empty nodes have `Maybe/None` stored in the `value` field, whilst non-empty nodes have `Maybe/Some` stored in the `value` field.
 - **Leaf**: Represents an unwritten, empty portion of the map.
 
 #### Syntax
@@ -241,22 +241,19 @@ Retrieves a `value` from the `map` based on the `key`.
 Returns a tuple with the value and the `map` unchanged.
 
 ```rust
-Map/get map key =
-  match map {
-    Map/Leaf: (*, map)
-    Map/Node:
-      switch _ = (== 0 key) {
-        0: switch _ = (% key 2) {
-          0:
-            let (got, rest) = (Map/get map.left (/ key 2))
-            (got, (Map/Node map.value rest map.right))
-          _:
-            let (got, rest) = (Map/get map.right (/ key 2))
-            (got, (Map/Node map.value map.left rest))
-        }
-        _: (map.value, map)
-      }
-  }
+def Map/get (map: Map(T), key: u24) -> (T, Map(T)):
+  match map:
+    case Map/Leaf:
+      return (unreachable(), map)
+    case Map/Node:
+      if (0 == key):
+        return (Maybe/unwrap(map.value), map)
+      elif (key % 2 == 0):
+        (got, rest) = Map/get(map.left, (key / 2))
+        return(got, Map/Node(map.value, rest, map.right))
+      else:
+        (got, rest) = Map/get(map.right, (key / 2))
+        return(got, Map/Node(map.value, map.left, rest))
 ```
 
 #### Syntax
@@ -281,29 +278,23 @@ And the value resultant from the get function would be:
 
 ### Map/set
 
-Sets a `value` in the `map` at the specified `key`.
-Returns the map with the new value.
-
 ```rust
-Map/set map key value =
-  match map {
-    Map/Node:
-      switch _ = (== 0 key) {
-        0: switch _ = (% key 2) {
-          0: (Map/Node map.value (Map/set map.left (/ key 2) value) map.right)
-          _: (Map/Node map.value map.left (Map/set map.right (/ key 2) value))
-        }
-        _: (Map/Node value map.left map.right)
-      }
-    Map/Leaf:
-      switch _ = (== 0 key) {
-        0: switch _ = (% key 2) {
-          0: (Map/Node * (Map/set Map/Leaf (/ key 2) value) Map/Leaf)
-          _: (Map/Node * Map/Leaf (Map/set Map/Leaf (/ key 2) value))
-        }
-        _: (Map/Node value Map/Leaf Map/Leaf)
-      }
-  }
+def Map/set (map: Map(T), key: u24, value: T) -> Map(T):
+  match map:
+    case Map/Node:
+      if (0 == key):
+        return Map/Node(Maybe/Some(value), map.left, map.right)
+      elif ((key % 2) == 0):
+        return Map/Node(map.value, Map/set(map.left, (key / 2), value), map.right)
+      else:
+        return Map/Node(map.value, map.left, Map/set(map.right, (key / 2), value))
+    case Map/Leaf:
+      if (0 == key):
+        return Map/Node(Maybe/Some(value), Map/Leaf, Map/Leaf)
+      elif ((key % 2) == 0):
+        return Map/Node(Maybe/None, Map/set(Map/Leaf, (key / 2), value), Map/Leaf)
+      else:
+        return Map/Node(Maybe/None, Map/Leaf, Map/set(Map/Leaf, (key / 2),value))
 ```
 
 #### Syntax
@@ -344,17 +335,17 @@ Applies a function to a value in the map.
 Returns the map with the value mapped.
 
 ```rust
-Map/map (Map/Leaf)                  key f = Map/Leaf
-Map/map (Map/Node value left right) key f =
-  switch _ = (== 0 key) {
-    0: switch _ = (% key 2) {
-      0:
-        (Map/Node value (Map/map left (/ key 2) f) right)
-      _:
-        (Map/Node value left (Map/map right (/ key 2) f))
-    }
-    _: (Map/Node (f value) left right)
-  }
+def Map/map (map: Map(T), key: u24, f: T -> T) -> Map(T):
+  match map:
+    case Map/Leaf:
+      return Map/Leaf
+    case Map/Node:
+      if (0 == key):
+        return Map/Node(Maybe/Some(f(Maybe/unwrap(map.value))), map.left, map.right)
+      elif ((key % 2) == 0):
+        return Map/Node(map.value, Map/map(map.left, (key / 2), f), map.right)
+      else:
+        return Map/Node(map.value, map.left, Map/map(map.right, (key / 2), f))
 ```
 
 #### Syntax
@@ -366,6 +357,40 @@ x[0] @= lambda y: String/concat(y, " and mapped")
 # x[0] now contains "swapped and mapped"
 ```
 
+
+### Map/contains
+Checks if a `map` contains a given `key` and returns 0 or 1 as a `u24` number and the `map` unchanged.
+```python
+def Map/contains (map: Map(T), key: u24) -> (u24, Map(T)):
+  match map:
+    case Map/Leaf:
+      return (0, map)
+    case Map/Node:
+      if (0 == key):
+        match map.value:
+          case Maybe/Some:
+            return (1, map)
+          case Maybe/None:
+            return (0, map)
+      elif ((key % 2) == 0):
+        (new_value, new_map) = Map/contains(map.left, (key / 2))
+        return (new_value, Map/Node(map.value, new_map, map.right))
+      else:
+        (new_value, new_map) = Map/contains(map.right, (key / 2))
+        return (new_value, Map/Node(map.value, map.left, new_map))
+```
+
+#### Syntax
+
+With the same map that we `set` in the previous section, we can call the function `Map/contains` explicitly:
+
+```python
+(num, map) = Map/contains(m, key)
+return num
+```
+Whilst the `num` variable will contain 0 or 1 depending on if the key is in the map or not.
+
+
 ## Nat
 
 ```python
diff --git a/examples/example_fun.bend b/examples/example_fun.bend
index dbac0765..8d701be0 100644
--- a/examples/example_fun.bend
+++ b/examples/example_fun.bend
@@ -45,6 +45,7 @@ bad_nums : Any = (+ id 1)
 # Write new data types like this
 type Option = (Some val) | None
 type Bool = True | False
+
 # You can have pattern matching on definitions
 # Use `*` to ignore a pattern
 (Option.unwrap_or (Option/Some val) *) = val
diff --git a/src/fun/builtins.bend b/src/fun/builtins.bend
index 1057308d..8b188bef 100644
--- a/src/fun/builtins.bend
+++ b/src/fun/builtins.bend
@@ -187,7 +187,7 @@ def Maybe/unwrap(m: Maybe(T)) -> T:
 # MAP Impl
 
 type Map(T):
-  Node { value: Maybe(T), ~left: Map(T), ~right: Map(T)}
+  Node { value: Maybe(T), ~left: Map(T), ~right: Map(T) }
   Leaf  
 
 # Creates an empty Map
diff --git a/tests/golden_tests/prelude/applies_function_to_map.bend b/tests/golden_tests/prelude/applies_function_to_map.bend
index 54755588..f069205d 100644
--- a/tests/golden_tests/prelude/applies_function_to_map.bend
+++ b/tests/golden_tests/prelude/applies_function_to_map.bend
@@ -1,13 +1,14 @@
 # Checks if a generic map contains a given key, and if it does, applies a function to the value, otherwise it returns the map
-def test(m: Map(u24), key: u24) -> Map(u24):
+def test(m: Map(u24), key: u24) -> u24:
   def addtwo (x: u24) -> u24:
     return (x + 2)
   (num, map) = Map/contains(m, key)
   if (num == 0):
-    return m
+    return unreachable()
   else:
-    return Map/map(m, key, addtwo())
-
+    m = Map/map(m, key, addtwo())
+    (value, map) = Map/get(m, key)
+    return value
 def main() -> _:
   m = {3: 255}
   return test(m, 3)
diff --git a/tests/golden_tests/prelude/get_values_from_map.bend b/tests/golden_tests/prelude/get_values_from_map.bend
index 8f44d9e6..8694e550 100644
--- a/tests/golden_tests/prelude/get_values_from_map.bend
+++ b/tests/golden_tests/prelude/get_values_from_map.bend
@@ -1,9 +1,9 @@
-def test1() -> (u24, Map(u24)):
+def test1() -> (u24):
   m = {}
   m = Map/set(Map/set(Map/set(Map/empty, 3, 4), 2, 3), 1, 2)
-  (val, map) = Map/get(m, 1) 
-  return Map/get(map, val)
- 
+  (val1, map1) = Map/get(m, 1) 
+  (val2, map2) = Map/get(map1, val1)
+  return val2
 
 def main() -> _:
   return test1()
diff --git a/tests/golden_tests/prelude/map_checked_test.bend b/tests/golden_tests/prelude/map_checked_test.bend
index 68849353..fa522b29 100644
--- a/tests/golden_tests/prelude/map_checked_test.bend
+++ b/tests/golden_tests/prelude/map_checked_test.bend
@@ -1,4 +1,5 @@
+#Tests the get_check function
 def main() -> _:
-  m1 = {0: 42, 1: 7, 2: 13, 3: 255, 4: 100} 
+  m1 = {0: 1, 3: 2} 
   return Map/get_check(m1, 3)
 
diff --git a/tests/golden_tests/prelude/map_contains_test.bend b/tests/golden_tests/prelude/map_contains_test.bend
index 6c2c227e..ca8c6abf 100644
--- a/tests/golden_tests/prelude/map_contains_test.bend
+++ b/tests/golden_tests/prelude/map_contains_test.bend
@@ -1,3 +1,3 @@
 def main() -> _:
-  m1 = {0: 42, 1: 7, 2: 13, 3: 255, 4: 100} 
+  m1 = {0: 23} 
   return Map/contains(m1, 3)
diff --git a/tests/snapshots/prelude__applies_function_to_map.bend.snap b/tests/snapshots/prelude__applies_function_to_map.bend.snap
index a279ced9..e13e58b5 100644
--- a/tests/snapshots/prelude__applies_function_to_map.bend.snap
+++ b/tests/snapshots/prelude__applies_function_to_map.bend.snap
@@ -3,4 +3,4 @@ source: tests/golden_tests.rs
 input_file: tests/golden_tests/prelude/applies_function_to_map.bend
 ---
 Strict mode:
-λa (a Map/Node/tag Maybe/None Map/Leaf λb (b Map/Node/tag Maybe/None Map/Leaf λc (c Map/Node/tag λd (d Maybe/Some/tag 257) Map/Leaf Map/Leaf)))
+257
diff --git a/tests/snapshots/prelude__builtin_Map_tests.bend.snap b/tests/snapshots/prelude__builtin_Map_tests.bend.snap
deleted file mode 100644
index ce31d0b7..00000000
--- a/tests/snapshots/prelude__builtin_Map_tests.bend.snap
+++ /dev/null
@@ -1,6 +0,0 @@
----
-source: tests/golden_tests.rs
-input_file: tests/golden_tests/prelude/builtin_Map_tests.bend
----
-Strict mode:
-((1, 3), (Map/Leaf, (λa (a Map/Node/tag λb (b Maybe/Some/tag 42) λc (c Map/Node/tag Maybe/None λd (d Map/Node/tag Maybe/None Map/Leaf λe (e Map/Node/tag λf (f Maybe/Some/tag 100) Map/Leaf Map/Leaf)) λg (g Map/Node/tag λh (h Maybe/Some/tag 13) Map/Leaf Map/Leaf)) λi (i Map/Node/tag λj (j Maybe/Some/tag 7) Map/Leaf λk (k Map/Node/tag λl (l Maybe/Some/tag 255) Map/Leaf Map/Leaf))), (Bool/False, (λm (m Map/Node/tag λn (n Maybe/Some/tag Nat/Zero) λo (o Map/Node/tag Maybe/None Map/Leaf λp (p Map/Node/tag λq (q Maybe/Some/tag λr (r Nat/Succ/tag λs (s Nat/Succ/tag Nat/Zero))) Map/Leaf Map/Leaf)) λt (t Map/Node/tag λu (u Maybe/Some/tag λv (v Nat/Succ/tag Nat/Zero)) Map/Leaf λw (w Map/Node/tag λx (x Maybe/Some/tag λy (y Nat/Succ/tag λz (z Nat/Succ/tag λab (ab Nat/Succ/tag Nat/Zero)))) Map/Leaf Map/Leaf))), (λbb (bb Map/Node/tag λcb (cb Maybe/Some/tag 42) λdb (db Map/Node/tag Maybe/None λeb (eb Map/Node/tag Maybe/None Map/Leaf λfb (fb Map/Node/tag λgb (gb Maybe/Some/tag λhb (hb 3)) Map/Leaf Map/Leaf)) λib (ib Map/Node/tag λjb (jb Maybe/Some/tag λkb (kb Nat/Succ/tag Nat/Zero)) Map/Leaf Map/Leaf)) λlb (lb Map/Node/tag λmb (mb Maybe/Some/tag Bool/True) λnb (nb Map/Node/tag Maybe/None Map/Leaf λob (ob Map/Node/tag λpb (pb Maybe/Some/tag Nat/Zero) Map/Leaf Map/Leaf)) λqb (qb Map/Node/tag λrb (rb Maybe/Some/tag 255) Map/Leaf Map/Leaf))), (λsb (sb Map/Node/tag Maybe/None λtb (tb Map/Node/tag Maybe/None Map/Leaf λub (ub Map/Node/tag λvb (vb Maybe/Some/tag 13) Map/Leaf Map/Leaf)) λwb (wb Map/Node/tag Maybe/None λxb (xb Map/Node/tag Maybe/None λyb (yb Map/Node/tag Maybe/None Map/Leaf λzb (zb Map/Node/tag λac (ac Maybe/Some/tag 144) Map/Leaf Map/Leaf)) λbc (bc Map/Node/tag λcc (cc Maybe/Some/tag 77) Map/Leaf Map/Leaf)) λdc (dc Map/Node/tag λec (ec Maybe/Some/tag 42) λfc (fc Map/Node/tag Maybe/None Map/Leaf λgc (gc Map/Node/tag λhc (hc Maybe/Some/tag 255) Map/Leaf Map/Leaf)) λic (ic Map/Node/tag λjc (jc Maybe/Some/tag 100) Map/Leaf Map/Leaf)))), λkc (kc Map/Node/tag λlc (lc Maybe/Some/tag 1) λmc (mc Map/Node/tag Maybe/None λnc (nc Map/Node/tag Maybe/None λoc (oc Map/Node/tag Maybe/None Map/Leaf λpc (pc Map/Node/tag λqc (qc Maybe/Some/tag 66) Map/Leaf Map/Leaf)) λrc (rc Map/Node/tag λsc (sc Maybe/Some/tag 36) Map/Leaf Map/Leaf)) λtc (tc Map/Node/tag λuc (uc Maybe/Some/tag 9) Map/Leaf Map/Leaf)) λvc (vc Map/Node/tag λwc (wc Maybe/Some/tag 4) λxc (xc Map/Node/tag Maybe/None Map/Leaf λyc (yc Map/Node/tag λzc (zc Maybe/Some/tag 25) Map/Leaf Map/Leaf)) λad (ad Map/Node/tag λbd (bd Maybe/Some/tag 16) Map/Leaf λcd (cd Map/Node/tag λdd (dd Maybe/Some/tag 49) Map/Leaf Map/Leaf)))))))))))
diff --git a/tests/snapshots/prelude__get_values_from_map.bend.snap b/tests/snapshots/prelude__get_values_from_map.bend.snap
index 166d4279..bfb008ea 100644
--- a/tests/snapshots/prelude__get_values_from_map.bend.snap
+++ b/tests/snapshots/prelude__get_values_from_map.bend.snap
@@ -3,4 +3,4 @@ source: tests/golden_tests.rs
 input_file: tests/golden_tests/prelude/get_values_from_map.bend
 ---
 Strict mode:
-(3, λa (a Map/Node/tag Maybe/None λb (b Map/Node/tag Maybe/None Map/Leaf λc (c Map/Node/tag λd (d Maybe/Some/tag 3) Map/Leaf Map/Leaf)) λe (e Map/Node/tag λf (f Maybe/Some/tag 2) Map/Leaf λg (g Map/Node/tag λh (h Maybe/Some/tag 4) Map/Leaf Map/Leaf))))
+3
diff --git a/tests/snapshots/prelude__map_checked_test.bend.snap b/tests/snapshots/prelude__map_checked_test.bend.snap
index 654f3fc9..c968bc11 100644
--- a/tests/snapshots/prelude__map_checked_test.bend.snap
+++ b/tests/snapshots/prelude__map_checked_test.bend.snap
@@ -3,4 +3,4 @@ source: tests/golden_tests.rs
 input_file: tests/golden_tests/prelude/map_checked_test.bend
 ---
 Strict mode:
-(λa (a Maybe/Some/tag 255), λb (b Map/Node/tag λc (c Maybe/Some/tag 42) λd (d Map/Node/tag Maybe/None λe (e Map/Node/tag Maybe/None Map/Leaf λf (f Map/Node/tag λg (g Maybe/Some/tag 100) Map/Leaf Map/Leaf)) λh (h Map/Node/tag λi (i Maybe/Some/tag 13) Map/Leaf Map/Leaf)) λj (j Map/Node/tag λk (k Maybe/Some/tag 7) Map/Leaf λl (l Map/Node/tag λm (m Maybe/Some/tag 255) Map/Leaf Map/Leaf))))
+(λa (a Maybe/Some/tag 2), λb (b Map/Node/tag λc (c Maybe/Some/tag 1) Map/Leaf λd (d Map/Node/tag Maybe/None Map/Leaf λe (e Map/Node/tag λf (f Maybe/Some/tag 2) Map/Leaf Map/Leaf))))
diff --git a/tests/snapshots/prelude__map_contains_test.bend.snap b/tests/snapshots/prelude__map_contains_test.bend.snap
index acaf0927..8036e853 100644
--- a/tests/snapshots/prelude__map_contains_test.bend.snap
+++ b/tests/snapshots/prelude__map_contains_test.bend.snap
@@ -3,4 +3,4 @@ source: tests/golden_tests.rs
 input_file: tests/golden_tests/prelude/map_contains_test.bend
 ---
 Strict mode:
-(1, λa (a Map/Node/tag λb (b Maybe/Some/tag 42) λc (c Map/Node/tag Maybe/None λd (d Map/Node/tag Maybe/None Map/Leaf λe (e Map/Node/tag λf (f Maybe/Some/tag 100) Map/Leaf Map/Leaf)) λg (g Map/Node/tag λh (h Maybe/Some/tag 13) Map/Leaf Map/Leaf)) λi (i Map/Node/tag λj (j Maybe/Some/tag 7) Map/Leaf λk (k Map/Node/tag λl (l Maybe/Some/tag 255) Map/Leaf Map/Leaf))))
+(0, λa (a Map/Node/tag λb (b Maybe/Some/tag 23) Map/Leaf Map/Leaf))