Add BUILTINS.MD

BUILTINS.md

@@ -0,0 +1,170 @@
+>this is a WIP based on [Builtins.bend](https://github.com/HigherOrderCO/Bend/blob/main/src/fun/builtins.bend).
+
+# Built-in Types and Functions
+**Bend** built-in types and functions, this document serves as a reference guide. Read more at [FEATURES.md](https://github.com/HigherOrderCO/Bend/blob/main/FEATURES.md).
+
+## String
+```python
+data String = (Cons head ~tail) | (Nil)
+```
+
+
+- **Nil**: Represents an empty string.
+- **Cons head ~tail**: Represents a string with a `head` character and a `tail` string.
+
+### Syntax
+A String literal is surrounded with `"`. Accepts the same values as characters literals.
+```
+"Hello, World!"
+```
+
+
+
+
+## List
+```python
+data List = (Cons head ~tail) | (Nil)
+```
+
+- **Nil**: Represents an empty list.
+- **Cons head ~tail**: Represents a list with a `head` element and a `tail` list.
+
+### Syntax
+A List of values can be written using `[ ]`, it can have multiple values inside, using `,` you can divide its value in a list of multiple elements.
+
+```
+["This", "List", "Has", "Multiple", "Values"]
+```
+
+
+
+
+## Nat
+```python
+data Nat = (Succ ~pred) | (Zero)
+```
+- **Succ ~pred**: Represents a natural number successor.
+- **Zero**: Represents the natural number zero.
+
+### Syntax
+A Natural Number can be written with literals with a `#` before the literal number.
+
+```
+#1337
+```
+
+
+
+## Result
+```python
+data Result = (Ok val) | (Err val)
+```
+
+- **Ok val**: Represents a successful result with value `val`.
+- **Err val**: Represents an error with value `val`.
+
+## Map
+```python
+data Map = (Node value ~left ~right) | (Leaf)
+```
+
+- **Node value ~left ~right**: Represents a map node with a `value` and `left` and `right` subtrees.
+- **Leaf**: Represents an empty map.
+
+#### Syntax
+**Bend** has a built-in binary tree map data structure where the key is a `u24`, meaning you can use numbers, characters, and symbols as keys.
+```python
+{ 0: 4, `hi`: "bye", 'c': 2 + 3 }
+```
+
+
+### Map/empty
+Initializes an empty map.
+```python
+Map/empty = Map/Leaf
+```
+
+### Map/get
+Retrieves a `value` from the `map` based on the `key`.
+```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)
+      }
+  }
+```
+
+
+#### Syntax
+Considering the following tree
+```python
+{ 0: "hello", 1: "bye", 2: "maybe", 3: "yes"}
+```
+The `get` function can be written as
+```
+return x[0]  # Gets the value of the key 0
+```
+And the value resultant from the get function would be:
+```
+"hello"
+```
+
+### Map/set
+Sets a `value` in the `map` at the specified `key`.
+```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)
+      }
+  }
+```
+#### Syntax
+Considering the following tree
+```python
+{ 0: "hello", 1: "bye", 2: "maybe", 3: "yes"}
+```
+The `set` function can be written as
+```
+x[0] = "swapped"     # Assigns the key 0 to the value "swapped"
+```
+And the value resultant from the get function would be:
+```
+{ 0: "swapped", 1: "bye", 2: "maybe", 3: "yes"}
+```
+If there's no matching `key` in the tree, it would add a new branch to that tree with the value `set`
+
+```
+x[4] = "added"     # Assigns the key 4 to the value "added"
+```
+The new tree
+```
+{ 0: "swapped", 1: "bye", 2: "maybe", 3: "yes", 4: "added"}
+```
+
+## IO
+IO Functions are in the **next milestone**!

README.md

@@ -152,9 +152,10 @@ Long-distance communication is performed by *global beta-reduction* (as per the
 and synchronized correctly and efficiently by
 [HVM2](https://github.com/HigherOrderCO/HVM)'s *atomic linker*.
 
+
 - To understand the tech behind Bend, check HVM2's [paper](https://paper.higherorderco.com).
 
-- Bend is developed by [HigherOrderCO.com](https://HigherOrderCO.com) - join our [Discord](https://discord.HigherOrderCO.com)!
+- Bend is developed by [HigherOrderCO](https://HigherOrderCO.com) - join our [Discord](https://discord.HigherOrderCO.com)!
 
 ## Note