From 36e1bf722a3d366cea20ab7315d63d588d23dc48 Mon Sep 17 00:00:00 2001
From: Dominick Allen <dominick.allen1989@gmail.com>
Date: Sat, 20 Jun 2020 13:38:03 -0500
Subject: Working on a simple LISP/scheme interpreter.

---
 src/lib/types.rs | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 src/lib/types.rs

(limited to 'src/lib/types.rs')

diff --git a/src/lib/types.rs b/src/lib/types.rs
new file mode 100644
index 0000000..4c2900a
--- /dev/null
+++ b/src/lib/types.rs
@@ -0,0 +1,97 @@
+use std::str::FromStr;
+
+#[derive(PartialEq, Debug, Clone, Copy)]
+pub enum Op {
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Modulo,
+    Equals,
+    Greater,
+    GrEqTo,
+    Less,
+    LsEqTo,
+    Define,
+}
+
+impl FromStr for Op {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "+" => Ok(Op::Add),
+            "-" => Ok(Op::Sub),
+            "*" => Ok(Op::Mul),
+            "/" => Ok(Op::Div),
+            "%" => Ok(Op::Modulo),
+            "=" => Ok(Op::Equals),
+            ">" => Ok(Op::Greater),
+            ">=" => Ok(Op::GrEqTo),
+            "<" => Ok(Op::Less),
+            "<=" => Ok(Op::LsEqTo),
+            "define" => Ok(Op::Define),
+            x => Err(format!("{} is not an operator", x))
+        }
+    }
+}
+
+#[derive(PartialEq, Debug, Clone)]
+pub enum Number {
+    Int(isize),
+    Float(f32)
+}
+
+#[derive(PartialEq, Debug, Clone)]
+pub enum Type {
+    Bool(bool),
+    Number(Number),
+    Str(String),
+    Symbol(String),
+    Operator(Op),
+}
+
+#[derive(PartialEq, Debug)]
+pub enum SEXP {
+    Atom(Type),
+    Sexpr(Vec<SEXP>)
+}
+
+#[test]
+fn construct() {
+    let atom1 = SEXP::Atom(Type::Number(Number::Int(1)));
+    let atom2 = SEXP::Atom(Type::Number(Number::Int(2)));
+    let atom3 = SEXP::Atom(Type::Number(Number::Int(3)));
+    let atom4 = SEXP::Atom(Type::Number(Number::Int(4)));
+    let sexp = SEXP::Sexpr(vec!(atom1, atom2, atom3, atom4));
+    match sexp {
+        SEXP::Sexpr(ref x) => {
+            assert_eq!(x[0], SEXP::Atom(Type::Number(Number::Int(1))));
+        },
+        _ => panic!("What")
+    }
+}
+
+#[test]
+fn mutability() {
+    let atom1 = SEXP::Atom(Type::Number(Number::Int(1)));
+    let atom2 = SEXP::Atom(Type::Number(Number::Int(2)));
+    let atom3 = SEXP::Atom(Type::Number(Number::Int(3)));
+    let atom4 = SEXP::Atom(Type::Number(Number::Int(4)));
+    let mut sexp = SEXP::Sexpr(vec!(atom1, atom2, atom3, atom4));
+    match sexp {
+        SEXP::Sexpr(ref mut x) => match x[0] {
+            SEXP::Atom(Type::Number(Number::Int(ref mut x))) => *x += 7,
+            _ => panic!("What")
+        },
+        _ => panic!("What")
+    }
+
+    match sexp {
+        SEXP::Sexpr(ref x) => {
+            assert_eq!(x[0], SEXP::Atom(Type::Number(Number::Int(8))));
+        },
+        _ => panic!("What")
+    }
+}
+
-- 
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