Moved AST node enums and functions into their own file.

src/ast.rs

@@ -0,0 +1,47 @@
+use crate::lexer::TokenKind;
+use std::mem;
+
+#[derive(Debug, Clone)]
+pub enum Stmt {
+    VarDecl(String, Box<Expr>),
+    FnDecl(String, Vec<String>, Box<Expr>),
+    Expr(Box<Expr>),
+}
+
+#[derive(Debug, Clone)]
+pub enum Expr {
+    Binary(Box<Expr>, TokenKind, Box<Expr>),
+    Unary(TokenKind, Box<Expr>),
+    Unit(Box<Expr>, TokenKind),
+    Var(String),
+    Group(Box<Expr>),
+    FnCall(String, Vec<Expr>),
+    Literal(String),
+}
+
+#[derive(Debug, Clone)]
+pub enum Unit {
+    Radians,
+    Degrees,
+}
+
+impl TokenKind {
+    pub fn is_unit(&self) -> bool {
+        match self {
+            TokenKind::Deg | TokenKind::Rad => true,
+            _ => false,
+        }
+    }
+
+    pub fn to_unit(&self) -> Result<Unit, String> {
+        match self {
+            TokenKind::Deg => Ok(Unit::Degrees),
+            TokenKind::Rad => Ok(Unit::Radians),
+            _ => Err(String::from("Invalid unit.")),
+        }
+    }
+}
+
+pub fn compare_enums<T>(first: &T, second: &T) -> bool {
+    mem::discriminant(first) == mem::discriminant(second)
+}

src/interpreter.rs

@@ -1,7 +1,5 @@
-use std::mem;
+use crate::ast::{compare_enums, Expr, Stmt, Unit};
-
 use crate::lexer::TokenKind;
-use crate::parser::{Expr, Stmt, Unit};
 use crate::prelude;
 use crate::symbol_table::SymbolTable;
 
@@ -43,23 +41,6 @@ impl<'a> Context<'a> {
     }
 }
 
-impl TokenKind {
-    fn to_unit(&self) -> Result<Unit, String> {
-        match self {
-            TokenKind::Deg => Ok(Unit::Degrees),
-            TokenKind::Rad => Ok(Unit::Radians),
-            _ => Err(String::from("Invalid unit.")),
-        }
-    }
-}
-
-impl Unit {
-    // TODO: Something more generic
-    fn compare(&self, second_token: &Unit) -> bool {
-        mem::discriminant(self) == mem::discriminant(second_token)
-    }
-}
-
 fn eval_stmt(context: &mut Context, stmt: &Stmt) -> Result<f64, String> {
     match stmt {
         Stmt::VarDecl(identifier, _) => eval_var_decl_stmt(context, stmt, identifier),
@@ -125,7 +106,7 @@ fn eval_unit_expr(context: &mut Context, expr: &Expr, kind: &TokenKind) -> Resul
     // Don't do any angle conversions if the defauly angle unit is the same as the unit kind
     match unit {
         Unit::Degrees | Unit::Radians => {
-            if context.angle_unit.compare(&unit) {
+            if compare_enums(&context.angle_unit, &unit) {
                 return x;
             }
         }

src/main.rs

@@ -1,14 +1,15 @@
 use std::{env, process};
 
+mod ast;
 mod interpreter;
 mod lexer;
 mod parser;
 mod prelude;
 mod symbol_table;
-use parser::Unit;
 
 use rustyline::error::ReadlineError;
 use rustyline::Editor;
+use ast::Unit;
 
 fn main() {
     let mut parser = parser::Context::new();

src/parser.rs

@@ -1,35 +1,10 @@
-use std::mem;
-
 use crate::{
+    ast::{compare_enums, Expr, Stmt, Unit},
     interpreter,
     lexer::{Lexer, Token, TokenKind},
     symbol_table::SymbolTable,
 };
 
-#[derive(Debug, Clone)]
-pub enum Stmt {
-    VarDecl(String, Box<Expr>),
-    FnDecl(String, Vec<String>, Box<Expr>),
-    Expr(Box<Expr>),
-}
-
-#[derive(Debug, Clone)]
-pub enum Expr {
-    Binary(Box<Expr>, TokenKind, Box<Expr>),
-    Unary(TokenKind, Box<Expr>),
-    Unit(Box<Expr>, TokenKind),
-    Var(String),
-    Group(Box<Expr>),
-    FnCall(String, Vec<Expr>),
-    Literal(String),
-}
-
-#[derive(Debug, Clone)]
-pub enum Unit {
-    Radians,
-    Degrees,
-}
-
 pub struct Context {
     //angle_unit: Unit,
     tokens: Vec<Token>,
@@ -37,19 +12,6 @@ pub struct Context {
     symbol_table: SymbolTable,
 }
 
-impl TokenKind {
-    pub fn is_unit(&self) -> bool {
-        match self {
-            TokenKind::Deg | TokenKind::Rad => true,
-            _ => false,
-        }
-    }
-
-    pub fn compare(&self, second_token: &TokenKind) -> bool {
-        mem::discriminant(self) == mem::discriminant(second_token)
-    }
-}
-
 impl Context {
     pub fn new() -> Self {
         Context {
@@ -279,7 +241,7 @@ fn match_token(context: &mut Context, kind: TokenKind) -> bool {
         return false;
     }
 
-    peek(context).kind.compare(&kind)
+    compare_enums(&peek(context).kind, &kind)
 }
 
 fn advance<'a>(context: &'a mut Context) -> &'a Token {
@@ -296,5 +258,5 @@ fn consume<'a>(context: &'a mut Context, kind: TokenKind) -> Result<&'a Token, S
 }
 
 fn is_at_end(context: &mut Context) -> bool {
-    context.pos >= context.tokens.len() || peek(context).kind.compare(&TokenKind::EOF)
+    context.pos >= context.tokens.len() || compare_enums(&peek(context).kind, &TokenKind::EOF)
 }

src/prelude.rs

@@ -1,4 +1,3 @@
-use crate::parser::Unit;
 use FuncType::*;
 
 pub const CONSTANTS: &[(&str, &str)] = &[
@@ -11,6 +10,7 @@ pub const CONSTANTS: &[(&str, &str)] = &[
     ("ϕ", "1.61803398"),
 ];
 
+use crate::ast::Unit;
 use funcs::*;
 pub const UNARY_FUNCS: phf::Map<&'static str, UnaryFuncInfo> = phf::phf_map! {
     "cos" => UnaryFuncInfo(cos, Trig),

src/symbol_table.rs

@@ -1,4 +1,4 @@
-use crate::{parser::Stmt, prelude};
+use crate::{ast::Stmt, prelude};
 use std::collections::HashMap;
 
 pub struct SymbolTable {