Introduce Ident alias

src/expr.rs

@@ -11,11 +11,11 @@ pub enum Expr {
     Char(char),
     Bool(bool),
 
-    Var(String),
+    Var(Ident),
     Let(Pattern, Box<Expr>, Box<Expr>),
 
     // Functions
-    Func(String, Vec<Expr>),
+    Func(Ident, Vec<Expr>),
     Apply(Box<Expr>, Vec<Expr>),
     Operator(Box<Expr>, Operator, Box<Expr>),
     Closure(SmallVec<[Pattern; 4]>, Box<Expr>),
@@ -34,6 +34,8 @@ pub enum Expr {
     Error(Problem),
 }
 
+type Ident = String;
+
 impl fmt::Display for Expr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {

src/parse.rs

@@ -1,5 +1,5 @@
 use expr::Operator;
-use expr::{Expr, Pattern};
+use expr::{Expr, Pattern, Ident};
 
 use std::char;
 use parse_state::{IndentablePosition};