From 49badc37a41039e98cad7b93d7e9ba09747b0e91 Mon Sep 17 00:00:00 2001
From: Dane Johnson <daneallenjohnson@protonmail.com>
Date: Tue, 1 Feb 2022 10:57:04 -0600
Subject: [PATCH] Blocks are a kind of expression now

---
 rust/src/parser.rs | 41 ++++++++++++++++-------------------------
 1 file changed, 16 insertions(+), 25 deletions(-)

diff --git a/rust/src/parser.rs b/rust/src/parser.rs
index 52b5ffd..06a48db 100644
--- a/rust/src/parser.rs
+++ b/rust/src/parser.rs
@@ -9,16 +9,11 @@ pub enum Expr<'a> {
     Id(&'a str),
     Num(f64),
     Funcall(&'a str, Vec<Expr<'a>>),
-    Funcdef(Option<&'a str>, Fun<'a>),
+    Funcdef(Option<&'a str>, Box<Expr<'a>>),
     Plus(Box<Expr<'a>>, Box<Expr<'a>>),
     Minus(Box<Expr<'a>>, Box<Expr<'a>>),
     Mult(Box<Expr<'a>>, Box<Expr<'a>>),
     Div(Box<Expr<'a>>, Box<Expr<'a>>),
-}
-
-#[derive(Debug,PartialEq)]
-pub enum Fun<'a> {
-    Oner(Box<Expr<'a>>),
     Block(Vec<Stmt<'a>>),
 }
 
@@ -42,6 +37,8 @@ peg::parser! {
             i:id() _ { Expr::Id(i) }
             n:num() _ { Expr::Num(n) }
         }
+        rule block() -> Expr<'input>
+            = stop() indent() __* s:stmt()+ dedent() { Expr::Block(s) }
 
         rule id() -> &'input str
             = i:$(letter() (letter() / digit() / ['?'|'.'|'-'])*) _ { i }
@@ -50,8 +47,8 @@ peg::parser! {
         rule funcall() -> Expr<'input>
             = i:id() "(" _ e:(expr() ** ("," _)) ")" _ { Expr::Funcall(i, e) }
         rule funcdef() -> Expr<'input>
-            = i:id()? "->" _ e:expr() { Expr::Funcdef(i, Fun::Oner(Box::new(e))) } /
-              i:id()? "->" _ stop() indent() __* s:stmt()+ dedent() { Expr::Funcdef(i, Fun::Block(s)) }
+            = i:id()? "->" _ e:expr() { Expr::Funcdef(i, Box::new(e)) } /
+              i:id()? "->" _ b:block() { Expr::Funcdef(i, Box::new(b)) }
 
         rule letter()
             = ['A'..='Z'] / ['a'..='z']
@@ -139,7 +136,7 @@ four <- (3 - 1) * 2";
             Stmt::Assignment("four",
                              Expr::Mult(
                                  Box::new(Expr::Minus(
-                                     Box::new(Expr::Num(3.0)),
+                                      Box::new(Expr::Num(3.0)),
                                      Box::new(Expr::Num(1.0)),
                                  )),
                                  Box::new(Expr::Num(2.0)),
@@ -179,36 +176,30 @@ foo <- x -> y -> x * y";
                 "foo",
                 Expr::Funcdef(
                     None,
-                    Fun::Oner(
-                        Box::new(Expr::Funcall("bar", vec![])),
-                    )
+                    Box::new(Expr::Funcall("bar", vec![])),
                 )
             ),
             Stmt::Assignment(
                 "foo",
                 Expr::Funcdef(
                     None,
-                    Fun::Block(vec![
+                    Box::new(Expr::Block(vec![
                         Stmt::Funcall(Expr::Funcall("bar", vec![])),
                         Stmt::Funcall(Expr::Funcall("baz", vec![])),
-                    ])
+                    ]))
                 )
             ),
             Stmt::Assignment(
                 "foo",
                 Expr::Funcdef(
                     Some("x"),
-                    Fun::Oner(
-                        Box::new(
-                            Expr::Funcdef(
-                                Some("y"),
-                                Fun::Oner(
-                                    Box::new(
-                                        Expr::Mult(
-                                            Box::new(Expr::Id("x")),
-                                            Box::new(Expr::Id("y")),
-                                        )
-                                    )
+                    Box::new(
+                        Expr::Funcdef(
+                            Some("y"),
+                            Box::new(
+                                Expr::Mult(
+                                    Box::new(Expr::Id("x")),
+                                    Box::new(Expr::Id("y")),
                                 )
                             )
                         )