[sc-524] Change Display impl of Book and Net to include lines bet…

…ween empty defs and indent redexes (HigherOrderCO#90)

Co-authored-by: tjjfvi <[email protected]>

src/ast.rs

@@ -458,8 +458,11 @@ impl FromStr for Tree {
 
 impl fmt::Display for Book {
   fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-    for (name, net) in self.iter() {
-      writeln!(f, "@{name} = {net}")?;
+    for (i, (name, net)) in self.iter().enumerate() {
+      if i != 0 {
+        f.write_str("\n\n")?;
+      }
+      write!(f, "@{name} = {net}")?;
     }
     Ok(())
   }
@@ -469,7 +472,7 @@ impl fmt::Display for Net {
   fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
     write!(f, "{}", &self.root)?;
     for (a, b) in &self.redexes {
-      write!(f, "\n& {a} ~ {b}")?;
+      write!(f, "\n  & {a} ~ {b}")?;
     }
     Ok(())
   }

tests/cli.rs

@@ -126,12 +126,16 @@ fn test_cli_transform() {
     ]).unwrap().1,
     @r###"
   @add = (<+ a b> (a b))
+
   @div = (</ a b> (a b))
+
   @main = ({3 </ a b> <% c d>} ({5 a c} [b d]))
+
   @mod = (<% a b> (a b))
+
   @mul = (<* a b> (a b))
-  @sub = (<- a b> (a b))
 
+  @sub = (<- a b> (a b))
   "###
   );
 
@@ -144,14 +148,18 @@ fn test_cli_transform() {
     ]).unwrap().1,
     @r###"
   @add = (<+ a b> (a b))
+
   @div = (</ a b> (a b))
+
   @main = ({3 a b} ({5 c d} [e f]))
-  & @mod ~ (b (d f))
-  & @div ~ (a (c e))
+    & @mod ~ (b (d f))
+    & @div ~ (a (c e))
+
   @mod = (<% a b> (a b))
+
   @mul = (<* a b> (a b))
-  @sub = (<- a b> (a b))
 
+  @sub = (<- a b> (a b))
   "###
   );
 
@@ -165,8 +173,7 @@ fn test_cli_transform() {
     ]).unwrap().1,
     @r###"
   @main = a
-  & @HVM.log ~ (#1 (#2 a))
-
+    & @HVM.log ~ (#1 (#2 a))
   "###
   );
 }

tests/transform.rs

@@ -78,7 +78,7 @@ pub fn test_eta() {
   assert_display_snapshot!(parse_and_reduce("<+ (a b) (a b)>"), @"<+ a a>");
   assert_display_snapshot!(parse_and_reduce("(a b) & ((a b) (c d)) ~ (c d) "), @r###"
   a
-  & (a c) ~ c
+    & (a c) ~ c
   "###);
   assert_display_snapshot!(parse_and_reduce("((a b) [a b])"), @"((a b) [a b])");
   assert_display_snapshot!(parse_and_reduce("((a b c) b c)"), @"((a b) b)");