From e47bcbe760a04f5c9400ba084de1445f9650c9fd Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg@everydayimshuflin.com>
Date: Fri, 2 Feb 2024 02:39:50 -0800
Subject: [PATCH] More representation work

---
 src/combinators.rs    | 21 ++++++++++++++++++--
 src/map.rs            |  9 ++++++---
 src/representation.rs | 46 ++++++++++++++++++++++++++++++++++++++++---
 src/test/mod.rs       |  3 +++
 4 files changed, 71 insertions(+), 8 deletions(-)

diff --git a/src/combinators.rs b/src/combinators.rs
index 9f8e0fe..5032b90 100644
--- a/src/combinators.rs
+++ b/src/combinators.rs
@@ -104,8 +104,12 @@ where
 
     fn representation(&self) -> Representation {
         let at_least = self.at_least.unwrap_or(0);
-        let at_most = self.at_most.unwrap_or(u32::MAX);
-        let production = EBNF::Repeated(Box::new(self.inner_parser.representation().production()));
+        //TODO flesh this out better
+        let _at_most = self.at_most.unwrap_or(u32::MAX);
+        let production = EBNF::Repeated {
+            inner: Box::new(self.inner_parser.representation().production()),
+            more_than_once: at_least >= 1,
+        };
         Representation::new().with_production(production)
     }
 }
@@ -204,6 +208,19 @@ where
 
         Ok((results, input))
     }
+
+    fn representation(&self) -> Representation {
+        let inner = &self.inner_repeated.inner_parser;
+        let at_least = self.inner_repeated.at_least.unwrap_or(0);
+        let inner_production = inner.representation().production();
+        let delimiter_production = self.delimiter.representation().production();
+
+        let production = EBNF::Repeated {
+            inner: Box::new(EBNF::Sequence(vec![inner_production, delimiter_production])),
+            more_than_once: at_least >= 1,
+        };
+        Representation::new().with_production(production)
+    }
 }
 
 pub fn optional<I, O, E>(parser: impl Parser<I, O, E>) -> impl Parser<I, Option<O>, E>
diff --git a/src/map.rs b/src/map.rs
index 7477308..c4de7ba 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -1,13 +1,16 @@
-use crate::Parser;
+use crate::{representation::Representation, Parser, ParserExtension};
 
 pub fn map<P, F, I, O1, O2, E>(parser: P, map_fn: F) -> impl Parser<I, O2, E>
 where
     P: Parser<I, O1, E>,
     F: Fn(O1) -> O2,
 {
-    move |input| {
+    let production = parser.representation().production();
+    (move |input| {
         parser
             .parse(input)
             .map(|(result, rest)| (map_fn(result), rest))
-    }
+    })
+    .to_anno()
+    .with_repr(Representation::new().with_production(production))
 }
diff --git a/src/representation.rs b/src/representation.rs
index b8f4fba..ce2b90b 100644
--- a/src/representation.rs
+++ b/src/representation.rs
@@ -38,13 +38,33 @@ pub enum EBNF {
     StringTerminal(String),
     LabeledTerminal(String),
     Alternation(Vec<EBNF>),
-    Repeated(Box<EBNF>),
+    Sequence(Vec<EBNF>),
+    Repeated {
+        inner: Box<EBNF>,
+        more_than_once: bool,
+    },
+}
+
+impl EBNF {
+    fn needs_wrapping(&self) -> bool {
+        match self {
+            EBNF::None => false,
+            EBNF::Nonterminal(_) => false,
+            EBNF::CharTerminal(_) => false,
+            EBNF::StringTerminal(_) => false,
+            EBNF::LabeledTerminal(_) => false,
+            EBNF::Sequence(items) => items.len() > 1,
+            EBNF::Alternation(_) => true,
+            EBNF::Repeated { .. } => false,
+        }
+    }
 }
 
 impl fmt::Display for EBNF {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            EBNF::None => write!(f, "none"),
+            //TODO should try to show the name if possible
+            EBNF::None => write!(f, "<no-representation>"),
             EBNF::CharTerminal(ch) => write!(f, "'{ch}'"),
             EBNF::Alternation(items) => {
                 for item in intersperse_option(items.iter()) {
@@ -58,7 +78,27 @@ impl fmt::Display for EBNF {
             EBNF::Nonterminal(name) => write!(f, "{name}"),
             EBNF::StringTerminal(term) => write!(f, r#""{term}""#),
             EBNF::LabeledTerminal(s) => write!(f, "<{s}>"),
-            EBNF::Repeated(inner) => write!(f, "[ {inner} ]"),
+            EBNF::Repeated {
+                inner,
+                more_than_once,
+            } => {
+                let sigil = if *more_than_once { '+' } else { '*' };
+                if inner.needs_wrapping() {
+                    write!(f, "[{inner}]{sigil}")
+                } else {
+                    write!(f, "{inner}{sigil}")
+                }
+            }
+            EBNF::Sequence(items) => {
+                for item in intersperse_option(items.iter()) {
+                    if let Some(item) = item {
+                        write!(f, "{item}")?;
+                    } else {
+                        write!(f, " ")?;
+                    }
+                }
+                write!(f, "")
+            }
         }
     }
 }
diff --git a/src/test/mod.rs b/src/test/mod.rs
index 045f18f..6f4363e 100644
--- a/src/test/mod.rs
+++ b/src/test/mod.rs
@@ -81,11 +81,14 @@ fn test_repeated() {
     let output = parser.parse("bongo bongo     bongo           bongo");
     let output = output.unwrap();
     assert_eq!(output.0, vec!["bongo", "bongo", "bongo", "bongo"]);
+    assert_eq!(parser.representation().show(), r#"["bongo" ' '+]*"#);
 
     let bongos = repeated(literal("bongo"));
     let output = bongos.parse("tra la la").unwrap();
     assert_eq!(output.0.len(), 0);
     assert_eq!(output.1, "tra la la");
+
+    assert_eq!(bongos.representation().show(), r#""bongo"*"#);
 }
 
 #[test]