From b25e82ed3696863ce85a9d6fea6989cca267e429 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=BCndler?= <n.muendler@posteo.de>
Date: Fri, 8 Dec 2023 17:51:13 +0100
Subject: [PATCH] Handle errors and format

---
 crates/uplc/src/parser.rs |  5 ++++-
 crates/uplc/src/pretty.rs | 20 +++++++++++---------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/crates/uplc/src/parser.rs b/crates/uplc/src/parser.rs
index 2d00aa9c..2a0d3924 100644
--- a/crates/uplc/src/parser.rs
+++ b/crates/uplc/src/parser.rs
@@ -232,7 +232,10 @@ peg::parser! {
           / "\\\"" { '\"' } // double quote
           / "\\'"  { '\'' } // single quote
           / "\\\\" { '\\' } // backslash
-          / "\\x" i:character() i2:character() { hex::decode([i, i2].iter().collect::<String>()).unwrap()[0].into() }
+          / "\\x" i:character() i2:character() {? match hex::decode([i,i2].iter().collect::<String>()) {
+              Ok(res) => {Ok(res[0].into())},
+              Err(_) => {Err("Invalid hex encoding of escaped byte")},
+          } } // hex encoded byte
           / [ ^ '"' ]
           / expected!("or any valid ascii character")
 
diff --git a/crates/uplc/src/pretty.rs b/crates/uplc/src/pretty.rs
index 140bb0aa..119bb15e 100644
--- a/crates/uplc/src/pretty.rs
+++ b/crates/uplc/src/pretty.rs
@@ -273,15 +273,17 @@ impl Constant {
         match self {
             Constant::Integer(i) => RcDoc::as_string(i),
             Constant::ByteString(bs) => RcDoc::text("#").append(RcDoc::text(hex::encode(bs))),
-            Constant::String(s) => RcDoc::text("\"").append(RcDoc::text(
-                String::from_utf8(
-                    s.as_bytes()
-                        .iter()
-                        .flat_map(|c| escape_default(*c).collect::<Vec<u8>>())
-                        .collect(),
-                )
-                .unwrap(),
-            )) .append(RcDoc::text("\"")),
+            Constant::String(s) => RcDoc::text("\"")
+                .append(RcDoc::text(
+                    String::from_utf8(
+                        s.as_bytes()
+                            .iter()
+                            .flat_map(|c| escape_default(*c).collect::<Vec<u8>>())
+                            .collect(),
+                    )
+                    .unwrap(),
+                ))
+                .append(RcDoc::text("\"")),
             Constant::Unit => RcDoc::text("()"),
             Constant::Bool(b) => RcDoc::text(if *b { "True" } else { "False" }),
             Constant::ProtoList(_, items) => RcDoc::text("[")