feat: clean up errors

crates/uplc/src/builtins.rs

@@ -1,3 +1,4 @@
+use flat::de;
 use strum_macros::EnumString;
 
 #[repr(u8)]
@@ -80,6 +81,8 @@ pub enum DefaultFunction {
 }
 
 impl TryFrom<u8> for DefaultFunction {
+    type Error = de::Error;
+
     fn try_from(v: u8) -> Result<Self, Self::Error> {
         match v {
             v if v == DefaultFunction::AddInteger as u8 => Ok(DefaultFunction::AddInteger),
@@ -184,9 +187,7 @@ impl TryFrom<u8> for DefaultFunction {
             v if v == DefaultFunction::MkPairData as u8 => Ok(DefaultFunction::MkPairData),
             v if v == DefaultFunction::MkNilData as u8 => Ok(DefaultFunction::MkNilData),
             v if v == DefaultFunction::MkNilPairData as u8 => Ok(DefaultFunction::MkNilPairData),
-            _ => Err("Default Function not found".to_string()),
+            _ => Err(de::Error::Message("Default Function not found".to_string())),
         }
     }
-
-    type Error = String;
 }

crates/uplc/src/debruijn.rs

@@ -9,7 +9,7 @@ struct Level(usize);
 
 #[derive(Error, Debug)]
 pub enum Error {
-    #[error("Free Unique: `{0}`")]
+    #[error("Free Unique `{0}`")]
     FreeUnique(Unique),
 }
 

crates/uplc/src/flat.rs

@@ -1,8 +1,6 @@
-use anyhow::anyhow;
-
 use flat::{
-    de::{Decode, Decoder},
-    en::{Encode, Encoder},
+    de::{self, Decode, Decoder},
+    en::{self, Encode, Encoder},
     Flat,
 };
 
@@ -16,8 +14,8 @@ const CONST_TAG_WIDTH: u32 = 4;
 const TERM_TAG_WIDTH: u32 = 4;
 
 pub trait Binder<'b>: Encode + Decode<'b> {
-    fn binder_encode(&self, e: &mut Encoder) -> Result<(), String>;
-    fn binder_decode(d: &mut Decoder) -> Result<Self, String>;
+    fn binder_encode(&self, e: &mut Encoder) -> Result<(), en::Error>;
+    fn binder_decode(d: &mut Decoder) -> Result<Self, de::Error>;
 }
 
 impl<'b, T> Flat<'b> for Program<T> where T: Binder<'b> {}
@@ -28,12 +26,12 @@ where
 {
     // convenient so that people don't need to depend on the flat crate
     // directly to call programs flat function
-    pub fn to_flat(&self) -> anyhow::Result<Vec<u8>> {
-        self.flat().map_err(|err| anyhow!("{}", err))
+    pub fn to_flat(&self) -> Result<Vec<u8>, en::Error> {
+        self.flat()
     }
 
-    pub fn flat_hex(&self) -> anyhow::Result<String> {
-        let bytes = self.flat().map_err(|err| anyhow!("{}", err))?;
+    pub fn flat_hex(&self) -> Result<String, en::Error> {
+        let bytes = self.flat()?;
 
         let hex = hex::encode(&bytes);
 
@@ -45,7 +43,7 @@ impl<'b, T> Encode for Program<T>
 where
     T: Binder<'b>,
 {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         let (major, minor, patch) = self.version;
 
         major.encode(e)?;
@@ -62,7 +60,7 @@ impl<'b, T> Decode<'b> for Program<T>
 where
     T: Binder<'b>,
 {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         let version = (usize::decode(d)?, usize::decode(d)?, usize::decode(d)?);
         let term = Term::decode(d)?;
         Ok(Program { version, term })
@@ -73,7 +71,7 @@ impl<'b, T> Encode for Term<T>
 where
     T: Binder<'b>,
 {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         match self {
             Term::Var(name) => {
                 encode_term_tag(0, e)?;
@@ -125,7 +123,7 @@ impl<'b, T> Decode<'b> for Term<T>
 where
     T: Binder<'b>,
 {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         match decode_term_tag(d)? {
             0 => Ok(Term::Var(T::decode(d)?)),
             1 => Ok(Term::Delay(Box::new(Term::decode(d)?))),
@@ -142,13 +140,16 @@ where
             5 => Ok(Term::Force(Box::new(Term::decode(d)?))),
             6 => Ok(Term::Error),
             7 => Ok(Term::Builtin(DefaultFunction::decode(d)?)),
-            x => Err(format!("Unknown term constructor tag: {}", x)),
+            x => Err(de::Error::Message(format!(
+                "Unknown term constructor tag: {}",
+                x
+            ))),
         }
     }
 }
 
 impl Encode for &Constant {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         match self {
             Constant::Integer(i) => {
                 encode_constant(0, e)?;
@@ -182,20 +183,23 @@ impl Encode for &Constant {
 }
 
 impl<'b> Decode<'b> for Constant {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         match decode_constant(d)? {
             0 => Ok(Constant::Integer(isize::decode(d)?)),
             1 => Ok(Constant::ByteString(Vec::<u8>::decode(d)?)),
             2 => Ok(Constant::String(String::decode(d)?)),
             3 => Ok(Constant::Unit),
             4 => Ok(Constant::Bool(bool::decode(d)?)),
-            x => Err(format!("Unknown constant constructor tag: {}", x)),
+            x => Err(de::Error::Message(format!(
+                "Unknown constant constructor tag: {}",
+                x
+            ))),
         }
     }
 }
 
 impl Encode for Unique {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         isize::from(*self).encode(e)?;
 
         Ok(())
@@ -203,13 +207,13 @@ impl Encode for Unique {
 }
 
 impl<'b> Decode<'b> for Unique {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(isize::decode(d)?.into())
     }
 }
 
 impl Encode for Name {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         self.text.encode(e)?;
         self.unique.encode(e)?;
 
@@ -218,7 +222,7 @@ impl Encode for Name {
 }
 
 impl<'b> Decode<'b> for Name {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(Name {
             text: String::decode(d)?,
             unique: Unique::decode(d)?,
@@ -227,19 +231,19 @@ impl<'b> Decode<'b> for Name {
 }
 
 impl<'b> Binder<'b> for Name {
-    fn binder_encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn binder_encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         self.encode(e)?;
 
         Ok(())
     }
 
-    fn binder_decode(d: &mut Decoder) -> Result<Self, String> {
+    fn binder_decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Name::decode(d)
     }
 }
 
 impl Encode for NamedDeBruijn {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         self.text.encode(e)?;
         self.index.encode(e)?;
 
@@ -248,7 +252,7 @@ impl Encode for NamedDeBruijn {
 }
 
 impl<'b> Decode<'b> for NamedDeBruijn {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(NamedDeBruijn {
             text: String::decode(d)?,
             index: DeBruijn::decode(d)?,
@@ -257,13 +261,13 @@ impl<'b> Decode<'b> for NamedDeBruijn {
 }
 
 impl<'b> Binder<'b> for NamedDeBruijn {
-    fn binder_encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn binder_encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         self.text.encode(e)?;
 
         Ok(())
     }
 
-    fn binder_decode(d: &mut Decoder) -> Result<Self, String> {
+    fn binder_decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(NamedDeBruijn {
             text: String::decode(d)?,
             index: DeBruijn::new(0),
@@ -272,7 +276,7 @@ impl<'b> Binder<'b> for NamedDeBruijn {
 }
 
 impl Encode for DeBruijn {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         usize::from(*self).encode(e)?;
 
         Ok(())
@@ -280,23 +284,23 @@ impl Encode for DeBruijn {
 }
 
 impl<'b> Decode<'b> for DeBruijn {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(usize::decode(d)?.into())
     }
 }
 
 impl<'b> Binder<'b> for DeBruijn {
-    fn binder_encode(&self, _: &mut Encoder) -> Result<(), String> {
+    fn binder_encode(&self, _: &mut Encoder) -> Result<(), en::Error> {
         Ok(())
     }
 
-    fn binder_decode(_d: &mut Decoder) -> Result<Self, String> {
+    fn binder_decode(_d: &mut Decoder) -> Result<Self, de::Error> {
         Ok(DeBruijn::new(0))
     }
 }
 
 impl Encode for DefaultFunction {
-    fn encode(&self, e: &mut Encoder) -> Result<(), String> {
+    fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         e.bits(BUILTIN_TAG_WIDTH as i64, self.clone() as u8);
 
         Ok(())
@@ -304,53 +308,55 @@ impl Encode for DefaultFunction {
 }
 
 impl<'b> Decode<'b> for DefaultFunction {
-    fn decode(d: &mut Decoder) -> Result<Self, String> {
+    fn decode(d: &mut Decoder) -> Result<Self, de::Error> {
         let builtin_tag = d.bits8(BUILTIN_TAG_WIDTH as usize)?;
         builtin_tag.try_into()
     }
 }
 
-fn encode_term_tag(tag: u8, e: &mut Encoder) -> Result<(), String> {
+fn encode_term_tag(tag: u8, e: &mut Encoder) -> Result<(), en::Error> {
     safe_encode_bits(TERM_TAG_WIDTH, tag, e)
 }
 
-fn decode_term_tag(d: &mut Decoder) -> Result<u8, String> {
+fn decode_term_tag(d: &mut Decoder) -> Result<u8, de::Error> {
     d.bits8(TERM_TAG_WIDTH as usize)
 }
 
-fn safe_encode_bits(num_bits: u32, byte: u8, e: &mut Encoder) -> Result<(), String> {
+fn safe_encode_bits(num_bits: u32, byte: u8, e: &mut Encoder) -> Result<(), en::Error> {
     if 2_u8.pow(num_bits) < byte {
-        Err(format!(
+        Err(en::Error::Message(format!(
             "Overflow detected, cannot fit {} in {} bits.",
             byte, num_bits
-        ))
+        )))
     } else {
         e.bits(num_bits as i64, byte);
         Ok(())
     }
 }
 
-pub fn encode_constant(tag: u8, e: &mut Encoder) -> Result<(), String> {
-    e.encode_list_with(encode_constant_tag, [tag].to_vec())
+pub fn encode_constant(tag: u8, e: &mut Encoder) -> Result<(), en::Error> {
+    e.encode_list_with([tag].to_vec(), encode_constant_tag)?;
+
+    Ok(())
 }
 
-pub fn decode_constant(d: &mut Decoder) -> Result<u8, String> {
+pub fn decode_constant(d: &mut Decoder) -> Result<u8, de::Error> {
     let u8_list = d.decode_list_with(decode_constant_tag)?;
     if u8_list.len() > 1 {
-        Err(
+        Err(de::Error::Message(
             "Improper encoding on constant tag. Should be list of one item encoded in 4 bits"
                 .to_string(),
-        )
+        ))
     } else {
         Ok(u8_list[0])
     }
 }
 
-pub fn encode_constant_tag(tag: u8, e: &mut Encoder) -> Result<(), String> {
+pub fn encode_constant_tag(tag: u8, e: &mut Encoder) -> Result<(), en::Error> {
     safe_encode_bits(CONST_TAG_WIDTH, tag, e)
 }
 
-pub fn decode_constant_tag(d: &mut Decoder) -> Result<u8, String> {
+pub fn decode_constant_tag(d: &mut Decoder) -> Result<u8, de::Error> {
     d.bits8(CONST_TAG_WIDTH as usize)
 }
 

crates/uplc/src/parser.rs

@@ -1,7 +1,9 @@
 use std::{collections::HashMap, str::FromStr};
 
 use combine::{
-    attempt, between, choice, many1,
+    attempt, between, choice,
+    error::StringStreamError,
+    many1,
     parser::{
         char::{alpha_num, digit, hex_digit, space, spaces, string},
         combinator::no_partial,
@@ -46,18 +48,15 @@ impl ParserState {
     }
 }
 
-pub fn program(src: &str) -> anyhow::Result<Program<Name>> {
+pub fn program(src: &str) -> Result<Program<Name>, StringStreamError> {
     let mut parser = program_();
 
-    let result = parser.parse(state::Stream {
+    let (program, _) = parser.parse(state::Stream {
         stream: position::Stream::new(src.trim()),
         state: ParserState::new(),
-    });
+    })?;
 
-    match result {
-        Ok((program, _)) => Ok(program),
-        Err(err) => Err(anyhow::anyhow!("{}", err)),
-    }
+    Ok(program)
 }
 
 fn program_<Input>() -> impl Parser<StateStream<Input>, Output = Program<Name>>