fix: fixed edge cases to get flat encode and decode working with stress test case

crates/cli/src/main.rs

@@ -36,7 +36,9 @@ fn main() -> anyhow::Result<()> {
 
                 let program = Program::<FakeNamedDeBruijn>::from_flat(&bytes)?;
 
-                println!("{:#?}", program);
+                let encoded_flat = program.to_flat()?;
+                println!("{}", encoded_flat.len());
+                assert!(bytes == encoded_flat)
             }
         },
     }

crates/flat/src/decode/decoder.rs

@@ -2,10 +2,11 @@ use crate::{decode::Decode, zigzag};
 
 use super::Error;
 
+#[derive(Debug)]
 pub struct Decoder<'b> {
-    buffer: &'b [u8],
+    pub buffer: &'b [u8],
-    used_bits: i64,
+    pub used_bits: i64,
-    pos: usize,
+    pub pos: usize,
 }
 
 impl<'b> Decoder<'b> {
@@ -71,7 +72,7 @@ impl<'b> Decoder<'b> {
         let mut final_word: usize = 0;
         let mut shl: usize = 0;
         // continue looping if lead bit is 1 otherwise exit
-        while leading_bit == 1 {
+        while leading_bit > 0 {
             let word8 = self.bits8(8)?;
             let word7 = word8 & 127;
             final_word |= (word7 as usize) << shl;
@@ -134,6 +135,7 @@ impl<'b> Decoder<'b> {
 
             blk_len = self.buffer[self.pos];
         }
+        self.pos += 1;
 
         Ok(blk_array)
     }

crates/flat/src/encode/encoder.rs

@@ -102,16 +102,17 @@ impl Encoder {
     }
 
     pub fn word(&mut self, c: usize) -> &mut Self {
+        let mut d = c;
         loop {
-            let mut w = (c & 127) as u8;
+            let mut w = (d & 127) as u8;
-            let c = c >> 7;
+            d >>= 7;
 
-            if c != 0 {
+            if d != 0 {
                 w |= 128;
             }
             self.bits(8, w);
 
-            if c == 0 {
+            if d == 0 {
                 break;
             }
         }

crates/uplc/src/builtins.rs

@@ -32,52 +32,52 @@ pub enum DefaultFunction {
     Sha3_256 = 19,
     Blake2b_256 = 20,
     VerifySignature = 21,
-    VerifyEcdsaSecp256k1Signature = 22,
+    VerifyEcdsaSecp256k1Signature = 52,
-    VerifySchnorrSecp256k1Signature = 23,
+    VerifySchnorrSecp256k1Signature = 53,
     // String functions
-    AppendString = 24,
+    AppendString = 22,
-    EqualsString = 25,
+    EqualsString = 23,
-    EncodeUtf8 = 26,
+    EncodeUtf8 = 24,
-    DecodeUtf8 = 27,
+    DecodeUtf8 = 25,
     // Bool function
-    IfThenElse = 28,
+    IfThenElse = 26,
     // Unit function
-    ChooseUnit = 29,
+    ChooseUnit = 27,
     // Tracing function
-    Trace = 30,
+    Trace = 28,
     // Pairs functions
-    FstPair = 31,
+    FstPair = 29,
-    SndPair = 32,
+    SndPair = 30,
     // List functions
-    ChooseList = 33,
+    ChooseList = 31,
-    MkCons = 34,
+    MkCons = 32,
-    HeadList = 35,
+    HeadList = 33,
-    TailList = 36,
+    TailList = 34,
-    NullList = 37,
+    NullList = 35,
     // Data functions
     // It is convenient to have a "choosing" function for a data type that has more than two
     // constructors to get pattern matching over it and we may end up having multiple such data
     // types, hence we include the name of the data type as a suffix.
-    ChooseData = 38,
+    ChooseData = 36,
-    ConstrData = 39,
+    ConstrData = 37,
-    MapData = 40,
+    MapData = 38,
-    ListData = 41,
+    ListData = 39,
-    IData = 42,
+    IData = 40,
-    BData = 43,
+    BData = 41,
-    UnConstrData = 44,
+    UnConstrData = 42,
-    UnMapData = 45,
+    UnMapData = 43,
-    UnListData = 46,
+    UnListData = 44,
-    UnIData = 47,
+    UnIData = 45,
-    UnBData = 48,
+    UnBData = 46,
-    EqualsData = 49,
+    EqualsData = 47,
-    SerialiseData = 50,
+    SerialiseData = 51,
     // Misc constructors
     // Constructors that we need for constructing e.g. Data. Polymorphic builtin
     // constructors are often problematic (See note [Representable built-in
     // functions over polymorphic built-in types])
-    MkPairData = 51,
+    MkPairData = 48,
-    MkNilData = 52,
+    MkNilData = 49,
-    MkNilPairData = 53,
+    MkNilPairData = 50,
 }
 
 impl TryFrom<u8> for DefaultFunction {

crates/uplc/src/flat.rs

@@ -1,3 +1,5 @@
+use std::fmt::Debug;
+
 use flat::{
     de::{self, Decode, Decoder},
     en::{self, Encode, Encoder},
@@ -18,11 +20,11 @@ pub trait Binder<'b>: Encode + Decode<'b> {
     fn binder_decode(d: &mut Decoder) -> Result<Self, de::Error>;
 }
 
-impl<'b, T> Flat<'b> for Program<T> where T: Binder<'b> {}
+impl<'b, T> Flat<'b> for Program<T> where T: Binder<'b> + Debug {}
 
 impl<'b, T> Program<T>
 where
-    T: Binder<'b>,
+    T: Binder<'b> + Debug,
 {
     // convenient so that people don't need to depend on the flat crate
     // directly to call programs flat function
@@ -45,7 +47,7 @@ where
 
 impl<'b, T> Encode for Program<T>
 where
-    T: Binder<'b>,
+    T: Binder<'b> + Debug,
 {
     fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         let (major, minor, patch) = self.version;
@@ -73,7 +75,7 @@ where
 
 impl<'b, T> Encode for Term<T>
 where
-    T: Binder<'b>,
+    T: Binder<'b> + Debug,
 {
     fn encode(&self, e: &mut Encoder) -> Result<(), en::Error> {
         match self {