Merge #378: Refactor opcode calculations

ae0ce13 Simplify algorithm for opcode counting (sanket1729)
239efd5 Fill in default definitions (sanket1729)

Pull request description:

  - Instead of explicitly counting all opcodes required while satisfaction,
  we explicitly track only additional opcodes while satisfaction and
  dissatisfaction.

  - Removes some unnecessary code around wrapper casting

  Double-checked and compared with the c++ codebase

ACKs for top commit:
  apoelstra:
    ACK ae0ce13

Tree-SHA512: 54f9c0bdd386645b595dc2de27513db15f2377525d7f9ad7899f07d3b434b0e40d9b24db8e87c2411c4d670ad17143f1ef50e490531f08395c136fa0897b986c

Author: sanket1729

src/miniscript/context.rs

@@ -381,7 +381,7 @@ impl ScriptContext for Legacy {
     fn check_local_consensus_validity<Pk: MiniscriptKey>(
         ms: &Miniscript<Pk, Self>,
     ) -> Result<(), ScriptContextError> {
-        match ms.ext.ops_count_sat {
+        match ms.ext.ops.op_count() {
             None => Err(ScriptContextError::MaxOpCountExceeded),
             Some(op_count) if op_count > MAX_OPS_PER_SCRIPT => {
                 Err(ScriptContextError::MaxOpCountExceeded)
@@ -494,7 +494,7 @@ impl ScriptContext for Segwitv0 {
     fn check_local_consensus_validity<Pk: MiniscriptKey>(
         ms: &Miniscript<Pk, Self>,
     ) -> Result<(), ScriptContextError> {
-        match ms.ext.ops_count_sat {
+        match ms.ext.ops.op_count() {
             None => Err(ScriptContextError::MaxOpCountExceeded),
             Some(op_count) if op_count > MAX_OPS_PER_SCRIPT => {
                 Err(ScriptContextError::MaxOpCountExceeded)
@@ -711,7 +711,7 @@ impl ScriptContext for BareCtx {
     fn check_local_consensus_validity<Pk: MiniscriptKey>(
         ms: &Miniscript<Pk, Self>,
     ) -> Result<(), ScriptContextError> {
-        match ms.ext.ops_count_sat {
+        match ms.ext.ops.op_count() {
             None => Err(ScriptContextError::MaxOpCountExceeded),
             Some(op_count) if op_count > MAX_OPS_PER_SCRIPT => {
                 Err(ScriptContextError::MaxOpCountExceeded)

src/miniscript/mod.rs

@@ -584,7 +584,7 @@ mod tests {
                 assert_eq!(format!("{:x}", ms.encode()), expected_hex);
                 assert_eq!(ms.ty.mall.non_malleable, non_mal);
                 assert_eq!(ms.ty.mall.safe, need_sig);
-                assert_eq!(ms.ext.ops_count_sat.unwrap(), ops);
+                assert_eq!(ms.ext.ops.op_count().unwrap(), ops);
             }
             (Err(_), false) => return,
             _ => unreachable!(),