feat(air): introduce explicit types for generation numbers [fixes VM-261]

air/src/execution_step/boxed_value/stream.rs

@@ -20,6 +20,7 @@ use crate::ExecutionError;
 use crate::JValue;
 use crate::UncatchableError;
 
+use air_interpreter_data::GenerationIdx;
 use air_interpreter_data::TracePos;
 use air_trace_handler::merger::ValueSource;
 use air_trace_handler::TraceHandler;
@@ -250,7 +251,7 @@ impl Stream {
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum Generation {
     Last,
-    Nth(u32),
+    Nth(GenerationIdx),
 }
 
 pub(crate) struct StreamIter<'result> {

air/src/execution_step/execution_context/streams_variables.rs

@@ -21,11 +21,13 @@ mod utils;
 use crate::execution_step::ExecutionResult;
 use crate::execution_step::Stream;
 use crate::ExecutionError;
+
 use stream_descriptor::*;
 pub(crate) use stream_value_descriptor::StreamValueDescriptor;
 
 use air_interpreter_data::GlobalStreamGens;
 use air_interpreter_data::RestrictedStreamGens;
+use air_interpreter_data::GenerationIdx;
 use air_parser::ast::Span;
 use air_parser::AirPos;
 use air_trace_handler::TraceHandler;
@@ -194,7 +196,7 @@ impl Streams {
             .copied()
     }
 
-    fn collect_stream_generation(&mut self, name: String, position: AirPos, generation: u32) {
+    fn collect_stream_generation(&mut self, name: String, position: AirPos, generation: GenerationIdx) {
         match self.new_restricted_stream_gens.entry(name) {
             Occupied(mut streams) => match streams.get_mut().entry(position) {
                 Occupied(mut iterations) => iterations.get_mut().push(generation),

crates/air-lib/interpreter-data/src/executed_state.rs

@@ -60,11 +60,14 @@ pub enum CallResult {
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
+
+pub type GenerationIdx = u32;
+
 pub enum ValueRef {
     Scalar(Rc<CID<JValue>>),
     Stream {
         cid: Rc<CID<JValue>>,
-        generation: u32,
+        generation: GenerationIdx,
     },
 }
 

crates/air-lib/interpreter-data/src/executed_state/impls.rs

@@ -48,7 +48,7 @@ impl CallResult {
         CallResult::Executed(value)
     }
 
-    pub fn executed_stream(cid: Rc<CID<JValue>>, generation: u32) -> CallResult {
+    pub fn executed_stream(cid: Rc<CID<JValue>>, generation: GenerationIdx) -> CallResult {
         let value = ValueRef::Stream { cid, generation };
 
         CallResult::Executed(value)
@@ -80,7 +80,7 @@ impl ExecutedState {
 }
 
 impl ApResult {
-    pub fn new(res_generation: u32) -> Self {
+    pub fn new(res_generation: GenerationIdx) -> Self {
         Self {
             res_generations: vec![res_generation],
         }

crates/air-lib/test-utils/src/executed_state.rs

@@ -31,6 +31,7 @@ use crate::SubTraceDesc;
 use air_interpreter_cid::value_to_json_cid;
 use air_interpreter_data::CanonCidAggregate;
 use air_interpreter_data::CidTracker;
+use air_interpreter_data::GenerationIdx;
 use avm_server::SecurityTetraplet;
 use serde::Deserialize;
 use serde::Serialize;
@@ -56,19 +57,19 @@ pub fn scalar_number(result: impl Into<serde_json::Number>) -> ExecutedState {
     scalar(result)
 }
 
-pub fn stream_call_result(result: JValue, generation: u32) -> CallResult {
+pub fn stream_call_result(result: JValue, generation: GenerationIdx) -> CallResult {
     let cid = value_to_json_cid(&result)
         .unwrap_or_else(|e| panic!("{:?}: failed to compute CID of {:?}", e, result));
     CallResult::executed_stream(Rc::new(cid), generation)
 }
 
-pub fn stream(result: JValue, generation: u32) -> ExecutedState {
+pub fn stream(result: JValue, generation: GenerationIdx) -> ExecutedState {
     ExecutedState::Call(stream_call_result(result, generation))
 }
 
 pub fn stream_tracked(
     value: impl Into<JValue>,
-    generation: u32,
+    generation: GenerationIdx,
     tracker: &mut CidTracker,
 ) -> ExecutedState {
     let cid = tracker.record_value(Rc::new(value.into())).unwrap();
@@ -90,19 +91,19 @@ pub fn scalar_string_array(result: Vec<impl Into<String>>) -> ExecutedState {
     scalar(value)
 }
 
-pub fn stream_string(result: impl Into<String>, generation: u32) -> ExecutedState {
+pub fn stream_string(result: impl Into<String>, generation: GenerationIdx) -> ExecutedState {
     let result = JValue::String(result.into());
 
     stream(result, generation)
 }
 
-pub fn stream_number(result: impl Into<serde_json::Number>, generation: u32) -> ExecutedState {
+pub fn stream_number(result: impl Into<serde_json::Number>, generation: GenerationIdx) -> ExecutedState {
     let result = JValue::Number(result.into());
 
     stream(result, generation)
 }
 
-pub fn stream_string_array(result: Vec<impl Into<String>>, generation: u32) -> ExecutedState {
+pub fn stream_string_array(result: Vec<impl Into<String>>, generation: GenerationIdx) -> ExecutedState {
     let result = result
         .into_iter()
         .map(|s| JValue::String(s.into()))
@@ -157,7 +158,7 @@ pub fn subtrace_desc(begin_pos: impl Into<TracePos>, subtrace_len: u32) -> SubTr
     }
 }
 
-pub fn ap(generation: u32) -> ExecutedState {
+pub fn ap(generation: GenerationIdx) -> ExecutedState {
     let ap_result = ApResult::new(generation);
     ExecutedState::Ap(ap_result)
 }

crates/air-lib/trace-handler/src/merger/ap_merger.rs

@@ -30,7 +30,7 @@ pub enum MergerApResult {
 
 #[derive(Debug, Clone)]
 pub struct MetApResult {
-    pub generation: u32,
+    pub generation: GenerationIdx,
     pub value_source: ValueSource,
 }
 
@@ -83,7 +83,7 @@ fn prepare_merge_result(
 }
 
 impl MetApResult {
-    pub(crate) fn new(generation: u32, value_source: ValueSource) -> Self {
+    pub(crate) fn new(generation: GenerationIdx, value_source: ValueSource) -> Self {
         Self {
             generation,
             value_source,