refactor: drop verify IR helpers orphaned by single-roundtrip

readTopology and initialName became unused when the perf commit
threaded a single loadIR result through Verify's builders via the
FromIR variants. Remove both wrapper functions; update the two prose
comments in reach.go and invariant.go that named readTopology.

Signed-off-by: Joshua Temple <joshua.temple@stablekernel.com>

Author: joshua-temple

state/verify/invariant.go

@@ -98,7 +98,7 @@ func NeverActive(s string) Invariant {
 
 // configGraph is the configuration-product view of a machine's IR: the structural
 // information needed to enumerate every reachable configuration of active leaves.
-// It is built from the same serialized public IR readTopology flattens, so a
+// It is built from the same serialized public IR Verify loads once, so a
 // code-built and a JSON-loaded machine explore identically.
 type configGraph struct {
 	// initial is the machine's initial state name; hasInitial guards the empty case.

state/verify/ir.go

@@ -21,19 +21,8 @@ type topology struct {
 	parent map[string]string
 }
 
-// readTopology flattens the machine's IR into a topology. A machine whose IR
-// cannot be read yields the zero topology rather than panicking, matching
-// Verify's no-panic contract.
-func readTopology[S comparable, E comparable, C any](m *state.Machine[S, E, C]) topology {
-	ir, ok := loadIR(m)
-	if !ok {
-		return topology{parent: map[string]string{}}
-	}
-	return topologyFromIR(ir)
-}
-
-// topologyFromIR builds a topology from an already-loaded IR, so a caller that has
-// round-tripped the machine once can reuse it instead of re-serializing.
+// topologyFromIR builds a topology from an already-loaded IR. Verify loads the IR
+// once and passes it here rather than letting each builder re-serialize.
 func topologyFromIR[S comparable, E comparable, C any](ir *state.IR[S, E, C]) topology {
 	t := topology{parent: map[string]string{}}
 	for i := range ir.States {
@@ -59,16 +48,6 @@ func collectStates[S comparable, E comparable, C any](s *state.State[S, E, C], p
 	}
 }
 
-// initialName returns the machine's initial state name, or "" when the machine
-// declares no initial state.
-func initialName[S comparable, E comparable, C any](m *state.Machine[S, E, C]) string {
-	ir, ok := loadIR(m)
-	if !ok {
-		return ""
-	}
-	return initialNameFromIR(ir)
-}
-
 // initialNameFromIR returns the initial state name from an already-loaded IR.
 func initialNameFromIR[S comparable, E comparable, C any](ir *state.IR[S, E, C]) string {
 	if !ir.HasInitial {

state/verify/reach.go

@@ -33,7 +33,7 @@ import (
 
 // searchGraph is the constrained-search view of a machine's IR: the structural
 // edges plus, for each node, the active-configuration members its entry brings
-// online. It is built from the same serialized public IR readTopology flattens,
+// online. It is built from the same serialized public IR Verify loads once,
 // so a code-built and a JSON-loaded machine search identically.
 type searchGraph struct {
 	// initial is the machine's initial state name; hasInitial guards the empty case.