From 7982488dbfeefa1831deeaa3fb6c52247ff80035 Mon Sep 17 00:00:00 2001
From: Ben Kushigian <ben.kushigian@certora.com>
Date: Tue, 12 Sep 2023 20:52:50 -0700
Subject: [PATCH] added comments, and return slice of generated mutants from
 apply_operators*

---
 src/mutator.rs | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/mutator.rs b/src/mutator.rs
index ba32f98..a281591 100644
--- a/src/mutator.rs
+++ b/src/mutator.rs
@@ -350,7 +350,10 @@ impl Mutator {
         &self.mutants
     }
 
-    pub fn apply_operators_to_expression(&mut self, expr: &Expression) {
+    /// Apply all regular mutation operators to an expression, and add those
+    /// mutants to self.mutants. Return the slice of new mutants
+    pub fn apply_operators_to_expression(&mut self, expr: &Expression) -> &[Mutant] {
+        let num_mutants_at_start = self.mutants.len();
         if expr.loc().try_file_no().is_some() {
             let mut mutants = vec![];
             for op in self.mutation_operators() {
@@ -361,9 +364,13 @@ impl Mutator {
             }
             self.mutants.append(&mut mutants);
         }
+        return &self.mutants[num_mutants_at_start..self.mutants.len()];
     }
 
-    pub fn apply_fallback_operators_to_expression(&mut self, expr: &Expression) {
+    /// Apply all fallback mutation operators to an expression, and add those
+    /// mutants to self.mutants. Return the slice of new mutants
+    pub fn apply_fallback_operators_to_expression(&mut self, expr: &Expression) -> &[Mutant] {
+        let num_mutants_at_start = self.mutants.len();
         if expr.loc().try_file_no().is_some() {
             let mut mutants = vec![];
             for op in self.fallback_mutation_operators() {
@@ -371,9 +378,13 @@ impl Mutator {
             }
             self.mutants.append(&mut mutants);
         }
+        return &self.mutants[num_mutants_at_start..self.mutants.len()];
     }
 
-    pub fn apply_operators_to_statement(&mut self, stmt: &Statement) {
+    /// Apply all regular mutation operators to a statement, and add those
+    /// mutants to self.mutants. Return the slice of new mutants
+    pub fn apply_operators_to_statement(&mut self, stmt: &Statement) -> &[Mutant] {
+        let num_mutants_at_start = self.mutants.len();
         if stmt.loc().try_file_no().is_some() {
             let mut mutants = vec![];
             for op in self.mutation_operators() {
@@ -381,6 +392,7 @@ impl Mutator {
             }
             self.mutants.append(&mut mutants);
         }
+        return &self.mutants[num_mutants_at_start..self.mutants.len()];
     }
 }