From c7459a9d095181b6ca91b869f59c93d1ee490b1d Mon Sep 17 00:00:00 2001
From: Tom French <tom@tomfren.ch>
Date: Tue, 28 Nov 2023 16:44:24 +0000
Subject: [PATCH] chore: remove `get_number_sequence` foreign calls

---
 .../brillig_oracle/src/main.nr                | 28 +++++++++++++----
 tooling/nargo/src/ops/foreign_calls.rs        | 31 -------------------
 2 files changed, 22 insertions(+), 37 deletions(-)

diff --git a/test_programs/execution_success/brillig_oracle/src/main.nr b/test_programs/execution_success/brillig_oracle/src/main.nr
index 86cf6ff1498..490b7b605e3 100644
--- a/test_programs/execution_success/brillig_oracle/src/main.nr
+++ b/test_programs/execution_success/brillig_oracle/src/main.nr
@@ -1,25 +1,41 @@
 use dep::std::slice;
+use dep::std::test::OracleMock;
+
 // Tests oracle usage in brillig/unconstrained functions
 fn main(x: Field) {
-    get_number_sequence_wrapper(20);
+    let size = 20;
+    // TODO: Add a method along the lines of `(0..size).to_array()`.
+    let mut mock_oracle_response = [0; 20];
+    // TODO: Add an `array.reverse()` method.
+    let mut reversed_mock_oracle_response = [0; 20];
+    for i in 0..size {
+        mock_oracle_response[i] = i;
+        reversed_mock_oracle_response[19 - i] = i;
+    }
+
+    // TODO: this method of returning a slice feels hacky.
+    let _ = OracleMock::mock("get_number_sequence").with_params(size).returns((20, mock_oracle_response));
+    let _ = OracleMock::mock("get_reverse_number_sequence").with_params(size).returns((20, reversed_mock_oracle_response));
+
+    get_number_sequence_wrapper(size);
 }
-// TODO(#1911): This function does not need to be an oracle but acts 
-// as a useful test while we finalize code generation for slices in Brillig
+
+// Define oracle functions which we have mocked above
 #[oracle(get_number_sequence)]
 unconstrained fn get_number_sequence(_size: Field) -> [Field] {}
-// TODO(#1911)
+
 #[oracle(get_reverse_number_sequence)]
 unconstrained fn get_reverse_number_sequence(_size: Field) -> [Field] {}
 
 unconstrained fn get_number_sequence_wrapper(size: Field) {
     let slice = get_number_sequence(size);
-    for i in 0..19 as u32 {
+    for i in 0..20 as u32 {
         assert(slice[i] == i as Field);
     }
 
     let reversed_slice = get_reverse_number_sequence(size);
     // Regression test that we have not overwritten memory
-    for i in 0..19 as u32 {
+    for i in 0..20 as u32 {
         assert(slice[i] == reversed_slice[19 - i]);
     }
 }
diff --git a/tooling/nargo/src/ops/foreign_calls.rs b/tooling/nargo/src/ops/foreign_calls.rs
index 6cc78febab3..1ca270a5bf7 100644
--- a/tooling/nargo/src/ops/foreign_calls.rs
+++ b/tooling/nargo/src/ops/foreign_calls.rs
@@ -2,7 +2,6 @@ use acvm::{
     acir::brillig::{ForeignCallParam, ForeignCallResult, Value},
     pwg::ForeignCallWaitInfo,
 };
-use iter_extended::vecmap;
 use noirc_printable_type::{decode_string_value, ForeignCallError, PrintableValueDisplay};
 
 pub trait ForeignCallExecutor {
@@ -16,8 +15,6 @@ pub trait ForeignCallExecutor {
 /// After resolution of a foreign call, nargo will restart execution of the ACVM
 pub(crate) enum ForeignCall {
     Println,
-    Sequence,
-    ReverseSequence,
     CreateMock,
     SetMockParams,
     SetMockReturns,
@@ -35,8 +32,6 @@ impl ForeignCall {
     pub(crate) fn name(&self) -> &'static str {
         match self {
             ForeignCall::Println => "println",
-            ForeignCall::Sequence => "get_number_sequence",
-            ForeignCall::ReverseSequence => "get_reverse_number_sequence",
             ForeignCall::CreateMock => "create_mock",
             ForeignCall::SetMockParams => "set_mock_params",
             ForeignCall::SetMockReturns => "set_mock_returns",
@@ -48,8 +43,6 @@ impl ForeignCall {
     pub(crate) fn lookup(op_name: &str) -> Option<ForeignCall> {
         match op_name {
             "println" => Some(ForeignCall::Println),
-            "get_number_sequence" => Some(ForeignCall::Sequence),
-            "get_reverse_number_sequence" => Some(ForeignCall::ReverseSequence),
             "create_mock" => Some(ForeignCall::CreateMock),
             "set_mock_params" => Some(ForeignCall::SetMockParams),
             "set_mock_returns" => Some(ForeignCall::SetMockReturns),
@@ -147,30 +140,6 @@ impl ForeignCallExecutor for DefaultForeignCallExecutor {
                 }
                 Ok(ForeignCallResult { values: vec![] })
             }
-            Some(ForeignCall::Sequence) => {
-                let sequence_length: u128 =
-                    foreign_call.inputs[0].unwrap_value().to_field().to_u128();
-                let sequence = vecmap(0..sequence_length, Value::from);
-
-                Ok(ForeignCallResult {
-                    values: vec![
-                        ForeignCallParam::Single(sequence_length.into()),
-                        ForeignCallParam::Array(sequence),
-                    ],
-                })
-            }
-            Some(ForeignCall::ReverseSequence) => {
-                let sequence_length: u128 =
-                    foreign_call.inputs[0].unwrap_value().to_field().to_u128();
-                let sequence = vecmap((0..sequence_length).rev(), Value::from);
-
-                Ok(ForeignCallResult {
-                    values: vec![
-                        ForeignCallParam::Single(sequence_length.into()),
-                        ForeignCallParam::Array(sequence),
-                    ],
-                })
-            }
             Some(ForeignCall::CreateMock) => {
                 let mock_oracle_name = Self::parse_string(&foreign_call.inputs[0]);
                 assert!(ForeignCall::lookup(&mock_oracle_name).is_none());