From dd3d0a188efbfa9523e2bea13c3a4316310940c9 Mon Sep 17 00:00:00 2001
From: Folkert <folkert@folkertdev.nl>
Date: Sun, 23 Apr 2023 18:16:08 +0200
Subject: [PATCH] string is empty for dev backend

---
 crates/compiler/builtins/bitcode/src/main.zig | 2 ++
 crates/compiler/builtins/bitcode/src/str.zig  | 4 ++++
 crates/compiler/builtins/src/bitcode.rs       | 1 +
 crates/compiler/gen_dev/src/lib.rs            | 4 ++++
 crates/compiler/test_gen/src/gen_str.rs       | 8 ++++----
 5 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/crates/compiler/builtins/bitcode/src/main.zig b/crates/compiler/builtins/bitcode/src/main.zig
index 6f0b59468d..9c871ccad1 100644
--- a/crates/compiler/builtins/bitcode/src/main.zig
+++ b/crates/compiler/builtins/bitcode/src/main.zig
@@ -133,6 +133,8 @@ comptime {
     exportStrFn(str.countSegments, "count_segments");
     exportStrFn(str.countGraphemeClusters, "count_grapheme_clusters");
     exportStrFn(str.countUtf8Bytes, "count_utf8_bytes");
+    exportStrFn(str.isEmpty, "is_empty");
+
     exportStrFn(str.getCapacity, "capacity");
     exportStrFn(str.startsWith, "starts_with");
     exportStrFn(str.startsWithScalar, "starts_with_scalar");
diff --git a/crates/compiler/builtins/bitcode/src/str.zig b/crates/compiler/builtins/bitcode/src/str.zig
index ea57a934e1..fc20537c5d 100644
--- a/crates/compiler/builtins/bitcode/src/str.zig
+++ b/crates/compiler/builtins/bitcode/src/str.zig
@@ -1525,6 +1525,10 @@ pub fn countUtf8Bytes(string: RocStr) callconv(.C) usize {
     return string.len();
 }
 
+pub fn isEmpty(string: RocStr) callconv(.C) bool {
+    return string.isEmpty();
+}
+
 pub fn getCapacity(string: RocStr) callconv(.C) usize {
     return string.getCapacity();
 }
diff --git a/crates/compiler/builtins/src/bitcode.rs b/crates/compiler/builtins/src/bitcode.rs
index d96496eae9..42c4c07260 100644
--- a/crates/compiler/builtins/src/bitcode.rs
+++ b/crates/compiler/builtins/src/bitcode.rs
@@ -308,6 +308,7 @@ pub const STR_SPLIT: &str = "roc_builtins.str.str_split";
 pub const STR_TO_SCALARS: &str = "roc_builtins.str.to_scalars";
 pub const STR_COUNT_GRAPEHEME_CLUSTERS: &str = "roc_builtins.str.count_grapheme_clusters";
 pub const STR_COUNT_UTF8_BYTES: &str = "roc_builtins.str.count_utf8_bytes";
+pub const STR_IS_EMPTY: &str = "roc_builtins.str.is_empty";
 pub const STR_CAPACITY: &str = "roc_builtins.str.capacity";
 pub const STR_STARTS_WITH: &str = "roc_builtins.str.starts_with";
 pub const STR_STARTS_WITH_SCALAR: &str = "roc_builtins.str.starts_with_scalar";
diff --git a/crates/compiler/gen_dev/src/lib.rs b/crates/compiler/gen_dev/src/lib.rs
index b78788269e..39acdce3b9 100644
--- a/crates/compiler/gen_dev/src/lib.rs
+++ b/crates/compiler/gen_dev/src/lib.rs
@@ -1120,6 +1120,10 @@ trait Backend<'a> {
 
                 self.build_fn_call(sym, intrinsic.to_string(), args, arg_layouts, ret_layout)
             }
+            LowLevel::StrIsEmpty => {
+                let intrinsic = bitcode::STR_IS_EMPTY.to_string();
+                self.build_fn_call(sym, intrinsic, args, arg_layouts, ret_layout);
+            }
             x => todo!("low level, {:?}", x),
         }
     }
diff --git a/crates/compiler/test_gen/src/gen_str.rs b/crates/compiler/test_gen/src/gen_str.rs
index 40cedb9136..cfb3cbd34e 100644
--- a/crates/compiler/test_gen/src/gen_str.rs
+++ b/crates/compiler/test_gen/src/gen_str.rs
@@ -497,23 +497,23 @@ fn str_concat_empty() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-dev"))]
 fn small_str_is_empty() {
     assert_evals_to!(r#"Str.isEmpty "abc""#, false, bool);
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-dev"))]
 fn big_str_is_empty() {
     assert_evals_to!(
-        r#"Str.isEmpty "this is more than 15 chars long""#,
+        r#"Str.isEmpty "this is more than 23 chars long""#,
         false,
         bool
     );
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-dev"))]
 fn empty_str_is_empty() {
     assert_evals_to!(r#"Str.isEmpty """#, true, bool);
 }