basic working test case

compiler/builtins/bitcode/src/num.zig

@@ -5,15 +5,17 @@ const RocList = @import("list.zig").RocList;
 const RocStr = @import("str.zig").RocStr;
 
 pub fn NumParseResult(comptime T: type) type {
+    // on the roc side we sort by alignment; putting the errorcode last
+    // always works out (no number with smaller alignment than 1)
     return extern struct {
-        errorcode: u8, // 0 indicates success
         value: T,
+        errorcode: u8, // 0 indicates success
     };
 }
 
 pub fn exportParseInt(comptime T: type, comptime name: []const u8) void {
     comptime var f = struct {
-        fn func(input: T, buf: RocStr) callconv(.C) NumParseResult(T) {
+        fn func(buf: RocStr) callconv(.C) NumParseResult(T) {
             // a radix of 0 will make zig determine the radix from the frefix:
             //  * A prefix of "0b" implies radix=2,
             //  * A prefix of "0o" implies radix=8,

compiler/can/src/builtins.rs

@@ -1355,12 +1355,12 @@ fn str_to_num(symbol: Symbol, var_store: &mut VarStore) -> Def {
                         Access {
                             record_var,
                             ext_var: var_store.fresh(),
-                            field: "errorcode".into(),
+                            field: "b_errorcode".into(),
                             field_var: errorcode_var,
                             loc_expr: Box::new(no_region(Var(Symbol::ARG_2))),
                         },
                     ),
-                    (errorcode_var, int(errorcode_var, Variable::NATURAL, 0)),
+                    (errorcode_var, int(errorcode_var, Variable::UNSIGNED8, 0)),
                 ],
                 ret_var: bool_var,
             }),
@@ -1382,7 +1382,7 @@ fn str_to_num(symbol: Symbol, var_store: &mut VarStore) -> Def {
                         Access {
                             record_var,
                             ext_var: var_store.fresh(),
-                            field: "value".into(),
+                            field: "a_value".into(),
                             field_var: num_var,
                             loc_expr: Box::new(no_region(Var(Symbol::ARG_2))),
                         },

compiler/gen_llvm/src/llvm/build.rs

@@ -5285,6 +5285,9 @@ fn run_low_level<'a, 'ctx, 'env>(
                     _ => unreachable!(),
                 };
 
+                let string =
+                    complex_bitcast(env.builder, string, env.str_list_c_abi().into(), "to_utf8");
+
                 call_bitcode_fn(env, &[string], intrinsic)
             } else {
                 unreachable!()

compiler/test_gen/src/gen_str.rs

@@ -1297,3 +1297,20 @@ fn str_trim_right_small_to_small_shared() {
         (RocStr, RocStr)
     );
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm"))]
+fn str_to_num() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            when Str.toNum "1" is
+                Ok n -> n
+                Err _ -> 0
+
+               "#
+        ),
+        1,
+        i64
+    );
+}