[Strings] stringview_*.slice (#4805)

Unfortunately one slice is the same as python [start:end], using 2 params,
and the other slice is one param, [CURR:CURR+num] (where CURR is implied
by the current state in the iter). So we can't use a single class here. Perhaps
a different name would be good, like slice vs substring (like JS does), but
I picked names to match the current spec.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index c4a5f362a..0a3ca1929 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -1269,6 +1269,23 @@ void StringIterMove::finalize() {
   }
 }
 
+void StringSliceWTF::finalize() {
+  if (ref->type == Type::unreachable || start->type == Type::unreachable ||
+      end->type == Type::unreachable) {
+    type = Type::unreachable;
+  } else {
+    type = Type(HeapType::string, NonNullable);
+  }
+}
+
+void StringSliceIter::finalize() {
+  if (ref->type == Type::unreachable || num->type == Type::unreachable) {
+    type = Type::unreachable;
+  } else {
+    type = Type(HeapType::string, NonNullable);
+  }
+}
+
 size_t Function::getNumParams() { return getParams().size(); }
 
 size_t Function::getNumVars() { return vars.size(); }