Add str::replace

src/lib/str.rs

@@ -52,6 +52,7 @@ export bytes_ivec;
 export unsafe_from_bytes_ivec;
 export is_empty;
 export is_not_empty;
+export replace;
 
 native "rust" mod rustrt {
     type sbuf;
@@ -511,6 +512,22 @@ fn to_upper(str s) -> str {
     }
     ret outstr;
 }
+
+// FIXME: This is super-inefficient
+fn replace(str s, str from, str to) : is_not_empty(from) -> str {
+    // FIXME (694): Shouldn't have to check this
+    check is_not_empty(from);
+    if (byte_len(s) == 0u) {
+        ret "";
+    } else if (starts_with(s, from)) {
+        ret to + replace(slice(s, byte_len(from), byte_len(s)),
+                             from, to);
+    } else {
+        ret unsafe_from_byte(s.(0))
+            + replace(slice(s, 1u, byte_len(s)), from, to);
+    }
+}
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;

src/test/run-pass/lib-str.rs

@@ -132,6 +132,19 @@ fn test_is_not_empty() {
   assert !str::is_not_empty("");
 }
 
+fn test_replace() {
+    auto a = "a";
+    check str::is_not_empty(a);
+    assert str::replace("", a, "b") == "";
+    assert str::replace("a", a, "b") == "b";
+    assert str::replace("ab", a, "b") == "bb";
+    auto test = "test";
+    check str::is_not_empty(test);
+    assert str::replace(" test test ", test, "toast")
+        == " toast toast ";
+    assert str::replace(" test test ", test, "") == "   ";
+}
+
 fn main() {
     test_bytes_len();
     test_index_and_rindex();
@@ -145,4 +158,15 @@ fn main() {
     test_ends_with();
     test_is_empty();
     test_is_not_empty();
-}
+    test_replace();
+}
+
+
+// Local Variables:
+// mode: rust;
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End: