stage2 更多的工具库 stage1 修复问题

stage2/utils/str.spl

@@ -138,6 +138,7 @@ fn expect_text(s: *Str, expected: []u8) {
 
 fn test_construction() {
     var s = new();
+    defer { drop(&s); }
     @assert(is_empty(s) && size(s) == 0, "empty new");
     expect_ok(append(&s, "hello"));
     expect_ok(append_byte(&s, ' '));
@@ -154,18 +155,19 @@ fn test_construction() {
         },
         .Err(error) => { @assert(false, "from_slice"); },
     }
-    drop(&s);
 }
 
 fn test_compare_and_search() {
     var hello_r = from_slice("hello");
     var hello: Str = new();
+    defer { drop(&hello); }
     match hello_r {
         .Ok(v) => { hello = v; },
         .Err(error) => { @assert(false, "hello"); },
     }
     var help_r = from_slice("help");
     var help: Str = new();
+    defer { drop(&help); }
     match help_r {
         .Ok(v) => { help = v; },
         .Err(error) => { @assert(false, "help"); },
@@ -181,12 +183,14 @@ fn test_compare_and_search() {
     @assert(ends_with(hello, hello), "ends_with");
     var pre_r = from_slice("he");
     var pre: Str = new();
+    defer { drop(&pre); }
     match pre_r { .Ok(v) => { pre = v; }, .Err(e) => { @assert(false, "pre"); } }
     @assert(starts_with(hello, pre), "starts he");
     @assert(!ends_with(hello, pre), "!ends he");
 
     var needle_r = from_slice("ll");
     var needle: Str = new();
+    defer { drop(&needle); }
     match needle_r { .Ok(v) => { needle = v; }, .Err(e) => { @assert(false, "needle"); } }
     match find(hello, needle) {
         .Found(index) => { @assert(index == 2, "find ll"); },
@@ -196,18 +200,15 @@ fn test_compare_and_search() {
         .Found(index) => { @assert(index == 0, "find he"); },
         .NotFound => { @assert(false, "he not found"); },
     }
-
-    drop(&needle);
-    drop(&pre);
-    drop(&help);
-    drop(&hello);
 }
 
 fn test_clone_take_and_failures() {
     var source = new();
+    defer { drop(&source); }
     expect_ok(append(&source, "owned"));
 
     var copy = new();
+    defer { drop(&copy); }
     expect_ok(clone(&copy, source));
     expect_text(&copy, "owned");
     expect_ok(append_byte(&source, '!')); // '!'
@@ -219,16 +220,13 @@ fn test_clone_take_and_failures() {
     expect_text(&copy, "owned");
 
     var moved = take(&copy);
+    defer { drop(&moved); }
     @assert(ByteBuffer.size(copy.storage) == 0 && ByteBuffer.capacity(copy.storage) == 0,
             "take empties source");
     expect_text(&moved, "owned");
 
     clear(&moved);
     @assert(is_empty(moved) && ByteBuffer.capacity(moved.storage) != 0, "clear keeps capacity");
-
-    drop(&moved);
-    drop(&copy);
-    drop(&source);
 }
 
 fn main() {