feat: Enhance HTTP and string handling, improve control flow parsing

- Updated HTTP client to correctly parse domain from URL
- Improved string `split` method to handle edge cases
- Extended control flow parsing to support `while let` syntax
- Refined diagnostic messages for `if/while let` conditions
- Refactored condition pre-processing for `if` and `while` statements

Author: Chronostasys

planglib/std/string.pi

@@ -13,22 +13,48 @@ pub trait StringExt {
 
 impl StringExt for string {
     fn split(s:string) [string] {
+        // 如果分隔符为空，直接返回原字符串作为唯一元素
+        if s.byte_len() == 0 {
+            return [*self];
+        }
+        
         let chars = self.chars();
         let subchars = s.chars();
         let re = arr::new<string>();
         let i = 0;
-        let j = 0;
-        while i < arr_len(chars) {
-            if chars[i] == subchars[j] {
+        let start = 0;
+        
+        while i <= arr_len(chars) - arr_len(subchars) {
+            let m = true;
+            let j = 0;
+            
+            // 检查当前位置是否匹配分隔符
+            while j < arr_len(subchars) {
+                if chars[i + j] != subchars[j] {
+                    m = false;
+                    break;
+                }
                 j = j + 1;
             }
-            if j == arr_len(subchars) {
-                let sub = self.slice(i, j);
-                re.push(sub);
-                j = 0;
+            
+            // 如果找到匹配
+            if m {
+                // 添加分隔符前的子字符串
+                re.push(self.slice(start, i - start));
+                // 跳过分隔符
+                i = i + arr_len(subchars);
+                // 更新下一个子字符串的起始位置
+                start = i;
+            } else {
+                i = i + 1;
             }
-            i = i + 1;
         }
+        
+        // 添加最后一个子字符串
+        if start < arr_len(chars) {
+            re.push(self.slice(start, arr_len(chars) - start));
+        }
+        
         return re.get_slice();
     }
     /// # index_of

planglib/std/task/http.pi

@@ -31,16 +31,18 @@ impl HttpClient {
             data: [u8*1024;],
             len: 0,
         };
+        let domain = url.split("://")[1].split("/")[0];
+
         sb.add_str("GET / HTTP/1.1\r\n");
         sb.add_str("Host: ");
-        sb.add_str(url);
+        sb.add_str(domain);
         sb.add_str("\r\n");
         sb.add_str("Connection: close\r\n\r\n");
 
         let request = sb.str();
         let bytes = request.bytes();
         let resolver = dns::new_dns_resolver();
-        let ip = await resolver.resolve_async(url);
+        let ip = await resolver.resolve_async(domain);
         let status = await self.socket.connect_async(ip, 80 as i32);
         // 发送请求
         await self.socket.write_async(bytes);
@@ -78,6 +80,7 @@ impl HttpClient {
         // 解析状态码
         let status_str = string_from_bytes(arr_slice(response_buf, 9, 12));
 
+        // TODO: 解析状态码
         return HttpResponse{
             status_code: 200 as i32,
             headers: headers,
@@ -115,12 +118,8 @@ impl HttpResponse {
     pub async fn read_all_async() Task<[u8]> {
         let content = arr::new<u8>();
         let buf = [u8*4096;];
-        while true {
-            if let n = (await self.read_async(buf)) as i64 {
-                content.append(arr::from_slice(arr_slice(buf, 0, n)));
-            } else {
-                break;
-            }
+        while let n = (await self.read_async(buf)) as i64 {
+            content.append(arr::from_slice(buf.slice(0, n)));
         }
         return content.get_slice();
     }

src/ast/diag.rs

@@ -182,8 +182,8 @@ define_diag!(
     MACRO_EXPANSION_FAILED = "macro expansion failed",
     SYNTAX_ERROR_FUNC_PARAM = "syntax error: function parameter",
     ONLY_AWAIT_IN_ASYNC_FN = "await is only expected in async functions",
-    IF_LET_DOES_NOT_EXPECT_TAIL = "`if let ...` does not expect `?` or `!` tail",
-    EXPECT_IF_LET_AS = "`if let .. as ...` is expected here",
+    IF_LET_DOES_NOT_EXPECT_TAIL = "`if/while let ...` does not expect `?` or `!` tail",
+    EXPECT_IF_LET_AS = "`if/while let .. as ...` is expected here",
     EXPECT_GENERIC_TYPE = "expect generic type",
     EXPECT_TAILING_SYMBOL = "expect tailing symbol `!` or `?`",
 );