diff --git a/apps/boko-framework/src/Boko.bux b/apps/boko-framework/src/Boko.bux
index 27ad29a..15c0e5b 100644
--- a/apps/boko-framework/src/Boko.bux
+++ b/apps/boko-framework/src/Boko.bux
@@ -5,7 +5,7 @@ module Boko {
 
 import Std::Io::{PrintLine, Print, PrintInt};
 import Std::Net::{Net_Create, Net_SetReuse, Net_Bind, Net_Listen, Net_Accept, Net_Send, Net_Recv, Net_Close, Net_LastError};
-import Std::String::{String_Len, String_Eq, String_StartsWith, String_Contains};
+import Std::String::{String_Len, String_Eq, String_StartsWith, String_Contains, String_Offset};
 import Std::Task::{Task_Join, TaskHandle};
 
 extern func bux_alloc(size: uint) -> *void;
@@ -239,8 +239,8 @@ func Query_Parse(req: *Request, queryString: String) {
         let eqPos: String = bux_strstr(pair, "=");
         var key: String = pair;
         var value: String = "";
-        if eqPos as uint != 0 {
-            let keyLen: uint = eqPos as uint - pair as uint;
+        if String_Len(eqPos) > 0 {
+            let keyLen: uint = String_Offset(eqPos, pair);
             key = bux_str_slice(pair, 0, keyLen);
             let valStart: uint = keyLen + 1;
             let pairLen: uint = bux_strlen(pair);
@@ -267,15 +267,15 @@ func Request_Parse(raw: String) -> Request {
     req.queryCount = 0;
     req.pathParamCount = 0;
 
-    if raw as uint == 0 { return req; }
+    if String_Len(raw) == 0 { return req; }
     let rawLen: uint = bux_strlen(raw);
     if rawLen == 0 { return req; }
 
     // Find header/body boundary
     let boundary: String = bux_strstr(raw, "\r\n\r\n");
     var headerLen: uint = rawLen;
-    if boundary as uint != 0 {
-        headerLen = boundary as uint - raw as uint;
+    if String_Len(boundary) > 0 {
+        headerLen = String_Offset(boundary, raw);
         let bodyStart: uint = headerLen + 4;
         if bodyStart < rawLen {
             req.body = bux_str_slice(raw, bodyStart, rawLen - bodyStart);
@@ -299,8 +299,8 @@ func Request_Parse(raw: String) -> Request {
         let fullPath: String = bux_str_split_part(requestLine, " ", 1);
         // Split path and query string
         let qmark: String = bux_strstr(fullPath, "?");
-        if qmark as uint != 0 {
-            let pathLen: uint = qmark as uint - fullPath as uint;
+        if String_Len(qmark) > 0 {
+            let pathLen: uint = String_Offset(qmark, fullPath);
             req.path = bux_str_slice(fullPath, 0, pathLen);
             let qsStart: uint = pathLen + 1;
             let fullLen: uint = bux_strlen(fullPath);
@@ -322,8 +322,8 @@ func Request_Parse(raw: String) -> Request {
     while i < lineCount {
         let line: String = bux_str_split_part(headerBlock, "\r\n", i);
         let colonPos: String = bux_strstr(line, ": ");
-        if colonPos as uint != 0 {
-            let keyLen: uint = colonPos as uint - line as uint;
+        if String_Len(colonPos) > 0 {
+            let keyLen: uint = String_Offset(colonPos, line);
             let key: String = bux_str_slice(line, 0, keyLen);
             let valStart: uint = keyLen + 2;
             let lineLen: uint = bux_strlen(line);
@@ -378,8 +378,8 @@ func Path_Match(pattern: String, path: String, req: *Request) -> bool {
             let braceOpen: uint = 1; // skip "{"
             let braceClose: String = bux_strstr(patPart, "}");
             var nameLen: uint = 0;
-            if braceClose as uint != 0 {
-                nameLen = braceClose as uint - patPart as uint - 1;
+            if String_Len(braceClose) > 0 {
+                nameLen = String_Offset(braceClose, patPart) - 1;
             }
             let name: String = bux_str_slice(patPart, braceOpen, nameLen);
             req.pathParamKeys[req.pathParamCount] = name;
@@ -416,7 +416,7 @@ func Boko_Router(req: Request) -> Response;
 // =============================================================================
 func App_HandleConnection(clientFd: int) {
     let raw: String = Net_Recv(clientFd, 8192);
-    if raw as uint == 0 { return; }
+    if String_Len(raw) == 0 { return; }
     if bux_strlen(raw) == 0 { return; }
 
     let req: Request = Request_Parse(raw);
diff --git a/apps/jwt-pitbul/src/Main.bux b/apps/jwt-pitbul/src/Main.bux
index 8d6d0aa..36f7d77 100644
--- a/apps/jwt-pitbul/src/Main.bux
+++ b/apps/jwt-pitbul/src/Main.bux
@@ -96,7 +96,7 @@ func ResolveKey(alg: JwtAlg, keyArg: String) -> String {
        alg.tag == JwtAlg_ES256 || alg.tag == JwtAlg_ES384 {
         if bux_file_exists(keyArg) != 0 {
             let pem: String = bux_read_file(keyArg);
-            if pem as uint != 0 && String_Len(pem) > 0 {
+            if String_Len(pem) > 0 && String_Len(pem) > 0 {
                 return pem;
             }
             Print("ERROR: could not read PEM file: ");
diff --git a/apps/nexus/src/Main.bux b/apps/nexus/src/Main.bux
index dc54019..ad4dcf5 100644
--- a/apps/nexus/src/Main.bux
+++ b/apps/nexus/src/Main.bux
@@ -9,7 +9,7 @@ module Main {
 // =============================================================================
 import Std::Io::{PrintLine, Print, PrintInt};
 import Std::Net::{Net_Create, Net_SetReuse, Net_Bind, Net_Listen, Net_Accept, Net_Send, Net_Recv, Net_Close, Net_LastError};
-import Std::String::{String_Len, String_Eq, String_StartsWith, String_EndsWith, String_Contains, String_Trim, String_FromInt};
+import Std::String::{String_Len, String_Eq, String_StartsWith, String_EndsWith, String_Contains, String_Trim, String_FromInt, String_Offset};
 import Std::Task::{Task_Join, TaskHandle};
 
 // =============================================================================
@@ -170,15 +170,15 @@ func Http_ParseRequest(raw: String) -> HttpRequest {
     RequestHeader_Init(&req);
 
     // Guard: null/empty input
-    if raw as uint == 0 { return req; }
+    if String_Len(raw) == 0 { return req; }
     let rawLen: uint = bux_strlen(raw);
     if rawLen == 0 { return req; }
 
     // Find \r\n\r\n separating headers from body
     let boundary: String = bux_strstr(raw, "\r\n\r\n");
     var headerLen: uint = rawLen;
-    if boundary as uint != 0 {
-        headerLen = boundary as uint - raw as uint;
+    if String_Len(boundary) > 0 {
+        headerLen = String_Offset(boundary, raw);
         let bodyStart: uint = headerLen + 4;
         if bodyStart < rawLen {
             req.body = bux_str_slice(raw, bodyStart, rawLen - bodyStart);
@@ -198,7 +198,7 @@ func Http_ParseRequest(raw: String) -> HttpRequest {
     if bux_strlen(requestLine) > 0 {
         req.method = Http_ParseMethod(bux_str_split_part(requestLine, " ", 0));
         req.path = bux_str_split_part(requestLine, " ", 1);
-        if String_Eq(req.path, "") || req.path as uint == 0 {
+        if String_Eq(req.path, "") || req.String_Len(path) == 0 {
             req.path = "/";
         }
     }
@@ -215,8 +215,8 @@ func Http_ParseRequest(raw: String) -> HttpRequest {
         var key: String = "";
         var value: String = "";
 
-        if colonPos as uint != 0 {
-            let keyLen: uint = colonPos as uint - line as uint;
+        if String_Len(colonPos) > 0 {
+            let keyLen: uint = String_Offset(colonPos, line);
             key = bux_str_slice(line, 0, keyLen);
             let valStart: uint = keyLen + 2;
             if valStart < lineLen {
@@ -225,8 +225,8 @@ func Http_ParseRequest(raw: String) -> HttpRequest {
         } else {
             // Try ":" without space
             let colonPos2: String = bux_strstr(line, ":");
-            if colonPos2 as uint != 0 {
-                let keyLen: uint = colonPos2 as uint - line as uint;
+            if String_Len(colonPos2) > 0 {
+                let keyLen: uint = String_Offset(colonPos2, line);
                 key = bux_str_slice(line, 0, keyLen);
                 let valStart: uint = keyLen + 1;
                 if valStart < lineLen {
@@ -341,7 +341,7 @@ func ServeStaticFile(requestPath: String) -> HttpResponse {
 
     // Read and serve
     let content: String = bux_read_file(fullPath);
-    if content as uint == 0 {
+    if String_Len(content) == 0 {
         return Http_NewResponse(500, "text/plain; charset=utf-8", "Internal Server Error");
     }
 
@@ -444,7 +444,7 @@ func HandleConnection(clientFd: int) {
     let raw: String = Net_Recv(clientFd, 8192);
 
     // Empty read → client disconnected
-    if raw as uint == 0 { return; }
+    if String_Len(raw) == 0 { return; }
     if bux_strlen(raw) == 0 { return; }
 
     // HTTP/2 connection preface detection
diff --git a/apps/simpledb/src/Main.bux b/apps/simpledb/src/Main.bux
index 2a4239f..650d851 100644
--- a/apps/simpledb/src/Main.bux
+++ b/apps/simpledb/src/Main.bux
@@ -2,7 +2,7 @@ module Main {
 
 import Std::Io::{PrintLine, Print, PrintInt, ReadFile, WriteFile, FileExists};
 import Std::Os::{Os_ArgsCount, Os_Args};
-import Std::String::{String_Len, String_Eq, String_StartsWith, String_Find, String_Slice};
+import Std::String::{String_Len, String_Eq, String_StartsWith, String_Find, String_Slice, String_Offset};
 
 extern func bux_strlen(s: String) -> uint;
 extern func bux_strstr(haystack: String, needle: String) -> String;
@@ -46,7 +46,7 @@ func DB_Load(self: *Database) -> bool {
     }
 
     let raw: String = ReadFile(self.path);
-    if raw as uint == 0 || bux_strlen(raw) == 0 {
+    if String_Len(raw) == 0 || bux_strlen(raw) == 0 {
         self.loaded = true;
         return true;
     }
@@ -76,7 +76,7 @@ func DB_Get(self: *Database, key: String) -> String {
         let line: String = bux_str_split_part(raw, "\n", i);
         if String_StartsWith(line, key) {
             let eqPos: String = String_Find(line, "=");
-            if eqPos as uint != 0 {
+            if String_Len(eqPos) > 0 {
                 let keyLen: uint = bux_strlen(key);
                 let valStart: uint = keyLen + 1;
                 let lineLen: uint = bux_strlen(line);
@@ -102,7 +102,7 @@ func DB_Set(self: *Database, key: String, value: String) {
         if bux_strlen(line) > 0 {
             if String_StartsWith(line, key) {
                 let eqPos: String = String_Find(line, "=");
-                if eqPos as uint != 0 {
+                if String_Len(eqPos) > 0 {
                     bux_sb_append(newSb, key);
                     SB_AppendChar(newSb, 61);
                     bux_sb_append(newSb, value);
@@ -144,7 +144,7 @@ func DB_Del(self: *Database, key: String) {
         if bux_strlen(line) > 0 {
             if String_StartsWith(line, key) {
                 let eqPos: String = String_Find(line, "=");
-                if eqPos as uint != 0 {
+                if String_Len(eqPos) > 0 {
                     delCount = delCount + 1;
                 } else {
                     bux_sb_append(newSb, line);
@@ -188,8 +188,8 @@ func DB_Keys(self: *Database) -> *String {
         let line: String = bux_str_split_part(raw, "\n", i);
         if bux_strlen(line) > 0 {
             let eqPos: String = String_Find(line, "=");
-            if eqPos as uint != 0 {
-                let keyLen: uint = eqPos as uint - line as uint;
+            if String_Len(eqPos) > 0 {
+                let keyLen: uint = String_Offset(eqPos, line);
                 keys[found] = bux_str_slice(line, 0, keyLen);
                 found = found + 1;
             }
diff --git a/lib/String.bux b/lib/String.bux
index 27e49fb..f7787f3 100644
--- a/lib/String.bux
+++ b/lib/String.bux
@@ -8,6 +8,8 @@ extern func bux_strcat(dest: *char8, src: String) -> *char8;
 extern func bux_strncpy(dest: *char8, src: String, n: uint) -> *char8;
 extern func bux_strstr(haystack: String, needle: String) -> String;
 extern func bux_str_contains(haystack: String, needle: String) -> int;
+extern func bux_str_offset(pos: String, base: String) -> uint;
+extern func bux_str_is_null(s: String) -> int;
 extern func bux_str_slice(s: String, start: uint, len: uint) -> String;
 extern func bux_str_trim_left(s: String) -> String;
 extern func bux_str_trim_right(s: String) -> String;
@@ -32,6 +34,10 @@ func String_Len(s: String) -> uint {
     return bux_strlen(s);
 }
 
+func String_IsNull(s: String) -> bool {
+    return bux_str_is_null(s) != 0;
+}
+
 func String_Eq(a: String, b: String) -> bool {
     return bux_strcmp(a, b) == 0;
 }
@@ -170,13 +176,17 @@ func String_Find(haystack: String, needle: String) -> String {
     return bux_strstr(haystack, needle);
 }
 
+func String_Offset(pos: String, base: String) -> uint {
+    return bux_str_offset(pos, base);
+}
+
 func String_Replace(s: String, old: String, new: String) -> String {
     let pos: String = bux_strstr(s, old);
-    if pos as uint == 0 {
+    if String_IsNull(pos) {
         return s;
     }
     let oldLen: uint = bux_strlen(old);
-    let prefixLen: uint = pos as uint - s as uint;
+    let prefixLen: uint = String_Offset(pos, s);
     let prefix: String = bux_str_slice(s, 0, prefixLen);
     let suffix: String = bux_str_slice(s, prefixLen + oldLen, bux_strlen(s) - prefixLen - oldLen);
     let temp: String = String_Concat(prefix, new);
diff --git a/rt/runtime.c b/rt/runtime.c
index 68d34bd..2e01ac7 100644
--- a/rt/runtime.c
+++ b/rt/runtime.c
@@ -232,11 +232,22 @@ const char* bux_strstr(const char* haystack, const char* needle) {
     return strstr(haystack, needle);
 }
 
+/* String offset: byte offset of pos within base (both must point into same string) */
+unsigned int bux_str_offset(const char* pos, const char* base) {
+    if (!pos || !base) return 0;
+    return (unsigned int)(pos - base);
+}
+
 /* String contains: returns 1 if haystack contains needle, 0 otherwise */
 int bux_str_contains(const char* haystack, const char* needle) {
     return bux_strstr(haystack, needle) != NULL;
 }
 
+/* String is null: returns 1 if string is NULL */
+int bux_str_is_null(const char* s) {
+    return s == NULL;
+}
+
 /* String slice: extract substring from start, length len */
 char* bux_str_slice(const char* s, unsigned int start, unsigned int len) {
     if (!s) return NULL;
diff --git a/src/parser.bux b/src/parser.bux
index ddc314e..f3e56b9 100644
--- a/src/parser.bux
+++ b/src/parser.bux
@@ -920,6 +920,12 @@ func parserParseParamList(p: *Parser) -> *Decl {
 
     discard parserExpect(p, tkLParen, "expected '('");
     while !parserCheck(p, tkRParen) && parserPeek(p, 0) != tkEndOfFile {
+        while parserCheck(p, tkNewLine) || parserCheck(p, tkSemicolon) {
+            discard parserAdvance(p);
+        }
+        if parserCheck(p, tkRParen) || parserPeek(p, 0) == tkEndOfFile {
+            break;
+        }
         if d.paramCount >= 9 { break; }
         let nameTok: LexToken = parserExpectIdentOrKeyword(p, "expected parameter name");
         discard parserExpect(p, tkColon, "expected ':' in parameter");