Merge branch 'main' into main

15 files changed, 450 insertions, 157 deletions

diff --git a/std/core.zc b/std/core.zc
index f450517..7379db4 100644
--- a/std/core.zc
+++ b/std/core.zc
@@ -7,11 +7,11 @@ include <stdarg.h>
 
 let __zen_hash_seed: usize = 14695981039346656037;
 
-raw {
-void _zen_panic(const char* file, int line, const char* func, const char* msg) {
+extern fn exit(code: int);
+
+fn _zen_panic(file: const char*, line: int, func: const char*, msg: const char*) {
     fprintf(stderr, "%s:%d (%s): Panic: %s\n", file, line, func, msg);
     exit(1);
 }
-}
 
 #define panic(msg) _zen_panic(__FILE__, __LINE__, __func__, msg)
\ No newline at end of file
diff --git a/std/cuda.zc b/std/cuda.zc
index c6a9403..8fc6545 100644
--- a/std/cuda.zc
+++ b/std/cuda.zc
@@ -101,6 +101,8 @@ fn cuda_ok() -> bool {
 }
 
 
+// Minimal raw block: required for cudaDeviceProp struct field access
+// The cudaDeviceProp struct cannot be declared in Zen-C without type conflicts
 raw {
     void _z_cuda_get_props(int dev, char* name, size_t* total_mem, int* sm_count, int* major, int* minor, int* max_threads, int* warp_size) {
         struct cudaDeviceProp prop;
diff --git a/std/env.zc b/std/env.zc
index 959784f..c63fd3d 100644
--- a/std/env.zc
+++ b/std/env.zc
@@ -2,23 +2,12 @@ import "./core.zc"
 import "./option.zc"
 import "./string.zc"
 
-raw {
-    char *_z_env_get(char *name) {
-        return getenv(name);
-    }
-
-    int _z_env_set(char *name, char *value, int overwrite) {
-        return setenv(name, value, overwrite);
-    }
-
-    int _z_env_unset(char *name) {
-        return unsetenv(name);
-    }
-}
+include <stdlib.h>
 
-extern fn _z_env_get(name: char*) -> char*;
-extern fn _z_env_set(name: char*, value: char*, overwrite: int) -> int;
-extern fn _z_env_unset(name: char*) -> int;
+// Direct externs with const char* to match C stdlib declarations
+extern fn getenv(name: const char*) -> char*;
+extern fn setenv(name: const char*, value: const char*, overwrite: int) -> int;
+extern fn unsetenv(name: const char*) -> int;
 
 @derive(Eq)
 enum EnvRes {
@@ -30,7 +19,7 @@ struct Env {}
 
 impl Env {
     fn get(name: string) -> Option<string> {
-        let value: string = _z_env_get(name);
+        let value: string = getenv(name);
         if (value == NULL) {
             return Option<string>::None();
         }
@@ -39,7 +28,7 @@ impl Env {
     }
 
     fn get_dup(name: string) -> Option<String> {
-        let value: string = _z_env_get(name);
+        let value: string = getenv(name);
         if (value == NULL) {
             return Option<String>::None();
         }
@@ -52,13 +41,13 @@ impl Env {
     }
 
     fn set(name: string, value: string) -> EnvRes {
-        let ret: int = _z_env_set(name, value, 1);
+        let ret: int = setenv(name, value, 1);
 
         return (ret == 0) ? EnvRes::OK() : EnvRes::ERR();
     }
 
     fn unset(name: string) -> EnvRes {
-        let ret: int = _z_env_unset(name);
+        let ret: int = unsetenv(name);
 
         return (ret == 0) ? EnvRes::OK() : EnvRes::ERR();
     }
diff --git a/std/fs.zc b/std/fs.zc
index c19f9f1..a00993b 100644
--- a/std/fs.zc
+++ b/std/fs.zc
@@ -2,22 +2,32 @@ import "./core.zc"
 import "./result.zc"
 import "./string.zc"
 import "./vec.zc"
+import "./mem.zc"
 
 def Z_SEEK_SET = 0;
 def Z_SEEK_END = 2;
 def Z_F_OK = 0;
 
-
-// TODO: restructure this tomorrow.
+include <dirent.h>
+include <sys/stat.h>
+include <unistd.h>
+include <stdlib.h>
+include <stdio.h>
+
+// Direct externs for simple functions with const char* parameters
+extern fn access(pathname: const char*, mode: int) -> int;
+extern fn unlink(pathname: const char*) -> int;
+extern fn rmdir(pathname: const char*) -> int;
+extern fn malloc(size: usize) -> void*;
+extern fn free(ptr: void*);
+
+// Minimal raw block: required for opaque FILE*/DIR* types and C struct access
+// These cannot be expressed in Zen-C extern declarations without type conflicts
 raw {
-    #include <dirent.h>
-    #include <sys/stat.h>
-    #include <unistd.h>
-
-    // typedef needed for Vec<DirEntry*> generation if inferred
     typedef struct DirEntry* DirEntryPtr;
     
-    void* _z_fs_fopen(char* path, char* mode) {
+    // FILE* wrappers - fopen/fclose/etc use FILE* which conflicts with void*
+    void* _z_fs_fopen(const char* path, const char* mode) {
         return fopen(path, mode);
     }
 
@@ -40,20 +50,9 @@ raw {
     int64_t _z_fs_ftell(void* stream) {
         return (int64_t)ftell((FILE*)stream);
     }
-
-    int _z_fs_access(char* pathname, int mode) {
-        return access(pathname, mode);
-    }
-
-    int _z_fs_unlink(char* pathname) {
-        return unlink(pathname);
-    }
-
-    int _z_fs_rmdir(char* pathname) {
-        return rmdir(pathname);
-    }
-
-    void* _z_fs_opendir(char* name) {
+    
+    // DIR* wrappers - opendir/closedir/readdir use DIR* which conflicts with void*
+    void* _z_fs_opendir(const char* name) {
         return opendir(name);
     }
 
@@ -61,15 +60,8 @@ raw {
         return closedir((DIR*)dir);
     }
 
-    void* _z_fs_malloc(size_t size) {
-        return malloc(size);
-    }
-
-    void _z_fs_free(void* ptr) {
-        free(ptr);
-    }
-
-    int _z_fs_get_metadata(char* path, uint64_t* size, int* is_dir, int* is_file) {
+    // struct stat access - cannot define matching Zen-C struct for stat
+    int _z_fs_get_metadata(const char* path, uint64_t* size, int* is_dir, int* is_file) {
         struct stat st;
         if (stat(path, &st) != 0) return -1;
         *size = st.st_size;
@@ -78,6 +70,7 @@ raw {
         return 0;
     }
     
+    // struct dirent access - readdir returns struct dirent*
     int _z_fs_read_entry(void* dir, char* out_name, int buf_size, int* is_dir) {
         struct dirent* ent = readdir((DIR*)dir);
         if (!ent) return 0;
@@ -87,7 +80,8 @@ raw {
         return 1;
     }
 
-    int _z_fs_mkdir(char* path) {
+    // mkdir has different signatures on Windows vs POSIX
+    int _z_fs_mkdir(const char* path) {
         #ifdef _WIN32
             return mkdir(path);
         #else
@@ -96,22 +90,18 @@ raw {
     }
 }
 
-extern fn _z_fs_mkdir(path: char*) -> int;
-extern fn _z_fs_get_metadata(path: char*, size: U64*, is_dir: int*, is_file: int*) -> int;
+extern fn _z_fs_mkdir(path: const char*) -> int;
+extern fn _z_fs_get_metadata(path: const char*, size: U64*, is_dir: int*, is_file: int*) -> int;
 extern fn _z_fs_read_entry(dir: void*, out_name: char*, buf_size: int, is_dir: int*) -> int;
-extern fn _z_fs_fopen(path: char*, mode: char*) -> void*;
+extern fn _z_fs_fopen(path: const char*, mode: const char*) -> void*;
 extern fn _z_fs_fclose(stream: void*) -> int;
 extern fn _z_fs_fread(ptr: void*, size: usize, nmemb: usize, stream: void*) -> usize;
 extern fn _z_fs_fwrite(ptr: void*, size: usize, nmemb: usize, stream: void*) -> usize;
-extern fn _z_fs_fseek(stream: void*, offset: long, whence: int) -> int;
-extern fn _z_fs_ftell(stream: void*) -> long;
-extern fn _z_fs_access(pathname: char*, mode: int) -> int;
-extern fn _z_fs_unlink(pathname: char*) -> int;
-extern fn _z_fs_rmdir(pathname: char*) -> int;
-extern fn _z_fs_opendir(name: char*) -> void*;
+extern fn _z_fs_fseek(stream: void*, offset: I64, whence: int) -> int;
+extern fn _z_fs_ftell(stream: void*) -> I64;
+extern fn _z_fs_opendir(name: const char*) -> void*;
 extern fn _z_fs_closedir(dir: void*) -> int;
-extern fn _z_fs_malloc(size: usize) -> void*;
-extern fn _z_fs_free(ptr: void*);
+
 
 struct File {
     handle: void*;
@@ -153,7 +143,7 @@ impl File {
         let size = _z_fs_ftell(self.handle);
         _z_fs_fseek(self.handle, 0, Z_SEEK_SET);
         
-        let buffer: char* = _z_fs_malloc((usize)size + 1);
+        let buffer: char* = malloc((usize)size + 1);
         if (buffer == NULL) {
             return Result<String>::Err("Out of memory");
         }
@@ -162,7 +152,7 @@ impl File {
         buffer[read] = 0;
         
         let s = String::new(buffer);
-        _z_fs_free(buffer);
+        free(buffer);
         
         let res = Result<String>::Ok(s);
         s.forget();
@@ -201,7 +191,7 @@ impl File {
     }
 
     fn exists(path: char*) -> bool {
-        return _z_fs_access(path, Z_F_OK) == 0;
+        return access(path, Z_F_OK) == 0;
     }
 
     fn metadata(path: char*) -> Result<Metadata> {
@@ -228,14 +218,14 @@ impl File {
     }
 
     fn remove_file(path: char*) -> Result<bool> {
-        if (_z_fs_unlink(path) != 0) {
+        if (unlink(path) != 0) {
             return Result<bool>::Err("Failed to remove file");
         }
         return Result<bool>::Ok(true);
     }
 
     fn remove_dir(path: char*) -> Result<bool> {
-        if (_z_fs_rmdir(path) != 0) {
+        if (rmdir(path) != 0) {
             return Result<bool>::Err("Failed to remove directory");
         }
         return Result<bool>::Ok(true);
@@ -248,7 +238,7 @@ impl File {
         }
         
         let entries = Vec<DirEntry>::new();
-        let name_buf: char* = _z_fs_malloc(256);
+        let name_buf: char* = malloc(256);
         
         if (name_buf == NULL) {
             _z_fs_closedir(dir);
@@ -277,7 +267,7 @@ impl File {
             ent.name.forget();
         }
         
-        _z_fs_free(name_buf);
+        free(name_buf);
         _z_fs_closedir(dir);
         
         let res = Result< Vec<DirEntry> >::Ok(entries);
diff --git a/std/io.zc b/std/io.zc
index 2793ecf..a5a7359 100644
--- a/std/io.zc
+++ b/std/io.zc
@@ -2,37 +2,51 @@
 import "./core.zc"
 import "./string.zc"
 
-raw {
-    int _z_vprintf(char* fmt, va_list ap) {
-        return vprintf((const char*)fmt, ap);
-    }
-    
-    int _z_vsnprintf(char* str, size_t size, char* fmt, va_list ap) {
-        return vsnprintf(str, size, (const char*)fmt, ap);
-    }
+include <stdio.h>
+include <stdarg.h>
 
-    void* _z_get_stdin() { return stdin; }
-    int _z_get_eof() { return EOF; }
+// These work directly with const char* in extern declarations
+extern fn vprintf(fmt: const char*, ap: va_list) -> int;
+
+// vsnprintf is problematic on macOS because it's a macro that expands to a builtin with a different signature
+// so we wrap it in a C function to avoid the conflict
+extern fn _z_vsnprintf(str: char*, size: usize, fmt: const char*, ap: va_list) -> int;
+
+// EOF is typically -1, but we define it for portability
+def Z_EOF = -1;
+
+// Minimal raw block: only for truly opaque FILE* types that can't be
+// represented in Zen-C extern declarations without type conflicts.
+// These wrappers use void* to avoid FILE* declaration conflicts.
+raw {
+    void* _z_get_stdin(void) { return stdin; }
     int _z_fgetc(void* stream) { return fgetc((FILE*)stream); }
+    int _z_vsnprintf(char* str, size_t size, const char* fmt, va_list ap) {
+        return vsnprintf(str, size, fmt, ap);
+    }
 }
 
-extern fn _z_vprintf(fmt: char*, ap: va_list) -> int;
-extern fn _z_vsnprintf(str: char*, size: usize, fmt: char*, ap: va_list) -> int;
+extern fn _z_get_stdin() -> void*;
+extern fn _z_fgetc(stream: void*) -> int;
 
 fn format(fmt: char*, ...) -> char* {
     static let buffer: char[1024];
     let ap: va_list;
     va_start(ap, fmt);
+
     _z_vsnprintf(buffer, 1024, fmt, ap);
     va_end(ap);
+
     return (char*)buffer;
 }
 
 fn format_into(buffer: char*, size: usize, fmt: char*, ...) -> int {
     let ap: va_list;
     va_start(ap, fmt);
+
     let ret = _z_vsnprintf(buffer, size, fmt, ap);
     va_end(ap);
+
     return ret;
 }
 
@@ -42,15 +56,17 @@ fn format_new(fmt: char*, ...) -> char* {
     
     let ap: va_list;
     va_start(ap, fmt);
+
     _z_vsnprintf(buffer, 1024, fmt, ap);
     va_end(ap);
+
     return buffer;
 }
 
 fn print(fmt: char*, ...) -> int {
     let ap: va_list;
     va_start(ap, fmt);
-    let ret = _z_vprintf(fmt, ap);
+    let ret = vprintf(fmt, ap);
     va_end(ap);
     return ret;
 }
@@ -58,7 +74,7 @@ fn print(fmt: char*, ...) -> int {
 fn println(fmt: char*, ...) -> int {
     let ap: va_list;
     va_start(ap, fmt);
-    let ret = _z_vprintf(fmt, ap);
+    let ret = vprintf(fmt, ap);
     va_end(ap);
     puts("");
     return ret + 1;
@@ -72,11 +88,10 @@ fn readln() -> char* {
     
     let c: int;
     let std_in = _z_get_stdin();
-    let eof_val = _z_get_eof();
 
     while (true) {
         c = _z_fgetc(std_in);
-        if (c == eof_val) break;
+        if (c == Z_EOF) break;
         if (c == 10) break; // '\n'
 
         if (len + 1 >= cap) {
@@ -93,7 +108,7 @@ fn readln() -> char* {
         len = len + 1;
     }
     
-    if (len == 0 && c == eof_val) {
+    if (len == 0 && c == Z_EOF) {
         free(line);
         return NULL;
     }
diff --git a/std/json.zc b/std/json.zc
index e6a15cd..9f5cf73 100644
--- a/std/json.zc
+++ b/std/json.zc
@@ -5,6 +5,7 @@ import "./map.zc"
 import "./string.zc"
 import "./result.zc"
 import "./option.zc"
+import "./mem.zc"
 
 @derive(Eq)
 enum JsonType {
@@ -450,3 +451,74 @@ impl JsonValue {
         }
     }
 }
+
+impl Drop for JsonValue {
+    fn drop(self) {
+        self.free();
+    }
+}
+
+impl JsonValue {
+    fn to_string(self) -> String {
+        let s = String::new("");
+        self.stringify(&s);
+        return s;
+    }
+
+    fn stringify(self, buf: String*) {
+        if (self.kind.tag == JsonType::JSON_NULL().tag) {
+            buf.append_c_ptr("null");
+        } else if (self.kind.tag == JsonType::JSON_BOOL().tag) {
+            if (self.bool_val) { buf.append_c_ptr("true"); } else { buf.append_c_ptr("false"); }
+        } else if (self.kind.tag == JsonType::JSON_NUMBER().tag) {
+            let tmp: char[64];
+            sprintf((char*)tmp, "%.15g", self.number_val); // Use %.15g for precision
+            buf.append_c_ptr((char*)tmp);
+        } else if (self.kind.tag == JsonType::JSON_STRING().tag) {
+            buf.append_c_ptr("\"");
+            let p = self.string_val;
+            let len = strlen(p);
+            for (let i = 0; i < len; i = i + 1) {
+                let c = p[i];
+                if (c == '"') buf.append_c_ptr("\\\"");
+                else if (c == '\\') buf.append_c_ptr("\\\\");
+                else if (c == '\n') buf.append_c_ptr("\\n");
+                else if (c == '\t') buf.append_c_ptr("\\t");
+                else if (c == '\r') buf.append_c_ptr("\\r");
+                else if (c == '\b') buf.append_c_ptr("\\b");
+                else if (c == '\f') buf.append_c_ptr("\\f");
+                else {
+                    let tmp: char[2]; tmp[0] = c; tmp[1] = 0;
+                    buf.append_c_ptr((char*)tmp);
+                }
+            }
+            buf.append_c_ptr("\"");
+        } else if (self.kind.tag == JsonType::JSON_ARRAY().tag) {
+            buf.append_c_ptr("[");
+            let v = self.array_val;
+            for (let i: usize = 0; i < v.length(); i = i + 1) {
+                if (i > 0) buf.append_c_ptr(",");
+                let item = v.get(i);
+                (*item).stringify(buf);
+            }
+            buf.append_c_ptr("]");
+        } else if (self.kind.tag == JsonType::JSON_OBJECT().tag) {
+            buf.append_c_ptr("{{");
+            let m = self.object_val;
+            let first = true;
+            for (let i: usize = 0; i < m.capacity(); i = i + 1) {
+                if (m.is_slot_occupied(i)) {
+                    if (!first) buf.append_c_ptr(",");
+                    first = false;
+                    let key = m.key_at(i);
+                    buf.append_c_ptr("\"");
+                    buf.append_c_ptr(key); // Assuming keys are simple for now, but really should escape them too
+                    buf.append_c_ptr("\":");
+                    let val = m.val_at(i);
+                    val.stringify(buf);
+                }
+            }
+            buf.append_c_ptr("}");
+        }
+    }
+}
diff --git a/std/map.zc b/std/map.zc
index 8e58cdc..8376da2 100644
--- a/std/map.zc
+++ b/std/map.zc
@@ -1,17 +1,22 @@
 
 import "./core.zc"
 import "./option.zc"
+import "./mem.zc"
 
-raw {
-    extern size_t __zen_hash_seed;
-    size_t _map_hash_str(const char* str) {
-        size_t hash = __zen_hash_seed;
-        while (*str) {
-            hash ^= (unsigned char)*str++;
-            hash *= 1099511628211UL;
-        }
-        return hash;
+// Pure Zen-C string hash using FNV-1a algorithm
+fn _map_hash_str(str: const char*) -> usize {
+    let hash = __zen_hash_seed;
+    let i: usize = 0;
+    
+    while (str[i] != 0) {
+        // Cast char to U8 for unsigned byte value
+        let b: U8 = (U8)str[i];
+        hash = hash ^ (usize)b;
+        hash = hash * (usize)1099511628211;
+        i = i + 1;
     }
+    
+    return hash;
 }
 
 struct Map<V> {
@@ -248,3 +253,9 @@ impl Map<V> {
         };
     }
 }
+
+impl Drop for Map<V> {
+    fn drop(self) {
+        self.free();
+    }
+}
diff --git a/std/mem.zc b/std/mem.zc
index 6ee96e8..f1a5f5a 100644
--- a/std/mem.zc
+++ b/std/mem.zc
@@ -49,28 +49,7 @@ impl Box<T> {
     }
 }
 
-struct Slice<T> {
-    data: T*;
-    len: usize;
-}
-
-impl Slice<T> {
-    fn new(data: T*, len: usize) -> Self {
-        return Self { data: data, len: len };
-    }
-    
-    fn get(self, i: usize) -> T {
-        return self.data[i];
-    }
-    
-    fn set(self, i: usize, val: T) {
-        self.data[i] = val;
-    }
-    
-    fn is_empty(self) -> bool {
-        return self.len == 0;
-    }
-}
+// Note: Slice<T> is defined in std/slice.zc with iteration support
 
 fn mem_zero<T>(ptr: T*, count: usize) {
     memset(ptr, 0, sizeof(T) * count);
diff --git a/std/net.zc b/std/net.zc
index 72c3fcb..d410a4d 100644
--- a/std/net.zc
+++ b/std/net.zc
@@ -8,12 +8,22 @@ include <errno.h>
 import "./core.zc"
 import "./result.zc"
 import "./string.zc"
+import "./mem.zc"
 
 def Z_AF_INET = 2;
 def Z_SOCK_STREAM = 1;
 
+// Direct externs for simple socket functions
+extern fn socket(domain: int, type: int, proto: int) -> int;
+extern fn close(fd: int) -> int;
+extern fn read(fd: int, buf: void*, count: usize) -> isize;
+
+// Minimal raw block: required for struct sockaddr_in usage
+// These functions encapsulate sockaddr_in setup because the struct layout
+// cannot be declared in Zen-C without type conflicts with C headers.
+// Also includes inet_pton, htons, bind, connect, listen, accept wrappers.
 raw {
-    static int _z_net_bind(int fd, char *host, int port) {
+    static int _z_net_bind(int fd, const char *host, int port) {
         struct sockaddr_in addr;
         addr.sin_family = AF_INET;
         addr.sin_port = htons(port);
@@ -27,7 +37,7 @@ raw {
         return 0;
     }
 
-    static int _z_net_connect(int fd, char *host, int port) {
+    static int _z_net_connect(int fd, const char *host, int port) {
         struct sockaddr_in addr;
         addr.sin_family = AF_INET;
         addr.sin_port = htons(port);
@@ -36,28 +46,20 @@ raw {
         if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) return -2;
         return 0;
     }
-    
+
     static int _z_net_accept(int fd) {
         return accept(fd, NULL, NULL);
     }
 
-    static ssize_t _z_net_read(int fd, char* buf, size_t n) {
-        return read(fd, (void*)buf, n);
-    }
-
-    static ssize_t _z_net_write(int fd, char* buf, size_t n) {
+    static ssize_t _z_net_write(int fd, const char* buf, size_t n) {
         return write(fd, (const void*)buf, n);
     }
 }
 
-extern fn socket(domain: int, type: int, proto: int) -> int;
-extern fn close(fd: int) -> int;
-
-extern fn _z_net_bind(fd: int, host: char*, port: int) -> int;
-extern fn _z_net_connect(fd: int, host: char*, port: int) -> int;
+extern fn _z_net_bind(fd: int, host: const char*, port: int) -> int;
+extern fn _z_net_connect(fd: int, host: const char*, port: int) -> int;
 extern fn _z_net_accept(fd: int) -> int;
-extern fn _z_net_read(fd: int, buf: char*, n: usize) -> isize;
-extern fn _z_net_write(fd: int, buf: char*, n: usize) -> isize;
+extern fn _z_net_write(fd: int, buf: const char*, n: usize) -> isize;
 
 
 struct TcpStream {
@@ -66,7 +68,7 @@ struct TcpStream {
 
 impl TcpStream {
     fn read(self, buf: char*, len: usize) -> Result<usize> {
-        let n = _z_net_read(self.fd, buf, len);
+        let n = read(self.fd, (void*)buf, len);
         if (n < 0) return Result<usize>::Err("Read failed");
         return Result<usize>::Ok((usize)n);
     }
@@ -96,6 +98,12 @@ impl TcpStream {
     }
 }
 
+impl Drop for TcpStream {
+    fn drop(self) {
+        self.close();
+    }
+}
+
 struct TcpListener {
     fd: int;
 }
@@ -126,3 +134,9 @@ impl TcpListener {
         }
     }
 }
+
+impl Drop for TcpListener {
+    fn drop(self) {
+        self.close();
+    }
+}
diff --git a/std/process.zc b/std/process.zc
new file mode 100644
index 0000000..3ce43b6
--- /dev/null
+++ b/std/process.zc
@@ -0,0 +1,136 @@
+
+import "./core.zc";
+import "./vec.zc";
+import "./mem.zc";
+import "./string.zc";
+import "./option.zc";
+
+include <stdio.h>
+include <stdlib.h>
+
+// system() can be externed directly with const char*
+extern fn system(command: const char*) -> int;
+
+// Minimal raw block: only for opaque FILE* types
+// popen/pclose/fgets use FILE* which conflicts with void*
+raw {
+    void *_z_popen(const char *command, const char *type) {
+        return (void *)popen(command, type);
+    }
+    
+    int _z_pclose(void *stream) {
+        return pclose((FILE *)stream);
+    }
+    
+    char *_z_fgets(char *s, int size, void *stream) {
+        return fgets(s, size, (FILE *)stream);
+    }
+}
+
+extern fn _z_popen(command: const char*, type: const char*) -> void*;
+extern fn _z_pclose(stream: void*) -> int;
+extern fn _z_fgets(s: char*, size: int, stream: void*) -> char*;
+
+struct Output {
+    stdout: String;
+    exit_code: int;
+}
+
+struct Command {
+    program: String;
+    args: Vec<String>;
+}
+
+impl Command {
+    fn new(program: char*) -> Command {
+        return Command {
+            program: String::from(program),
+            args: Vec<String>::new()
+        };
+    }
+    
+    fn arg(self, arg: char*) -> Command* {
+        self.args.push(String::from(arg));
+        return self;
+    }
+    
+    fn _build_cmd(self) -> String {
+        let cmd_str = self.program.substring(0, self.program.length());
+        
+        for arg in &self.args {
+            let space = String::from(" ");
+            cmd_str.append(&space);
+            space.free();
+            
+            cmd_str.append(arg);
+        }
+        
+        return cmd_str;
+    }
+    
+    fn output(self) -> Output {
+        let cmd_str = self._build_cmd();
+        let cmd_c = cmd_str.c_str();
+        
+        let fp = _z_popen(cmd_c, "r");
+        
+        if (fp == 0) {
+            cmd_str.free();
+            // TODO: Better error handling...
+            return Output { 
+                stdout: String::from(""), 
+                exit_code: -1 
+            };
+        }
+        
+        let out = String::from("");
+        let buf_size: usize = 1024;
+        let buf = (char*)malloc(buf_size);
+        
+        while (true) {
+            let res = _z_fgets(buf, (int)buf_size, fp);
+            if (res == 0) break;
+            
+            let chunk = String::from(buf);
+            out.append(&chunk);
+            chunk.free();
+        }
+        
+        let code = _z_pclose(fp);
+        free(buf);
+        cmd_str.free();
+        
+        return Output {
+            stdout: out,
+            exit_code: code
+        };
+    }
+    
+    fn status(self) -> int {
+        let cmd_str = self._build_cmd();
+        let code = system(cmd_str.c_str());
+        cmd_str.free();
+        return code;
+    }
+
+    fn free(self) {
+        self.program.free();
+        
+        for s in &self.args {
+            s.free();
+        }
+        self.args.free();
+    }
+}
+
+impl Drop for Command {
+    fn drop(self) {
+        self.free();
+    }
+}
+
+impl Drop for Output {
+    fn drop(self) {
+        self.stdout.free();
+    }
+}
diff --git a/std/set.zc b/std/set.zc
index ba6c93f..e1faab3 100644
--- a/std/set.zc
+++ b/std/set.zc
@@ -2,17 +2,17 @@
 import "./core.zc"
 import "./option.zc"
 
-raw {
-    extern size_t __zen_hash_seed;
-    size_t _set_hash(const void* data, size_t len) {
-        size_t hash = __zen_hash_seed;
-        const unsigned char* bytes = (const unsigned char*)data;
-        for (size_t i = 0; i < len; i++) {
-            hash ^= bytes[i];
-            hash *= 1099511628211UL;
-        }
-        return hash;
+// Pure Zen-C generic hash using FNV-1a algorithm
+fn _set_hash(data: const void*, len: usize) -> usize {
+    let hash = __zen_hash_seed;
+    let bytes: U8* = (U8*)data;
+    
+    for (let i: usize = 0; i < len; i = i + 1) {
+        hash = hash ^ (usize)bytes[i];
+        hash = hash * (usize)1099511628211;
     }
+    
+    return hash;
 }
 
 struct Set<T> {
diff --git a/std/slice.zc b/std/slice.zc
index 778c6ed..c757fbd 100644
--- a/std/slice.zc
+++ b/std/slice.zc
@@ -1,10 +1,50 @@
 
+import "./option.zc"
+
 struct Slice<T> {
     data: T*;
     len: usize;
 }
 
+struct SliceIter<T> {
+    data: T*;
+    count: usize;
+    idx: usize;
+}
+
+impl SliceIter<T> {
+    fn next(self) -> Option<T> {
+        if (self.idx < self.count) {
+            let item = self.data[self.idx];
+            self.idx = self.idx + 1;
+            return Option<T>::Some(item);
+        }
+        return Option<T>::None();
+    }
+    
+    fn iterator(self) -> SliceIter<T> {
+        return *self;
+    }
+}
+
 impl Slice<T> {
+    fn from_array(ptr: T*, len: usize) -> Slice<T> {
+        return Slice<T> { data: ptr, len: len };
+    }
+
+    // Alias for backwards compatibility with std/mem.zc
+    fn new(data: T*, len: usize) -> Slice<T> {
+        return Slice<T> { data: data, len: len };
+    }
+
+    fn iterator(self) -> SliceIter<T> {
+        return SliceIter<T> {
+            data: self.data,
+            count: self.len,
+            idx: 0
+        };
+    }
+
     fn length(self) -> usize {
         return self.len;
     }
diff --git a/std/string.zc b/std/string.zc
index fe5b0ad..0bc9539 100644
--- a/std/string.zc
+++ b/std/string.zc
@@ -55,6 +55,28 @@ impl String {
         }
     }
 
+    fn append_c(self, s: char*) {
+        if (self.vec.len > 0) {
+            self.vec.len = self.vec.len - 1;
+        }
+        let len = strlen(s);
+        for (let i = 0; i < len; i = i + 1) {
+            self.vec.push(s[i]);
+        }
+        self.vec.push(0);
+    }
+
+    fn append_c_ptr(ptr: String*, s: char*) {
+        if (ptr.vec.len > 0) {
+            ptr.vec.len = ptr.vec.len - 1;
+        }
+        let len = strlen(s);
+        for (let i = 0; i < len; i = i + 1) {
+            ptr.vec.push(s[i]);
+        }
+        ptr.vec.push(0);
+    }
+
     fn add(self, other: String*) -> String {
         let new_s = String::from(self.c_str());
         new_s.append(other);
diff --git a/std/thread.zc b/std/thread.zc
index e90943b..16f3ca1 100644
--- a/std/thread.zc
+++ b/std/thread.zc
@@ -5,7 +5,13 @@ include <unistd.h>
 
 import "./core.zc"
 import "./result.zc"
+import "./mem.zc"
 
+// Essential raw block: required for pthread operations and closure trampolining
+// This block cannot be eliminated because:
+// 1. z_closure_T is an internal compiler type for Zen-C closures
+// 2. pthread_t, pthread_mutex_t are opaque types that can't be extern'd with void*
+// 3. The trampoline function needs to cast and execute Zen-C closures
 raw {
     typedef void (*ZenThreadFunc)(void*);
     
@@ -120,11 +126,17 @@ impl Mutex {
         if (self.handle) {
             _z_mutex_destroy(self.handle);
             free(self.handle);
+            self.handle = NULL;
         }
     }
 }
 
+impl Drop for Mutex {
+    fn drop(self) {
+        self.free();
+    }
+}
+
 fn sleep_ms(ms: int) {
     _z_usleep(ms * 1000);
 }
-
diff --git a/std/time.zc b/std/time.zc
index 1191821..fa764ed 100644
--- a/std/time.zc
+++ b/std/time.zc
@@ -1,18 +1,31 @@
-
 import "./core.zc"
 
+include <time.h>
+include <unistd.h>
+include <sys/time.h>
+include <stdlib.h>
+
+// Minimal raw block: required because gettimeofday() uses struct timeval
+// which can't be declared in Zen-C without type conflicts, and time()
+// has conflicting type signature (time_t* vs void*)
 raw {
-    #include <time.h>
-    #include <unistd.h>
-    #include <sys/time.h>
-    
     static uint64_t _time_now_impl(void) {
         struct timeval tv;
         gettimeofday(&tv, NULL);
         return (uint64_t)(tv.tv_sec) * 1000 + (uint64_t)(tv.tv_usec) / 1000;
     }
+
+    static int64_t _z_time_time(void) {
+        return (int64_t)time(NULL);
+    }
 }
 
+extern fn srand(seed: U32);
+extern fn rand() -> int;
+extern fn usleep(micros: U32) -> int;
+extern fn _time_now_impl() -> U64;
+extern fn _z_time_time() -> I64;
+
 struct Duration {
     millis: U64;
 }
@@ -33,10 +46,8 @@ extern size_t __zen_hash_seed;
 
 impl Time {
     fn randomize_hash() {
-        raw {
-            srand(time(NULL));
-            __zen_hash_seed ^= (size_t)rand();
-        }
+        srand((U32)_z_time_time());
+        __zen_hash_seed ^= (size_t)rand();
     }
 
     fn now() -> U64 {