More docs, and a few improvements for the standard library

3 files changed, 159 insertions, 28 deletions

diff --git a/std/io.zc b/std/io.zc
index 02018a8..10ac712 100644
--- a/std/io.zc
+++ b/std/io.zc
@@ -1,5 +1,6 @@
 
 import "./core.zc"
+import "./string.zc"
 
 raw {
     char* format(const char* fmt, ...) {
@@ -34,8 +35,29 @@ raw {
     { 
         return fgetc((FILE*)stream); 
     }
+    
+    char* _z_format_alloc(const char* fmt, va_list args) {
+         int len = vsnprintf(NULL, 0, fmt, args);
+         if (len < 0) return NULL;
+         char* buffer = malloc(len + 1);
+         if (!buffer) return NULL;
+         vsnprintf(buffer, len + 1, fmt, args);
+         return buffer;
+    }
+    
+    char* format_s_raw(char* fmt, ...) {
+        va_list args;
+        va_start(args, fmt);
+        char* ret = _z_format_alloc(fmt, args);
+        va_end(args);
+        return ret;
+    }
 }
 
+extern fn format_s_raw(fmt: char*, ...) -> char*;
+
+// TODO: add format function. We will need to do a few updates...
+//       like adding support for varargs in Zen C functions.
 
 
 fn readln() -> char* {
diff --git a/std/queue.zc b/std/queue.zc
index 3e99eba..0b00ee2 100644
--- a/std/queue.zc
+++ b/std/queue.zc
@@ -3,13 +3,15 @@ import "./mem.zc"
 
 struct Queue<T> {
   data: T*;
-  len: usize;
   cap: usize;
+  head: usize;
+  tail: usize;
+  count: usize;
 }
 
 impl Queue<T> {
   fn new() -> Queue<T> {
-    return Queue<T>{data: NULL, len: 0, cap: 0};
+    return Queue<T>{data: NULL, cap: 0, head: 0, tail: 0, count: 0};
   }
 
   fn free(self) {
@@ -17,54 +19,91 @@ impl Queue<T> {
       free(self.data);
       self.data = NULL;
     }
-    self.len = 0;
+    self.cap = 0;
+    self.head = 0;
+    self.tail = 0;
+    self.count = 0;
+  }
+
+  fn _grow(self) {
+    var new_cap = (self.cap == 0) ? 8 : self.cap * 2;
+    var new_data = malloc(sizeof(T) * new_cap);
+    
+    if (self.count > 0) {
+        if (self.tail > self.head) {
+            memcpy(new_data, self.data + self.head, sizeof(T) * self.count);
+        } else {
+            var first_part = self.cap - self.head;
+            var second_part = self.tail;
+            memcpy(new_data, self.data + self.head, sizeof(T) * first_part);
+            memcpy(new_data + first_part, self.data, sizeof(T) * second_part);
+        }
+    }
+    
+    if (self.data) free(self.data);
+    self.data = new_data;
+    self.cap = new_cap;
+    self.head = 0;
+    self.tail = self.count;
   }
 
   fn clone(self) -> Queue<T> {
     var new_queue = Queue<T>::new();
-    new_queue.len = self.len;
+    new_queue.data = malloc(sizeof(T) * self.cap);
     new_queue.cap = self.cap;
-    new_queue.data = malloc(sizeof(T) * new_queue.cap);
-    memcpy(new_queue.data, self.data, sizeof(T) * new_queue.len);
+    new_queue.head = 0;
+    new_queue.tail = self.count;
+    new_queue.count = self.count;
+    
+    if (self.count > 0) {
+        if (self.tail > self.head) {
+            memcpy(new_queue.data, self.data + self.head, sizeof(T) * self.count);
+        } 
+        else {
+            var first_part = self.cap - self.head;
+            var second_part = self.tail;
+            memcpy(new_queue.data, self.data + self.head, sizeof(T) * first_part);
+            memcpy(new_queue.data + first_part, self.data, sizeof(T) * second_part);
+        }
+    }
+    
     return new_queue;
   }
 
   fn push(self, value: T) {
-    if (!self.data) {
-      self.cap = 8;
-      self.data = malloc(sizeof(T) * self.cap);
+    if (self.count == self.cap) {
+      self._grow();
     }
-    if (self.len == self.cap) {
-      self.cap = self.cap * 2;
-      self.data = realloc(self.data, sizeof(T) * self.cap);
-    }
-    self.data[self.len] = value;
-    self.len = self.len + 1;
+    
+    self.data[self.tail] = value;
+    self.tail = (self.tail + 1) % self.cap;
+    self.count = self.count + 1;
   }
 
   fn pop(self) -> Option<T> {
-    if (self.len > 0) {
-      var value = self.data[0];
-      self.len = self.len - 1;
-
-      // Shifts the data in the queue "forward"
-      memcpy(self.data, self.data + 1, sizeof(T) * self.len);
-
-      return Option<T>::Some(value);
+    if (self.count == 0) {
+      return Option<T>::None();
     }
-    return Option<T>::None();
+    
+    var value = self.data[self.head];
+    self.head = (self.head + 1) % self.cap;
+    self.count = self.count - 1;
+    
+    return Option<T>::Some(value);
   }
 
   fn length(self) -> usize {
-    return self.len;
+    return self.count;
   }
 
   fn clear(self) {
-    self.len = 0;
+    self.head = 0;
+    self.tail = 0;
+    self.count = 0;
   }
 
   fn is_empty(self) -> bool {
-    return self.len == 0;
+    return self.count == 0;
   }
 }
 
diff --git a/std/string.zc b/std/string.zc
index 3f96053..a7dd6ce 100644
--- a/std/string.zc
+++ b/std/string.zc
@@ -31,7 +31,6 @@ impl String {
         return String::new(s);
     }
 
-    // Fixed: 'self' implies pointer in generated C
     fn c_str(self) -> char* {
         return self.vec.data;
     }
@@ -245,4 +244,75 @@ impl String {
         
         return parts;
     }
+
+    fn trim(self) -> String {
+        var start: usize = 0;
+        var len = self.length();
+        var end = len;
+
+        // Find start
+        while (start < len) {
+            var c = self.vec.get(start);
+            if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
+                break;
+            }
+            start = start + 1;
+        }
+
+        if (start == len) {
+            return String::new("");
+        }
+
+        // Find end
+        while (end > start) {
+            var c = self.vec.get(end - 1);
+            if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
+                break;
+            }
+            end = end - 1;
+        }
+
+        return self.substring(start, end - start);
+    }
+    
+    fn replace(self, target: char*, replacement: char*) -> String {
+        var t_len = strlen(target);
+        if (t_len == 0) return self.substring(0, self.length()); // clone
+        
+
+        var s_len = self.length();
+        var result = String::new("");
+        
+        var i: usize = 0;
+        while (i < s_len) {
+            // Check if match
+            if (i + t_len <= s_len) {
+                var is_match = true;
+                // Manual strncmp against vec data
+                for (var k: usize = 0; k < t_len; k = k + 1) {
+                    if (self.vec.get(i + k) != target[k]) {
+                        is_match = false;
+                        break;
+                    }
+                }
+                
+                if (is_match) {
+                    var r_str = String::new(replacement);
+                    result.append(&r_str);
+                    i = i + t_len;
+                    continue;
+                }
+            }
+            
+            // Append single char
+            var v = Vec<char>::new();
+            v.push(self.vec.get(i));
+            v.push(0);
+            var ch_s = String::new(v.data);
+            result.append(&ch_s);
+            v.free();
+            i = i + 1;
+        }
+        return result;
+    }
 }
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