Make add_char and set_char work

reid/lib/std.reid

@@ -25,6 +25,7 @@ struct String {
     inner: *char,
     length: u64,
     max_length: u64,
+    must_be_freed: bool,
 }
 
 pub fn new_string() -> String {
@@ -32,6 +33,7 @@ pub fn new_string() -> String {
         inner: allocate(0),
         length: 0,
         max_length: 0,
+        must_be_freed: true,
     }
 }
 
@@ -42,7 +44,8 @@ pub fn from_str(str: *char) -> String {
     return String {
         inner: cloned,
         length: length,
-        max_length: length
+        max_length: length,
+        must_be_freed: false,
     };
 }
 
@@ -51,9 +54,12 @@ pub fn add_char(string: &mut String, c: char) {
         let new = allocate((*string).max_length + 4) as *char;
         copy_bits((*string).inner, new, 0, (*string).max_length);
 
-        free((*string).inner as *u8);
+        if (*string).must_be_freed == true {
+            free((*string).inner as *u8);
+        }
         (*string).max_length = (*string).max_length + 4;
         (*string).inner = new;
+        (*string).must_be_freed = true;
     }
 
     (*string).inner[(*string).length] = c;
@@ -61,6 +67,12 @@ pub fn add_char(string: &mut String, c: char) {
     (*string).length = (*string).length + 1;
 }
 
+pub fn set_char(string: &mut String, c: char, position: u64) {
+    if position <= (*string).length {
+        (*string).inner[position] = c;
+    }
+}
+
 pub fn free_string(string: &mut String) {
     free((*string).inner as *u8);
 }
@@ -74,7 +86,7 @@ fn copy_bits(from: *char, to: *char, pos: u64, max: u64) -> u8 {
 }
 
 fn str_length(string: *char, position: u32) -> u32 {
-    if ((string[position] as u8) == 0) {
+    if (string[position] == '\0') {
         return 0;
     }
     return str_length(string, position + 1) + 1;

reid/src/codegen.rs

@@ -1135,7 +1135,7 @@ impl mir::IfExpression {
         if let Some(debug) = &scope.debug {
             let before_location = self.0 .1.into_debug(scope.tokens, debug.scope).unwrap();
             let before_v = debug.info.location(&debug.scope, before_location);
-            scope.block.set_terminator_location(before_v).unwrap();
+            scope.block.set_terminator_location(before_v).ok();
 
             let then_location = self
                 .1

reid_src/hello_world.reid

@@ -1,10 +1,14 @@
 import std::print;
 import std::from_str;
 import std::add_char;
+import std::set_char;
 import std::free_string;
 
 fn main() -> i32 {
     let mut test = from_str("hello world");
+
+    add_char(&mut test, '!');
+    set_char(&mut test, 'B', 0);
     
     print(&test);