Add optional arena to a Noh_String

src/noh.h

@@ -187,6 +187,17 @@ do {
     (da)->elems[(da)->count++] = (elem);                                                     \
 } while(0)
 
+// The same as noh_da_append, but uses an arena to allocate more data. No data is freed.
+#define noh_da_append_arena(arena, da, elem)                                         \
+do {                                                                                 \
+    if ((da)->count >= (da)->capacity) {                                             \
+        (da)->capacity = (da)->capacity == 0 ? NOH_DA_INIT_CAP : (da)->capacity * 2; \
+        (da)->elems = noh_arena_alloc((arena), (da)->capacity * sizeof(*(da)->elems));   \
+    }                                                                                \
+                                                                                     \
+    (da)->elems[(da)->count++] = (elem);                                             \
+} while(0)
+
 // Appends multiple elements to a dynamic array. Allocates more memory and moves all elements to newly allocated memory
 // if needed.
 #define noh_da_append_multiple(da, new_elems, new_elems_count)                               \
@@ -201,6 +212,19 @@ do {
     (da)->count += new_elems_count;                                                          \
 } while (0)
 
+// The same as noh_da_append_multiple, but uses an arena to allocate more data. No data is freed.
+#define noh_da_append_multiple_arena(arena, da, new_elems, new_elems_count)               \
+do {                                                                                      \
+    if ((da)->count + new_elems_count > (da)->capacity) {                                 \
+        if ((da)->capacity == 0) (da)->capacity = NOH_DA_INIT_CAP;                        \
+        while ((da)->count + new_elems_count > (da)->capacity) (da)->capacity *= 2;       \
+        (da)->elems = noh_arena_alloc((arena), (da)->capacity * sizeof(*(da)->elems));    \
+    }                                                                                     \
+                                                                                          \
+    memcpy((da)->elems + (da)->count, new_elems, new_elems_count * sizeof(*(da)->elems)); \
+    (da)->count += new_elems_count;                                                       \
+} while (0)
+
 // Removes the element at the specified location.
 #define noh_da_remove_at(da, index)                              \
 do {                                                             \
@@ -335,6 +359,9 @@ typedef struct {
     char *elems;
     size_t count;
     size_t capacity;
+    // If set, memory will be allocated in this arena when adding to the string.
+    // if set or unset halfway through using a string, this will cause undefined behaviour.
+    Noh_Arena *arena;
 } Noh_String;
 
 // Copies a Noh_String to the arena, and frees the Noh_String
@@ -343,6 +370,10 @@ char *noh_arena_consume_string(Noh_Arena *arena, Noh_String *string);
 // Creates a Noh_String from a c-string.
 Noh_String noh_string_from_cstr(const char *cstr);
 
+// Creates a Noh_String from a c-string.
+// Provide a Noh_Arena to allocate the string's data in.
+Noh_String noh_string_from_cstr_arena(Noh_Arena *arena, const char *cstr);
+
 // Appends a null-terminated string into a Noh_String.
 void noh_string_append_cstr(Noh_String *string, const char *cstr);
 
@@ -353,7 +384,10 @@ void noh_string_append_null(Noh_String *string);
 void noh_string_replace(Noh_String *string, const char from, const char to);
 
 // Frees a Noh_String, freeing the memory used and settings the count and capacity to 0.
-#define noh_string_free(string) noh_da_free(string)
+#define noh_string_free(string) do {                                           \
+    noh_assert(!(string)->arena && "A string with an arena cannot be freed."); \
+    noh_da_free(string);                                                       \
+} while(0)
 
 // Resets a Noh_String, setting the count to 0.
 #define noh_string_reset(string) noh_da_reset(string)
@@ -857,31 +891,54 @@ char *noh_arena_consume_string(Noh_Arena *arena, Noh_String *string) {
 }
 
 Noh_String noh_string_from_cstr(const char *cstr) {
+    return noh_string_from_cstr_arena(cstr, NULL);
+}
+
+Noh_String noh_string_from_cstr_arena(Noh_Arena *arena, const char *cstr) {
     Noh_String str = {0};
+    if (arena) str.arena = arena;
+
     noh_string_append_cstr(&str, cstr);
     return str;
 }
 
 void noh_string_append_cstr(Noh_String *string, const char *cstr) {
     size_t len = strlen(cstr);
+
+    if (string->arena) {
+        noh_da_append_multiple_arena(string->arena, string, cstr, len);
+    } else {
         noh_da_append_multiple(string, cstr, len);
+    }
 }
 
 void noh_string_append_null(Noh_String *string) {
+    if (string->arena) {
+        noh_da_append_arena(string->arena, string, '\0');
+    } else {
         noh_da_append(string, '\0');
+    }
 }
 
 void noh_string_replace(Noh_String *string, const char from, const char to) {
     Noh_String result = {0};
     for (size_t i = 0; i < string->count; i++) {
+        if (result.arena) {
+            if (string->elems[i] == from) {
+                noh_da_append_arena(result.arena, &result, to);
+            } else {
+                noh_da_append_arena(result.arena, &result, string->elems[i]);
+            }
+        } else {
             if (string->elems[i] == from) {
                 noh_da_append(&result, to);
             } else {
                 noh_da_append(&result, string->elems[i]);
             }
         }
+    }
 
-    noh_string_free(string);
+    if (!string->arena) noh_string_free(string);
     string->elems = result.elems;
     string->count = result.count;
     string->capacity = result.capacity;
@@ -906,7 +963,11 @@ bool noh_string_read_file(Noh_String *string, const char *filename) {
 
     size_t n = fread(buf, 1, buf_size, f);
     while (n > 0) {
+        if (string->arena) {
+            noh_da_append_multiple_arena(string->arena, string, buf, n);
+        } else {
             noh_da_append_multiple(string, buf, n);
+        }
         n = fread(buf, 1, buf_size, f);
     }
 
@@ -951,7 +1012,11 @@ Noh_String_View noh_sv_copy_cstr(Noh_Arena *arena, const char *cstr) {
 }
 
 void noh_string_append_sv(Noh_String *string, Noh_String_View sv) {
+    if (string->arena) {
+        noh_da_append_multiple_arena(string->arena, string, sv.elems, sv.count);
+    } else {
         noh_da_append_multiple(string, sv.elems, sv.count);
+    }
 }
 
 void noh_sv_increase_position(Noh_String_View *sv, size_t distance) {
@@ -1292,11 +1357,17 @@ bool noh_procs_wait(Noh_Procs procs) {
 void noh_quote_if_needed(const char *value, Noh_String *string) {
     if (!strchr(value, ' ')) {
         noh_string_append_cstr(string, value);
+    } else {
+        if (string->arena) {
+            noh_da_append_arena(string->arena, string, '\'');
+            noh_string_append_cstr(string, value);
+            noh_da_append_arena(string->arena, string, '\'');
         } else {
             noh_da_append(string, '\'');
             noh_string_append_cstr(string, value);
             noh_da_append(string, '\'');
         }
+    }
 }
 
 void noh_cmd_render(Noh_Cmd cmd, Noh_String *string) {