diff --git a/Makefile b/Makefile
index b8b447d..af96f82 100644
--- a/Makefile
+++ b/Makefile
@@ -26,6 +26,7 @@ $(COMMON_OUT_DIR)/%.o: src/common/%.c
 .PHONY: clean
 clean:
 	rm -rf $(COMMON_OUT_DIR)
+	@mkdir -p $(COMMON_OUT_DIR)
 
 # generate compile commands with bear if u got it!!! 
 # very good highly recommended ʕ·ᴥ·ʔ
diff --git a/include/common/arena.h b/include/common/arena.h
index b992089..573741e 100644
--- a/include/common/arena.h
+++ b/include/common/arena.h
@@ -13,7 +13,7 @@ typedef struct ArenaState {
 
 void arena_init(Arena* arena);
 void arena_destroy(Arena* arena);
-void* arena_alloc(Arena* arena, usize size, usize align);
+ALLOC_ALIGN(2, 3) void* arena_alloc(Arena* arena, usize size, usize align);
 
 ArenaState arena_save(Arena* arena);
 void arena_restore(Arena* arena, ArenaState save);
diff --git a/include/common/portability.h b/include/common/portability.h
index 0693c2d..aa48f19 100644
--- a/include/common/portability.h
+++ b/include/common/portability.h
@@ -38,6 +38,9 @@
     #define FALLTHROUGH __attribute__((fallthrough))
     #define UNUSED __attribute__((unused))
     #define NORETURN __attribute__((noreturn))
+    #define ALLOC_ALIGN(sz, al) __attribute__((malloc, alloc_size(sz), alloc_align(al)))
+    #define ALLOC_SIZE(sz) __attribute__((malloc, alloc_size(sz)))
+    #define FORMAT_CHECK(fmt_pos, args_pos) __attribute__((format(printf, fmt_pos, args_pos)))
 #elif defined(_MSC_VER)
     #define WEAK __declspec(selectany)
     #define INLINE __forceinline
diff --git a/include/common/str.h b/include/common/str.h
index 3e19a58..a0516fc 100644
--- a/include/common/str.h
+++ b/include/common/str.h
@@ -4,12 +4,14 @@
 #include <stdlib.h>
 
 #include "common/type.h"
+#include "common/portability.h"
+#include "common/util.h"
 
 // strings and string-related utils.
 
 typedef struct string {
     char*  raw;
-    size_t len;
+    usize len;
 } string;
 
 #define NULL_STR ((string){nullptr, 0})
@@ -27,18 +29,91 @@ typedef struct string {
 #define string_wrap(cstring) ((string){(char*)(cstring), strlen((cstring))})
 #define strlit(cstring) ((string){(char*)cstring, sizeof(cstring)-1})
 
-char*  clone_to_cstring(string str); // this allocates
-void   printstr(string str);
-string strprintf(char* format, ...);
+#define string_lt(a, b) (string_cmp((a), (b)) < 0)
+#define string_gt(a, b) (string_cmp((a), (b)) > 0)
+#define string_le(a, b) (string_cmp((a), (b)) <= 0)
+#define string_ge(a, b) (string_cmp((a), (b)) >= 0)
 
-string  string_alloc(size_t len);
 #define string_free(str) free(str.raw)
-string  string_clone(string str); // this allocates as well
-string  string_concat(string a, string b); // allocates
-void  string_concat_buf(string buf, string a, string b); // this does not
 
-int  string_cmp(string a, string b);
+/// \brief Allocates len bytes for a new string
+///
+/// \param len Length of buffer
+///
+/// \return string A string with a buffer of at least length len. The resulting 
+///               buffer is zero-filled.
+///
+/// \note a null-terminated string can be allocated by providing len + 1.
+static inline string string_alloc(usize len);
+
+/// \brief Clones the source string to owned C string.
+///
+/// Allocates a null-terminated C string, and copies the source string.
+///
+/// \return cstring Owned null terminated C string.
+///
+/// \see clone_to_string
+static inline char* clone_to_cstring(string str);
+
+/// \brief Prints a string
+///
+/// Emits each character up to the sources length to stdout.
+static inline void printstr(string str);
+
+/// \brief Prints to a newly allocated string.
+///
+/// \param format printf format specifier
+/// \param ... printf format arguments
+///
+/// \return str null-terminated string, or NULL_STR on allocation fail.
+string strprintf(char* format, ...) FORMAT_CHECK(1, 2);
+
+/// \brief Clones the source string.
+///
+/// Allocates and copies the source string, without inserting a null terminator.
+///
+/// \return string Owned string
+///
+/// \see clone_to_cstring
+string string_clone(string str);
+
+/// \brief Concatenates two strings.
+///
+/// Allocates a buffer containing the concatenation of a and b.
+///
+/// \return str Allocated string containing ab, without a null terminator.
+string string_concat(string a, string b);
+
+/// \brief Concatenates two strings into buf.
+///
+/// \param[out] buf buffer of minimum length a.len + b.len.
+///            buf is filled with the concatenation ab, without a null terminator
+///
+/// \warning buffer must be large enough contain a and b, crashes otherwise.
+void string_concat_buf(string buf, string a, string b);
+
+/// \brief Compares two strings.
+///
+/// \return cond Returns 0 when equal, -1 when a < b, and 1 when a > b
+///             (their byte-wise, aggregate u8 difference is used to compare).
+///
+/// \note for equality, string_eq is more efficient, using heuristic length 
+/// checks before checking character by character.
+///
+/// \see string_eq
+isize string_cmp(string a, string b);
+
+/// \brief Checks if two strings are equal.
+///
+/// \return cond true if equal, else false
+///
+/// \see string_cmp
 bool string_eq(string a, string b);
+
+/// \brief Checks if string ends with another.
+///
+/// \return cond true if yes, else false. If the ending string is larger than 
+///              the source, returns false.
 bool string_ends_with(string source, string ending);
 
 #endif // ORBIT_STRING_H
diff --git a/include/common/vec.h b/include/common/vec.h
index 545e713..5715270 100644
--- a/include/common/vec.h
+++ b/include/common/vec.h
@@ -5,6 +5,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "common/str.h"
 
 ///
 /// +--------+--------+--------+--------+--------+--------+
@@ -37,7 +38,7 @@ typedef struct VecHeader {
 /// This vector's `VecHeader`.
 #define vec_header(vec) ((VecHeader*)((char*)(vec) - sizeof(VecHeader)))
 /// Get the pointer to a vec's elements from the header.
-#define vec_elems_from_header(header) ((void*)((char*)(header) + sizeof(VecHeader)))
+#define vec_elems_from_header(header) ((void*)((u8*)(header) + sizeof(VecHeader)))
 /// This vector's length.
 #define vec_len(vec) vec_header(vec)->len
 /// This vector's capacity.
@@ -89,4 +90,82 @@ void _vec_reserve1(Vec(void)* v, size_t stride);
 void _vec_shrink(Vec(void)* v, size_t stride);
 void _vec_destroy(Vec(void)* v);
 
+/* string specifics */
+
+/// \brief Copies string to newly allocated owned vector.
+///
+/// \param str source slice to copy
+/// \return vec char vector containing str
+///              (of capacity equal to the input's length).
+///
+/// \warning The result is not null-terminated.
+///
+/// It may be preferable to realloc in-place to reduce fragmentation. For
+/// dynamically allocated strings,
+/// \see realloc_string_to_vec
+Vec(char) string_to_vec(string str);
+
+/// \brief Copies a C string to newly allocated owned vector.
+///
+/// \param str source C string to copy
+/// \return vec char vector containing str
+///              (of capacity equal to the input's length).
+///
+/// \warning The result is not null-terminated.
+///
+/// It may be preferable to create a vector in-place to reduce fragmentation.
+/// For dynamically allocated C strings,
+/// \see realloc_string_to_vec
+static inline Vec(char) cstring_to_vec(const char* str);
+
+/// \brief Takes ownership of string and creates a char vector.
+///
+/// Allocates a new space for a header at the start of the string's raw pointer,
+/// then moves the string in-place, and returning the new vec.
+///
+/// \param str dynamically allocated string, possibly null-terminated.
+/// \return vec char vector containing str
+///         (with a capacity of 1.5x the input's length).
+///
+/// \warning The result is not null-terminated.
+///
+/// \warning To allocate space, the function uses realloc, so the underlying
+/// data must have been allocated by an *alloc family function (i.e malloc,
+/// calloc, alligned_alloc etc).
+///
+/// For a copy only function,
+/// \see string_to_vec
+Vec(char) realloc_string_to_vec(string str);
+
+/// \brief Takes ownership of string and creates a char vector.
+///
+/// Allocates a new space for a header at the start of the str,
+/// then moves the string in-place, and returning the new vec.
+///
+/// \param str dynamically allocated null-terminated string.
+/// \return vec char vector containing str
+///         (with a capacity of 1.5x the input's length).
+///
+/// \warning The result is not null-terminated.
+///
+/// \warning To allocate space, the function uses realloc, so the source str
+/// must have been allocated by an *alloc family function (i.e malloc,
+/// calloc, alligned_alloc etc).
+///
+/// For a copy only function,
+/// \see cstring_to_vec
+static inline Vec(char) realloc_cstring_to_vec(char* str);
+
+/// \brief Format print to the end of a char vec
+///
+/// Appends formatted string to a Vec(char), reallocating to make space.
+///
+/// \param str string vector, possibly null-terminated
+/// \param format printf format specifier
+/// \param ... printf format arguments
+///
+/// \warning The result is not null-terminated, nor does the function write
+///          over any old null terminators.
+FORMAT_CHECK(2, 3) void vec_appendf(Vec(char) str, const char* format, ...);
+
 #endif // VEC_H
diff --git a/src/common/str.c b/src/common/str.c
index 99d4307..11a5fb9 100644
--- a/src/common/str.c
+++ b/src/common/str.c
@@ -3,7 +3,6 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "common/portability.h"
 #include "common/str.h"
 
 string strprintf(char* format, ...) {
@@ -12,7 +11,7 @@ string strprintf(char* format, ...) {
     va_start(a, format);
     va_list b;
     va_copy(b, a);
-    size_t bufferlen = 1 + vsnprintf("", 0, format, a);
+    usize bufferlen = 1 + vsnprintf("", 0, format, a);
     c = string_alloc(bufferlen);
     vsnprintf(c.raw, c.len, format, b);
     c.len--;
@@ -28,11 +27,15 @@ string string_concat(string a, string b) {
 }
 
 void string_concat_buf(string buf, string a, string b) {
-    for (size_t i = 0; i < a.len; ++i) {
+    if (buf.len < a.len + b.len)
+        CRASH("Buffer is too small. %zu < %zu + %zu", buf.len, a.len, b.len);
+
+    usize i;
+    for_n(i, 0, a.len) {
         buf.raw[i] = a.raw[i];
     }
-    for (size_t i = 0; i < b.len; ++i) {
-        buf.raw[i + a.len] = b.raw[i];
+    for_n(i, 0, b.len) {
+        buf.raw[a.len + i] = b.raw[i];
     }
 }
 
@@ -42,16 +45,11 @@ bool string_ends_with(string source, string ending) {
     return string_eq(substring_len(source, source.len-ending.len, ending.len), ending);
 }
 
-string string_alloc(size_t len) {
-    char* raw = malloc(len);
-
-    memset(raw, '\0', len);
-
-    return (string){raw, len};
+static inline string string_alloc(usize len) {
+    return (string){calloc(len, sizeof(char*)), len};
+};
 
-}
-
-int string_cmp(string a, string b) {
+isize string_cmp(string a, string b) {
     // copied from odin's implementation lmfao
     int res = memcmp(a.raw, b.raw, a.len < b.len ? a.len : b.len);
     if (res == 0 && a.len != b.len) return a.len <= b.len ? -1 : 1;
@@ -67,14 +65,11 @@ bool string_eq(string a, string b) {
     return true;
 }
 
-char* clone_to_cstring(string str) {
-    if (is_null_str(str)) return "";
-
-    char* cstr = malloc(str.len + 1);
-    if (cstr == nullptr) return nullptr;
-    memcpy(cstr, str.raw, str.len);
-    cstr[str.len] = '\0';
-    return cstr;
+static inline char* clone_to_cstring(string str) {
+    // NOTE: the returned char* is always allocated, so no null literal
+    // (otherwise subsequent realloc results in undefined behaviour).
+    // The last null character is always allocated internally.
+    return strndup(str.raw, str.len);
 }
 
 string string_clone(string str) {
@@ -83,12 +78,12 @@ string string_clone(string str) {
     return new_str;
 }
 
-void printn(char* text, size_t len) {
-    size_t c = 0;
+void printn(char* text, usize len) {
+    usize c = 0;
     while (c < len && text[c] != '\0')
         putchar(text[c++]);
 }
 
-void printstr(string str) {
+static inline void printstr(string str) {
     printn(str.raw, str.len);
 }
diff --git a/src/common/vec.c b/src/common/vec.c
index ecf3270..bcaef43 100644
--- a/src/common/vec.c
+++ b/src/common/vec.c
@@ -1,5 +1,6 @@
 #include <string.h>
 #include <stdio.h>
+#include <stdarg.h>
 
 #include "common/portability.h"
 #include "common/vec.h"
@@ -40,3 +41,55 @@ WEAK void _vec_destroy(Vec(void)* v) {
     free(vec_header(*v));
     *v = nullptr;
 }
+
+/* string specifics */
+
+Vec(char) string_to_vec(string str) {
+    Vec(char) v = vec_new(char, str.len);
+
+    memcpy(v, str.raw, str.len);
+    return v;
+}
+
+static inline Vec(char) cstring_to_vec(const char* str) {
+    return string_to_vec(string_wrap(str));
+}
+
+Vec(char) realloc_string_to_vec(string str) {
+    // The assumption is that you make a vec to append to it, so we reserve
+    // more up-front.
+    str.raw = realloc(str.raw, str.len * 1.5 + sizeof(VecHeader));
+
+    // memmove so that strings can overlap.
+    memmove(str.raw, (u8*)str.raw + sizeof(VecHeader), str.len);
+
+    Vec(char) v = vec_elems_from_header(str.raw);
+
+    if (v == nullptr)
+        return nullptr;
+
+    vec_cap(v) += str.len / 2;
+    vec_len(v) = str.len;
+
+    return v;
+}
+
+static inline Vec(char) realloc_cstring_to_vec(char* str) {
+    return realloc_string_to_vec(string_wrap(str));
+}
+
+void vec_appendf(Vec(char) str, const char* format, ...) {
+    va_list a;
+    va_start(a, format);
+    va_list b;
+    va_copy(b, a);
+
+    usize printlen = 1 + vsnprintf("", 0, format, a);
+
+    vec_reserve(&str, printlen);
+
+    vsnprintf(&str[vec_len(str)], printlen, format, b);
+
+    va_end(a);
+    va_end(b);
+}