some progress

Common/str.h

@@ -0,0 +1,61 @@
+/*
+    Routines for string processing.
+
+    *_ext_* functions are provided for foreign strings we're not in control of.
+*/
+
+#ifndef COM_STR_H
+#define COM_STR_H
+
+#include "def.h"
+#include <stdbool.h>
+#include <stdint.h>
+
+#define COM_STR_GROWABLE (1 << 0)        /* Data can grow and be reallocated. */
+#define COM_STR_STACK (1 << 1)           /* Stack residing. */
+#define COM_STR_SUB (1 << 2)             /* Substring of an existing one. */
+#define COM_STR_NULL_TERMINATED (1 << 3) /* Whether there's NULL at last. */
+
+/* Internal strings are assumed to have vectorizable alignment. */
+/* Instead of growing strings on joining we implement ropes. */
+typedef struct com_str {
+  struct com_str *next;
+  /* Actual size is +1, to fit NULL terminator. */
+  uint32_t len;
+  uint32_t flags;
+  char data[] __attribute__((aligned(COM_DEF_ALIGNMENT)));
+
+} com_str;
+
+/* NOTE: Have to be moved to static or global memory. */
+#define com_str_lit(p_l) {NULL, sizeof(p_l) - 1, COM_STR_NULL_TERMINATED, (p_l)}
+
+static inline uint32_t com_str_ext_len(char const *s) {
+  char const *p = s;
+  for (; *p != 0; ++p) {
+  }
+  return p - s;
+}
+
+/* Returns index of a char or -1 if it's not found. */
+static inline int32_t com_str_ext_find_char(char const *s, char ch) {
+  for (char const *p = s; *p != 0; ++p)
+    if (*p == ch)
+      return p - s;
+  return -1;
+}
+
+/* Returns true if string 'a' is prefixed by 'b'. */
+static inline bool com_str_ext_prefixed(char const *__restrict a,
+                                        struct com_str prefix) {
+  uint32_t n = prefix.len;
+  char *b = prefix.data;
+  while (n && *a && (*a == *b)) {
+    ++a;
+    ++b;
+    --n;
+  }
+  return n == 0;
+}
+
+#endif