Initial commit

sources/strview.c

@@ -0,0 +1,180 @@
+#include <string.h>
+#include "malunal/strview.h"
+
+
+strview_t
+strview(
+  malunal_cstr_t data,
+  malunal_size_t length
+) {
+  return (strview_t) {
+    .beg = data,
+    .end = data + length
+  };
+}
+
+strview_t
+strview_from_cstr(
+  malunal_cstr_t data
+) {
+  return data != null
+    ? strview(data, strlen(data))
+    : strview(null, 0);
+}
+
+malunal_size_t
+strview_length(
+  strview_iptr_t self
+) {
+  return self != null
+    ? self->end - self->beg
+    : 0;
+}
+
+malunal_void_t
+strview_ltrim(
+  strview_mptr_t self,
+  malunal_size_t count
+) {
+  malunal_size_t length =
+    strview_length(self);
+  if (length == 0)
+    return;
+
+  if (length < count)
+    count = length;
+  self->beg += count;
+}
+
+malunal_void_t
+strview_rtrim(
+  strview_mptr_t self,
+  malunal_size_t count
+) {
+  malunal_size_t length =
+    strview_length(self);
+  if (length == 0)
+    return;
+
+  if (length < count)
+    count = length;
+  self->end -= count;
+}
+
+strview_t
+strview_subview(
+  strview_iptr_t self,
+  malunal_size_t start,
+  malunal_size_t count
+) {
+  if (self == null)
+    return strview(null, 0);
+
+  strview_t      res = { self->beg, self->end };
+  malunal_size_t len = strview_length(&res);
+  if (start > len)
+    return strview(null, 0);
+
+  strview_ltrim(&res, start);
+  len = strview_length(&res);
+  if (count > len)
+    return strview(null, 0);
+
+  strview_rtrim(&res, len - count);
+  return res;
+}
+
+malunal_bool_t
+strview_equals(
+  strview_iptr_t self,
+  strview_iptr_t other
+) {
+  return strview_compare(self, other) == 0;
+}
+
+malunal_int32_t
+strview_compare(
+  strview_iptr_t self,
+  strview_iptr_t other
+) {
+  if (self == null || other == null) {
+    if (self <  other) return -1;
+    if (self >  other) return  1;
+    if (self == other) return  0;
+  }
+
+  malunal_size_t hlen = strview_length(self);
+  malunal_size_t nlen = strview_length(other);
+  if (hlen < nlen) return -1;
+  if (hlen > nlen) return  1;
+
+  malunal_size_t smallest = hlen < nlen ? hlen : nlen;
+  return strncmp(self->beg, other->beg, smallest);
+}
+
+malunal_bool_t
+strview_starts_with(
+  strview_iptr_t self,
+  strview_iptr_t other
+) {
+  if (self  == null) return false;
+  if (other == null) return true;
+
+  malunal_size_t hlen = strview_length(self);
+  malunal_size_t nlen = strview_length(other);
+  if (nlen == 0)
+    return true;
+
+  return hlen >= nlen
+    ? strncmp(self->beg, other->beg, nlen) == 0
+    : false;
+}
+
+malunal_bool_t
+strview_ends_with(
+  strview_iptr_t self,
+  strview_iptr_t other
+) {
+  if (self  == null) return false;
+  if (other == null) return true;
+
+  malunal_size_t hlen = strview_length(self);
+  malunal_size_t nlen = strview_length(other);
+  if (nlen == 0)
+    return true;
+
+  if (hlen < nlen)
+    return false;
+
+  malunal_size_t diff = hlen - nlen;
+  malunal_cstr_t beg  = self->beg + diff;
+  return strncmp(beg, other->beg, nlen) == 0;
+}
+
+malunal_bool_t
+strview_contains(
+  strview_iptr_t self,
+  strview_iptr_t other
+) {
+  if (self  == null) return false;
+  if (other == null) return true;
+
+  malunal_size_t hlen = strview_length(self);
+  malunal_size_t nlen = strview_length(other);
+  if (nlen == 0)
+    return true;
+
+  if (hlen < nlen)
+    return false;
+
+  // Poor man's sliding window
+  malunal_cstr_t beg = self->beg;
+  while (hlen >= nlen) {
+    if (strncmp(beg, other->beg, nlen) == 0)
+      return true;
+    beg++;
+    hlen--;
+  }
+
+  return false;
+}