1 files changed, 247 insertions, 0 deletions
diff --git a/kernel/lib/sv.c b/kernel/lib/sv.c
new file mode 100644
index 0000000..580e63a
--- /dev/null
+++ b/kernel/lib/sv.c
@@ -0,0 +1,247 @@
+#include <ctype.h>
+#include <kmalloc.h>
+#include <lib/sv.h>
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct sv sv_init(const char *s, size_t length) {
+  return (struct sv){.s = s, .length = length};
+}
+
+char *SV_TO_C(struct sv s) {
+  char *c_string = kmalloc(s.length + 1);
+  memcpy(c_string, s.s, s.length);
+  c_string[s.length] = '\0';
+  return c_string;
+}
+
+size_t sv_to_cstring_buffer(struct sv s, char *buffer, size_t length) {
+  if (0 == length || length - 1 < s.length) {
+    return s.length;
+  }
+  memcpy(buffer, s.s, s.length);
+  buffer[s.length] = '\0';
+  return s.length;
+}
+
+struct sv sv_next(struct sv s) {
+  if (0 == s.length) {
+    return s;
+  }
+  s.length--;
+  s.s++;
+  return s;
+}
+
+struct sv sv_skip_chars(const struct sv input, const char *chars) {
+  struct sv r = input;
+  for (; r.length > 0;) {
+    int found = 0;
+    const char *p = chars;
+    for (; *p; p++) {
+      if (*p == r.s[0]) {
+        r.s++;
+        r.length--;
+        found = 1;
+        break;
+      }
+    }
+    if (!found) {
+      break;
+    }
+  }
+  return r;
+}
+
+uint64_t sv_parse_unsigned_number(struct sv input, struct sv *rest) {
+  uint64_t r = 0;
+  size_t i = 0;
+  for (; i < input.length; i++) {
+    if (!isdigit(input.s[i])) {
+      break;
+    }
+    r *= 10;
+    r += input.s[i] - '0';
+  }
+  input.length -= i;
+  input.s += i;
+  if (rest) {
+    *rest = input;
+  }
+  return r;
+}
+
+struct sv sv_split_function(const struct sv input, struct sv *rest,
+                            int (*function)(int)) {
+  struct sv r = {
+      .s = input.s,
+  };
+  for (size_t i = 0; i < input.length; i++) {
+    if (function(input.s[i])) {
+      r.length = i;
+      if (rest) {
+        rest->s += i;
+        rest->length -= i;
+      }
+      return r;
+    }
+  }
+
+  if (rest) {
+    rest->s = NULL;
+    rest->length = 0;
+  }
+  return input;
+}
+
+struct sv sv_split_space(const struct sv input, struct sv *rest) {
+  return sv_split_function(input, rest, isspace);
+}
+
+struct sv sv_end_split_delim(const struct sv input, struct sv *rest,
+                             char delim) {
+  for (size_t i = input.length - 1; i > 0; i--) {
+    if (delim == input.s[i]) {
+      struct sv r = {
+          .s = (input.s + i),
+          .length = input.length - i,
+      };
+      if (rest) {
+        rest->s = input.s;
+        rest->length = i;
+      }
+      return r;
+    }
+  }
+
+  if (rest) {
+    rest->s = NULL;
+    rest->length = 0;
+  }
+  return input;
+}
+
+struct sv sv_split_delim(const struct sv input, struct sv *rest, char delim) {
+  struct sv r = {
+      .s = input.s,
+  };
+  for (size_t i = 0; i < input.length; i++) {
+    if (delim == input.s[i]) {
+      r.length = i;
+      if (rest) {
+        rest->s += i + 1;
+        rest->length -= (i + 1);
+      }
+      return r;
+    }
+  }
+
+  if (rest) {
+    rest->s = NULL;
+    rest->length = 0;
+  }
+  return input;
+}
+
+int sv_isempty(struct sv s) {
+  return (0 == s.length);
+}
+
+char sv_peek(struct sv s) {
+  if (0 == s.length) {
+    return '\0';
+  }
+  return s.s[0];
+}
+
+int sv_partial_eq(struct sv a, struct sv b) {
+  if (a.length < b.length) {
+    return 0;
+  }
+  for (size_t i = 0; i < b.length; i++) {
+    if (a.s[i] != b.s[i]) {
+      return 0;
+    }
+  }
+  return 1;
+}
+
+int sv_eq(struct sv a, struct sv b) {
+  if (a.length != b.length) {
+    return 0;
+  }
+  for (size_t i = 0; i < a.length; i++) {
+    if (a.s[i] != b.s[i]) {
+      return 0;
+    }
+  }
+  return 1;
+}
+
+struct sv sv_take(struct sv s, struct sv *rest, size_t n) {
+  if (s.length < n) {
+    if (rest) {
+      rest->length = 0;
+    }
+    return s;
+  }
+  s.length = n;
+  if (rest) {
+    rest->length -= n;
+    rest->s += n;
+  }
+  return s;
+}
+
+struct sv sv_take_end(struct sv s, struct sv *rest, size_t n) {
+  if (s.length < n) {
+    if (rest) {
+      rest->length = 0;
+    }
+    return s;
+  }
+  if (rest) {
+    rest->length = s.length - n;
+  }
+  s.s += (s.length - n);
+  s.length = n;
+  return s;
+}
+
+struct sv sv_trim_left(struct sv s, size_t n) {
+  if (s.length < n) {
+    s.s += s.length;
+    s.length = 0;
+    return s;
+  }
+  s.s += n;
+  s.length -= n;
+  return s;
+}
+
+struct sv sv_clone(struct sv s) {
+  struct sv new_sv;
+  new_sv.length = s.length;
+  char *new_string = kmalloc(s.length);
+  memcpy(new_string, s.s, s.length);
+  new_sv.s = new_string;
+  return new_sv;
+}
+
+char *sv_copy_to_c(struct sv s, char *out, size_t buffer_length) {
+  int copy_len = min(s.length + 1, buffer_length);
+  if (0 == copy_len) {
+    return NULL;
+  }
+  if (!out) {
+    out = kmalloc(copy_len);
+  }
+  memcpy(out, s.s, copy_len - 1);
+  out[copy_len - 1] = '\0';
+  return out;
+}
+
+struct sv sv_clone_from_c(const char *s) {
+  return sv_clone(C_TO_SV(s));
+}