1 files changed, 143 insertions, 0 deletions
diff --git a/advent-of-code/2023/lib/str.c b/advent-of-code/2023/lib/str.c
new file mode 100644
index 0000000..511e45b
--- /dev/null
+++ b/advent-of-code/2023/lib/str.c
@@ -0,0 +1,143 @@
+// Copyright (C) 2023 Mistivia <i@mistivia.com>
+// Licensed under GPLv3. See LICENSE for details.
+
+#include "str.h"
+
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vec.h"
+
+void *str_split(const char *str, char delim) {
+    void* ret = new_vec();
+
+    if (str == NULL) return NULL;
+    if (*str == '\n') {
+        return ret;
+    }
+    int count = 0;
+    const char *begin = str;
+    for (const char *p = str; *p != '\0'; p++) {
+        if (*p != delim && !(delim == '\0' && isspace(*p))) {
+            continue;
+        }
+        int size = p - begin;
+        if (size > 0) count++;
+    }
+    count++;
+
+    begin = str;
+    int i = 0;
+    bool finished = false;
+    for (const char *p = str; !finished; p++) {
+        if (*p == '\0') finished = true;
+        if (*p != delim && *p != '\0' && !(delim == '\0' && isspace(*p))) {
+            continue;
+        }
+        int size = p - begin;
+        if (size == 0) {
+            begin = p + 1;
+            continue;
+        }
+        char *buf = malloc(sizeof(char) * (size + 1));
+        buf[size] = '\0';
+        memcpy(buf, begin, size * sizeof(char));
+        begin = p + 1;
+        vec_push_back(ret, buf);
+    }
+    return ret;
+}
+
+char *str_strip(const char *str) {
+    if (str == NULL) return NULL;
+    int len = strlen(str);
+    const char *begin = str;
+    const char *end = str + len - 1;
+    while (isspace(*begin) && begin < end) {
+        begin++;
+    }
+    while (isspace(*end) && end >= begin) {
+        end--;
+    }
+    len = end - begin + 1;
+    char *buf = malloc(sizeof(char) * (len) + 1);
+    buf[len] = '\0';
+    memcpy(buf, begin, len);
+    return buf;
+}
+
+typedef struct {
+    size_t size;
+    size_t cap;
+    char *buf;
+} str_builder_t;
+
+// string stream
+void* new_ss() {
+    str_builder_t *self = malloc(sizeof(str_builder_t));
+    *self = (str_builder_t){.size = 0, .cap = 16};
+    self->buf = malloc(sizeof(char) * 17);
+    return self;
+}
+
+static void ss_reserve(str_builder_t *self, int extra) {
+    if (self->size + extra <= self->cap) {
+        return;
+    }
+    int new_cap = (self->size + extra) * 2;
+    self->buf = realloc(self->buf, new_cap + 1);
+    memset(self->buf + self->cap, 0, new_cap - self->cap + 1);
+    self->cap = new_cap;
+}
+
+void ss_add(void *self_, char *format, ...) {
+    str_builder_t *self = self_;
+    va_list va1;
+    va_list va2;
+    va_start(va1, format);
+    va_copy(va2, va1);
+    int size = vsnprintf(NULL, 0, format, va1);
+    ss_reserve(self, size);
+    vsnprintf(self->buf + self->size, self->cap - self->size + 1, format, va2);
+    self->size += size;
+}
+
+void ss_addc(void *self_, char c) {
+    str_builder_t *self = self_;
+    ss_reserve(self, 1);
+    self->buf[self->size] = c;
+    self->size++;
+}
+
+char *ss_cstr(void *self_) {
+    str_builder_t *self = self_;
+    return self->buf;    
+}
+
+size_t ss_size(void *self_) {
+    str_builder_t *self = self_;
+    return self->size;
+}
+
+char *fgetline(FILE *fp) {
+    void *ss = new_ss();
+    while (true) {
+        int c = fgetc(fp);
+        if (c == EOF && ss_size(ss) == 0) return NULL;
+        if (c != EOF) ss_addc(ss, c);
+        if (c == EOF || c == '\n') return ss_cstr(ss);
+    }
+    return NULL;
+}
+
+int fpeek(FILE *fp) {
+    int c = fgetc(fp);
+    if (c == EOF) return c;
+    ungetc(c, fp);
+    return c;
+}