4 files changed, 45 insertions, 5 deletions
diff --git a/src/2015/day1/aoc.cpp b/src/2015/day1/aoc.cpp
index e69de29..2263558 100644
--- a/src/2015/day1/aoc.cpp
+++ b/src/2015/day1/aoc.cpp
@@ -0,0 +1,13 @@
+#include "aoc.h"
+
+namespace aoc2015 {
+
+int day1(line_view lv) {
+  int level = 0;
+  for (size_t i = 0; i < lv.length; ++i) {
+    level += lv.line[i] == '(' ? 1 : -1;
+  }
+  return level;
+}
+
+} // namespace aoc2015
diff --git a/src/2015/day1/aoc.h b/src/2015/day1/aoc.h
index 6f70f09..b83b525 100644
--- a/src/2015/day1/aoc.h
+++ b/src/2015/day1/aoc.h
@@ -1 +1,9 @@
 #pragma once
+
+#include "common.h"
+
+namespace aoc2015 {
+
+int day1(line_view lv);
+
+}
diff --git a/src/common.cpp b/src/common.cpp
index 8ac3a96..d4457c6 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -5,9 +5,28 @@
 #include <sys/stat.h>
 
 line_view load_file(const char* path) {
-  return {nullptr, 0};
+  int fd;
+  struct stat fs;
+  fd = open(path, O_RDONLY);
+  if (fd == -1)
+    return {nullptr, 0};
+  if (fstat(fd, &fs) == -1)
+    return {nullptr, 0};
+
+  line_view lv;
+  lv.length = fs.st_size;
+  lv.line = static_cast<const char*>(mmap(NULL, lv.length, PROT_READ, MAP_PRIVATE, fd, 0));
+  return lv;
 }
 
-line_view next_line(const char* file, size_t offset) {
-  return {nullptr, 0};
+line_view next_line(line_view file) {
+  static size_t offset = 0;
+  line_view lv;
+  lv.line = file.line + offset;
+  lv.length = 0;
+  while (offset < file.length && file.line[offset] != '\n') {
+    lv.length += 1;
+    offset++;
+  }
+  return lv;
 }
diff --git a/src/common.h b/src/common.h
index f242f48..e320b66 100644
--- a/src/common.h
+++ b/src/common.h
@@ -3,9 +3,9 @@
 #include <stdlib.h>
 
 struct line_view {
-  char* line;
+  const char* line;
   size_t length;
 };
 
 line_view load_file(const char*);
-line_view next_line(const char*, size_t);
+line_view next_line(line_view);