per line

2 files changed, 23 insertions, 3 deletions

diff --git a/src/common.cpp b/src/common.cpp
index be45494..d608a22 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -19,6 +19,13 @@ line_view load_file(const char* path) {
   return lv;
 }
 
-line_view next_line(line_view file) {
-  return {nullptr, 0};
+line_view next_line(line_view file, size_t* offset) {
+  const char* p1 = file.line + *offset;
+  const char* p2 = p1;
+  const char* end = file.line + file.length;
+  while (p2 < end && *p2 != '\n') {
+    p2++;
+  }
+  *offset = p2 - file.line + 1;
+  return {p1, static_cast<size_t>(p2 - p1 + 1)};
 }
diff --git a/src/common.h b/src/common.h
index e320b66..93da70b 100644
--- a/src/common.h
+++ b/src/common.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <stdlib.h>
+#include <utility>
 
 struct line_view {
   const char* line;
@@ -8,4 +9,16 @@ struct line_view {
 };
 
 line_view load_file(const char*);
-line_view next_line(line_view);
+line_view next_line(line_view, size_t*);
+
+template <typename F, typename... Args>
+void per_line(line_view file, F&& f, Args&&... args) {
+  size_t offset = 0;
+  line_view lv;
+  do {
+    lv = next_line(file, &offset);
+    if (!f(lv, std::forward<Args>(args)...)) {
+      break;
+    }
+  } while (offset < file.length);
+}