From a5788ba94cbbd0c165462e64d66e3063a5d5e524 Mon Sep 17 00:00:00 2001
From: Tenari <djz24@case.edu>
Date: Tue, 2 Jun 2026 07:33:28 -0500
Subject: [PATCH] more string fns

---
 all.h    |  7 +++++--
 string.c | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/all.h b/all.h
index d126b95..3378a4a 100644
--- a/all.h
+++ b/all.h
@@ -345,8 +345,8 @@ typedef struct Codepoint {
 } Codepoint;
 
 typedef struct TextPos {
-  i64 line;
-  i64 column;
+  u32 line;
+  u32 column;
 } TextPos;
 
 typedef struct TextRange {
@@ -680,6 +680,9 @@ fn String stringFromRawCodepoint(Arena* a, u32 c);
 fn bool stringInsertCodepointAtByte(String* s, Codepoint c, u32 byte_offset, bool keep_trailing_zero);
 fn u8 stringDeleteCodepointAtByte(String* s, u32 byte_offset);
 fn bool stringDeleteCodepointsBetweenByteOffsetsInclusive(String* s, u32 start, u32 end);
+fn u32 stringCountLines(String s);
+fn u32 stringLineLen(String s, u32 line_number);
+fn u32 stringLineStartByteOffset(String s, u32 line_number);
 
 ///// OS-wrapped apis
 void      osInit();
diff --git a/string.c b/string.c
index 57659c2..2f701e6 100644
--- a/string.c
+++ b/string.c
@@ -428,3 +428,41 @@ fn StringUTF16Const str16FromStr8(Arena* arena, String string) {
 	return result;
 }
 
+fn u32 stringCountLines(String s) {
+  u32 result = 1;
+  for (u32 i = 0; i < s.length; i++) {
+    if (s.bytes[i] == '\n') {
+      result += 1;
+    }
+  }
+  return result;
+}
+
+fn u32 stringLineLen(String s, u32 line_number) {
+  u32 result = 0;
+  u32 current_line = 0;
+  for (u32 i = 0; i < s.length && current_line <= line_number; i++) {
+    if (current_line == line_number) {
+      result += 1;
+    }
+    if (s.bytes[i] == '\n') {
+      current_line += 1;
+    }
+  }
+  return result;
+}
+
+fn u32 stringLineStartByteOffset(String s, u32 line_number) {
+  u32 current_line = 0;
+  for (u32 i = 0; i < s.length; i++) {
+    // do this check first, so we won't return '\n' character pos, but the following char pos
+    if (current_line == line_number) {
+      return i;
+    }
+    if (s.bytes[i] == '\n') {
+      current_line += 1;
+    }
+  }
+  return s.length;
+}
+