From 815c8536f4e9e50e3ae58b191bd6d4bcd09f8796 Mon Sep 17 00:00:00 2001
From: Meghan Denny <hello@nektro.net>
Date: Thu, 12 Feb 2026 02:24:59 -0800
Subject: [PATCH] add parseDigits

---
 src/lib.zig         |  1 +
 src/parseDigits.zig | 39 +++++++++++++++++++++++++++++++++++++++
 src/parse_int.zig   |  2 +-
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 src/parseDigits.zig

diff --git a/src/lib.zig b/src/lib.zig
index b1e19c6f381c3441384bbd28a0b54c6aa8850466..e4947bf716741ad2e75a25da45974ecd85ac6252 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -118,3 +118,4 @@ pub usingnamespace @import("./compareFnBasic.zig");
 pub usingnamespace @import("./compareFnField.zig");
 pub usingnamespace @import("./compareFnRange.zig");
 pub usingnamespace @import("./asciiLower.zig");
+pub usingnamespace @import("./parseDigits.zig");
diff --git a/src/parseDigits.zig b/src/parseDigits.zig
new file mode 100644
index 0000000000000000000000000000000000000000..fe6d8613d7c45d7602d180a5a8889e747ca6b79e
--- /dev/null
+++ b/src/parseDigits.zig
@@ -0,0 +1,39 @@
+const std = @import("std");
+const string = []const u8;
+const extras = @import("./lib.zig");
+
+/// Simple number parser with no extra detection or handling. Alphabet is [0-9][a-z] with respect to base.
+/// Partially motivated by https://codeberg.org/ziglang/zig/issues/30881 + https://github.com/ziglang/zig/issues/24687
+pub fn parseDigits(comptime T: type, buf: []const u8, base: u8) !T {
+    std.debug.assert(base > 0);
+    std.debug.assert(base <= 36);
+    if (buf.len == 0) return error.InvalidCharacter;
+
+    var result: T = 0;
+    for (0..buf.len) |i| {
+        const c = buf[buf.len - 1 - i];
+        const d = switch (c) {
+            '0'...'9' => |a| a - '0',
+            'a'...'z' => |a| a - 'a' + 10,
+            'A'...'Z' => |a| a - 'A' + 10,
+            else => return error.InvalidCharacter,
+        };
+        if (d == 0) continue;
+        if (d >= base) return error.Overflow;
+        const _x = if (i == 0) 1 else std.math.powi(T, @intCast(base), @intCast(i)) catch return error.Overflow;
+        const _y = try std.math.mul(T, @intCast(d), _x);
+        const _z = try std.math.add(T, result, _y);
+        result = _z;
+    }
+    return result;
+}
+
+test {
+    try std.testing.expect(try parseDigits(u8, "10", 10) == 10);
+}
+test {
+    try std.testing.expect(try parseDigits(u8, "20", 16) == 32);
+}
+test {
+    try std.testing.expect(try parseDigits(u8, "EF", 16) == 239);
+}
diff --git a/src/parse_int.zig b/src/parse_int.zig
index a601095adf97c1f012f55d799c1de58ecc3f7dbe..c848f75ac3b38567657349db20cd952bc2fab130 100644
--- a/src/parse_int.zig
+++ b/src/parse_int.zig
@@ -4,7 +4,7 @@ const extras = @import("./lib.zig");
 
 pub fn parse_int(comptime T: type, s: ?string, b: u8, d: T) T {
     if (s == null) return d;
-    return std.fmt.parseInt(T, s.?, b) catch d;
+    return extras.parseDigits(T, s.?, b) catch d;
 }
 
 test {
-- 
2.54.0