From e91ae6e01828b9609b17b78c4b488dea3b6f1b50 Mon Sep 17 00:00:00 2001
From: Marsel Mavletkulov <mmavletkulov@maxmind.com>
Date: Thu, 16 Apr 2026 20:43:05 -0400
Subject: [PATCH 1/3] Add json escaping

---
 src/any.zig | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/any.zig b/src/any.zig
index d98dddd..1c35b71 100644
--- a/src/any.zig
+++ b/src/any.zig
@@ -36,14 +36,11 @@ pub const Value = union(enum) {
         }
     }
 
-    /// Formats the Value as JSON using a writer (unbounded output).
-    /// Strings are not escaped.
+    /// Formats the Value as JSON using a writer.
     pub fn format(self: Value, writer: anytype) !void {
         switch (self) {
             .string => |s| {
-                try writer.writeByte('"');
-                try writer.writeAll(s);
-                try writer.writeByte('"');
+                try std.json.Stringify.encodeJsonString(s, .{}, writer);
             },
             .int32 => |v| try writer.print("{}", .{v}),
             .uint16, .uint32, .uint64 => |v| try writer.print("{}", .{v}),
@@ -72,9 +69,7 @@ pub const Value = union(enum) {
                         try writer.writeByte(',');
                     }
 
-                    try writer.writeByte('"');
-                    try writer.writeAll(entry.key);
-                    try writer.writeByte('"');
+                    try std.json.Stringify.encodeJsonString(entry.key, .{}, writer);
                     try writer.writeByte(':');
                     try entry.value.format(writer);
                 }
@@ -106,6 +101,18 @@ test "encode scalars" {
             .value = .{ .string = "" },
             .want = "\"\"",
         },
+        .{
+            .value = .{ .string = "\"VOLZ\" LLC" },
+            .want = "\"\\\"VOLZ\\\" LLC\"",
+        },
+        .{
+            .value = .{ .string = "back\\slash" },
+            .want = "\"back\\\\slash\"",
+        },
+        .{
+            .value = .{ .string = "line\nnewline" },
+            .want = "\"line\\nnewline\"",
+        },
         .{
             .value = .{ .int32 = 0 },
             .want = "0",

From baca00d15c8fb35af6229d6c22710761aab38bdf Mon Sep 17 00:00:00 2001
From: Marsel Mavletkulov <mmavletkulov@maxmind.com>
Date: Thu, 16 Apr 2026 21:41:36 -0400
Subject: [PATCH 2/3] Check a string before escaping

Escaping causes 40% regression, but adding a check before
escaping a string lowers the regression to 24%.
---
 src/any.zig | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/any.zig b/src/any.zig
index 1c35b71..561de35 100644
--- a/src/any.zig
+++ b/src/any.zig
@@ -36,11 +36,29 @@ pub const Value = union(enum) {
         }
     }
 
+    // Checks if a string contains bytes that must be escaped in JSON:
+    // control characters (0x00-0x1F), double quote, or backslash.
+    fn jsonStringNeedsEscape(s: []const u8) bool {
+        for (s) |c| {
+            if (c < 0x20 or c == '"' or c == '\\') {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /// Formats the Value as JSON using a writer.
     pub fn format(self: Value, writer: anytype) !void {
         switch (self) {
             .string => |s| {
-                try std.json.Stringify.encodeJsonString(s, .{}, writer);
+                if (!jsonStringNeedsEscape(s)) {
+                    try writer.writeByte('"');
+                    try writer.writeAll(s);
+                    try writer.writeByte('"');
+                } else {
+                    try std.json.Stringify.encodeJsonString(s, .{}, writer);
+                }
             },
             .int32 => |v| try writer.print("{}", .{v}),
             .uint16, .uint32, .uint64 => |v| try writer.print("{}", .{v}),
@@ -69,7 +87,13 @@ pub const Value = union(enum) {
                         try writer.writeByte(',');
                     }
 
-                    try std.json.Stringify.encodeJsonString(entry.key, .{}, writer);
+                    if (!jsonStringNeedsEscape(entry.key)) {
+                        try writer.writeByte('"');
+                        try writer.writeAll(entry.key);
+                        try writer.writeByte('"');
+                    } else {
+                        try std.json.Stringify.encodeJsonString(entry.key, .{}, writer);
+                    }
                     try writer.writeByte(':');
                     try entry.value.format(writer);
                 }

From 1afed30e68c8e117ec3e3cb20423028fab60fd96 Mon Sep 17 00:00:00 2001
From: Marsel Mavletkulov <mmavletkulov@maxmind.com>
Date: Thu, 16 Apr 2026 22:04:07 -0400
Subject: [PATCH 3/3] Don't escape field names, only 14% regression

---
 src/any.zig | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/any.zig b/src/any.zig
index 561de35..4184b97 100644
--- a/src/any.zig
+++ b/src/any.zig
@@ -87,13 +87,10 @@ pub const Value = union(enum) {
                         try writer.writeByte(',');
                     }
 
-                    if (!jsonStringNeedsEscape(entry.key)) {
-                        try writer.writeByte('"');
-                        try writer.writeAll(entry.key);
-                        try writer.writeByte('"');
-                    } else {
-                        try std.json.Stringify.encodeJsonString(entry.key, .{}, writer);
-                    }
+                    // No need to escape field names, e.g., "city", "names",
+                    try writer.writeByte('"');
+                    try writer.writeAll(entry.key);
+                    try writer.writeByte('"');
                     try writer.writeByte(':');
                     try entry.value.format(writer);
                 }