From c74d615131c6fc5c93206bc7543459616c6c947a Mon Sep 17 00:00:00 2001
From: torque <torque@epicyclic.dev>
Date: Tue, 18 Jun 2024 18:30:27 -0700
Subject: [PATCH] parser.value.convertTo: simplify struct field usage

This avoids having to clone the map while maintaining the same
conversion strictness.
---
 src/parser/value.zig | 47 +++++++++++++++-----------------------------
 1 file changed, 16 insertions(+), 31 deletions(-)

diff --git a/src/parser/value.zig b/src/parser/value.zig
index f1795b4..9fd5603 100644
--- a/src/parser/value.zig
+++ b/src/parser/value.zig
@@ -209,39 +209,24 @@ pub const Value = union(enum) {
                     .map, .inline_map => |map| {
                         var result: T = undefined;
 
-                        if (options.ignore_extra_fields) {
-                            inline for (stt.fields) |field| {
-                                if (map.get(field.name)) |value| {
-                                    @field(result, field.name) = try value.convertTo(field.type, allocator, options);
-                                } else if (options.allow_omitting_default_values) {
-                                    if (comptime field.default_value) |def|
-                                        @field(result, field.name) = @as(*align(1) const field.type, @ptrCast(def)).*
-                                    else
-                                        return error.BadValue;
-                                } else {
+                        if (!options.ignore_extra_fields and (map.count() > stt.fields.len))
+                            return error.BadValue;
+
+                        var use_count: usize = 0;
+                        inline for (stt.fields) |field| {
+                            if (map.get(field.name)) |val| {
+                                @field(result, field.name) = try val.convertTo(field.type, allocator, options);
+                                use_count += 1;
+                            } else if (options.allow_omitting_default_values) {
+                                if (comptime field.default_value) |def|
+                                    @field(result, field.name) = @as(*align(1) const field.type, @ptrCast(def)).*
+                                else
                                     return error.BadValue;
-                                }
-                            }
-                        } else {
-                            // TODO: consider not cloning the map here. This would
-                            //       result in the requirement that the raw value object
-                            //       not be used after it has been converted to a type,
-                            //       based on the parse options.
-                            var clone = try map.clone();
-                            defer clone.deinit();
-                            inline for (stt.fields) |field| {
-                                if (clone.fetchSwapRemove(field.name)) |kv| {
-                                    @field(result, field.name) = try kv.value.convertTo(field.type, allocator, options);
-                                } else if (options.allow_omitting_default_values) {
-                                    if (comptime field.default_value) |def|
-                                        @field(result, field.name) = @as(*align(1) const field.type, @ptrCast(def)).*
-                                    else
-                                        return error.BadValue;
-                                } else return error.BadValue;
-                            }
-                            // there were extra fields in the data
-                            if (clone.count() > 0) return error.BadValue;
+                            } else return error.BadValue;
                         }
+                        // there were extra fields in the data
+                        if (!options.ignore_extra_fields and (map.count() > use_count))
+                            return error.BadValue;
 
                         return result;
                     },