Parse and serialize a json string-string map

Help
1

What is the recommended way to parse and serialize a string-string map to/from JSON?

Here is an example json:

{
"user23" : "john doe",
"user26" : "jane eyre"
}

I’m not sure how best to represent this in zig. It could be StringArrayHashMap or []const struct {[]const u8, []const u8}.

2

std.json.ArrayHashMap would be the easiest, it is a wrapper around StringArrayHashMap and just provides json parsing/stringifying.

define ‘best’, what are your requirements?

1 Like
3

Thanks, for others looking at this, just put std.json.ArrayHashMap as the type.

In this example, annotations is a string-string map.

/// Ref: https://specs.opencontainers.org/image-spec/image-index/?v=v1.1.1
const Index = @This();

const std = @import("std");

const Descriptor = @import("Descriptor.zig");

schemaVersion: u8 = 2,
mediaType: []const u8,
artifactType: ?[]const u8 = null,
manifests: []const Descriptor,
subject: ?Descriptor = null,
annotations: ?std.json.ArrayHashMap([]const u8) = null,

const index: oci.spec.image.Index = .{
        .mediaType = "application/vnd.oci.image.index.v1+json",
        .manifests = manifest_descriptors.items,
        .annotations = .{ .map = try .init(arena, &.{"org.opencontainers.image.ref.name"}, &.{args.tag}) },
    };

    var index_file = try std.fs.createFileAbsolute(args.output_path_index_json, .{});
    defer index_file.close();
    var index_file_writer_buffer: [4096]u8 = undefined;
    var index_file_writer = index_file.writer(&index_file_writer_buffer);
    var stringifier = std.json.Stringify{
        .writer = &index_file_writer.interface,
        .options = .{
            .emit_null_optional_fields = false,
            .whitespace = .indent_4,
        },
    };
    try stringifier.write(index);
    try index_file_writer.interface.flush();