renderStructInit

fn renderStructInit(
    r: *Render,
    struct_node: Ast.Node.Index,
    struct_init: Ast.full.StructInit,
    space: Space,
) Error!void {
    const tree = r.tree;
    const ais = r.ais;

    if (struct_init.ast.type_expr.unwrap()) |type_expr| {
        try renderExpression(r, type_expr, .none); // T
    } else {
        try renderToken(r, struct_init.ast.lbrace - 1, .none); // .
    }

    if (struct_init.ast.fields.len == 0) {
        try ais.pushIndent(.normal);
        try renderToken(r, struct_init.ast.lbrace, .none); // lbrace
        ais.popIndent();
        return renderToken(r, struct_init.ast.lbrace + 1, space); // rbrace
    }

    const rbrace = tree.lastToken(struct_node);
    const trailing_comma = tree.tokenTag(rbrace - 1) == .comma;
    if (trailing_comma or hasComment(tree, struct_init.ast.lbrace, rbrace)) {
        // Render one field init per line.
        try ais.pushIndent(.normal);
        try renderToken(r, struct_init.ast.lbrace, .newline);

        for (0.., struct_init.ast.fields) |i, field_init| {
            const init_token = tree.firstToken(field_init);
            if (i != 0)
                try renderExtraNewlineToken(r, init_token - 3);
            try renderToken(r, init_token - 3, .none); // .
            try renderIdentifier(r, init_token - 2, .space, .eagerly_unquote); // name
            try renderToken(r, init_token - 1, .maybe_space); // =

            try ais.pushSpace(.comma);
            try renderExpressionFixup(r, field_init, .comma);
            ais.popSpace();
        }

        ais.popIndent();
    } else {
        // Render all on one line, no trailing comma.
        try renderToken(r, struct_init.ast.lbrace, .space);

        for (struct_init.ast.fields) |field_init| {
            const init_token = tree.firstToken(field_init);
            try renderToken(r, init_token - 3, .none); // .
            try renderIdentifier(r, init_token - 2, .space, .eagerly_unquote); // name
            try renderToken(r, init_token - 1, .maybe_space); // =
            try renderExpressionFixup(r, field_init, .comma_space);
        }
    }

    return renderToken(r, rbrace, space);
}