Tabular configuration for generating tables/reports from XML document

config.json

{
    "classes": {
        "deviation": [
            [ "printf", { "format": "%.2f%%" } ],
            [ "balance" ]
        ],
        "memory": [
            [ "printf", { "format": "%d<comment>b</comment>" }]
        ],
        "rps": [
            [ "number", { "decimal_places": 2 }],
            [ "printf", { "format": "%s<comment>rps</comment>" }]
        ],
        "time": [
            [ "number", { "decimal_places": 2 }],
            [ "printf", { "format": "%s<comment>\u03bcs</comment>" }]
        ]
    },
    "rows": [
        {
            "cells": {
                "benchmark": {
                    "expr": "class_name(string(ancestor-or-self::benchmark/@class))"
                },
                "subject": {
                    "expr": "string(ancestor-or-self::subject/@name)"
                },
                "group": {
                    "expr": "string(ancestor-or-self::group/@name)"
                },
                "params": {
                    "expr": "parameters_to_json(ancestor-or-self::variant/parameter)"
                },
                "revs": {
                    "expr": "number(descendant-or-self::iteration/@revs)"
                },
                "iter": {
                    "expr": "count(descendant-or-self::iteration/preceding-sibling::*)"
                },
                "time": {
                    "class": "time",
                    "expr": "number(descendant-or-self::iteration/@time) div sum(descendant-or-self::iteration/@revs)"
                },
                "time_net": {
                    "class": "time",
                    "expr": "number(descendant-or-self::iteration/@time)"
                },
                "memory": {
                    "class": "memory",
                    "expr": "number(descendant-or-self::iteration/@memory)"
                },
                "rps": {
                    "class": "rps",
                    "expr": "(1000000 div number(descendant-or-self::iteration//@time)) * number(descendant-or-self::iteration/@revs)"
                },
                "deviation": {
                    "class": "deviation",
                    "expr": "deviation(min(//@time), number(descendant-or-self::iteration/@time))"
                }
            },
            "with_query": "//iteration"
        },
        {
            "cells": {
                "deviation": {
                    "literal": "<info><< {{ row.item }}</info>"
                },
                "{{ cell.item  }}": {
                    "literal": "<comment>--</comment>",
                    "with_items": [
                        "benchmark",
                        "subject",
                        "group",
                        "params",
                        "iter"
                    ]
                },
                "{{ cell.col }}": {
                    "expr": "{{ row.item }}(//group[@name=\"_default\"]//cell[@name=\"{{ cell.col }}\"])",
                    "pass": 1,
                    "class": "{{ cell.class }}",
                    "with_items": [
                        {
                            "col": "memory", 
                            "class": "memory"
                        },
                        {
                            "col": "revs", 
                            "class": null
                        },
                        {
                            "col": "time", 
                            "class": "time"
                        },
                        {
                            "col": "time_net", 
                            "class": "time"
                        },
                        {
                            "col": "rps",
                            "class": "rps"
                        }
                    ]
                }
            },
            "group": "footer",
            "with_items": [ "average" ]
        }
    ]
}