You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: engine.rs
    path of file: ./repos/tectonic/crates/xetex_format/src
    
    the code of the file until where you have to start completion: // Copyright 2021-2022 the Tectonic Project
// Licensed under the MIT License.

#![deny(missing_docs)]

//! The overall interface provided by the engine.

use std::{cmp::Ordering, io::Write};
use tectonic_errors::prelude::*;

use crate::{
    commands::{self, Commands},
    cshash, dimenpars, enums, eqtb, etexpenalties, gluepars, intpars, locals,
    symbols::{SymbolCategory, SymbolTable},
    FormatVersion, LATEST_VERSION,
};

/// Information about the engine implementation.
#[derive(Debug)]
pub struct Engine {
    /// The interface version implemented by this engine.
    pub version: FormatVersion,

    /// The table of named symbols associated with this engine version.
    pub symbols: SymbolTable,

    /// The low-level commands provided by the engine.
    pub commands: Commands,

    /// The integer parameters defined in this engine implementation.
    pub int_pars: Vec<intpars::IntPar>,

    /// The dimension parameters defined in this engine implementation.
    pub dimen_pars: Vec<dimenpars::DimenPar>,

    /// The glue parameters defined in this engine implementation.
    pub glue_pars: Vec<gluepars::GluePar>,

    /// The "local" (token list and shape, excluding e-TeX penalties) parameters
    /// defined in this engine implementation.
    pub local_pars: Vec<locals::LocalPar>,

    /// The e-TeX penalties parameters defined in this engine implementation.
    pub etex_penalties_pars: Vec<etexpenalties::EtexPenaltiesPar>,
}

impl Engine {
    /// Get an engine definition for a specific version.
    pub fn new_for_version(version: FormatVersion) -> Result<Engine> {
        let mut symbols = SymbolTable::default();
        symbols.add(
            SymbolCategory::FormatVersion,
            "TECTONIC_FORMAT_VERSION",
            version as isize,
        )?;

        cshash::initialize_cshash_symbols(&mut symbols)?;

        // Version 32 passed 500 primitives! In version 33, we sync with TeXLive
        // 2022 and bump prim_size to 2100.
        let (prim_size, prim_prime) = match version.cmp(&32) {
            Ordering::Greater => (2100, 1777),
            Ordering::Equal => (510, 431),
            Ordering::Less => (500, 431),
        };

        symbols.add(SymbolCategory::FixedArrays, "PRIM_SIZE", prim_size)?;
        symbols.add(SymbolCategory::FixedArrays, "PRIM_PRIME", prim_prime)?;
        symbols.add(SymbolCategory::FixedArrays, "MAX_FONT_MAX", 9000)?;
        symbols.add(SymbolCategory::FixedArrays, "MEM_TOP", 4_999_999)?;
        symbols.add(SymbolCategory::FixedArrays, "NUMBER_MATH_FAMILIES", 256)?;

        let int_pars = intpars::get_intpars_for_version(version, &mut symbols)?;
        let dimen_pars = dimenpars::get_dimenpars_for_version(version, &mut symbols)?;
        let glue_pars = gluepars::get_gluepars_for_version(version, &mut symbols)?;
        let lo
    
    fn check_version_31() {
        let eng = Engine::new_for_version(31).unwrap();

        check!(
            eng [
                TECTONIC_FORMAT_VERSION = 31,
                MEM_TOP = 4_999_999,

                INT_PARS = 85,
                DIMEN_PARS = 23,
                GLUE_PARS = 19,
                NUM_LOCALS = 13,
                NUM_ETEX_PENALTIES = 4,

                // eqtb
                UNDEFINED_CONTROL_SEQUENCE = 2_252_739,
                BOX_BASE = 2_253_544,
                EQTB_SIZE = 10_053_972,
                EQTB_TOP = 10_653_972,

                // command codes
                MAX_CHAR_CODE = 15,
                MIN_INTERNAL = 68,
                CHAR_GIVEN = 68,
                MAX_NON_PREFIXED_COMMAND = 71,
                LAST_ITEM = 71,
                MAX_INTERNAL = 91,
                REGISTER = 91,
                MAX_COMMAND = 102,
                SET_INTERACTION = 102,
                DATA = 122,

                HMODE = 104,
                MMODE = 207,

                UNSET_NODE = 13,
                ORD_NOAD = 16,
                RIGHT_NOAD = 31,

                // Whatsit node subtypes
                LANGUAGE_NODE = 4,
                PDF_SAVE_POS_NODE = 21,
                NATIVE_WORD_NODE = 40,
                NATIVE_WORD_NODE_AT = 41,
                GLYPH_NODE = 42,
                PIC_NODE = 43,
                PDF_NODE = 44,

                VTOP_CODE = 4,
                TT_VBOX_CODE = 5,
                TT_HBOX_CODE = 108,

                // CONVERT codes
                ETEX_CONVERT_BASE = 5,
                ETEX_REVISION_CODE = 5,
                PDFTEX_FIRST_EXPAND_CODE = 7,
                LEFT_MARGIN_KERN_CODE = 16,
                PDF_CREATION_DATE_CODE = 22,
                UNIFORM_DEVIATE_CODE = 29,
                PDFTEX_CONVERT_CODES = 33,
                XETEX_FIRST_EXPAND_CODE = 33,
                XETEX_REVISION_CODE = 33,
                XETEX_CONVERT_CODES = 40,
                JOB_NAME_CODE = 40,

                // EXTENSION codes
                IMMEDIATE_CODE = 4,
                RESET_TIMER_CODE = 31,
                SET_RANDOM_SEED_CODE = 33,
                PIC_FILE_CODE = 41,
                PDF_FILE_CODE = 42,
                GLYPH_CODE = 43,
                XETEX_LINEBREAK_LOCALE_EXTENSION_CODE = 46,

                // LAST_ITEM codes
                LAST_NODE_TYPE_CODE = 3,
                BADNESS_CODE = 5,
                PDFTEX_FIRST_RINT_CODE = 6,
                PDF_LAST_X_POS_CODE = 12,
                ELAPSED_TIME_CODE = 16,
                ETEX_INT = 19,
                ETEX_VERSION_CODE = 19,
                XETEX_INT = 27,
                XETEX_VERSION_CODE = 27,
                XETEX_PDF_PAGE_COUNT_CODE = 54,
                XETEX_LAST_ITEM_CODES = 54,
                XETEX_DIM = 55,
                XETEX_GLYPH_BOUNDS_CODE = 55,
                XETEX_LAST_DIM_CODES = 55,
                ETEX_DIM = 56,
                FONT_CHAR_WD_CODE = 56,
                ETEX_GLUE = 65,
                MU_TO_GLUE_CODE = 65,
                ETEX_MU = 66,
                GLUE_TO_MU_CODE = 66,
                ETEX_EXPR = 67,
                TT_ETEX_NUM_EXPR_CODE = 67,
                TT_ETEX_MU_EXPR_CODE = 70,

                SPAN_CODE = 1_114_113,
            ]
        );
    }