tinymux/mux/modules/engine/funmath.cpp

/*! \file funmath.cpp
 * \brief MUX math function handlers.
 *
 */

#include "copyright.h"
#include "autoconf.h"
#include "config.h"
#include "externs.h"
#include "sha1.h"

#include <algorithm>
#include <climits>
#include <memory>
#include <vector>

static const long nMaximums[10] =
{
    0, 9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999
};

static double g_aDoubles[MAX_WORDS];

FUNCTION(fun_add)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int nArgs = nfargs;
    if (MAX_WORDS < nArgs)
    {
        nArgs = MAX_WORDS;
    }

    int i;
    for (i = 0; i < nArgs; i++)
    {
        int nDigits;
        long nMaxValue = 0;
        if (  !is_integer(fargs[i], &nDigits)
           || nDigits > 9
           || (nMaxValue += nMaximums[nDigits]) > 999999999L)
        {
            // Do it the slow way.
            //
            for (int j = 0; j < nArgs; j++)
            {
                g_aDoubles[j] = mux_atof(fargs[j]);
            }

            fval(buff, bufc, AddDoubles(nArgs, g_aDoubles));
            return;
        }
    }

    // We can do it the fast way.
    //
    int64_t sum = 0;
    for (i = 0; i < nArgs; i++)
    {
        sum += mux_atoi64(fargs[i]);
    }
    safe_i64toa(sum, buff, bufc);
}

FUNCTION(fun_ladd)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int n = 0;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_ladd.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (  cp
              && n < MAX_WORDS)
        {
            UTF8 *curr = split_token(&cp, sep);
            g_aDoubles[n++] = mux_atof(curr);
        }
    }
    fval(buff, bufc, AddDoubles(n, g_aDoubles));
}

/////////////////////////////////////////////////////////////////
// Function : iadd(Arg[0], Arg[1],..,Arg[n])
//
// Written by : Chris Rouse (Seraphim) 04/04/2000
/////////////////////////////////////////////////////////////////

FUNCTION(fun_iadd)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    // #1861: signed overflow is UB; wrap via i64Add (see #1472 / timeutil.h).
    //
    int64_t sum = 0;
    for (int i = 0; i < nfargs; i++)
    {
        sum = i64Add(sum, mux_atoi64(fargs[i]));
    }
    safe_i64toa(sum, buff, bufc);
}

FUNCTION(fun_sub)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        safe_i64toa(a - b, buff, bufc);
    }
    else
    {
        g_aDoubles[0] = mux_atof(fargs[0]);
        g_aDoubles[1] = -mux_atof(fargs[1]);
        fval(buff, bufc, AddDoubles(2, g_aDoubles));
    }
}

/////////////////////////////////////////////////////////////////
// Function : isub(Arg[0], Arg[1])
//
// Written by : Chris Rouse (Seraphim) 04/04/2000
/////////////////////////////////////////////////////////////////

FUNCTION(fun_isub)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    // #1861: wrap via i64Sub rather than signed a - b.
    //
    int64_t a = mux_atoi64(fargs[0]);
    int64_t b = mux_atoi64(fargs[1]);
    safe_i64toa(i64Sub(a, b), buff, bufc);
}

FUNCTION(fun_mul)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double prod = 1.0;
    for (int i = 0; i < nfargs; i++)
    {
        prod *= mux_atof(fargs[i]);
    }
    fval(buff, bufc, NearestPretty(prod));
}

/////////////////////////////////////////////////////////////////
// Function : imul(Arg[0], Arg[1], ... , Arg[n])
//
// Written by : Chris Rouse (Seraphim) 04/04/2000
/////////////////////////////////////////////////////////////////

FUNCTION(fun_imul)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    // #1861: wrap via i64Mul rather than signed *=.
    //
    int64_t prod = 1;
    for (int i = 0; i < nfargs; i++)
    {
        prod = i64Mul(prod, mux_atoi64(fargs[i]));
    }
    safe_i64toa(prod, buff, bufc);
}

FUNCTION(fun_gt)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = false;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a > b);
    }
    else
    {
        double a = mux_atof(fargs[0]);
        double b = mux_atof(fargs[1]);
        bResult = (a > b);
    }
    safe_bool(bResult, buff, bufc);
}

FUNCTION(fun_gte)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = false;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a >= b);
    }
    else
    {
        double a = mux_atof(fargs[0]);
        double b = mux_atof(fargs[1]);
        bResult = (a >= b);
    }
    safe_bool(bResult, buff, bufc);
}

FUNCTION(fun_lt)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = false;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a < b);
    }
    else
    {
        double a = mux_atof(fargs[0]);
        double b = mux_atof(fargs[1]);
        bResult = (a < b);
    }
    safe_bool(bResult, buff, bufc);
}

FUNCTION(fun_lte)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = false;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a <= b);
    }
    else
    {
        double a = mux_atof(fargs[0]);
        double b = mux_atof(fargs[1]);
        bResult = (a <= b);
    }
    safe_bool(bResult, buff, bufc);
}

FUNCTION(fun_eq)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = true;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a == b);
    }
    else
    {
        if (strcmp(reinterpret_cast<const char *>(fargs[0]), reinterpret_cast<const char *>(fargs[1])) != 0)
        {
            double a = mux_atof(fargs[0]);
            double b = mux_atof(fargs[1]);
            bResult = (a == b);
        }
    }
    safe_bool(bResult, buff, bufc);
}

FUNCTION(fun_neq)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bResult = false;
    int nDigits;
    if (  is_integer(fargs[0], &nDigits)
       && nDigits <= 9
       && is_integer(fargs[1], &nDigits)
       && nDigits <= 9)
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        bResult = (a != b);
    }
    else
    {
        if (strcmp(reinterpret_cast<const char *>(fargs[0]), reinterpret_cast<const char *>(fargs[1])) != 0)
        {
            double a = mux_atof(fargs[0]);
            double b = mux_atof(fargs[1]);
            bResult = (a != b);
        }
    }
    safe_bool(bResult, buff, bufc);
}

/*
 * ---------------------------------------------------------------------------
 * * fun_max, fun_min: Return maximum (minimum) value.
 */

FUNCTION(fun_max)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double maximum = 0.0;
    for (int i = 0; i < nfargs; i++)
    {
        double tval = mux_atof(fargs[i]);
        if (  i == 0
           || tval > maximum)
        {
            maximum = tval;
        }
    }
    fval(buff, bufc, maximum);
}

FUNCTION(fun_lmax)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double maximum = 0.0;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        int n = 0;
        LBuf scList = LBuf_Src("fun_lmax.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (nullptr != cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            double tval = mux_atof(curr);
            if (  n++ == 0
               || tval > maximum)
            {
                maximum = tval;
            }
        }
    }
    fval(buff, bufc, maximum);
}

FUNCTION(fun_min)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double minimum = 0.0;
    for (int i = 0; i < nfargs; i++)
    {
        double tval = mux_atof(fargs[i]);
        if (  i == 0
           || tval < minimum)
        {
            minimum = tval;
        }
    }
    fval(buff, bufc, minimum);
}

FUNCTION(fun_lmin)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double minimum = 0.0;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        int n = 0;
        LBuf scList = LBuf_Src("fun_lmin.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (nullptr != cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            double tval = mux_atof(curr);
            if (  n++ == 0
               || tval < minimum)
            {
                minimum = tval;
            }
        }
    }
    fval(buff, bufc, minimum);
}

FUNCTION(fun_lmath)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    // lmath(<operation>, <list>[, <delim>])
    //
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    int n = 0;
    LBuf scList = LBuf_Src("fun_lmath.list");
    UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[1]), sep);
    while (  cp
          && n < MAX_WORDS)
    {
        UTF8 *curr = split_token(&cp, sep);
        g_aDoubles[n++] = mux_atof(curr);
    }

    if (n == 0)
    {
        safe_chr('0', buff, bufc);
        return;
    }

    const UTF8 *op = fargs[0];

    if (  mux_stricmp(op, T("add")) == 0
       || mux_stricmp(op, T("sum")) == 0)
    {
        fval(buff, bufc, AddDoubles(n, g_aDoubles));
    }
    else if (mux_stricmp(op, T("mul")) == 0)
    {
        double prod = 1.0;
        for (int i = 0; i < n; i++)
        {
            prod *= g_aDoubles[i];
        }
        fval(buff, bufc, NearestPretty(prod));
    }
    else if (mux_stricmp(op, T("sub")) == 0)
    {
        double result = g_aDoubles[0];
        for (int i = 1; i < n; i++)
        {
            result -= g_aDoubles[i];
        }
        fval(buff, bufc, NearestPretty(result));
    }
    else if (mux_stricmp(op, T("div")) == 0)
    {
        double result = g_aDoubles[0];
        for (int i = 1; i < n; i++)
        {
            if (g_aDoubles[i] == 0.0)
            {
                safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
                return;
            }
            result /= g_aDoubles[i];
        }
        fval(buff, bufc, NearestPretty(result));
    }
    else if (mux_stricmp(op, T("mod")) == 0)
    {
        int64_t result = static_cast<int64_t>(g_aDoubles[0]);
        for (int i = 1; i < n; i++)
        {
            int64_t divisor = static_cast<int64_t>(g_aDoubles[i]);
            if (divisor == 0)
            {
                safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
                return;
            }
            result = i64Mod(result, divisor);
        }
        safe_i64toa(result, buff, bufc);
    }
    else if (mux_stricmp(op, T("min")) == 0)
    {
        double minimum = g_aDoubles[0];
        for (int i = 1; i < n; i++)
        {
            if (g_aDoubles[i] < minimum)
            {
                minimum = g_aDoubles[i];
            }
        }
        fval(buff, bufc, minimum);
    }
    else if (mux_stricmp(op, T("max")) == 0)
    {
        double maximum = g_aDoubles[0];
        for (int i = 1; i < n; i++)
        {
            if (g_aDoubles[i] > maximum)
            {
                maximum = g_aDoubles[i];
            }
        }
        fval(buff, bufc, maximum);
    }
    else if (  mux_stricmp(op, T("mean")) == 0
            || mux_stricmp(op, T("avg")) == 0)
    {
        fval(buff, bufc, AddDoubles(n, g_aDoubles) / n);
    }
    else if (mux_stricmp(op, T("median")) == 0)
    {
        // #1119: O(n log n) sort — insertion sort was O(n²) up to MAX_WORDS.
        //
        if (alarm_clock.alarmed)
        {
            safe_str(S_("#-1 CPU LIMITED"), buff, bufc);
            return;
        }
        std::sort(g_aDoubles, g_aDoubles + n);
        if (n % 2 == 1)
        {
            fval(buff, bufc, g_aDoubles[n / 2]);
        }
        else
        {
            g_aDoubles[0] = g_aDoubles[n / 2 - 1];
            g_aDoubles[1] = g_aDoubles[n / 2];
            fval(buff, bufc, AddDoubles(2, g_aDoubles) / 2.0);
        }
    }
    else if (mux_stricmp(op, T("stddev")) == 0)
    {
        double mean = AddDoubles(n, g_aDoubles) / n;
        double sumSqDiff = 0.0;
        for (int i = 0; i < n; i++)
        {
            double diff = g_aDoubles[i] - mean;
            sumSqDiff += diff * diff;
        }
        fval(buff, bufc, sqrt(sumSqDiff / n));
    }
    else
    {
        safe_str(S_("#-1 UNKNOWN OPERATION"), buff, bufc);
    }
}

// ---------------------------------------------------------------------------
// limath: Integer-only list reduction, parallel to lmath().
//
// limath(<operation>, <list>[, <delim>])
//
// Supported operations: add/sum, sub, mul, div, mod, min, max, median.
// All arithmetic is 64-bit integer.
//
FUNCTION(fun_limath)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    // #1110: heap-allocate — vals[MAX_WORDS] was ~256 KiB on the stack and
    // ate recursion margin under deep mux_exec (leaf, but still one big frame).
    //
    std::vector<int64_t> vals;
    vals.reserve(64);
    LBuf scList = LBuf_Src("fun_limath.list");
    UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[1]), sep);
    while (cp)
    {
        if (static_cast<int>(vals.size()) >= MAX_WORDS)
        {
            safe_str(S_("#-1 LIST TOO LONG"), buff, bufc);
            return;
        }
        UTF8 *curr = split_token(&cp, sep);
        if (!is_integer(curr, nullptr))
        {
            safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
            return;
        }
        vals.push_back(mux_atoi64(curr));
    }

    const int n = static_cast<int>(vals.size());
    if (n == 0)
    {
        safe_chr('0', buff, bufc);
        return;
    }

    const UTF8 *op = fargs[0];

    if (  mux_stricmp(op, T("add")) == 0
       || mux_stricmp(op, T("sum")) == 0)
    {
        // #1861: wrap via i64Add (see timeutil.h / #1472).
        //
        int64_t sum = 0;
        for (int i = 0; i < n; i++)
        {
            sum = i64Add(sum, vals[i]);
        }
        safe_i64toa(sum, buff, bufc);
    }
    else if (mux_stricmp(op, T("mul")) == 0)
    {
        int64_t prod = 1;
        for (int i = 0; i < n; i++)
        {
            prod = i64Mul(prod, vals[i]);
        }
        safe_i64toa(prod, buff, bufc);
    }
    else if (mux_stricmp(op, T("sub")) == 0)
    {
        int64_t result = vals[0];
        for (int i = 1; i < n; i++)
        {
            result = i64Sub(result, vals[i]);
        }
        safe_i64toa(result, buff, bufc);
    }
    else if (mux_stricmp(op, T("div")) == 0)
    {
        int64_t result = vals[0];
        for (int i = 1; i < n; i++)
        {
            if (vals[i] == 0)
            {
                safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
                return;
            }
            result = i64Division(result, vals[i]);
        }
        safe_i64toa(result, buff, bufc);
    }
    else if (mux_stricmp(op, T("mod")) == 0)
    {
        int64_t result = vals[0];
        for (int i = 1; i < n; i++)
        {
            if (vals[i] == 0)
            {
                safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
                return;
            }
            result = i64Mod(result, vals[i]);
        }
        safe_i64toa(result, buff, bufc);
    }
    else if (mux_stricmp(op, T("min")) == 0)
    {
        int64_t minimum = vals[0];
        for (int i = 1; i < n; i++)
        {
            if (vals[i] < minimum)
            {
                minimum = vals[i];
            }
        }
        safe_i64toa(minimum, buff, bufc);
    }
    else if (mux_stricmp(op, T("max")) == 0)
    {
        int64_t maximum = vals[0];
        for (int i = 1; i < n; i++)
        {
            if (vals[i] > maximum)
            {
                maximum = vals[i];
            }
        }
        safe_i64toa(maximum, buff, bufc);
    }
    else if (mux_stricmp(op, T("median")) == 0)
    {
        // #1119: O(n log n) sort — insertion sort was O(n²) up to MAX_WORDS.
        //
        if (alarm_clock.alarmed)
        {
            safe_str(S_("#-1 CPU LIMITED"), buff, bufc);
            return;
        }
        std::sort(vals.begin(), vals.end());
        if (n % 2 == 1)
        {
            safe_i64toa(vals[n / 2], buff, bufc);
        }
        else
        {
            // Integer median of even-length list: floor of average.
            // a + (b - a) / 2 with defined wrap (#1861) so INT64_MIN/MAX
            // pairs cannot invoke signed overflow.
            //
            int64_t a = vals[n / 2 - 1];
            int64_t b = vals[n / 2];
            safe_i64toa(i64Add(a, i64Division(i64Sub(b, a), 2)), buff, bufc);
        }
    }
    else
    {
        safe_str(S_("#-1 UNKNOWN OPERATION"), buff, bufc);
    }
}

/* ---------------------------------------------------------------------------
 * fun_sign: Returns -1, 0, or 1 based on the the sign of its argument.
 */

FUNCTION(fun_sign)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double num = mux_atof(fargs[0]);
    if (num < 0)
    {
        safe_str(T("-1"), buff, bufc);
    }
    else
    {
        safe_bool(num > 0, buff, bufc);
    }
}

// fun_isign: Returns -1, 0, or 1 based on the the sign of its argument.
//
FUNCTION(fun_isign)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t num = mux_atoi64(fargs[0]);

    if (num < 0)
    {
        safe_str(T("-1"), buff, bufc);
    }
    else
    {
        safe_bool(num > 0, buff, bufc);
    }
}

// shl() and shr() borrowed from PennMUSH 1.50
//
FUNCTION(fun_shl)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (  is_integer(fargs[0], nullptr)
       && is_integer(fargs[1], nullptr))
    {
        // #1109: shift count must be in [0, 63] for int64_t — larger is UB.
        //
        int64_t b = mux_atoi64(fargs[1]);
        if (0 <= b && b < 64)
        {
            // #1472: bounding the count is necessary but not sufficient.
            // Left-shifting a negative value is undefined however small the
            // count, and so is shifting a bit into or past the sign bit --
            // shl(-2,1), shl(1,63) and shl(3,63) all reach it.  Shift in
            // uint64_t, where the operation is defined as the modular one
            // this function already documents, and convert back.  Every
            // result is bit-for-bit what the wrap produced before.
            //
            int64_t a = mux_atoi64(fargs[0]);
            uint64_t ua = static_cast<uint64_t>(a) << b;
            safe_i64toa(static_cast<int64_t>(ua), buff, bufc);
        }
        else if (b < 0)
        {
            // Keep historical wording for smoke tests (0 is allowed).
            safe_str(S_("#-1 SECOND ARGUMENT MUST BE A POSITIVE NUMBER"), buff, bufc);
        }
        else
        {
            safe_str(S_("#-1 SECOND ARGUMENT MUST BE LESS THAN 64"), buff, bufc);
        }
    }
    else
    {
        safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
    }
}

FUNCTION(fun_shr)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (  is_integer(fargs[0], nullptr)
       && is_integer(fargs[1], nullptr))
    {
        // #1109: shift count must be in [0, 63] for int64_t — larger is UB.
        //
        int64_t b = mux_atoi64(fargs[1]);
        if (0 <= b && b < 64)
        {
            int64_t a = mux_atoi64(fargs[0]);
            safe_i64toa(a >> b, buff, bufc);
        }
        else if (b < 0)
        {
            safe_str(S_("#-1 SECOND ARGUMENT MUST BE A POSITIVE NUMBER"), buff, bufc);
        }
        else
        {
            safe_str(S_("#-1 SECOND ARGUMENT MUST BE LESS THAN 64"), buff, bufc);
        }
    }
    else
    {
        safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
    }
}

FUNCTION(fun_inc)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (nfargs == 1)
    {
        // #1472: wraps at INT64_MAX, which is signed overflow.  Add in
        // uint64_t for the same wrap without the undefined behaviour.
        //
        uint64_t v = static_cast<uint64_t>(mux_atoi64(fargs[0]));
        safe_i64toa(static_cast<int64_t>(v + 1), buff, bufc);
    }
    else
    {
        safe_chr('1', buff, bufc);
    }
}

FUNCTION(fun_dec)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (nfargs == 1)
    {
        // #1472: wraps at INT64_MIN, which is signed overflow.  Subtract in
        // uint64_t for the same wrap without the undefined behaviour.
        //
        uint64_t v = static_cast<uint64_t>(mux_atoi64(fargs[0]));
        safe_i64toa(static_cast<int64_t>(v - 1), buff, bufc);
    }
    else
    {
        safe_str(T("-1"), buff, bufc);
    }
}

FUNCTION(fun_trunc)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double rArg = mux_atof(fargs[0]);
    double rIntegerPart;

    mux_FPRestore();
    (void)modf(rArg, &rIntegerPart);
    mux_FPSet();

#ifdef HAVE_IEEE_FP_FORMAT
    int fpc = mux_fpclass(rIntegerPart);
    if (MUX_FPGROUP(fpc) == MUX_FPGROUP_PASS)
    {
#endif // HAVE_IEEE_FP_FORMAT
        fval(buff, bufc, rIntegerPart);
#ifdef HAVE_IEEE_FP_FORMAT
    }
    else
    {
        safe_str(mux_FPStrings[MUX_FPCLASS(fpc)], buff, bufc);
    }
#endif // HAVE_IEEE_FP_FORMAT
}

FUNCTION(fun_fdiv)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double bot = mux_atof(fargs[1]);
    double top = mux_atof(fargs[0]);
#ifndef HAVE_IEEE_FP_SNAN
    if (bot == 0.0)
    {
        if (top > 0.0)
        {
            safe_str(T("+Inf"), buff, bufc);
        }
        else if (top < 0.0)
        {
            safe_str(T("-Inf"), buff, bufc);
        }
        else
        {
            safe_str(T("Ind"), buff, bufc);
        }
    }
    else
    {
        fval(buff, bufc, top/bot);
    }
#else
    fval(buff, bufc, top/bot);
#endif
}

FUNCTION(fun_idiv)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t bot, top;

    bot = mux_atoi64(fargs[1]);
    if (bot == 0)
    {
        safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
    }
    else
    {
        top = mux_atoi64(fargs[0]);
        top = i64Division(top, bot);
        safe_i64toa(top, buff, bufc);
    }
}

FUNCTION(fun_floordiv)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t bot, top;

    bot = mux_atoi64(fargs[1]);
    if (bot == 0)
    {
        safe_str(S_("#-1 DIVIDE BY ZERO"), buff, bufc);
    }
    else
    {
        top = mux_atoi64(fargs[0]);
        top = i64FloorDivision(top, bot);
        safe_i64toa(top, buff, bufc);
    }
}

FUNCTION(fun_mod)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t bot, top;

    bot = mux_atoi64(fargs[1]);
    if (bot == 0)
    {
        bot = 1;
    }
    top = mux_atoi64(fargs[0]);
    top = i64Mod(top, bot);
    safe_i64toa(top, buff, bufc);
}

FUNCTION(fun_remainder)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t bot, top;

    bot = mux_atoi64(fargs[1]);
    if (bot == 0)
    {
        bot = 1;
    }
    top = mux_atoi64(fargs[0]);
    top = i64Remainder(top, bot);
    safe_i64toa(top, buff, bufc);
}

/* ---------------------------------------------------------------------------
 * fun_abs: Returns the absolute value of its argument.
 */

FUNCTION(fun_abs)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    // #1255: |INT64_MIN| is 2**63.  mux_atof can take the literal, but
    // fval formats whole numbers near that magnitude as int64 and wraps
    // back to a negative string — abs() returning a negative.  Reject
    // the exact integer domain like iabs() (#1114): error beats silent
    // nonsense.  Non-integer strings still take the float path.
    //
    int nDigits = 0;
    if (  is_integer(fargs[0], &nDigits)
       && 0 < nDigits
       && mux_atoi64(fargs[0]) == INT64_MIN)
    {
        safe_range(buff, bufc);
        return;
    }

    double num = mux_atof(fargs[0]);
    if (0.0 == num)
    {
        safe_chr('0', buff, bufc);
    }
    else if (num < 0.0)
    {
        fval(buff, bufc, -num);
    }
    else
    {
        fval(buff, bufc, num);
    }
}

// fun_iabs: Returns the absolute value of its argument.
//
FUNCTION(fun_iabs)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    int64_t num = mux_atoi64(fargs[0]);

    if (num == 0)
    {
        safe_chr('0', buff, bufc);
    }
    else if (num == INT64_MIN)
    {
        // #1114: |INT64_MIN| is 2**63, which int64_t cannot represent —
        // negating it is UB.  Reject rather than hand back the magnitude
        // as a string: "9223372036854775808" is not a valid int64, and
        // every consumer corrupts it.  Measured on this tree, feeding it
        // to an integer-path function re-parses through mux_atoi64 (which
        // wraps rather than saturates) straight back to INT64_MIN —
        // idiv(iabs(-9223372036854775808),1) and shl(...,0) both yield
        // -9223372036854775808 — while the float path loses precision
        // instead (add(...,0) -> 9223372036854769664).  Either way iabs()'s
        // one invariant is silently broken.  Failing loudly matches how the
        // integer family handles an out-of-domain argument (fun_table,
        // fun_columns).
        //
        safe_range(buff, bufc);
    }
    else if (num < 0)
    {
        safe_i64toa(-num, buff, bufc);
    }
    else
    {
        safe_i64toa(num, buff, bufc);
    }
}

FUNCTION(fun_dist2d)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double a, b, d;
    double sum;

    a = mux_atof(fargs[0]);
    b = mux_atof(fargs[2]);
    d = a - b;
    sum  = d * d;
    a = mux_atof(fargs[1]);
    b = mux_atof(fargs[3]);
    d = a - b;
    sum += d * d;

    mux_FPRestore();
    double result = sqrt(sum);
    mux_FPSet();

    fval(buff, bufc, result);
}

FUNCTION(fun_dist3d)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double a, b, d;
    double sum;

    a = mux_atof(fargs[0]);
    b = mux_atof(fargs[3]);
    d = a - b;
    sum  = d * d;
    a = mux_atof(fargs[1]);
    b = mux_atof(fargs[4]);
    d = a - b;
    sum += d * d;
    a = mux_atof(fargs[2]);
    b = mux_atof(fargs[5]);
    d = a - b;
    sum += d * d;

    mux_FPRestore();
    double result = sqrt(sum);
    mux_FPSet();

    fval(buff, bufc, result);
}

//------------------------------------------------------------------------
// Vector functions: VADD, VSUB, VMUL, VCROSS, VMAG, VUNIT, VDIM
// Vectors are space-separated numbers.
//
#define VADD_F   0
#define VSUB_F   1
#define VMUL_F   2
#define VDOT_F   3
#define VCROSS_F 4

static void handle_vectors
(
    const UTF8 *vecarg1, const UTF8 *vecarg2, UTF8 *buff, UTF8 **bufc,
    const SEP &sep, const SEP &osep, int flag
)
{
    // Return if the list is empty.
    //
    if (!vecarg1 || !*vecarg1 || !vecarg2 || !*vecarg2)
    {
        return;
    }

    // Uninitialized on purpose (#2145): list2arr writes arr[i] only for
    // i < its return value and nothing reads past it, so value-initializing
    // 2x 128 KB of pointers per call bought nothing — and was ~170x the
    // cost of actually splitting a small vector.
    //
    std::unique_ptr<UTF8*[]> v1(new UTF8*[(LBUF_SIZE+1)/2]);
    std::unique_ptr<UTF8*[]> v2(new UTF8*[(LBUF_SIZE+1)/2]);

    // Split the lists up, or return if a list is empty.  Non-destructive
    // (#2136): vecarg1/vecarg2 are the caller's fargs, borrowed memory.
    //
    LBuf sc1 = LBuf_Src("handle_vectors.1");
    LBuf sc2 = LBuf_Src("handle_vectors.2");
    int n = list2arr_nd(v1.get(), (LBUF_SIZE+1)/2, vecarg1, sep, sc1);
    int m = list2arr_nd(v2.get(), (LBUF_SIZE+1)/2, vecarg2, sep, sc2);

    // vmul() and vadd() accepts a scalar in the first or second arg,
    // but everything else has to be same-dimensional.
    //
    if (  n != m
       && !(  (  flag == VMUL_F
              || flag == VADD_F
              || flag == VSUB_F)
           && (  n == 1
              || m == 1)))
    {
        safe_str(S_("#-1 VECTORS MUST BE SAME DIMENSIONS"), buff, bufc);
        return;
    }

    double scalar;
    int i;

    switch (flag)
    {
    case VADD_F:

        // If n or m is 1, this is scalar addition.
        // otherwise, add element-wise.
        //
        if (n == 1)
        {
            scalar = mux_atof(v1[0]);
            for (i = 0; i < m; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, mux_atof(v2[i]) + scalar);
            }
            n = m;
        }
        else if (m == 1)
        {
            scalar = mux_atof(v2[0]);
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, mux_atof(v1[i]) + scalar);
            }
        }
        else
        {
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                double a = mux_atof(v1[i]);
                double b = mux_atof(v2[i]);
                fval(buff, bufc, a + b);
            }
        }
        break;

    case VSUB_F:

        if (n == 1)
        {
            // This is a scalar minus a vector.
            //
            scalar = mux_atof(v1[0]);
            for (i = 0; i < m; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, scalar - mux_atof(v2[i]));
            }
        }
        else if (m == 1)
        {
            // This is a vector minus a scalar.
            //
            scalar = mux_atof(v2[0]);
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, mux_atof(v1[i]) - scalar);
            }
        }
        else
        {
            // This is a vector minus a vector.
            //
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                double a = mux_atof(v1[i]);
                double b = mux_atof(v2[i]);
                fval(buff, bufc, a - b);
            }
        }
        break;

    case VMUL_F:

        // If n or m is 1, this is scalar multiplication.
        // otherwise, multiply elementwise.
        //
        if (n == 1)
        {
            scalar = mux_atof(v1[0]);
            for (i = 0; i < m; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, mux_atof(v2[i]) * scalar);
            }
        }
        else if (m == 1)
        {
            scalar = mux_atof(v2[0]);
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                fval(buff, bufc, mux_atof(v1[i]) * scalar);
            }
        }
        else
        {
            // Vector element-wise product.
            //
            for (i = 0; i < n; i++)
            {
                if (i != 0)
                {
                    print_sep(osep, buff, bufc);
                }
                double a = mux_atof(v1[i]);
                double b = mux_atof(v2[i]);
                fval(buff, bufc, a * b);
            }
        }
        break;

    case VDOT_F:

        scalar = 0.0;
        for (i = 0; i < n; i++)
        {
            double a = mux_atof(v1[i]);
            double b = mux_atof(v2[i]);
            scalar +=  a * b;
        }
        fval(buff, bufc, scalar);
        break;

    case VCROSS_F:

        // cross product: (a,b,c) x (d,e,f) = (bf - ce, cd - af, ae - bd)
        //
        // Or in other words:
        //
        //      | a  b  c |
        //  det | d  e  f | = i(bf-ce) + j(cd-af) + k(ae-bd)
        //      | i  j  k |
        //
        // where i, j, and k are unit vectors in the x, y, and z
        // cartisian coordinate space and are understood when expressed
        // in vector form.
        //
        if (n != 3)
        {
            safe_str(S_("#-1 VECTORS MUST BE DIMENSION OF 3"), buff, bufc);
        }
        else
        {
            double a[2][3];
            for (i = 0; i < 3; i++)
            {
                a[0][i] = mux_atof(v1[i]);
                a[1][i] = mux_atof(v2[i]);
            }
            fval(buff, bufc, (a[0][1] * a[1][2]) - (a[0][2] * a[1][1]));
            print_sep(osep, buff, bufc);
            fval(buff, bufc, (a[0][2] * a[1][0]) - (a[0][0] * a[1][2]));
            print_sep(osep, buff, bufc);
            fval(buff, bufc, (a[0][0] * a[1][1]) - (a[0][1] * a[1][0]));
        }
        break;

    default:

        // If we reached this, we're in trouble.
        //
        safe_str(S_("#-1 UNIMPLEMENTED"), buff, bufc);
    }
}

FUNCTION(fun_vadd)
{
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    SEP osep = sep;
    if (!OPTIONAL_DELIM(4, osep, DELIM_NULL|DELIM_CRLF|DELIM_STRING|DELIM_INIT))
    {
        return;
    }
    handle_vectors(fargs[0], fargs[1], buff, bufc, sep, osep, VADD_F);
}

FUNCTION(fun_vsub)
{
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    SEP osep = sep;
    if (!OPTIONAL_DELIM(4, osep, DELIM_NULL|DELIM_CRLF|DELIM_STRING|DELIM_INIT))
    {
        return;
    }
    handle_vectors(fargs[0], fargs[1], buff, bufc, sep, osep, VSUB_F);
}

FUNCTION(fun_vmul)
{
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    SEP osep = sep;
    if (!OPTIONAL_DELIM(4, osep, DELIM_NULL|DELIM_CRLF|DELIM_STRING|DELIM_INIT))
    {
        return;
    }
    handle_vectors(fargs[0], fargs[1], buff, bufc, sep, osep, VMUL_F);
}

FUNCTION(fun_vdot)
{
    // dot product: (a,b,c) . (d,e,f) = ad + be + cf
    //
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    SEP osep = sep;
    if (!OPTIONAL_DELIM(4, osep, DELIM_NULL|DELIM_CRLF|DELIM_STRING|DELIM_INIT))
    {
        return;
    }
    handle_vectors(fargs[0], fargs[1], buff, bufc, sep, osep, VDOT_F);
}

FUNCTION(fun_vcross)
{
    // cross product: (a,b,c) x (d,e,f) = (bf - ce, cd - af, ae - bd)
    //
    SEP sep;
    if (!OPTIONAL_DELIM(3, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    SEP osep = sep;
    if (!OPTIONAL_DELIM(4, osep, DELIM_NULL|DELIM_CRLF|DELIM_STRING|DELIM_INIT))
    {
        return;
    }
    handle_vectors(fargs[0], fargs[1], buff, bufc, sep, osep, VCROSS_F);
}

FUNCTION(fun_vmag)
{
    SEP sep;
    if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    // Split the list up, or return if the list is empty.
    //
    if (!fargs[0] || !*fargs[0])
    {
        return;
    }

    std::unique_ptr<UTF8*[]> v1(new UTF8*[LBUF_SIZE/2]);   // uninit (#2145): past-count reads are UB now, not nullptr
    LBuf sc = LBuf_Src("fun_vmag.nd");
    int n = list2arr_nd(v1.get(), LBUF_SIZE/2, fargs[0], sep, sc);

    // Calculate the magnitude.
    //
    double res = 0.0;
    for (int i = 0; i < n; i++)
    {
        double tmp = mux_atof(v1[i]);
        res += tmp * tmp;
    }

    if (res > 0)
    {
        mux_FPRestore();
        double result = sqrt(res);
        mux_FPSet();

        fval(buff, bufc, result);
    }
    else
    {
        safe_chr('0', buff, bufc);
    }
}

FUNCTION(fun_vunit)
{
    SEP sep;
    if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
    {
        return;
    }

    // Split the list up, or return if the list is empty.
    //
    if (!fargs[0] || !*fargs[0])
    {
        return;
    }

    std::unique_ptr<UTF8*[]> v1(new UTF8*[LBUF_SIZE/2]);   // uninit (#2145): past-count reads are UB now, not nullptr
    LBuf sc = LBuf_Src("fun_vunit.nd");
    int n = list2arr_nd(v1.get(), LBUF_SIZE/2, fargs[0], sep, sc);

    // Calculate the magnitude.
    //
    int i;
    double res = 0.0;
    for (i = 0; i < n; i++)
    {
        double tmp = mux_atof(v1[i]);
        res += tmp * tmp;
    }

    if (res <= 0)
    {
        safe_str(S_("#-1 CANNOT MAKE UNIT VECTOR FROM ZERO-LENGTH VECTOR"),
            buff, bufc);
        return;
    }

    for (i = 0; i < n; i++)
    {
        if (0 != i)
        {
            print_sep(sep, buff, bufc);
        }

        mux_FPRestore();
        double result = sqrt(res);
        mux_FPSet();

        fval(buff, bufc, mux_atof(v1[i]) / result);
    }
}

FUNCTION(fun_floor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    mux_FPRestore();
    double r = floor(mux_atof(fargs[0]));
    mux_FPSet();

#ifdef HAVE_IEEE_FP_FORMAT
    int fpc = mux_fpclass(r);
    if (MUX_FPGROUP(fpc) == MUX_FPGROUP_PASS)
    {
#endif // HAVE_IEEE_FP_FORMAT
        fval(buff, bufc, r);
#ifdef HAVE_IEEE_FP_FORMAT
    }
    else
    {
        safe_str(mux_FPStrings[MUX_FPCLASS(fpc)], buff, bufc);
    }
#endif // HAVE_IEEE_FP_FORMAT
}

FUNCTION(fun_ceil)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    mux_FPRestore();
    double r = ceil(mux_atof(fargs[0]));
    mux_FPSet();

#ifdef HAVE_IEEE_FP_FORMAT
    int fpc = mux_fpclass(r);
    if (MUX_FPGROUP(fpc) == MUX_FPGROUP_PASS)
    {
#endif // HAVE_IEEE_FP_FORMAT
        fval(buff, bufc, r);
#ifdef HAVE_IEEE_FP_FORMAT
    }
    else
    {
        safe_str(mux_FPStrings[MUX_FPCLASS(fpc)], buff, bufc);
    }
#endif // HAVE_IEEE_FP_FORMAT
}

FUNCTION(fun_round)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double r = mux_atof(fargs[0]);
#ifdef HAVE_IEEE_FP_FORMAT
    int fpc = mux_fpclass(r);
    if (  MUX_FPGROUP(fpc) == MUX_FPGROUP_PASS
       || MUX_FPGROUP(fpc) == MUX_FPGROUP_ZERO)
    {
        if (MUX_FPGROUP(fpc) == MUX_FPGROUP_ZERO)
        {
            r = 0.0;
        }
#endif // HAVE_IEEE_FP_FORMAT
        int64_t frac = mux_atoi64(fargs[1]);
        safe_str(mux_ftoa(r, true, frac), buff, bufc);
#ifdef HAVE_IEEE_FP_FORMAT
    }
    else
    {
        safe_str(mux_FPStrings[MUX_FPCLASS(fpc)], buff, bufc);
    }
#endif // HAVE_IEEE_FP_FORMAT
}

FUNCTION(fun_pi)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(fargs);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_str(T("3.141592653589793"), buff, bufc);
}

FUNCTION(fun_e)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(fargs);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_str(T("2.718281828459045"), buff, bufc);
}

static double ConvertRDG2R(double d, const UTF8 *szUnits)
{
    switch (szUnits[0])
    {
    case 'd':
    case 'D':
        // Degrees to Radians.
        //
        d *= 0.017453292519943295;
        break;

    case 'g':
    case 'G':
        // Gradians to Radians.
        //
        d *= 0.015707963267948967;
        break;
    }
    return d;
}

static double ConvertR2RDG(double d, const UTF8 *szUnits)
{
    switch (szUnits[0])
    {
    case 'd':
    case 'D':
        // Radians to Degrees.
        //
        d *= 57.29577951308232;
        break;

    case 'g':
    case 'G':
        // Radians to Gradians.
        //
        d *= 63.66197723675813;
        break;
    }
    return d;
}

FUNCTION(fun_ctu)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val = mux_atof(fargs[0]);
    val = ConvertRDG2R(val, fargs[1]);
    val = ConvertR2RDG(val, fargs[2]);
    fval(buff, bufc, val);
}

FUNCTION(fun_sin)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double d = mux_atof(fargs[0]);
    if (nfargs == 2)
    {
        d = ConvertRDG2R(d, fargs[1]);
    }

    mux_FPRestore();
    d = sin(d);
    mux_FPSet();

    fval(buff, bufc, d);
}

FUNCTION(fun_cos)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double d = mux_atof(fargs[0]);
    if (nfargs == 2)
    {
        d = ConvertRDG2R(d, fargs[1]);
    }

    mux_FPRestore();
    d = cos(d);
    mux_FPSet();

    fval(buff, bufc, d);
}

FUNCTION(fun_tan)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double d = mux_atof(fargs[0]);
    if (nfargs == 2)
    {
        d = ConvertRDG2R(d, fargs[1]);
    }

    mux_FPRestore();
    d = tan(d);
    mux_FPSet();

    fval(buff, bufc, d);
}

FUNCTION(fun_asin)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val = mux_atof(fargs[0]);
#ifndef HAVE_IEEE_FP_SNAN
    if ((val < -1.0) || (val > 1.0))
    {
        safe_str(T("Ind"), buff, bufc);
        return;
    }
#endif
    mux_FPRestore();
    val = asin(val);
    mux_FPSet();

    if (nfargs == 2)
    {
        val = ConvertR2RDG(val, fargs[1]);
    }
    fval(buff, bufc, val);
}

FUNCTION(fun_acos)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val = mux_atof(fargs[0]);
#ifndef HAVE_IEEE_FP_SNAN
    if ((val < -1.0) || (val > 1.0))
    {
        safe_str(T("Ind"), buff, bufc);
        return;
    }
#endif
    mux_FPRestore();
    val = acos(val);
    mux_FPSet();

    if (nfargs == 2)
    {
        val = ConvertR2RDG(val, fargs[1]);
    }
    fval(buff, bufc, val);
}

FUNCTION(fun_atan)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val = mux_atof(fargs[0]);

    mux_FPRestore();
    val = atan(val);
    mux_FPSet();

    if (nfargs == 2)
    {
        val = ConvertR2RDG(val, fargs[1]);
    }
    fval(buff, bufc, val);
}

FUNCTION(fun_atan2)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val1 = mux_atof(fargs[0]);
    double val2 = mux_atof(fargs[1]);

    mux_FPRestore();
    val1 = atan2(val1, val2);
    mux_FPSet();

    if (3 == nfargs)
    {
        val1 = ConvertR2RDG(val1, fargs[2]);
    }
    fval(buff, bufc, val1);
}

FUNCTION(fun_exp)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val = mux_atof(fargs[0]);

    mux_FPRestore();
    val = exp(val);
    mux_FPSet();

    fval(buff, bufc, val);
}

FUNCTION(fun_power)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val, val1, val2;

    val1 = mux_atof(fargs[0]);
    val2 = mux_atof(fargs[1]);
#ifndef HAVE_IEEE_FP_SNAN
    if (val1 < 0.0)
    {
        safe_str(T("Ind"), buff, bufc);
    }
    else
    {
        mux_FPRestore();
        val = pow(val1, val2);
        mux_FPSet();
        fval(buff, bufc, val);
    }
#else
    mux_FPRestore();
    val = pow(val1, val2);
    mux_FPSet();
    fval(buff, bufc, val);
#endif
}

FUNCTION(fun_fmod)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val, val1, val2;

    val1 = mux_atof(fargs[0]);
    val2 = mux_atof(fargs[1]);
#ifndef HAVE_IEEE_FP_SNAN
    // The indeterminate case is a zero *divisor* (fmod(x,0) is NaN);
    // fmod(0,y) is a valid 0.  The guard checked val1 (the dividend),
    // copy-pasted from fun_power's val1 sign check — so on a
    // NO_IEEE_FP_SNAN lane fmod(0,3) wrongly returned Ind and fmod(x,0)
    // fell through unguarded.  Reported by ThresholdOps.
    if (val2 == 0.0)
    {
        safe_str(T("Ind"), buff, bufc);
    }
    else
    {
        mux_FPRestore();
        val = fmod(val1, val2);
        mux_FPSet();
        fval(buff, bufc, val);
    }
#else
    mux_FPRestore();
    val = fmod(val1, val2);
    mux_FPSet();
    fval(buff, bufc, val);
#endif
}

FUNCTION(fun_ln)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val;

    val = mux_atof(fargs[0]);
#ifndef HAVE_IEEE_FP_SNAN
    if (val < 0.0)
    {
        safe_str(T("Ind"), buff, bufc);
    }
    else if (val == 0.0)
    {
        safe_str(T("-Inf"), buff, bufc);
    }
    else
    {
        mux_FPRestore();
        val = log(val);
        mux_FPSet();
    }
#else
    mux_FPRestore();
    val = log(val);
    mux_FPSet();
#endif
    fval(buff, bufc, val);
}

FUNCTION(fun_log)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    typedef enum
    {
#ifdef HAVE_LOG2
        kBinary,
#endif
        kNatural,
        kCommon,
        kOther
    } logarithm_base;

    logarithm_base kBase;

    double val = mux_atof(fargs[0]);

    double base;
    if (2 == nfargs)
    {
        int nDigits;
        if (  is_integer(fargs[1], &nDigits)
           && nDigits <= 2)
        {
            int64_t iBase = mux_atoi64(fargs[1]);
            if (10 == iBase)
            {
                kBase = kCommon;
            }
#ifdef HAVE_LOG2
            else if (2 == iBase)
            {
                kBase = kBinary;
            }
#endif
            else
            {
                kBase = kOther;
                base = mux_atof(fargs[1]);
            }
        }
        else if (  'e' == fargs[1][0]
                && '\0' == fargs[1][1])
        {
            kBase = kNatural;
        }
        else
        {
            kBase = kOther;
            base = mux_atof(fargs[1]);
        }
    }
    else
    {
        kBase = kCommon;
    }

    if (  kOther == kBase
       && base <= 1)
    {
        safe_str(S_("#-1 BASE OUT OF RANGE"), buff, bufc);
        return;
    }

#ifndef HAVE_IEEE_FP_SNAN
    if (val < 0.0)
    {
        safe_str(T("Ind"), buff, bufc);
        return;
    }
    else if (0.0 == val)
    {
        safe_str(T("-Inf"), buff, bufc);
        return;
    }
    else
#endif
    {
        mux_FPRestore();
        if (kCommon == kBase)
        {
            val = log10(val);
        }
        else if (kNatural == kBase)
        {
            val = log(val);
        }
#ifdef HAVE_LOG2
        else if (kBinary == kBase)
        {
            val = log2(val);
        }
#endif
        else
        {
            val = log(val)/log(base);
        }
        mux_FPSet();
    }
    fval(buff, bufc, val);
}

FUNCTION(fun_sqrt)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    double val;

    val = mux_atof(fargs[0]);
#ifndef HAVE_IEEE_FP_SNAN
    if (val < 0.0)
    {
        safe_str(T("Ind"), buff, bufc);
    }
    else if (val == 0.0)
    {
        safe_chr('0', buff, bufc);
    }
    else
    {
        mux_FPRestore();
        val = sqrt(val);
        mux_FPSet();
    }
#else
    mux_FPRestore();
    val = sqrt(val);
    mux_FPSet();
#endif
    fval(buff, bufc, val);
}

/* ---------------------------------------------------------------------------
 * isnum: is the argument a number?
 */

FUNCTION(fun_isnum)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_bool(is_real(fargs[0]), buff, bufc);
}

/* ---------------------------------------------------------------------------
 * israt: is the argument an rational?
 */

FUNCTION(fun_israt)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_bool(is_rational(fargs[0]), buff, bufc);
}

/* ---------------------------------------------------------------------------
 * isint: is the argument an integer?
 */

FUNCTION(fun_isint)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_bool(is_integer(fargs[0], nullptr), buff, bufc);
}

FUNCTION(fun_and)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool val = true;
    for (int i = 0; i < nfargs && val; i++)
    {
        val = isTRUE(mux_atoi64(fargs[i]));
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_or)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool val = false;
    for (int i = 0; i < nfargs && !val; i++)
    {
        val = isTRUE(mux_atoi64(fargs[i]));
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_andbool)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool val = true;
    for (int i = 0; i < nfargs && val; i++)
    {
        val = xlate(fargs[i]);
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_orbool)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool val = false;
    for (int i = 0; i < nfargs && !val; i++)
    {
        val = xlate(fargs[i]);
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_cand)
{
    bool val = true;
    LBuf temp = LBuf_Src("fun_cand");
    for (int i = 0; i < nfargs && val && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';
        val = isTRUE(mux_atoi64(temp));
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_cor)
{
    bool val = false;
    LBuf temp = LBuf_Src("fun_cor");
    for (int i = 0; i < nfargs && !val && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';
        val = isTRUE(mux_atoi64(temp));
    }
    safe_bool(val, buff, bufc);
}

// firstof(arg1, arg2, ...) — return the first true (non-zero) argument.
// Evaluates left-to-right, stops at first true.  If none are true,
// returns the last evaluated value.
//
FUNCTION(fun_firstof)
{
    if (0 == nfargs)
    {
        return;
    }

    LBuf temp = LBuf_Src("fun_firstof");
    for (int i = 0; i < nfargs && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';

        if (isTRUE(mux_atoi64(temp)) || i == nfargs - 1)
        {
            safe_str(temp, buff, bufc);
            return;
        }
    }
}

// strfirstof(arg1, arg2, ...) — return the first non-empty string argument.
// Evaluates left-to-right, stops at first non-empty.  If all are empty,
// returns empty string.
//
FUNCTION(fun_strfirstof)
{
    if (0 == nfargs)
    {
        return;
    }

    LBuf temp = LBuf_Src("fun_strfirstof");
    for (int i = 0; i < nfargs && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';

        if ('\0' != temp[0] || i == nfargs - 1)
        {
            safe_str(temp, buff, bufc);
            return;
        }
    }
}

// allof(arg1, arg2, ...[, osep]) — return all true (non-zero) arguments,
// separated by osep.  Last arg is the output separator if nfargs >= 2.
//
FUNCTION(fun_allof)
{
    if (0 == nfargs)
    {
        return;
    }

    // Last argument is the output separator.
    //
    int nArgs = nfargs;
    LBuf osep = LBuf_Src("fun_allof");
    osep[0] = ' ';
    osep[1] = '\0';
    size_t nOsep = 1;
    if (nfargs >= 2)
    {
        UTF8 *sp = osep;
        mux_exec(fargs[nfargs - 1], LBUF_SIZE-1, osep, &sp, executor, caller,
            enactor, eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *sp = '\0';
        nOsep = sp - osep;
        nArgs = nfargs - 1;
    }

    bool bFirst = true;
    LBuf temp = LBuf_Src("fun_allof");
    for (int i = 0; i < nArgs && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';

        if (isTRUE(mux_atoi64(temp)))
        {
            if (!bFirst)
            {
                safe_copy_buf(osep, nOsep, buff, bufc);
            }
            safe_str(temp, buff, bufc);
            bFirst = false;
        }
    }
}

// strallof(arg1, arg2, ...[, osep]) — return all non-empty string arguments,
// separated by osep.  Last arg is the output separator if nfargs >= 2.
//
FUNCTION(fun_strallof)
{
    if (0 == nfargs)
    {
        return;
    }

    int nArgs = nfargs;
    LBuf osep = LBuf_Src("fun_strallof");
    osep[0] = ' ';
    osep[1] = '\0';
    size_t nOsep = 1;
    if (nfargs >= 2)
    {
        UTF8 *sp = osep;
        mux_exec(fargs[nfargs - 1], LBUF_SIZE-1, osep, &sp, executor, caller,
            enactor, eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *sp = '\0';
        nOsep = sp - osep;
        nArgs = nfargs - 1;
    }

    bool bFirst = true;
    LBuf temp = LBuf_Src("fun_strallof");
    for (int i = 0; i < nArgs && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';

        if ('\0' != temp[0])
        {
            if (!bFirst)
            {
                safe_copy_buf(osep, nOsep, buff, bufc);
            }
            safe_str(temp, buff, bufc);
            bFirst = false;
        }
    }
}

FUNCTION(fun_candbool)
{
    bool val = true;
    LBuf temp = LBuf_Src("fun_candbool");
    for (int i = 0; i < nfargs && val && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';
        val = xlate(temp);
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_corbool)
{
    bool val = false;
    LBuf temp = LBuf_Src("fun_corbool");
    for (int i = 0; i < nfargs && !val && !alarm_clock.alarmed; i++)
    {
        UTF8 *bp = temp.get();
        mux_exec(fargs[i], LBUF_SIZE-1, temp, &bp, executor, caller, enactor,
            eval|EV_STRIP_CURLY|EV_FCHECK|EV_EVAL, cargs, ncargs);
        *bp = '\0';
        val = xlate(temp);
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_xor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool val = false;
    for (int i = 0; i < nfargs; i++)
    {
        // Test truthiness on the full 64-bit value, matching and()/or()/
        // lxor(); narrowing to int drops the high bits of large operands.
        //
        bool tval = isTRUE(mux_atoi64(fargs[i]));
        val = (val && !tval) || (!val && tval);
    }
    safe_bool(val, buff, bufc);
}

FUNCTION(fun_not)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    safe_bool(!xlate(fargs[0]), buff, bufc);
}

FUNCTION(fun_t)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (  nfargs <= 0
       || fargs[0][0] == '\0')
    {
        safe_chr('0', buff, bufc);
    }
    else
    {
        safe_bool(xlate(fargs[0]), buff, bufc);
    }
}
static const UTF8 *bigones[] =
{
    T(""),
    T("thousand"),
    T("million"),
    T("billion"),
    T("trillion")
};

static const UTF8 *singles[] =
{
    T(""),
    T("one"),
    T("two"),
    T("three"),
    T("four"),
    T("five"),
    T("six"),
    T("seven"),
    T("eight"),
    T("nine")
};

static const UTF8 *teens[] =
{
    T("ten"),
    T("eleven"),
    T("twelve"),
    T("thirteen"),
    T("fourteen"),
    T("fifteen"),
    T("sixteen"),
    T("seventeen"),
    T("eighteen"),
    T("nineteen")
};

static const UTF8 *tens[] =
{
    T(""),
    T(""),
    T("twenty"),
    T("thirty"),
    T("forty"),
    T("fifty"),
    T("sixty"),
    T("seventy"),
    T("eighty"),
    T("ninety")
};

static const UTF8 *th_prefix[] =
{
    T(""),
    T("ten"),
    T("hundred")
};

class CSpellNum
{
public:
    void SpellNum(const UTF8 *p, UTF8 *buff_arg, UTF8 **bufc_arg);

private:
    void TwoDigits(const UTF8 *p);
    void ThreeDigits(const UTF8 *p, size_t iBigOne);
    void ManyDigits(size_t n, const UTF8 *p, bool bHundreds);
    void FractionalDigits(size_t n, const UTF8 *p);

    void StartWord(void);
    void AddWord(const UTF8 *p);

    UTF8 *buff;
    UTF8 **bufc;
    bool bNeedSpace;
};

void CSpellNum::StartWord(void)
{
    if (bNeedSpace)
    {
        safe_chr(' ', buff, bufc);
    }
    bNeedSpace = true;
}

void CSpellNum::AddWord(const UTF8 *p)
{
    safe_str(p, buff, bufc);
}

// Handle two-character sequences.
//
void CSpellNum::TwoDigits(const UTF8 *p)
{
    int n0 = p[0] - '0';
    int n1 = p[1] - '0';

    if (n0 == 0)
    {
        if (n1 != 0)
        {
            StartWord();
            AddWord(singles[n1]);
        }
        return;
    }
    else if (n0 == 1)
    {
        StartWord();
        AddWord(teens[n1]);
        return;
    }
    if (n1 == 0)
    {
        StartWord();
        AddWord(tens[n0]);
    }
    else
    {
        StartWord();
        AddWord(tens[n0]);
        AddWord(T("-"));
        AddWord(singles[n1]);
    }
}

// Handle three-character sequences.
//
void CSpellNum::ThreeDigits(const UTF8 *p, size_t iBigOne)
{
    if (  p[0] == '0'
       && p[1] == '0'
       && p[2] == '0')
    {
        return;
    }

    // Handle hundreds.
    //
    if (p[0] != '0')
    {
        StartWord();
        AddWord(singles[p[0]-'0']);
        StartWord();
        AddWord(T("hundred"));
    }
    TwoDigits(p+1);
    if (iBigOne > 0)
    {
        StartWord();
        AddWord(bigones[iBigOne]);
    }
}

// Handle a series of patterns of three.
//
void CSpellNum::ManyDigits(size_t n, const UTF8 *p, bool bHundreds)
{
    // Handle special Hundreds cases.
    //
    if (  bHundreds
       && n == 4
       && p[1] != '0')
    {
        TwoDigits(p);
        StartWord();
        AddWord(T("hundred"));
        TwoDigits(p+2);
        return;
    }

    // Handle normal cases.
    //
    size_t ndiv = ((n + 2) / 3) - 1;
    size_t nrem = n % 3;
    UTF8 buf[3];
    if (nrem == 0)
    {
        nrem = 3;
    }

    size_t j = nrem;
    for (int i = 2; 0 <= i; i--)
    {
        if (j)
        {
            j--;
            buf[i] = p[j];
        }
        else
        {
            buf[i] = '0';
        }
    }
    ThreeDigits(buf, ndiv);
    p += nrem;
    while (ndiv-- > 0)
    {
        ThreeDigits(p, ndiv);
        p += 3;
    }
}

// Handle precision ending for part to the right of the decimal place.
//
void CSpellNum::FractionalDigits(size_t n, const UTF8 *p)
{
    ManyDigits(n, p, false);
    if (  0 < n
       && n < 15)
    {
        size_t d = n / 3;
        size_t r = n % 3;
        StartWord();
        if (r != 0)
        {
            AddWord(th_prefix[r]);
            if (d != 0)
            {
                AddWord(T("-"));
            }
        }
        AddWord(bigones[d]);
        AddWord(T("th"));
        int64_t i64 = mux_atoi64(p);
        if (i64 != 1)
        {
            AddWord(T("s"));
        }
    }
}

void CSpellNum::SpellNum(const UTF8 *number, UTF8 *buff_arg, UTF8 **bufc_arg)
{
    buff = buff_arg;
    bufc = bufc_arg;
    bNeedSpace = false;

    // Trim Spaces from beginning.
    //
    while (mux_isspace(*number))
    {
        number++;
    }

    if (*number == '-')
    {
        StartWord();
        AddWord(T("negative"));
        number++;
    }

    // Trim Zeroes from Beginning.
    //
    while (*number == '0')
    {
        number++;
    }

    const UTF8 *pA = number;
    while (mux_isdigit(*number))
    {
        number++;
    }
    size_t nA = number - pA;

    const UTF8 *pB  = nullptr;
    size_t nB = 0;
    if (*number == '.')
    {
        number++;
        pB = number;
        while (mux_isdigit(*number))
        {
            number++;
        }
        nB = number - pB;
    }

    // Skip trailing spaces.
    //
    while (mux_isspace(*number))
    {
        number++;
    }

    if (  *number
       || nA >= 16
       || nB >= 15)
    {
        safe_str(S_("#-1 ARGUMENT MUST BE A NUMBER"), buff, bufc);
        return;
    }

    if (nA == 0)
    {
        if (nB == 0)
        {
            StartWord();
            AddWord(T("zero"));
        }
    }
    else
    {
        ManyDigits(nA, pA, true);
        if (nB)
        {
            StartWord();
            AddWord(T("and"));
        }
    }
    if (nB)
    {
        FractionalDigits(nB, pB);
    }
}

FUNCTION(fun_spellnum)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    CSpellNum sn;
    sn.SpellNum(fargs[0], buff, bufc);
}

FUNCTION(fun_roman)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    const UTF8 *number = fargs[0];

    // Trim Spaces from beginning.
    //
    while (mux_isspace(*number))
    {
        number++;
    }

    // Trim Zeroes from Beginning.
    //
    while (*number == '0')
    {
        number++;
    }

    const UTF8 *pA = number;
    while (mux_isdigit(*number))
    {
        number++;
    }
    size_t nA = number - pA;

    // Skip trailing spaces.
    //
    while (mux_isspace(*number))
    {
        number++;
    }

    // Validate that argument is numeric with a value between 1 and 3999.
    //
    if (*number || nA < 1)
    {
        safe_str(S_("#-1 ARGUMENT MUST BE A POSITIVE NUMBER"), buff, bufc);
        return;
    }
    else if (  nA > 4
            || (  nA == 1
               && pA[0] == '0')
            || (  nA == 4
               && '3' < pA[0]))
    {
        safe_range(buff, bufc);
        return;
    }

    // I:1, V:5, X:10, L:50, C:100, D:500, M:1000
    //
    // Ones:      _ I II III IV V VI VII VIII IX
    // Tens:      _ X XX XXX XL L LX LXX LXXX XC
    // Hundreds:  _ C CC CCC CD D DC DCC DCCC CM
    // Thousands: _ M MM MMM
    //
    static const UTF8 aLetters[4][3] =
    {
        { 'I', 'V', 'X' },
        { 'X', 'L', 'C' },
        { 'C', 'D', 'M' },
        { 'M', ' ', ' ' }
    };

    static const UTF8 *aCode[10] =
    {
        T(""),
        T("1"),
        T("11"),
        T("111"),
        T("12"),
        T("2"),
        T("21"),
        T("211"),
        T("2111"),
        T("13")
    };

    while (nA--)
    {
        const UTF8 *pCode = aCode[*pA - '0'];
        const UTF8 *pLetters = aLetters[nA];

        while (*pCode)
        {
            safe_chr(pLetters[*pCode - '1'], buff, bufc);
            pCode++;
        }
        pA++;
    }
}

/*-------------------------------------------------------------------------
 * List-based numeric functions.
 */

FUNCTION(fun_land)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bValue = true;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp && bValue)
        {
            UTF8 *curr = split_token(&cp, sep);
            bValue = isTRUE(mux_atoi64(curr));
        }
    }
    safe_bool(bValue, buff, bufc);
}

FUNCTION(fun_lor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bValue = false;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp && !bValue)
        {
            UTF8 *curr = split_token(&cp, sep);
            bValue = isTRUE(mux_atoi64(curr));
        }
    }
    safe_bool(bValue, buff, bufc);
}

FUNCTION(fun_lxor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    bool bValue = false;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            bool bCurr = isTRUE(mux_atoi64(curr));
            bValue = (bValue && !bCurr) || (!bValue && bCurr);
        }
    }
    safe_bool(bValue, buff, bufc);
}

FUNCTION(fun_lband)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = UINT64_MAX;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            if (!is_integer(curr, nullptr))
            {
                safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
                return;
            }
            val &= mux_atoi64(curr);
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_lbor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = 0;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            if (!is_integer(curr, nullptr))
            {
                safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
                return;
            }
            val |= mux_atoi64(curr);
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_lbxor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = 0;
    if (0 < nfargs)
    {
        SEP sep;
        if (!OPTIONAL_DELIM(2, sep, DELIM_DFLT|DELIM_STRING))
        {
            return;
        }

        LBuf scList = LBuf_Src("fun_lbool.list");
        UTF8 *cp = trim_space_sep(list_copy_for_split(scList, fargs[0]), sep);
        while (cp)
        {
            UTF8 *curr = split_token(&cp, sep);
            if (!is_integer(curr, nullptr))
            {
                safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
                return;
            }
            val ^= mux_atoi64(curr);
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_band)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = UINT64_MAX;
    for (int i = 0; i < nfargs; i++)
    {
        if (is_integer(fargs[i], nullptr))
        {
            val &= mux_atoi64(fargs[i]);
        }
        else
        {
            safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
            return;
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_bor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = 0;
    for (int i = 0; i < nfargs; i++)
    {
        if (is_integer(fargs[i], nullptr))
        {
            val |= mux_atoi64(fargs[i]);
        }
        else
        {
            safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
            return;
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_bnand)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(nfargs);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    if (  is_integer(fargs[0], nullptr)
       && is_integer(fargs[1], nullptr))
    {
        int64_t a = mux_atoi64(fargs[0]);
        int64_t b = mux_atoi64(fargs[1]);
        safe_i64toa(a & ~(b), buff, bufc);
    }
    else
    {
        safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
    }
}

FUNCTION(fun_bxor)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint64_t val = 0;
    for (int i = 0; i < nfargs; i++)
    {
        if (is_integer(fargs[i], nullptr))
        {
            val ^= mux_atoi64(fargs[i]);
        }
        else
        {
            safe_str(S_("#-1 ARGUMENTS MUST BE INTEGERS"), buff, bufc);
            return;
        }
    }
    safe_i64toa(val, buff, bufc);
}

FUNCTION(fun_crc32)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    uint32_t ulCRC32 = 0;
    for (int i = 0; i < nfargs; i++)
    {
        size_t n = strlen(reinterpret_cast<const char *>(fargs[i]));
        ulCRC32 = CRC32_ProcessBuffer(ulCRC32, fargs[i], n);
    }
    safe_i64toa(ulCRC32, buff, bufc);
}

void safe_hex(uint8_t md[], size_t len, bool bUpper, UTF8 *buff, UTF8 **bufc)
{
    std::vector<UTF8> buf((len * 2) + 1);

    int bufoffset = 0;
    const UTF8 *Digits16 = bUpper ? Digits16U : Digits16L;
    for (size_t i = 0; i < len; i++)
    {
        uint8_t c = md[i];
        buf[bufoffset++] = Digits16[(c >> 4) & 0x0F];
        buf[bufoffset++] = Digits16[(c     ) & 0x0F];
    }
    buf[bufoffset] = '\0';
    safe_str(buf.data(), buff, bufc);
}

void sha1_helper(int nfargs, const UTF8 * const fargs[], UTF8 *buff, UTF8 **bufc)
{
#ifdef UNIX_DIGEST
    uint8_t md[EVP_MAX_MD_SIZE];
#else
    uint8_t md[MUX_SHA1_DIGEST_LENGTH];
#endif
    unsigned int len = 0;
    std::vector<size_t> lens(nfargs);
    for (int i = 0; i < nfargs; i++)
    {
        lens[i] = strlen(reinterpret_cast<const char *>(fargs[i]));
    }
    if (!mux_sha1_digest(fargs, lens.data(), nfargs, md, &len))
    {
        safe_str(S_("#-1 UNSUPPORTED"), buff, bufc);
        return;
    }
    safe_hex(md, len, true, buff, bufc);
}

FUNCTION(fun_sha1)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

    sha1_helper(nfargs, fargs, buff, bufc);
}

FUNCTION(fun_digest)
{
    UNUSED_PARAMETER(executor);
    UNUSED_PARAMETER(caller);
    UNUSED_PARAMETER(enactor);
    UNUSED_PARAMETER(eval);
    UNUSED_PARAMETER(cargs);
    UNUSED_PARAMETER(ncargs);

#ifdef UNIX_DIGEST
    EVP_MD_CTX *ctx;
#if HAVE_EVP_MD_CTX_NEW
    ctx = EVP_MD_CTX_new();
#elif HAVE_EVP_MD_CTX_CREATE
    ctx = EVP_MD_CTX_create();
#else
#error Need EVP_MD_CTX_new() or EVP_MD_CTX_create().
#endif

    // Resolve the (user-supplied) digest name.  On OpenSSL 3.0+ use the
    // provider-native EVP_MD_fetch(): unlike the legacy EVP_get_digestbyname(),
    // it resolves algorithm aliases such as "sha-1" deterministically from a
    // cold process, with no dependence on an earlier digest call having lazily
    // loaded the default provider (#1961).  A fetched EVP_MD is a reference that
    // must be freed; the legacy pointer is a static const that must not be.
#if OPENSSL_VERSION_NUMBER >= 0x30000000L && !defined(LIBRESSL_VERSION_NUMBER)
    EVP_MD *mp = EVP_MD_fetch(nullptr, reinterpret_cast<const char *>(fargs[0]), nullptr);
#else
    const EVP_MD *mp = EVP_get_digestbyname(reinterpret_cast<const char *>(fargs[0]));
#endif
    if (nullptr == mp)
    {
        // Release the context allocated above before bailing (#1961 leak fix).
#if HAVE_EVP_MD_CTX_NEW
        EVP_MD_CTX_free(ctx);
#elif HAVE_EVP_MD_CTX_CREATE
        EVP_MD_CTX_destroy(ctx);
#endif
        safe_str(S_("#-1 UNSUPPORTED DIGEST TYPE"), buff, bufc);
        return;
    }

    EVP_DigestInit(ctx, mp);

    int i;
    for (i = 1; i < nfargs; i++)
    {
        EVP_DigestUpdate(ctx, fargs[i], strlen(reinterpret_cast<const char *>(fargs[i])));
    }

    unsigned int len = 0;
    uint8_t md[EVP_MAX_MD_SIZE];
    EVP_DigestFinal(ctx, md, &len);
#if OPENSSL_VERSION_NUMBER >= 0x30000000L && !defined(LIBRESSL_VERSION_NUMBER)
    EVP_MD_free(mp);
#endif
#if HAVE_EVP_MD_CTX_NEW
    EVP_MD_CTX_free(ctx);
#elif HAVE_EVP_MD_CTX_CREATE
    EVP_MD_CTX_destroy(ctx);
#else
#error Need EVP_MD_CTX_new() or EVP_MD_CTX_create().
#endif
    safe_hex(md, len, true, buff, bufc);
#else
    // CNG backend (#1963): sha1/sha256/sha384/sha512/md5, resolved by
    // mux_digest.  Same #-1 on unknown names as the OpenSSL side.
    uint8_t md[MUX_MAX_DIGEST_LENGTH];
    unsigned int len = 0;
    std::vector<size_t> lens(nfargs > 1 ? nfargs - 1 : 0);
    for (int i = 1; i < nfargs; i++)
    {
        lens[i-1] = strlen(reinterpret_cast<const char *>(fargs[i]));
    }
    if (mux_digest(fargs[0], const_cast<const UTF8 **>(fargs + 1), lens.data(),
                   nfargs - 1, md, &len))
    {
        safe_hex(md, len, true, buff, bufc);
    }
    else
    {
        safe_str(S_("#-1 UNSUPPORTED DIGEST TYPE"), buff, bufc);
    }
#endif // UNIX_DIGEST
}