--
-- pprntfN.e
-- =========
--
-- The Phix sprintf() function.
-- This file is automatically included by the compiler if (and only if) needed.
-- Compared to the C version, this is just over twice as slow, which is rather
-- surprising (I expected it would be around 8 to 10 times slower). I suspect
-- the biggest overhead is allocating space for the result (string), which is
-- pretty much going to be the same for the C and Phix routines. This may be
-- converted to asm at a later date, but not until it has been completely
-- bug- and enhancement- free for at least six months.
--
--
-- **************************************
-- **** WARNING: FRAGILE CODE AHEAD! ****
-- **************************************
--  Test changes exhaustively before rebuilding p.exe!
--  In particular, take care with type string; subtle changes (such as a
--  missing floor()) can make the back-end expand a string to a sequence
--  (which is something prepend, as opposed to append, /always/ does)
--  which causes a fatal error, eg see 'elsif fmt[i]='s' then'.

--!/**/without debug -- remove to debug (just keeps ex.err clutter-free)
--!/**/with debug
--  NB the "without debug" in both pdiag.e and ppp.e overshadow the one
--      here; use "with debug" and/or "-nodiag" to get a listing.

--without trace -- ditto, plus important this be off when running trace(3)
--with trace

-- Bugfix history:
--  14/01/06. Did not handle negative numbers ("sgn" added).
--  09/03/06. printed 2700000000 as "27".
--  22/05/06. precision errors on big numbers.
--  19/08/07. nzdigitprinted flag added. [ummm?]
--  19/06/08. bug with trailing 0s in 'g'.
--  20/03/09. moved exp to end for K_noclr reasons.
--  05/03/12. made thread-safe (no file-level vars) [DEV multiple returns rqd?]

--include builtins\VM\pUnassigned.e -- :%pRTErn (DEV/temp)
include builtins\VM\pPower.e

--/* Not required for Phix (string is builtin):
type string(object o) return sequence(o) end type
--*/

function round_str(string result, atom f, integer exponent, integer charflag, integer digit)--, integer minfieldwidth)
--
-- Apply rounding to partially printed float, if required
--
integer tmp
integer dot, dotm1
--?result   --DOH, infinite loop! (use puts(1,<string>) instead!)
--1/11/22:
--integer one = iff(result[1]='-'?2:1)
integer one = iff(find(result[1],"-+")?2:1)
    if exponent>=1 then
        f /= power(10,exponent)
    end if
--2/12/18:
--  if f>5 or (f=5 and remainder(digit,2)=1) then
    if f>5 or (f=5 and remainder(digit,2)=1) or digit=10 then
        for i=length(result) to one by -1 do
            dot = result[i]
            if dot='9' then
                result[i] = '0'
            elsif dot!='.' then
--              result[i] += 1      --DEV 26/9/9: try dot += 1 result[i] = dot... (better type info)
                dot += 1
                result[i] = dot
                exit
            end if
            if i=one then
--DEV: (oldschool, from when prepend string did not work) [prepend always yields T_Seq now anyways] [DEV: lies, 28/3/2014]
--              result = prepend(result,'1')
                if one=1 then
--                  result = "1"&result
                    result = '1'&result
                else
--                  result = "-1"&result[2..$]
                    result = '-'&'1'&result[2..$]
                end if
                if charflag!='f' then
                    dot = find('.',result)
                    if dot then
                        dotm1 = dot-1
                        result[dot] = result[dotm1]
--                      result[dotm1] = '.'
                        result[dotm1] = '!'
--DEV gives bounds error...
--DEV I suppose we should check it is a '0' as well.
--                      result = result[1..length(result)-1]
--                      exponent += 1
                    end if
                end if
            end if
        end for
    end if
--  if charflag='g' then
--  if charflag='g' and find('.',result) then   -- find '.' added 9/3/6
    if charflag='g' 
    and (find('.',result) or find('!',result)) then
        tmp = length(result)
--14/1/15:
--      while tmp>1 and tmp>minfieldwidth do
        while tmp>1 do
            dot = result[tmp]
-- 20/10/15: sprintf("%g",1e-14) was yielding "1e-15"!! It now keeps the the trailing '!' to adjust exponent.
--          if dot='.' 
--          or dot='!' then
            if dot='!' then exit end if
            if dot='.' then
                tmp -= 1
                exit
            end if
            if dot!='0' then exit end if
            tmp -= 1
        end while
        result = result[1..tmp]
    end if
    return result
end function

integer init2
        init2 = 0

atom inf,nan

-- do we still need these?? (yes)
function Nan() -- thread-safe alternative to "nan"
    string res = repeat('n',3)
    res[2] = 'a'
    return res
end function

function Inf() -- thread-safe alternative to "inf"
    string res = repeat('i',3)
    res[2] = 'n'
    res[3] = 'f'
    return res
end function

function sprintf2(atom pf, integer charflag, integer showplus, integer minfieldwidth, integer precision)
integer dotdone, nzdigitprinted
string reve
integer revelen
integer expadj
integer capE    -- 'e' or 'E'
integer ewk
integer tmp
integer digit
atom f, fwk, epwr
string result
integer exponent, k

--?result   --DOH, infinite loop! (use puts(1,<string>) instead!)
    f = pf
--  result = ""
    result = repeat(' ',0)
    dotdone = 0
    nzdigitprinted = 0
    if f=nan then
--DEV not thread safe
--      return "nan"
        return Nan()
    end if
    if f<0 then
--      result = "-"
        result = repeat('-',1)
        f = -f
    elsif showplus then
--      result = "+"
--      result = repeat('+',1)
        result = repeat(showplus,1) -- '+' or ' '
    end if
    exponent = 0
    if f=nan then
--      return result&"nan"
        return result&Nan()
    end if
    if f=inf then
--      return result&"inf"
        return result&Inf()
    end if
    if f>=10 then
        fwk = f
        while fwk>=10 do
            exponent += 1
            fwk /= 10
        end while
    else
        while f<1 and f!=0 do
            exponent -= 1
            f *= 10
        end while
    end if
    capE = 'e'
    if charflag<'a' then
        charflag += 32
        capE = 'E'
    end if
--  if charflag='e' or (charflag='g' and (exponent>9 or exponent<-4)) then
--1/11/15:
--  if charflag='e' or (charflag='g' and (exponent>precision or exponent<-4)) then
    if charflag='e' or (charflag='g' and (exponent>=precision or exponent<-4)) then
        ewk = exponent
        if exponent>0 then
--DEV problems on 64bit: (opPow needs improvement!)
--          epwr = power(10,exponent)
epwr = 10
for i=2 to exponent do
    epwr *= 10
end for
            fwk = 0--epwr
            digit = 0
            while f>=fwk+epwr do
                fwk += epwr
                digit += 1
            end while
--24/2/24:
            f -= fwk
        else
            digit = floor(f)
--21/2/24:
            f = (f-digit)*10
        end if
        result &= digit+'0'
        expadj = 1
        if precision>0 then
            result &= '.'
            dotdone = 1
--24/2/24:
--          atom fadj = 0
--1/11/15
--          for i=1 to precision do
            for i=1 to precision-(charflag='g') do
                if ewk>0 then
--24/2/24:
--                  f -= fwk
                    ewk -= 1
                    epwr = power(10,ewk)
                    fwk = 0--epwr
                    digit = 0
                    while f>=fwk+epwr do
                        fwk += epwr
                        digit += 1
                    end while
--24/2/24:
--30/10/21
--                  fadj = fwk
                    f -= fwk
--26/2/24:
                    if ewk=0 then f *= 10 end if
                else
--21/2/24
--                  f = (f-digit)*10
                    digit = floor(f)
                    f = (f-digit)*10
--24/2/24:
--                  fadj = 0
                end if
--12/7/16:
                if digit=10 then exit end if
                result &= digit+'0'
                expadj += 1
            end for
--24/2/24:
--          f -= fadj
        else
            if ewk>0 then
                f -= fwk
            else
                f = (f-digit)*10
            end if
        end if
        exponent -= expadj
        result = round_str(result,f,exponent,charflag,digit)--,minfieldwidth)
        k = find('!',result)
        if k then
--          if k=length(result) then
--              result = result[1..-2]
--          else
                result[k] = '.'
--24/3/23!
                result = result[1..-2]
--          end if
            exponent += 1
        end if
        exponent += expadj
        result &= capE
        if exponent<0 then
            result &= '-'
            exponent = 0-exponent
        else
            result &= '+'
        end if
        if exponent=0 then
--          reve = "0"
            reve = repeat('0',1)
        else
--          reve = ""
            reve = repeat(' ',0)
            while exponent do
                reve = append(reve,floor(remainder(exponent,10)+'0'))
                exponent = floor(exponent/10)
            end while
            revelen = length(reve)
            for j=1 to revelen do
                if j>=revelen then exit end if
                tmp = reve[j]
                reve[j] = reve[revelen]
                reve[revelen] = tmp
                revelen -= 1
            end for
        end if
        result &= reve
    else
        digit = 0
        if exponent<-1 then
--DEV not thread safe
--          result &= "0."
            result &= '0'
            if charflag!='g' or f!=0 then
                result &= '.'
                dotdone = 1
                while exponent<-1
                  and (charflag!='g' or f!=0) do
                    exponent += 1
                    if precision then
                        result &= '0'
--24/5/20 (check removed)
--28/12/21 (check restored... [can no longer remember why it was removed, nowt in the release notes...])
--06/02/22 (removed again, for demo/pGUI/graph1.exw ["%.1f", -5.55e-17 printing as "-0.00000000000000006"])
--         (can't be absolutely sure, but I probably made that change for the approximate equality task..)
--                      if minfieldwidth>0 then
                            precision -= 1
--                      end if
                    else
                        f /= 10
                    end if
                end while
            end if
        end if

        while true do
            if exponent=-1 then
                if precision>0 then
                    if not dotdone then
                        if charflag='g' then
                            if f=0 then exit end if
                        end if
--                      if find(result,{"","-","+"}) then
                        if length(result)=0
--                      or (length(result)=1 and (result[1]='-' or result[1]='+')) then
                        or (length(result)=1 and find(result[1],"-+ ")) then
                            result &= '0'
                        end if
                        result &= '.'
                    end if
                    for j=1 to precision do
                        digit = floor(f)
                        result &= digit+'0'
                        f = (f-digit)*10
                        if charflag='g' then
                            if f=0 then exit end if
                        end if
                    end for
                end if
                exit
            end if
            if exponent>=1 then
                epwr = power(10,exponent)
                fwk = 0--epwr
                digit = 0
                while f>=fwk+epwr do
                    fwk += epwr
                    digit += 1
                end while
                f -= fwk    --epwr
            else
                digit = floor(f)
                f = (f-digit)*10
            end if
--2/12/18!
if digit=10 then exit end if
            result &= digit+'0'
            if digit then
                nzdigitprinted = 1
            end if
            exponent -= 1
            if charflag='g' then
                if length(result)>=minfieldwidth and f=0 then exit end if
--DEV: try printf(1,"%6.2f\n%6.2g\n",96.5)
-- (same results as RDS Eu, but that does not necessarily make it right!)
-- Possible fix is to remove this line...(19/8 put the new flag test round it instead)
                if nzdigitprinted then
                    precision -= 1
                end if
            end if
        end while
        if length(result)=0 then
--          result = "0"
            result = repeat('0',1)
        end if
        result = round_str(result,f,exponent,charflag,digit)--,minfieldwidth)
        k = find('!',result)
        if k then
            if k=length(result) then
                result = result[1..-2]
            else
                result[k] = '.'
            end if
            exponent += 1
        end if
        if exponent>-1 then
            while exponent>-1 do
                result &= '0'
                exponent -= 1
            end while
-- kludge 24/9/2020:
        elsif dotdone and result[$]='.' then
            result = result[1..$-1]
        end if
        if result="-0"
        or result="-" then
            result = "0"
        end if
    end if
    return result
end function

procedure ueofmt()
    crash("unexpected end of format string",{},4)
end procedure

function useFlatString(sequence args, integer nxt, sequence fmt, integer i)
-- permit printf(1,"%s","Hello") to work as {"Hello"} - but only if:
-- 1) this is the first % (nxt=1)
-- 2) there are no more %'s in the fmt, except for %%
-- 3) args is a flat string
object o
    if nxt!=1 then return 0 end if
    for j=i+1 to length(fmt) do
        if fmt[j]='%' then
            if j=length(fmt) or fmt[j+1]!='%' then return 0 end if
        end if
    end for
    for j=1 to length(args) do
        o = args[j]
        if not integer(o) then return 0 end if
        if o<1 or o>255 then return 0 end if
    end for
    return 1
end function

bool prefer_backtick = false
--constant tnr = "tnr"
--constant tnr = "tnr\\\"\'\0"
--constant tnr = "tnr\\\"\'0e"

--function allascii(string x, bool withquotes)
function allascii(string x, integer enquote='q')
-- Phix allows "strings" to hold binary data, so double check 
-- before printing it as a string.
integer c
bool backtick = (enquote='q')
--sequence bsi = {}
sequence bsi = repeat(0,0)
    for i=length(x) to 1 by -1 do
        c = x[i]
--31/1/15:
--      if c<' ' then
--      if c<' ' or c>#FF or find(c,"\\\"\'") then
        if c='\\' or c='\"'or c='\'' then
            if backtick then
                bsi &= i
            else
                x[i..i] = '\\'&c    -- NB does not work on RDS Eu/OpenEuphoria
            end if
        elsif c<' ' or c>#FF then
--          c = find(c,"\t\n\r")
--          c = find(c,"\t\n\r\\\"\'\0\e")
            if c='\t' then c='t'
            elsif c='\n' then c='n'
            elsif c='\r' then c='r'
            elsif c='\0' then c='0'
            elsif c='\e' then c='e'
            else
--DEV or crash?
                return 0
            end if
            if backtick then
                for j=1 to length(bsi) do   -- (still "last first", btw/iyswim)
                    integer k = bsi[j]
                    x[k..k] = '\\'&x[k]
                end for
                backtick = false
            end if
            x[i..i] = '\\'&c    -- NB does not work on RDS Eu/OpenEuphoria
        end if
    end for
--  if withquotes then
--  if backtick then
--  if backtick and enquote='q' and length(bsi)!=0 then
    if backtick and (prefer_backtick or length(bsi)!=0) then
        x = '`'&x&'`'
    else
        x = '"'&x&'"'
    end if
    return x
end function

string hexchar, dxoetc
sequence bases

--integer r_len = 0
bool unicode_align = false

--forward function sprint(object x, integer asCh=false, maxlen=-1, nest=0)

procedure init_2()
-- [DEV] technically this isn't thread safe... (code shown commented out should be enough, once those routines work)
    -- (uncommented 25/11/16)
    enter_cs()
    if not init2 then
--DEV make INF a builtin (like PI), ditto NAN:
--      inf = 1e300*1e300
        #ilASM{ fld1
                fldz
                fdivp
            [32]
                lea edi,[inf]
            [64]
                lea rdi,[inf]
            []
                call :%pStoreFlt }

        -- Erm, this one is a bit bizarre...
        -- On the one hand it seems RDS Eu does not support nan properly, but then it somehow does...
        -- If you try testing for nan, it seems to go all pear-shaped, but avoiding the tests
        --  seems to make it happy again, and yet print "nan" and "inf" like a good little boy...
        -- Of course, you shouldn't be using this code on RDS Eu anyway.
        --
--/**/  nan = -(inf/inf)        --/* Phix
        nan = 3.245673689e243   --   RDS --*/

        bases = {10,16,8,2}
--      hexchar = "0123456789ABCDEFabcdef"
--      hexchar = tagset('9','0') & tagset('Z','A') & tagset('z','a')
        hexchar = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
--  ?hexchar
--  ?hexchar[1+10]&""       -- 'A'
--  ?hexchar[1+10+26]&""    -- 'a'

--      dxoetc = "dxobscvefgEXG"
--      dxoetc = "dxobstncvVefgEXG"
        dxoetc = "dxobstncvVRefgEXG"
        init2 = 1
    end if
    leave_cs()
end procedure

local function toRoman(integer n, bool lowercase)
    assert(n>=1 and n<=3999,"roman numerals must be 1..3999",4)
    string res = ""
    integer idx = 1, -- (..7, to "MDCLXVI")
             rn = 1000, -- 500,100,50,10,5,1
          tenth =  100  -- 100, 10,10, 1,1,0
    while n>0 do
        while n>=rn do
            res &= "MDCLXVI"[idx];
            n -= rn;
        end while
        if n+tenth>=rn then
            res &= "CXI"[floor((idx+1)/2)];
            n += tenth -- above loop once more
        elsif n then
            idx += 1;
            rn /= iff(odd(idx)?5:2);
--(sip, untested:)
--          if odd(idx) then tenth = floor(rn/10) end if
            if odd(idx) then tenth = rn/10 end if
        end if
    end while
    if lowercase then res = lower(res) end if
    return res
end function

--without trace
local function sprintf_(sequence fmt, object args)
integer i, fi, fidx
integer nxt
string result, r1
object o, oj
atom work
integer base, sgn, r1len, hc
bool lowerHex
--?result   --DOH, infinite loop! (use puts(1,<string>) instead!)
integer zerofill
integer leftjustify
integer centre
integer showplus
integer showcommas
integer enquote
integer blankTZ
integer minfieldwidth
--      minfieldwidth = 0
integer precision
--      precision = 0
integer tmp

    if not init2 then init_2() end if
    nxt = 1
--  result = ""
    result = repeat(' ',0)
    i = 1
    while i<=length(fmt) do
        fi = fmt[i]
        if fi='%' then
            i += 1
            if i>length(fmt) then ueofmt() end if
            fi = fmt[i]
            if fi='%' then
                result &= '%'
            else
                zerofill = 0
                leftjustify = 0
                centre = 0
                showplus = 0
                showcommas = 0
                enquote = 0
                if fi='[' then
                    integer e = find(']',fmt,i+1)
                    if e=0 then
                        crash("missing ] in format string",{},3)
                    end if
                    nxt = to_integer(fmt[i+1..e-1])
                    if nxt=0 then
                        crash("[%s] is 0 or not a number",{fmt[i+1..e-1]},3)
                    end if
                    i = e+1
                    if i>length(fmt) then ueofmt() end if
                    fi = fmt[i]
                end if
                -- Note that -=| are mutually exclusive, and cannot co-exist with 0. 
                -- Likewise 0 and + are also mutually exclusive, however a + can
                -- co-exist with -=| as long as it is specified first, and , can be
                -- used in combination with any, as long as it is specified last.
                if fi='0' then
                    zerofill = 1
                    i += 1
                else
--                  if fi='+' then
                    if fi='+' or fi='_' then
--                      showplus = 1
                        showplus = iff(fi='+'?'+':' ')
                        i += 1
                        if i>length(fmt) then ueofmt() end if
                        fi = fmt[i]
                    end if
                    if fi='-' then
                        leftjustify = 1
                        i += 1
                    elsif fi='=' then
                        centre = 1
                        i += 1
                    elsif fi='|' then
                        centre = 2
                        i += 1
                    end if
                end if
                if i>length(fmt) then ueofmt() end if
                fi = fmt[i]
                if fi=',' then
                    showcommas = 3
                    i+=1
                end if
                if i>length(fmt) then ueofmt() end if
                minfieldwidth = 0
                while 1 do
                    fi = fmt[i]
                    if fi<'0' or fi>'9' then exit end if
                    minfieldwidth = minfieldwidth*10 + (fi-'0')
                    i += 1
                    if i>length(fmt) then ueofmt() end if
                end while
                precision = -1
                if fi='.' then
                    i += 1
                    if i>length(fmt) then ueofmt() end if
                    precision = 0
                    while 1 do
                        fi = fmt[i]
                        if fi<'0' or fi>'9' then exit end if
                        precision = precision*10 + (fi-'0')
                        i += 1
                        if i>length(fmt) then ueofmt() end if
                    end while
                end if

                lowerHex = false
                -- 23/2/10 'b' added
                -- 12/1/19 'v' added
                -- 11/12/19 't' added
                -- 16/11/20 'q' and 'Q' added
                -- 22/05/21 'a' and 'A' added
                -- 10/08/22 'F' added
                -- 08/02/24 'r', 'R' added
                blankTZ = false
                if fi='a' or fi='A' then
                    lowerHex = fi='a'
                    fidx = 0
                    bool bBad = atom(args) or nxt>length(args)
                    if not bBad then
                        o = args[nxt]
                        bBad = atom(o) or length(o)!=2 or not integer(o[1]) or not atom(o[2])
                        if not bBad then
                            {base,work} = o
                            bBad = base<2 or base>iff(lowerHex?36:62)
                        end if
                    end if
                    if bBad then
                        crash("%%%c requires {base,num}",fi,3)
                    end if
                else

                    if fi='q' or fi='Q' then
                        enquote = fi
                        fi = 's'
                    elsif fi='F' then
                        blankTZ = true
                        fi = 'f'
                    elsif fi='r' then
                        lowerHex = true -- (repurposed here)
                        fi = 'R'
                    end if
--                  fidx = find(fi,"dxobstcvefgEXG")
--                  fidx = find(fi,"dxobstncvefgEXG")
                    fidx = find(fi,dxoetc)
--                  fidx = 0
--                  for dx=1 to length(dxoetc) do
--                      if fi=dxoetc[dx] then
--                          fidx = dx
--                          exit
--                      end if
--                  end for
                    if fi='X' then
                        --
                        -- Yup, I know it's a wee bit confusing, but for compatibility
                        --  reasons, %x is upper case hex and %X is lower case hex!
                        -- Assuming any objections from the backwards compatibility crowd 
                        --  are drowned out by many more from the logical behaviour crowd,
                        --  set lowerHex to 1/0 rather than the 0/1 it is now.
                        --
                        lowerHex = true
                        fidx = 2
                    end if

--                  if fidx=0
----                    or (showcommas and find(fi,"df")=0) then
--                  or (showcommas and fi!='d' and fi!='f') then
--                      badfmt()
--                  end if
                    if fidx=0 then
                        crash("unknown specifier:%c",fi,3)
                    elsif showcommas and fi!='d' and fi!='f' then
                        crash("comma fill not supported on %c",fi,3)
                    end if

                    if not atom(args) and nxt>length(args) then
----/**/                    #ilASM{
----!/**/                   [32]
----/**/                            mov al,70                           -- Phix
----!/**/                       xor edi,edi         -- ep1 unused   -- Phix
----!/**/                       xor esi,esi         -- ep2 unused   -- Phix
----!/**/                   [64]
----!/**/                       call :%pRTErn }     -- fatal error  -- Phix
----/**/                            mov ecx,2                           -- Phix
----/**/                            jmp :!fatalN                        -- Phix
----/**/                            int3 }                              -- Phix
----/**/                                                    --/*    -- Phix
--                      puts(1,"insufficient values for sprintf\n") -- RDS
--                      if getc(0) then end if                      -- RDS
--                      abort(1)                                    -- RDS --*/
                        crash("insufficient values for [s]printf",{},3)
                    end if
                end if
                if fidx<=4 then -- aA(0, work set), dxob (1..4)
                    if fidx!=0 then
                        base = bases[fidx]  --{10,16,8,2}
                        o = args
                        work = 0
                        if atom(o) then
                            if o!=nan and o!=-nan and o!=inf and o!=-inf then
                                work = floor(o)
                            end if
                        else
                            o = args[nxt]
                            if atom(o) then
                                if o!=nan and o!=-nan and o!=inf and o!=-inf then
                                    work = floor(o)
                                end if
                            else
                                o = 0
                            end if
                        end if
                    end if
                    if work then
                        sgn = 0
                        if work<0 then
                            sgn = 1
                            if base=10 then
                                work = 0-work
                            else
--DEV (found this(/64-bit version) commented out 23/7/19, no idea why... putting it back fixed my issue)
if machine_bits()=64 then
                                work = and_bits(work,#7FFFFFFFFFFFFFFF)+#8000000000000000
else
                                work = and_bits(work,#7FFFFFFF)+#80000000
end if
                            end if
                        end if
--                      r1 = ""
                        r1 = repeat(' ',0)
--1/11/22: (print powers of 2 exactly, by avoiding discrepancies that creep in for /10 when work>2^75, but don't for /2)
                        bool bViaBase2 = (base=10 and 
                                          work>37778931862957161709568 and -- (power(2,75), btw)
                                          count_bits(work)=1)
                        if bViaBase2 then base = 2 end if
                        while work do
                            -- NB: The result of prepend is always a sequence, 
                            --      for performance reasons. Hence use append 
                            --      to build it backwards, then reverse it.
                            hc = floor(remainder(work,base)+1)
--20/3/2013:
--                          if hc=0 then exit end if
                            if lowerHex and hc>10 then
--                              hc += 6
                                hc += 26
                            end if
                            if not bViaBase2 
                            and showcommas 
                            and showcommas=length(r1) then
                                r1 = append(r1,',')
                                showcommas += 4
                            end if
                            r1 = append(r1,hexchar[hc])
                            -- this is ok, ^ , hexchar[] is equally valid for 
                            --  base 16/10/8/2 (just less chars get used).
                            work = floor(work/base)
                        end while
                        if bViaBase2 then
                            -- convert r1 to base 10, from base 2
                            sequence d2 = sq_sub(reverse(r1),'0')
                            r1 = ""
                            while length(d2) do
                                integer d2r = 0
                                for d2i,d2digit in d2 do
                                    d2r = d2r*2+d2digit
                                    d2[d2i] = floor(d2r/10)
                                    d2r = rmdr(d2r,10)
                                end for
                                r1 &= d2r+'0'
                                if showcommas and showcommas=length(r1) then
                                    r1 = append(r1,',')
                                    showcommas += 4
                                end if
                                d2 = trim_head(d2,0)
                            end while
                            base = 10
                        end if
                        if sgn then
                            if base=10 then
                                r1 = append(r1,'-')
                            elsif minfieldwidth>length(r1) then
                                r1 &= repeat(hexchar[base],minfieldwidth-length(r1))
                            end if
                        elsif showplus then
                            if base=10 then
--                              r1 = append(r1,'+')
                                r1 = append(r1,showplus)
                            elsif minfieldwidth>length(r1) then
                                r1 &= repeat('0',minfieldwidth-length(r1))
                            end if
                        end if
                        r1len = length(r1)
                        -- as promised, reverse it:
                        for j=1 to r1len do     -- stops at mid-point[-1]
                            if j>=r1len then exit end if
                            tmp = r1[j]
                            r1[j] = r1[r1len]
                            r1[r1len] = tmp
                            r1len -= 1
                        end for
                    else
--DEV not thread safe:
                        if o=nan then
--                          r1 = "nan"
                            r1 = Nan()
                        elsif o=-nan then
--                          r1 = "-nan"
                            r1 = '-'&Nan()
                        elsif o=inf then
--                          r1 = "inf"
                            r1 = Inf()
                        else
--                          r1 = "0"
                            r1 = repeat('0',1)
                        end if
                    end if
--              elsif fidx<=10 then -- one of "stncvV"
                elsif fidx<=11 then -- one of "stncvVR"
                    if showplus then
                        crash("show plus not supported on %c",fi,3)
                    end if
                    if atom(args) then
                        o = args
--12/9/15:
--                  elsif useFlatString(args,nxt,fmt,i) then
--12/1/19:
--                  elsif fidx!=6 and useFlatString(args,nxt,fmt,i) then -- (not %c (ie %s) and useFlat..)
                    elsif fi='s' and useFlatString(args,nxt,fmt,i) then -- (not %c (ie %s) and useFlat..)
                        o = args
                        args = {}
                    else
                        o = args[nxt]
                    end if
--14/01/2022 %v and %V flipped
                    if fi='v' then
                        o = sprint(o,-1)
                    elsif fi='V' then
                        o = sprint(o)
                        -- aside: in the following if construct, only the  
                        -- last (ie precision) branch is relevant to %v.
                    elsif fi='R' then
                        o = toRoman(o,lowerHex)
                    elsif fi='t' then
                        o = iff(o?"true":"false")
                    elsif fi='n' then
                        o = iff(o?"\n":"")
                    elsif enquote then
                        o = allascii(o,enquote)
                    end if
                    if atom(o) then
--                      r1 = " "
                        r1 = repeat(' ',1)
                        r1[1] = and_bits(#FF,o) -- (nb: keeps r1 a string)
--                  elsif fidx=6 then -- 'c'
                    elsif fi='c' then
--/**/                  #ilASM{ mov al,76                           -- Phix
--!/**/                         xor edi,edi         -- ep1 unused   -- Phix
--!/**/                         xor esi,esi         -- ep2 unused   -- Phix
--!/**/                         call :%pRTErn }     -- fatal error  -- Phix
--/**/                          mov ecx,2                           -- Phix
--/**/                          jmp :!fatalN                        -- Phix
--/**/                          int3 }                              -- Phix
--/**/                                                      --/*    -- Phix
                        puts(1,"%c requires an atom value\n")       -- RDS
                        if getc(0) then end if                      -- RDS
                        abort(1)                                    -- RDS --*/
                    elsif not string(o) then
                        if precision!=-1 and precision<length(o) then
                            r1 = repeat(' ',precision)
                        else
                            r1 = repeat(' ',length(o))
                        end if
                        for j=1 to length(r1) do
                            oj = o[j]
                            if not integer(oj) then
--                          if not integer(oj) or oj<#07 or oj>#FF then
--/**/                          #ilASM{ mov al,65                               -- Phix
--!/**/                                 xor edi,edi         -- ep1 unused       -- Phix
--!/**/                                 xor esi,esi         -- ep2 unused       -- Phix
--!/**/                                 call :%pRTErn }     -- fatal error      -- Phix
--/**/                                  mov ecx,2                               -- Phix
--/**/                                  jmp :!fatalN                            -- Phix
--/**/                                  int3 }                                  -- Phix
--/**/                                                                  --/*    -- Phix
                                puts(1,"sequence found in character string\n")  -- RDS
                                if getc(0) then end if                          -- RDS
                                abort(1)                                        -- RDS --*/
                            end if
--                          r1[j] = oj
                            r1[j] = and_bits(oj,#FF)
                        end for
                    elsif precision!=-1 and precision<length(o) then
                        r1 = o[1..precision]
                    else
                        r1 = o
                    end if
                else    -- efg/EG
                    if atom(args) then
                        o = args
                    else
                        o = args[nxt]
                        if not atom(o) then
                            o = 0
                        end if
                    end if
                    if precision=-1 then
                        precision = 6
-- 1/11/22 (print fractional powers of 2 exactly, and this lot moved after o is set)
                    elsif count_bits(o)!=1 then
                        if precision>20 then
                            crash("floating point precision may not exceed 20",{},3)
                        elsif machine_bits()=32
                          and precision>16 then
                            precision = 16
                        end if
                    end if
--1/11/22: (print powers of 2 exactly, with above 2^-1074 to 2^1024 [on 32 bit, >on 64-bit??])
--                  if fi='f' and o>37778931862957161709568 and count_bits(o)=1 then
                    if fi='f' 
                    and atom_to_float64(o)[$]!=127 -- not [+/-]nan/inf
                    and o>37778931862957161709568 
-- sug/untested, see docs/Helping Hands/printf(2^i)
--                  and (o>37778931862957161709568 or o<1e-22)
                    and count_bits(o)=1 then
                        sequence d2 = {}
                        while o do
                            d2 = prepend(d2,rmdr(o,2))
                            o = floor(o/2)
                        end while
                        r1 = ""
                        while length(d2) do
                            integer d2r = 0
                            for d2i,d2digit in d2 do
                                d2r = d2r*2+d2digit
                                d2[d2i] = floor(d2r/10)
                                d2r = rmdr(d2r,10)
                            end for
                            r1 &= d2r+'0'
                            d2 = trim_head(d2,0)
                        end while
                        r1 = reverse(r1)
                    else
                        r1 = sprintf2(o,fi,showplus,minfieldwidth,precision)
                    end if
                    if showcommas then -- ('f' only)
--19/09/2020 bugfix (caused by the introduction of %t)
--                      if fidx!=9 then badfmt() end if
--                      if fidx!=10 then badfmt() end if
--                      if fidx!=11 then badfmt() end if
--                      if fidx!=12 then 
-- 30/5/23 is not this just much easier? (untested)
                        if fi!='f' then 
                            crash("comma fill not supported on %c",fi,3)
                        end if
                        showcommas = find('.',r1)
                        if showcommas=0 then showcommas = length(r1)+1 end if
--19/09/2020 bugfix ("-999" -> "-,999")
--                      while showcommas>4 do
                        while showcommas>(4+(r1[1]='-')) do
                            showcommas -= 3
                            r1 = r1[1..showcommas-1]&','&r1[showcommas..length(r1)]
                        end while
                    end if
                    if blankTZ and find('.',r1) then
                        for r1dx=length(r1) to 1 by -1 do
                            integer r1ch = r1[r1dx]
                            if r1ch='0' or r1ch='.' then
                                r1[r1dx] = ' '
                            end if
                            if r1ch!='0' then exit end if
                        end for
                    end if
                end if
-- replaced 19/10/17:
--              minfieldwidth -= length(r1)
--              minfieldwidth -= length(utf8_to_utf32(r1))
--DEV/SUG:
--              minfieldwidth -= length(iff(r_len!=0?call_func(r_len,{r1}):r1))
                minfieldwidth -= length(iff(unicode_align?utf8_to_utf32(r1):r1))
                if minfieldwidth>0 then
-- 20/9/2020
--                  if zerofill then
                    if zerofill and find('-',r1)=0 then
                        r1 = repeat('0',minfieldwidth)&r1
                    elsif leftjustify then
                        r1 = r1&repeat(' ',minfieldwidth)
--DEV/SUG:
                    elsif centre then
                        integer mh = floor(minfieldwidth/2)
                        if centre=1 then    -- '=', split 3:4
                            r1 = repeat(' ',mh)&r1&repeat(' ',minfieldwidth-mh)
                        else                -- '|', split 4:3
                            r1 = repeat(' ',minfieldwidth-mh)&r1&repeat(' ',mh)
                        end if
                    else
                        r1 = repeat(' ',minfieldwidth)&r1
                    end if
                end if
                result &= r1
                nxt += 1
            end if
        else
--puts(1,"?{result,fi}\n")
--?{result,fi}
            result &= fi
--?result
        end if
        i += 1
    end while
--DEV this should be a warning??? (Interpret mode only!)
--  if not atom(args) and nxt<=length(args) then
----/**/    #ilASM{ mov al,105                              -- Phix
----!/**/           xor edi,edi         -- ep1 unused       -- Phix
----!/**/           xor esi,esi         -- ep2 unused       -- Phix
----/**/            call :%pRTErn }     -- fatal error      -- Phix
----/**/                                            --/*    -- Phix
--      puts(1,"not enough format strings to print data\n") -- RDS
--      if getc(0) then end if                              -- RDS
--      abort(1)                                            -- RDS --*/
--  end if
    return result
end function

-- (This is a wrapper so that the internal routine can apply 
--  identical error handling for both sprintf and printf: we
--  typically want to point at the application source code
--  line, rather than confuse by landing developer in here.)
global function sprintf(sequence fmt, object args)
    return sprintf_(fmt,args)
end function

--DEV move this (once newEmit is done) [better yet put it in the optable]
-- note: printf is now defined in pfileioN.e
global procedure printf(integer fn, sequence fmt, object args={})
--DEV/SUG:
    if fn=0 and fmt="" then
--      -- args is settings-pairs, eg {"r_len",routine_id("utf8_to_utf32")}
        -- args is settings-pairs, eg printf(0,"",{"unicode_align",true})
--DEV 20/4/19 broke p -c -test:
--      if remainder(length(args),2) then throw("must be even length") end if
        if remainder(length(args),2) then ?9/0 end if
        for i=1 to length(args) by 2 do
            string setting = args[i]
            switch setting do
--              case "r_len": r_len = args[i+1]
                case "unicode_align": unicode_align = args[i+1]
                case "prefer_backtick": prefer_backtick = args[i+1]
--20/4/19:
--              default: throw("unknown printf setting")
                default: ?9/0
            end switch
        end for
    else
        puts(fn,sprintf_(fmt,args))
    end if
end procedure

local integer asChdef = false

--global function sprint(object x, integer asCh=false, maxlen=-1, nest=0)
global function sprint(object x, integer asCh=asChdef, maxlen=-1, nest=0)
-- Return the string representation of any data object. 
-- This is the same as the output from print(1, x) or '?', 
--  but returned as a string sequence rather than printed.
-- asCh: true: print eg 65 as 65'A', 
--       false: not top-level,
--           -1: sticky false
--       """"+10: (ie 9,10,11) new default (-1,0,1 respectively)
-- maxlen, nest: see docs
-- Alternative: see ppp.e (ppf/ppOpt/ppExf).
    object s, xi
    if asCh>=9 then
        asCh -= 10
        assert(asCh>=-1 and asCh<=1)
        if nest=0 then asChdef = asCh end if
    end if
    if atom(x) then
--      if asCh and integer(x) and ((x>=' ' and x<='~') or find(x,"\r\n\t"))
        if asCh=true    -- (not false or -1)
        and integer(x) 
        and (x>=' ' and x<='~') then
            s = sprintf("%d'%c'",x)
        else
--          s = sprintf("%.10g", x)
--28/12/21 (get rid of this nonsense and cut out the middleman, why not. [spotted in passing])
--          string fmt = '%'&'.'&'1'&'0'&'g'
--          s = sprintf(fmt,x)
            if not init2 then init_2() end if
            s = sprintf2(x,'g',/*showplus:=*/0,/*minfieldwidth:=*/0,/*precision:=*/10)
            if not integer(x)
--removed 3/11/15 (so that eg 2000000000 gets the ".0")
--          and integer(floor(x))
            and not find('.',s)
            and not find('e',s)         -- eg 1e308
            and not find('n',s) then    -- (inf/nan)
                -- make sure you can tell 5 and 5.00000000001 
                --  apart in ex.err, trace, ?x, and the like.
--              s &= ".0"
                s &= '.'
                s &= '0'
            end if
        end if
        return s
    end if
--  if string(x) then

--      s = allascii(x)
--      if string(s) then return s end if
--  end if
--8/8/16:
--  if maxlen!=-1 and length(x)>maxlen then
    if maxlen>4 and length(x)>maxlen then
        x = x[1..maxlen]
--8/8/16: (change as above)
        if string(x) then
--      if string(x) and length(x)>4 then
--          s = allascii(x[1..maxlen-4],true)
            s = allascii(x[1..maxlen-4])
--          if string(s) then return s&".." end if
            if string(s) then
                s &= '.'
                s &= '.'
                return s
            end if
        end if
    elsif string(x) then
--      s = allascii(x,nest!=0)
        s = allascii(x)
        if string(s) then return s end if
    end if
--  s = "{"
    s = repeat('{',1)
    if asCh=false then asCh=true end if -- (nb -1 and true left as-is)
    for i=1 to length(x) do
--      s &= sprint(x[i])
        xi = x[i]
        if maxlen=-1 then
--          s &= sprint(xi)
            s &= sprint(xi,asCh,-1,nest+1)
        else
            if maxlen>length(s) then
                s &= sprint(xi,asCh,maxlen-length(s),nest+1)
            end if
            if length(s)>=maxlen then
                if nest=0 then
                    s = s[1..maxlen-2]
--                  s &= ".."
                    s &= '.'
                    s &= '.'
                else
                    s = s[1..maxlen]
                end if
                return s
            end if
        end if
        if i<length(x) then
            s &= ','
        end if
    end for
--  s &= "}"
    s &= '}'
    return s
end function

--DEV move this to pfileioN.e:
global procedure print(integer fn, object x, integer asCh=asChdef, maxlen=-1)
-- Print a string representation of any data object.
-- Alternative: see ppp.e (pp/ppOpt/ppEx).
--printf(1,"asCh:%d\n",asCh)
    puts(fn,sprint(x,asCh,maxlen))
end procedure