zOs/REXX.O13/M

/* copy m begin ********************************************************
  we use variables as follows
    m. stem m: all global data and object data that must survive
               a procedure call  (m for memory in Memoria of B5000)
        m.<mbr>.** to avoid conflicts: every rexx Module (copy) should
               only allocate addresses m.<mbr>.** with <mbr> the name of
               the rexx module
        we pass parameters around (e.g. a=address, m=memory, st=stem)
            and the called function may use m.a or m.a.subField etc.
    gg*: local variable in subroutines without procedure
    everything else: temporary data within procedure

  every subroutine is declared as procedure expose m.
        (also if no m. variable is used, because e.g. of error handling)
  the few subroutines that cannot use procedure, should use only
        variables starting with gg
***********************************************************************/
/*---make an area -----*/

mNewArea: procedure expose m.
parse arg nm, adr
    m.m.area.0 = m.m.area.0 + 1
    a = 'M.AREA.'m.m.area.0
    if adr == '=' then
        adr = nm
    else if adr == '' then
        adr = 'M.'m.m.area.0
    if symbol('m.m.n2a.adr') == 'VAR' then
        call err 'adr' adr 'for area' nm 'already used'
    m.m.n2a.adr = a
    call mAlias adr, nm
    m.m.p2a.adr = a

    m.a.0 = 0
    m.a.free.0 = 0
    m.a.address = adr
    return nm
endProcedure mNewArea

mAlias: procedure expose m.
parse arg oldNa, newNa
    if symbol('m.m.n2a.oldNa') \== 'VAR' then
        call err 'area' oldNa 'does not exist'
    if oldNa == newNa then
        return
    if symbol('m.m.n2a.newNa') == 'VAR' then
        call err 'newName' newNa 'for old' oldNa 'already used'
    m.m.n2a.newNa = m.m.n2a.oldNa
    return
endProcedure mAlias

mNew: procedure expose m. ggArea
parse arg name
    if symbol('m.m.n2a.name') \== 'VAR' then
        call err 'area' name 'does not exists'
    ggArea = m.m.n2a.name
    if m.ggArea.free.0 > 0 then do
        fx = m.ggArea.free.0
        m.ggArea.free.0 = fx-1
        m = m.ggArea.free.fx
        end
    else do
        m.ggArea.0 = m.ggArea.0 + 1
        m = m.ggArea.address'.'m.ggArea.0
        end
    return m
endProcedure mNew

mFree: procedure expose m.
parse arg m
    p = 'M.P2A.'left(m, lastPos('.', m)-1)
    area = m.p
    fx = m.area.free.0 + 1
    m.area.free.0 = fx
    m.area.free.fx = m
    return
endProcedure mFree
/*--- iterate over all allocate elements of an area ------------------*/
mIterBegin: procedure expose m.
parse arg nm
    a = m.m.n2a.nm
    return m.a.address'.0'
endProcedure mIterBegin

mIter: procedure expose m.
parse arg cur
    if cur == '' then
        return ''
    lx = lastPos('.', cur)
    p = 'M.P2A.'left(cur, lx-1)
    a = m.p
    ix = substr(cur, lx+1)
    do ix=ix+1 to m.a.0
        n = m.a.address'.'ix
        do fx=1 to m.a.free.0 while m.a.free \== n
            end
        if fx > m.a.free.0 then
            return n
        end
    return ''
endProcedure mIter

/*--- get m.a --------------------------------------------------------*/
mGet: procedure expose m.
parse arg a
    return m.a
endProcedure mGet

/*--- put value v into m.a -------------------------------------------*/
mPut: procedure expose m.
parse arg a, v
    m.a = v
    return v
endProcedure mPut

/*--- cut stem a to length len ---------------------------------------*/
mCut: procedure expose m.
parse arg a, len
    m.a.0 = len
    return a
endProcedure mCut

/*--- add one or several arguments to stem m.a -----------------------*/
mAdd: procedure expose m.
parse arg a
    ix = m.a.0
    do ax = 2 to arg()
        ix = ix + 1
        m.a.ix = arg(ax)
        end
    m.a.0 = ix
    return a'.'ix
endProcedure mAdd

/*--- pop last element from stem m.a ---------------------------------*/
mPop: procedure expose m.
parse arg a
    ix = m.a.0
    if ix < 1 then
        call err 'pop from empty stem' a
    m.a.0 = ix-1
    return m.a.ix
endProcedure mPop

/*--- add to m.dst.* a (sub)sequence of m.src.* ----------------------*/
mAddSt: procedure expose m.
    parse arg dst, src, fx , tx
    dx = m.dst.0
    if fx == '' then
        fx = 1
    if tx == '' then
        tx = m.src.0
    do sx = fx to tx
        dx = dx + 1
        m.dst.dx = m.src.sx
        end
    m.dst.0 = dx
    return
endProcedure mAddSt

/*--- find position of first occurrence of ele in stem m,
        return 0 if nonemove a part of a stem -----------------------*/
mPos: procedure expose m.
parse arg m, ele, sx
    if sx == '' then
        sx = 1
    do x=sx to m.m.0
        if m.m.x = ele then
            return x
        end
    return 0
endProcedure mPos

/*--- move a part of a stem ------------------------------------------*/
mMove: procedure expose m.
parse arg m, sx, dx
    if dx < sx then do
        y = dx
        do x=sx to m.m.0
            m.m.y = m.m.x
            y = y + 1
            end
        end
    else if dx > sx then do
        y = m.m.0 + dx - sx
        do x=m.m.0 by -1 to sx
            m.m.y = m.m.x
            y = y - 1
            end
        end
    m.m.0 = m.m.0 + dx - sx
    return
endProcedure mMove

/*--- insert a stem into another ------------------------------------*/
mInsert: procedure expose m.
parse arg m, tx, st
    call mMove m, tx, tx+m.st.0
    do sx=1 to m.st.0
        dx = tx-1+sx
            m.m.dx = m.st.sx
            end
    return
endProcedure mInsert

/*--- strip all elements of a stem -----------------------------------*/
mStrip: procedure expose m.
parse arg st, opt
    if opt == '' then
        opt = 'b'
    do x=1 to m.st.0
        m.st.x = strip(m.st.x, opt)
        end
    return st
endProcedure mStrip


/* cat the lines of a stem, possibly repeated --------------------------
       args: stem, fmt see fGen: -------------------------------------*/
mCat: procedure expose m.
parse arg st, fmt
    return mCatFT(st, 1, m.st.0, fmt)

mCatFT: procedure expose m.
parse arg st, fx, tx, fmt
    if tx < fx then
        return ''
    fmt = '%s%qn%s%qe%q^'fmt
    res = f(fmt, m.st.fx)
    do sx=fx+1 to tx
        res = res || f(fmt'%Qn', m.st.sx)
        end
    return res || f(fmt'%Qe')
endProcedure mCatFT

mIni: procedure expose m.
    if m.m.ini == 1 then
        return
    m.m.ini = 1
    call utIni
    m.mBase64 = m.ut.alfUC || m.ut.alfLc || m.ut.digits'+-'
    m.m.area.0 = 0
    call mNewArea
    return
endProcedure mIni

/* copy m end *********************************************************/