{def fmt
 {def padd {lambda {:n :x} {if {< :n 1} then else :x{padd {- :n 1} :x}}}}
 {def trunc {lambda {:n} {if {> :n 0} then {floor :n} else {ceil :n}}}}
 {lambda {:a :b :n}
  {let { {:a :a} {:b :b} {:n {abs :n}} {:sign {if {>= :n 0} then + else -}}
         {:int {trunc :n}}
         {:dec {ceil {* 1.0e:b {abs {- :n {trunc :n}}}}} }
       } {br}{padd {- :a {W.length {trunc :n}}} >}
         {if {W.equal? :sign -} then else :sign}:int.:dec{padd {- :b {W.length :dec}} 0} }}}
-> fmt

{def numbers
     7.125
     10.7
     0.980
     -1000
     559.8
     -69.99
     4970.430}
-> numbers

{S.map {fmt 10 3} {numbers}}
->
>>>>>>>>> +7.125
>>>>>>>> +10.699
>>>>>>>>> +0.980
>>>>>> -1000.000
>>>>>>> +559.799
>>>>>>>> -69.990
>>>>>> +4970.430