factor/library/format.factor

72 lines
2.4 KiB
Factor

! :folding=indent:collapseFolds=0:
! $Id$
!
! Copyright (C) 2004 Slava Pestov.
!
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions are met:
!
! 1. Redistributions of source code must retain the above copyright notice,
! this list of conditions and the following disclaimer.
!
! 2. Redistributions in binary form must reproduce the above copyright notice,
! this list of conditions and the following disclaimer in the documentation
! and/or other materials provided with the distribution.
!
! THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
! INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
! DEVELOPERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
! SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
! OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
! WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
! OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
! ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
IN: format
USE: combinators
USE: kernel
USE: math
USE: namespaces
USE: strings
USE: stack
: decimal-split ( string -- string string )
#! Split a string before and after the decimal point.
dup "." index-of dup -1 = [ drop f ] [ str// ] ifte ;
: decimal-tail ( str count -- string )
#! Given a decimal, trims all but a count of decimal places.
over str-length min str-head ;
: decimal-cat ( before after -- string )
#! If after is of zero length, return before, otherwise
#! return "before.after".
dup str-length 0 = [
drop
] [
"." swap cat3
] ifte ;
: decimal-places ( num count -- string )
#! Trims the number to a count of decimal places.
swap decimal-split dup [
rot decimal-tail decimal-cat
] [
drop nip
] ifte ;
: digits ( string count -- string )
#! Make sure string has at least count digits, padding it
#! with zeroes on the left if needed.
over str-length - dup 0 <= [
drop
] [
"0" fill swap cat2
] ifte ;
: pad-string ( len str -- str )
str-length - " " fill ;