\ miscelleneous words

\ Copyright (C) 1996,1997,1998,2000,2003 Free Software Foundation, Inc.

\ This file is part of Gforth.

\ Gforth is free software; you can redistribute it and/or
\ modify it under the terms of the GNU General Public License
\ as published by the Free Software Foundation; either version 2
\ of the License, or (at your option) any later version.

\ This program is distributed in the hope that it will be useful,
\ but WITHOUT ANY WARRANTY; without even the implied warranty of
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
\ GNU General Public License for more details.

\ You should have received a copy of the GNU General Public License
\ along with this program; if not, write to the Free Software
\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.

require glocals.fs

' require alias needs ( ... "name" -- ... ) \ gforth
\G An alias for @code{require}; exists on other systems (e.g., Win32Forth).
\ needs is an F-PC name. we will probably switch to 'needs' in the future

\ a little more compiler security

\ currently not used by Gforth, but maybe by add-ons e.g., the 486asm
AUser CSP

: !CSP ( -- )
    sp@ csp ! ;

: ?CSP ( -- )
    sp@ csp @ <> -22 and throw ;

\ DMIN and DMAX

: dmin ( d1 d2 -- d ) \ double d-min
    2over 2over d> IF  2swap  THEN 2drop ;


: dmax ( d1 d2 -- d ) \ double d-max
    2over 2over d< IF  2swap  THEN 2drop ;

\ shell commands

0 Value $? ( -- n ) \ gforth dollar-question
\G @code{Value} -- the exit status returned by the most recently executed
\G @code{system} command.

: system ( c-addr u -- ) \ gforth
\G Pass the string specified by @var{c-addr u} to the host operating system
\G for execution in a sub-shell.
    (system) throw TO $? ;

: sh ( "..." -- ) \ gforth
\G Parse a string and use @code{system} to pass it to the host
\G operating system for execution in a sub-shell.
    '# parse cr system ;

\ stuff

: ]L ( compilation: n -- ; run-time: -- n ) \ gforth
    \G equivalent to @code{] literal}
    ] postpone literal ;

[ifundef] in-dictionary?
: in-dictionary? ( x -- f )
    forthstart dictionary-end within ;
[endif]

: in-return-stack? ( addr -- f )
    rp0 @ swap - [ forthstart 6 cells + ]L @ u< ;

\ const-does>

: compile-literals ( w*u u -- ; run-time: -- w*u ) recursive
    \ compile u literals, starting with the bottommost one
    ?dup-if
	swap >r 1- compile-literals
	r> POSTPONE literal
    endif ;

: compile-fliterals ( r*u u -- ; run-time: -- w*u ) recursive
    \ compile u fliterals, starting with the bottommost one
    ?dup-if
	{ F: r } 1- compile-fliterals
	r POSTPONE fliteral
    endif ;

: (const-does>) ( w*uw r*ur uw ur target "name" -- )
    \ define a colon definition "name" containing w*uw r*ur as
    \ literals and a call to target.
    { uw ur target }
    header docol: cfa, \ start colon def without stack junk
    ur compile-fliterals uw compile-literals
    target compile, POSTPONE exit reveal ;

: const-does> ( run-time: w*uw r*ur uw ur "name" -- )
    \G Defines @var{name} and returns.@sp 0
    \G @var{name} execution: pushes @var{w*uw r*ur}, then performs the
    \G code following the @code{const-does>}.
    here >r 0 POSTPONE literal
    POSTPONE (const-does>)
    POSTPONE ;
    noname : POSTPONE rdrop
    lastxt r> cell+ ! \ patch the literal
; immediate

\ !! rewrite slurp-file using slurp-fid
: slurp-file ( c-addr1 u1 -- c-addr2 u2 )
    \G @var{c-addr1 u1} is the filename, @var{c-addr2 u2} is the file's contents
    r/o bin open-file throw >r
    r@ file-size throw abort" file too large"
    dup allocate throw swap
    2dup r@ read-file throw over <> abort" could not read whole file"
    r> close-file throw ;

: slurp-fid { fid -- addr u }
    \G @var{addr u} is the content of the file @var{fid}
    0 0 begin ( awhole uwhole )
	dup 1024 + dup >r extend-mem ( anew awhole uwhole R: unew )
	rot r@ fid read-file throw ( awhole uwhole uread R: unew )
	r> 2dup =
    while ( awhole uwhole uread unew )
	2drop
    repeat
    - + dup >r resize throw r> ;

\ ]] ... [[

: compile-literal ( n -- )
    postpone literal ;

: [[ ( -- )
\G switch from postpone state to compile state
    \ this is only a marker; it is never really interpreted
    compile-only-error ; immediate

: postponer ( c-addr u -- )
    2dup find-name dup if ( c-addr u nt )
	nip nip name>comp
	2dup [comp'] [[ d= if
	    2drop ['] compiler is parser
	else
	    postpone,
	endif
    else
	drop
	2dup snumber? dup if
	    0> IF
		swap postpone literal postpone compile-literal
	    THEN
	    postpone Literal postpone compile-literal
	    2drop
	ELSE
	    drop no.extensions
	THEN
    then ;

: ]] ( -- )
    \ switch into postpone state
    ['] postponer is parser state on ; immediate restrict

\ f.rdp

: push-right ( c-addr u1 u2 cfill -- )
    \ move string at c-addr u1 right by u2 chars (without exceeding
    \ the original bound); fill the gap with cfill
    >r over min dup >r rot dup >r ( u1 u2 c-addr R: cfill u2 c-addr )
    dup 2swap /string cmove>
    r> r> r> fill ;

: f>buf-rdp-try { f: rf c-addr ur nd up um1 -- um2 }
    \ um1 is the mantissa length to try, um2 is the actual mantissa length
    c-addr ur um1 /string '0 fill
    rf c-addr um1 represent if { nexp fsign }
	nd nexp + up >=
	ur nd - 1- dup { beforep } fsign + nexp 0 max >= and if
	    \ fixed-point notation
	    c-addr ur beforep nexp - dup { befored } '0 push-right
	    c-addr beforep 1- befored min dup { beforez } 0 max bl fill
	    fsign if
		'- c-addr beforez 1- 0 max + c!
	    endif
	    c-addr ur beforep /string 1 '. push-right
	    nexp nd +
	else \ exponential notation
	    c-addr ur 1 /string 1 '. push-right
	    fsign if
		c-addr ur 1 '- push-right
	    endif
	    nexp 1- s>d tuck dabs <<# #s rot sign 'E hold #> { explen }
	    ur explen - 1- fsign + { mantlen }
	    mantlen 0< if \ exponent too large
		drop c-addr ur '* fill
	    else
		c-addr ur + 0 explen negate /string move
	    endif
	    #>> mantlen
	endif
    else \ inf or nan
	if \ negative
	    c-addr ur 1 '- push-right
	endif
	drop ur
	\ !! align in some way?
    endif
    1 max ur min ;

: f>buf-rdp ( rf c-addr +nr +nd +np -- ) \ gforth
\G Convert @i{rf} into a string at @i{c-addr nr}.  The conversion
\G rules and the meanings of @i{nr nd np} are the same as for
\G @code{f.rdp}.
    \ first, get the mantissa length, then convert for real.  The
    \ mantissa length is wrong in a few cases because of different
    \ rounding; In most cases this does not matter, because the
    \ mantissa is shorter than expected and the final digits are 0;
    \ but in a few cases the mantissa gets longer.  Then it is
    \ conceivable that you will see a result that is rounded too much.
    \ However, I have not been able to construct an example where this
    \ leads to an unexpected result.
    swap 0 max swap 0 max
    fdup 2over 2over 2 pick f>buf-rdp-try f>buf-rdp-try drop ;

: f>str-rdp ( rf +nr +nd +np -- c-addr nr ) \ gforth
\G Convert @i{rf} into a string at @i{c-addr nr}.  The conversion
\G rules and the meanings of @i{nr +nd np} are the same as for
\G @code{f.rdp}.  The result in in the pictured numeric output buffer
\G and will be destroyed by anything destroying that buffer.
    rot holdptr @ 1- 0 rot negate /string ( rf +nd np c-addr nr )
    over holdbuf u< -&17 and throw
    2tuck 2>r f>buf-rdp 2r> ;

: f.rdp ( rf +nr +nd +np -- ) \ gforth
\G Print float @i{rf} formatted.  The total width of the output is
\G @i{nr}.  For fixed-point notation, the number of digits after the
\G decimal point is @i{+nd} and the minimum number of significant
\G digits is @i{np}.  @code{Set-precision} has no effect on
\G @code{f.rdp}.  Fixed-point notation is used if the number of
\G siginicant digits would be at least @i{np} and if the number of
\G digits before the decimal point would fit.  If fixed-point notation
\G is not used, exponential notation is used, and if that does not
\G fit, asterisks are printed.  We recommend using @i{nr}>=7 to avoid
\G the risk of numbers not fitting at all.  We recommend
\G @i{nr}>=@i{np}+5 to avoid cases where @code{f.rdp} switches to
\G exponential notation because fixed-point notation would have too
\G few significant digits, yet exponential notation offers fewer
\G significant digits.  We recommend @i{nr}>=@i{nd}+2, if you want to
\G have fixed-point notation for some numbers.  We recommend
\G @i{np}>@i{nr}, if you want to have exponential notation for all
\G numbers.
    f>str-rdp type ;

0 [if]
: testx ( rf ur nd up -- )
    '| emit f.rdp ;

: test ( -- )
    -0.123456789123456789e-20
    40 0 ?do
	cr
	fdup 7 3 1 testx
	fdup 7 3 4 testx
	fdup 7 3 0 testx
	fdup 7 7 1 testx
	fdup 7 5 1 testx
	fdup 7 0 2 testx
	fdup 5 2 1 testx
	fdup 4 2 1 testx
	fdup 18 8 5 testx
	'| emit
	10e f*
    loop ;
[then]