From bleikamp@rsn.hp.com Fri Jan 17 17:51:08 1997 Received: from hplb.hpl.hp.com (hplb.hpl.hp.com [15.255.59.2]) by dkuug.dk (8.6.12/8.6.12) with ESMTP id RAA13149 for ; Fri, 17 Jan 1997 17:50:52 +0100 Received: from kiwi.rsn.hp.com by hplb.hpl.hp.com; Fri, 17 Jan 1997 16:50:45 GMT Received: from kiwi (localhost) by kiwi.rsn.hp.com with SMTP (1.39.111.2/16.2) id AA247749838; Fri, 17 Jan 1997 10:50:38 -0600 Sender: bleikamp@rsn.hp.com Message-Id: <32DFADDD.10DD@rsn.hp.com> Date: Fri, 17 Jan 1997 10:50:37 -0600 From: Richard Bleikamp Organization: Hewlett Packard Company X-Mailer: Mozilla 3.01 (X11; I; HP-UX B.10.01 9000/712) Mime-Version: 1.0 To: "sc22wg5@dkuug.dk" Subject: postscript version of derived type i/o spec. Content-Type: multipart/mixed; boundary="------------718C5BC2341E" This is a multi-part message in MIME format. --------------718C5BC2341E Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Miles and Mallory, please add this postscript version to the ftp servers also. thanks. --------------718C5BC2341E Content-Type: application/postscript; name="97-101.ps" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="97-101.ps" %!PS-Adobe-3.0 %%BoundingBox: 24 24 588 768 %%Title: enscript output %%For: Richard Bleikamp,d1w36-r,, %%Creator: GNU enscript 1.4.0 %%CreationDate: Fri Jan 17 10:46:17 1997 %%Orientation: Portrait %%Pages: (atend) %%DocumentMedia: Letter 612 792 0 () () %%DocumentNeededResources: (atend) %%EndComments %%BeginProlog %%BeginResource: procset Enscript-Prolog 1.4 0 % % Procedures. % /_S { % save current state /_s save def } def /_R { % restore from saved state _s restore } def /S { % showpage protecting gstate gsave showpage grestore } bind def /MF { % fontname newfontname -> - make a new encoded font /newfontname exch def /fontname exch def /fontdict fontname findfont def /newfont fontdict maxlength dict def fontdict { exch dup /FID eq { % skip FID pair pop pop } { % copy to the new font dictionary exch newfont 3 1 roll put } ifelse } forall newfont /FontName newfontname put % insert only valid encoding vectors encoding_vector length 256 eq { newfont /Encoding encoding_vector put } if newfontname newfont definefont pop } def /M {moveto} bind def /s {show} bind def /Box { % x y w h -> - define box path /d_h exch def /d_w exch def /d_y exch def /d_x exch def d_x d_y moveto d_w 0 rlineto 0 d_h rlineto d_w neg 0 rlineto closepath } def % Highlight bars. /highlight_bars { % nlines lineheight output_y_margin gray -> - gsave setgray /ymarg exch def /lineheight exch def /nlines exch def % This 2 is just a magic number to sync highlight lines to text. 0 d_header_y ymarg sub 2 sub translate /cw d_output_w cols div def /nrows d_output_h ymarg 2 mul sub lineheight div floor def % for each column 0 1 cols 1 sub { cw mul /xp exch def % for each rows 0 1 nrows 1 sub { /rn exch def rn lineheight mul neg /yp exch def rn nlines idiv 2 mod 0 eq { % Draw highlight bar. 4 is just a magic indentation. xp 4 add yp cw 8 sub lineheight neg Box fill } if } for } for grestore } def % Line highlight bar. /line_highlight { % x y width height gray -> - gsave /gray exch def Box gray setgray fill grestore } def % Column separator lines. /column_lines { gsave .1 setlinewidth 0 d_footer_h translate /cw d_output_w cols div def 1 1 cols 1 sub { cw mul 0 moveto 0 d_output_h rlineto stroke } for grestore } def % Column borders. /column_borders { gsave .1 setlinewidth 0 d_footer_h moveto 0 d_output_h rlineto d_output_w 0 rlineto 0 d_output_h neg rlineto closepath stroke grestore } def % Do the actual underlay drawing /draw_underlay { ul_style 0 eq { ul_str true charpath stroke } { ul_str show } ifelse } def % Underlay /underlay { % - -> - gsave 0 d_page_h translate d_page_h neg d_page_w atan rotate ul_gray setgray ul_font setfont /dw d_page_h dup mul d_page_w dup mul add sqrt def ul_str stringwidth pop dw exch sub 2 div ul_ptsize -2 div moveto draw_underlay grestore } def /user_underlay { % - -> - gsave ul_x ul_y translate ul_angle rotate ul_gray setgray ul_font setfont 0 0 ul_ptsize 2 div sub moveto draw_underlay grestore } def % Page prefeed /page_prefeed { % bool -> - statusdict /prefeed known { statusdict exch /prefeed exch put } { pop } ifelse } def % EPSF import. /BeginEPSF { /b4_Inc_state save def % Save state for cleanup /dict_count countdictstack def % Count objects on dict stack /op_count count 1 sub def % Count objects on operand stack userdict begin /showpage { } def 0 setgray 0 setlinecap 1 setlinewidth 0 setlinejoin 10 setmiterlimit [ ] 0 setdash newpath /languagelevel where { pop languagelevel 1 ne { false setstrokeadjust false setoverprint } if } if } bind def /EndEPSF { count op_count sub { pos } repeat % Clean up stacks countdictstack dict_count sub { end } repeat b4_Inc_state restore } bind def % Check PostScript language level. /languagelevel where { pop /gs_languagelevel languagelevel def } { /gs_languagelevel 1 def } ifelse %%EndResource %%BeginResource: procset Enscript-Encoding-latin1 1.4 0 /encoding_vector [ /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /space /exclam /quotedbl /numbersign /dollar /percent /ampersand /quoteright /parenleft /parenright /asterisk /plus /comma /minus /period /slash /zero /one /two /three /four /five /six /seven /eight /nine /colon /semicolon /less /equal /greater /question /at /A /B /C /D /E /F /G /H /I /J /K /L /M /N /O /P /Q /R /S /T /U /V /W /X /Y /Z /bracketleft /backslash /bracketright /asciicircum /underscore /quoteleft /a /b /c /d /e /f /g /h /i /j /k /l /m /n /o /p /q /r /s /t /u /v /w /x /y /z /braceleft /bar /braceright /tilde /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /.notdef /space /exclamdown /cent /sterling /currency /yen /brokenbar /section /dieresis /copyright /ordfeminine /guillemotleft /logicalnot /hyphen /registered /macron /degree /plusminus /twosuperior /threesuperior /acute /mu /paragraph /bullet /cedilla /dotlessi /ordmasculine /guillemotright /onequarter /onehalf /threequarters /questiondown /Agrave /Aacute /Acircumflex /Atilde /Adieresis /Aring /AE /Ccedilla /Egrave /Eacute /Ecircumflex /Edieresis /Igrave /Iacute /Icircumflex /Idieresis /Eth /Ntilde /Ograve /Oacute /Ocircumflex /Otilde /Odieresis /multiply /Oslash /Ugrave /Uacute /Ucircumflex /Udieresis /Yacute /Thorn /germandbls /agrave /aacute /acircumflex /atilde /adieresis /aring /ae /ccedilla /egrave /eacute /ecircumflex /edieresis /igrave /iacute /icircumflex /idieresis /eth /ntilde /ograve /oacute /ocircumflex /otilde /odieresis /divide /oslash /ugrave /uacute /ucircumflex /udieresis /yacute /thorn /ydieresis ] def %%EndResource %%EndProlog %%BeginSetup %%IncludeResource: font Courier-Bold %%IncludeResource: font Courier /user_header_p false def /HFpt 10 def /Courier-Bold /HF-gs-font MF /HF /HF-gs-font findfont HFpt scalefont def /Courier /F-gs-font MF /F-gs-font findfont 10 scalefont setfont /#copies 1 def /d_page_w 564 def /d_page_h 744 def /d_header_x 0 def /d_header_y 744 def /d_header_w 564 def /d_header_h 0 def /d_footer_x 0 def /d_footer_y 0 def /d_footer_w 564 def /d_footer_h 0 def /d_output_w 564 def /d_output_h 744 def /cols 1 def %%EndSetup %%Page: (1) 1 %%BeginPageSetup _S 24 24 translate /pagenum 1 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 731 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 720 M ( X3J3/97-101) s 5 709 M ( page 1 of 10) s 5 698 M ( ) s 5 687 M ( To: X3J3/WG5) s 5 676 M ( From: Rich Bleikamp \(/io\)) s 5 665 M ( Subject: Functional Specification for Derived Type I/O) s 5 654 M ( Date: Jan. 17, 1997) s 5 643 M ( ) s 5 632 M ( Revised version of X3J3/96-177. Look for "|"s in the left) s 5 621 M ( margin for significant changes.) s 5 599 M ( One possible activity for WG5/X3J3 at the Feb. '97 meeting is to) s 5 588 M ( start on the edits to F95 for this proposal. Any volunteers?) s 5 566 M ( | Changes since 97-177:) s 5 555 M ( |) s 5 544 M ( | - added UNFORMATTED I/O support. Useful to avoid the) s 5 533 M ( | restrictions such as "no pointers", ... which limits) s 5 522 M ( | F90 functionality for unformatted derived type I/O.) s 5 511 M ( |) s 5 500 M ( | Since the so-called "user defined formatting routines" now) s 5 489 M ( | support unformatted I/O, I have renamed them) s 5 478 M ( | "user defined I/O routines".) s 5 467 M ( | ) s 5 456 M ( | - Allow internal I/O in one of these user-defined I/O) s 5 445 M ( | routines. Or in any routine called therefrom.) s 5 434 M ( |) s 5 423 M ( | - Added a Rationale.) s 5 412 M ( |) s 5 401 M ( | - Added a Conceptual Model \(how will this be implemented\).) s 5 390 M ( |) s 5 379 M ( | - Added a small example routine.) s 5 368 M ( |) s 5 357 M ( |) s 5 346 M ( | Unresolved Issues) s 5 335 M ( |) s 5 324 M ( | - Should the "err", "eor", and "eof" dummy arguments) s 5 313 M ( | be a derived type? Or is logical type sufficient?) s 5 302 M ( |) s 5 291 M ( | - How can the writer of a user defined I/O routine) s 5 280 M ( | debug anything, without the ability to WRITE stuff out?) s 5 269 M ( |) s 5 258 M ( | - Should the I/O statements executed within a user) s 5 247 M ( | defined I/O routine be IMPLICITLY non-advancing?) s 5 236 M ( | This would only work for sequential formatted I/O.) s 5 225 M ( | ) s 5 214 M ( | How do we describe UNFORMATTED and direct access I/O?) s 5 203 M ( | Non-advancing is only allowed for formatted sequential I/O,) s 5 192 M ( | so we need some other term to describe how we insert/extract) s 5 181 M ( | characters from the middle of a record in the user defined) s 5 170 M ( | I/O routine.) s 5 159 M ( |) s 5 148 M ( | Perhaps we need to describe these nested/recursive) s 5 137 M ( | I/O calls in other terms, to avoid confusion with normal) s 5 126 M ( | Fortran I/O. ) s 5 115 M ( |) s 5 104 M ( | - Should we allow a "text error string" to be returned) s 5 93 M ( | when an ERR is to be reported, in case the original I/O) s 5 82 M ( | statement did not have an ERR= or IOSTAT= ?) s _R S %%Page: (2) 2 %%BeginPageSetup _S 24 24 translate /pagenum 2 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 2 of 10) s 5 687 M ( |) s 5 676 M ( | - Should we add an IOSTAT variable, so specific values) s 5 665 M ( | can be passed back to the user?) s 5 654 M ( |) s 5 643 M ( | - Having to handle internal and external units separately) s 5 632 M ( | is inconvenient. Should we only pass in a unit ?) s 5 610 M ( ) s 5 599 M ( This document is the \(proposed\) functional specification for) s 5 588 M ( enhanced derived type I/O. The goals are to provide a powerful) s 5 577 M ( and portable way to encapsulate I/O support in a MODULE which) s 5 566 M ( defines a derived type. This I/O support is provided by) s 5 555 M ( simple, easy to use extensions to the traditional Fortran) s 5 544 M ( READ and WRITE statements.) s 5 522 M ( This specification, in a earlier form, was approved as the) s 5 511 M ( generally correct approach for supporting derived type I/O) s 5 500 M ( at X3J3 meeting 139.) s 5 478 M ( ) s 5 467 M ( Management Synopsis:) s 5 456 M ( ) s 5 445 M ( - The provider of a derived type may also provide two) s 5 434 M ( I/O routines, called "user defined I/O routines",) s 5 423 M ( which are called by the Fortran I/O library when) s 5 412 M ( certain conditions are met. These user supplied) s 5 401 M ( routines handle input and output of a list item of derived) s 5 390 M ( type. In essense, the effect is as if the user defined) s 5 379 M ( I/O routines were substituting list items into the) s 5 368 M ( original I/O list \(where the derived type item was\), and) s 5 357 M ( adding edit descriptors into the middle of the original) s 5 346 M ( format specification, under control of the provided) s 5 335 M ( routines.) s 5 313 M ( - The F90 way of doing formatted and unformatted I/O) s 5 302 M ( on derived types still works the same as before. Only) s 5 291 M ( the presence of an interface for the appropriate user) s 5 280 M ( defined I/O routine triggers this new functionality.) s 5 269 M ( ) s 5 258 M ( - FORMATs have a new edit descriptor, "DT". When the) s 5 247 M ( I/O library encounters this, it must match up with a) s 5 236 M ( derived type list item. The I/O library will call a) s 5 225 M ( user supplied I/O routine, which will actually do the) s 5 214 M ( I/O. Typically, the provider of a derived type) s 5 203 M ( would provide these user defined I/O routines.) s 5 192 M ( ) s 5 181 M ( - The user supplied procedures \(one for READs, one for) s 5 170 M ( WRITEs\), will be called with a unit number, the) s 5 159 M ( derived type variable/value, and other misc.) s 5 148 M ( information. The procedure will use normal I/O) s 5 137 M ( statements \(READ/WRITE\) on the supplied unit to) s 5 126 M ( read/write the derived type item.) s 5 115 M ( This use of "recursive" I/O will be restricted to) s 5 104 M ( | this particular feature of the language. Internal) s 5 93 M ( | I/O will be permitted in the user defined I/O) s 5 82 M ( | routines.) s _R S %%Page: (3) 3 %%BeginPageSetup _S 24 24 translate /pagenum 3 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 3 of 10) s 5 687 M ( ) s 5 676 M ( - Full support for complicated data structures is) s 5 665 M ( provided. These user defined I/O routines can invoke) s 5 654 M ( themselves indirectly thru formatted I/O \(to traverse a) s 5 643 M ( linked list for example\), and can invoke the user defined) s 5 632 M ( I/O routines for another derived type \(indirectly, thru) s 5 621 M ( formatted I/O\) to handle nested derived types.) s 5 610 M ( | Internal I/O may be used to easily construct character) s 5 599 M ( | string values.) s 5 588 M ( ) s 5 577 M ( - The user supplied procedures will be able to inquire) s 5 566 M ( about, and in the most general \(robust\) case, have) s 5 555 M ( to worry about:) s 5 544 M ( | - Formatted and unformatted I/O) s 5 533 M ( - list directed and namelist I/O) s 5 522 M ( - sequential and direct access I/O) s 5 511 M ( - non-advancing and advancing I/O) s 5 500 M ( - the DELIM= and PAD= values for this file) s 5 489 M ( \(accessible via INQUIRE\)) s 5 478 M ( ) s 5 467 M ( - List directed and NAMELIST I/O will also call these) s 5 456 M ( same user supplied routines under certain, F90) s 5 445 M ( | compatible circumstances. \(when an appropriate interface) s 5 434 M ( | is visible\)) s 5 423 M ( ) s 5 412 M ( ) s 5 401 M ( Detailed Specification:) s 5 390 M ( ) s 5 379 M ( User defined I/O routines shall have the following) s 5 368 M ( interface:) s 5 357 M ( ) s 5 346 M ( INTERFACE FORMAT \( READ \)) s 5 335 M ( RECURSIVE SUBROUTINE my_read_routine \(unit,) s 5 324 M ( ifu,) s 5 313 M ( dtv,) s 5 302 M ( iotype, w, d, m,) s 5 291 M ( rec, eof, err, eor\)) s 5 280 M ( INTEGER, OPTIONAL :: unit) s 5 269 M ( CHARACTER \(LEN=*\), OPTIONAL :: ifu) s 5 258 M ( TYPE \(whateveritis\) dtv ! the derived type value/variable) s 5 247 M ( CHARACTER \(*\) iotype ! the edit descriptor string) s 5 236 M ( INTEGER, OPTIONAL :: w,d,m) s 5 225 M ( INTEGER, OPTIONAL :: rec) s 5 214 M ( LOGICAL :: eof, err, eor) s 5 203 M ( END) s 5 192 M ( END INTERFACE) s _R S %%Page: (4) 4 %%BeginPageSetup _S 24 24 translate /pagenum 4 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 4 of 10) s 5 687 M ( INTERFACE FORMAT \( WRITE \)) s 5 676 M ( RECURSIVE SUBROUTINE my_write_routine \(unit,) s 5 665 M ( ifu,) s 5 654 M ( dtv,) s 5 643 M ( iotype, w, d, m,) s 5 632 M ( rec, err\)) s 5 621 M ( INTEGER, OPTIONAL :: unit) s 5 610 M ( CHARACTER \(LEN=*\), OPTIONAL :: ifu) s 5 599 M ( TYPE \(whateveritis\) dtv ! the derived type value/variable) s 5 588 M ( CHARACTER \(*\) iotype ! the edit descriptor string) s 5 577 M ( INTEGER, OPTIONAL :: w,d,m) s 5 566 M ( INTEGER, OPTIONAL :: rec) s 5 555 M ( LOGICAL :: err) s 5 544 M ( END) s 5 533 M ( END INTERFACE) s 5 522 M ( ) s 5 511 M ( where the actual specific routine names \(my_xxx_routine) s 5 500 M ( above\) and the dummy argument names may be chosen by the) s 5 489 M ( user. These routines shall not be invoked directly by the) s 5 478 M ( users program.) s 5 467 M ( ) s 5 456 M ( The user defined I/O routines are called when:) s 5 434 M ( | - for unformatted i/o, list directed, and namelist i/o,) s 5 423 M ( | an appropriate interface for the derived type of a) s 5 412 M ( | particular list item is visible) s 5 390 M ( | - for I/O statements with a ,) s 5 379 M ( | there must be an appropriate interface AND the) s 5 368 M ( | list item must match up with a "DT" edit descriptor.) s 5 346 M ( What the user defined I/O routines are passed:) s 5 324 M ( If the original I/O statement specified list directed I/O,) s 5 313 M ( the "iotype" argument will have the value "LISTDIRECTED". If) s 5 302 M ( the original I/O statement specified NAMELIST I/O, the "iotype") s 5 291 M ( | argument will have the value "NAMELIST". When the original) s 5 280 M ( | I/O statement specified UNFORMATTED I/O, the "iotype" argument) s 5 269 M ( | will have the value "UNFORMATTED".) s 5 247 M ( When the original I/O statement included a) s 5 236 M ( format-specification, then the user defined I/O) s 5 225 M ( routines are accessible via the new "DT" edit descriptor.) s 5 203 M ( A new edit descriptor, "DT", with the usual \(optional\)) s 5 192 M ( "[w[.d[.m]]]" widths is provided for use with format) s 5 181 M ( specifications. It must match up with a variable/value) s 5 170 M ( of a derived type.) s 5 159 M ( ) s 5 148 M ( The DT characters may be followed by an arbitrary \(up to) s 5 137 M ( 253?\) number of alphabetic characters \(interspersed) s 5 126 M ( blanks allowed\) \(ex. "DTLNKLST"\). The entire string of) s 5 115 M ( alphabetic characters, including the initial "DT", will) s 5 104 M ( be passed into the user defined I/O routine \(the "iotype") s 5 93 M ( argument\).) s _R S %%Page: (5) 5 %%BeginPageSetup _S 24 24 translate /pagenum 5 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 5 of 10) s 5 676 M ( This argument will be converted to UPPERCASE and have all) s 5 665 M ( blanks removed. The user can support different types of) s 5 654 M ( formatting for one derived type via this extended edit) s 5 643 M ( descriptor.) s 5 632 M ( ) s 5 621 M ( For example, the consecutive characters after the "DT") s 5 610 M ( could be used to request different formatting rules for) s 5 599 M ( consecutive components in the derived type, or different) s 5 588 M ( formatting rules for nested derived types, etc.) s 5 577 M ( ) s 5 566 M ( If a derived type variable/value is specified in an I/O) s 5 555 M ( list, and that variable/value will match up with a "DT") s 5 544 M ( edit descriptor, the user must have also provided the) s 5 533 M ( matching read/write procedure for that derived type , with) s 5 522 M ( a visible interface thats matches the definition in this) s 5 511 M ( paper. These procedures are called the "user defined) s 5 500 M ( I/O routines". If such an interface is visible, the) s 5 489 M ( derived type item may either match a "DT" edit descriptor or) s 5 478 M ( use original F90 conventions.) s 5 467 M ( When the user defined I/O routines are called, either) s 5 456 M ( "unit" or "ifu" will be present, but not both.) s 5 445 M ( ) s 5 434 M ( If "unit" is present, the original I/O statement specified) s 5 423 M ( an external unit \(possibly *\), and all I/O statements for) s 5 412 M ( | external units in the user defined I/O routine) s 5 401 M ( | \(including INQUIRE\) shall specify this dummy argument for the) s 5 390 M ( | UNIT= specifier. \(we used to only require the same value\)) s 5 379 M ( ) s 5 368 M ( The "unit" dummy argument, if present, contains a processor) s 5 357 M ( dependent value, that may, or may not, be the same unit) s 5 346 M ( number specified by the user in the original I/O statement.) s 5 335 M ( ) s 5 324 M ( Note that an INQUIRE statement cannot be executed when "unit") s 5 313 M ( is absent.) s 5 291 M ( | If "ifu" is present, the original I/O statement specified an) s 5 280 M ( | internal unit, and all I/O statements in the user defined) s 5 269 M ( | I/O routine shall specify an internal unit specifier.) s 5 258 M ( | If the dummy argument "ifu" is used as the unit specifier,) s 5 247 M ( | the I/O statement processes the record\(s\) from the original) s 5 236 M ( | I/O statement which triggered this user defined I/O routine.) s 5 225 M ( | Other internal unit variables will behave as if no other I/O) s 5 214 M ( | were active.) s 5 192 M ( | Note that "ifu" may not have any obvious relationship with) s 5 181 M ( | the internal unit specified in the original I/O statement) s 5 170 M ( | \(i.e. "ifu" may not point to the original internal unit) s 5 159 M ( | in any discernable manner\).) s 5 148 M ( ) s 5 137 M ( If the original I/O statement is a READ statement, the "dtv") s 5 126 M ( dummy arg should be assigned a value by the user defined) s 5 115 M ( I/O "read" routine.) s _R S %%Page: (6) 6 %%BeginPageSetup _S 24 24 translate /pagenum 6 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 6 of 10) s 5 687 M ( ) s 5 676 M ( If the original I/O statement is a WRITE or PRINT, the "dtv") s 5 665 M ( dummy arg contains the value of the list item from the) s 5 654 M ( original I/O statement, to be output by the user defined) s 5 643 M ( I/O routine.) s 5 632 M ( ) s 5 621 M ( The "w", "d", and "m" arguments contain the user specified) s 5 610 M ( values from the FORMAT \(i.e. FORMAT\(DT12.5.2 \) \). If the) s 5 599 M ( user did not specify "w", "d", and/or "m", those dummy) s 5 588 M ( arguments will not be present. They will not be present if) s 5 577 M ( the original I/O statement specified unformatted, list) s 5 566 M ( directed, or namelist i/o.) s 5 555 M ( ) s 5 544 M ( The "rec" dummy arg will be present if the original I/O) s 5 533 M ( statement contained a REC= sepcifier, and will not be) s 5 522 M ( present otherwise. Note that the READ or WRITE statements) s 5 511 M ( for "unit" or "ifu" contained in the user defined I/O routine) s 5 500 M ( shall contain a REC=rec specifier if dummy arg "rec" is present,) s 5 489 M ( and shall not contain a REC= specifier otherwise.) s 5 478 M ( ) s 5 467 M ( The user defined I/O routines for reads shall assign) s 5 456 M ( a value of .FALSE. or .TRUE. to the "end", "err", "eof", and) s 5 445 M ( "eor" dummy args. The value assigned to these dummy) s 5 434 M ( arguments shall determine whether or not the corresponding) s 5 423 M ( condition will be triggered in the I/O library when the user) s 5 412 M ( defined I/O routine returns.) s 5 401 M ( ) s 5 390 M ( In the absence of an appropriate visible interface in the) s 5 379 M ( | scope of the I/O statement, unformatted, list-directed, and) s 5 368 M ( namelist I/O will behave as it did in Fortran 90.) s 5 357 M ( ) s 5 346 M ( When an appropriate interface is visible for a particular) s 5 335 M ( derived type, and either:) s 5 324 M ( | 1. The original I/O statement specified unformatted,) s 5 313 M ( list directed, or namelist I/O, OR) s 5 302 M ( ) s 5 291 M ( 2. the original I/O statement specified a FORMAT and) s 5 280 M ( the list item of derived type matches up with a "DT") s 5 269 M ( edit descriptor, THEN) s 5 258 M ( ) s 5 247 M ( the restrictions on derived type I/O, such as no private) s 5 236 M ( components, all components must be defined, no ultimate) s 5 225 M ( components with the pointer attribute, etc. do not apply to) s 5 214 M ( the list item of derived type, but) s 5 203 M ( the normal rules in F95 still apply, about not referencing) s 5 192 M ( undefined entities, not referencing/defining POINTERS which) s 5 181 M ( are not associated, etc.) s 5 170 M ( ) s 5 159 M ( If NO appropriate interface is visible for a particular) s 5 148 M ( derived type, the processor will perform "F90" style I/O,) s 5 137 M ( and a "DT" edit descriptor which matches that derived type) s 5 126 M ( list item will cause an error \(at runtime possibly\).) s 5 115 M ( ) s 5 104 M ( When F90 style I/O is selected, all the old F90 restrictions) s 5 93 M ( on derived type list items still apply.) s _R S %%Page: (7) 7 %%BeginPageSetup _S 24 24 translate /pagenum 7 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 7 of 10) s 5 687 M ( ) s 5 676 M ( The users routine may chose to interpret the "w" argument as) s 5 665 M ( a field width, but this is NOT required. If it does so, it) s 5 654 M ( would be appropriate, but not required, to fill an output) s 5 643 M ( field with "***"s if the value does not fit.) s 5 632 M ( ) s 5 621 M ( When the original I/O statement was a READ, the user defined) s 5 610 M ( I/O routine may only do READs. Similarly for WRITE.) s 5 599 M ( ) s 5 588 M ( The user defined I/O routines ARE permitted to use a FORMAT with a) s 5 577 M ( DT edit descriptor, for handling components of the derived) s 5 566 M ( type which are themselves a derived type. List directed and) s 5 555 M ( NAMELIST I/O are also permitted for the "recursive" I/O) s 5 544 M ( statement.) s 5 533 M ( ) s 5 522 M ( WRITE statements contained in the user defined I/O) s 5 511 M ( routine will insert the characters "written" into the record) s 5 500 M ( started by the original WRITE statement, starting at the) s 5 489 M ( position in the record where the last edit descriptor left) s 5 478 M ( off. Record boundaries may be created by WRITE statements) s 5 467 M ( in the user defined I/O routine. Non-advancing I/O) s 5 456 M ( may be used to avoid creating record boundaries.) s 5 445 M ( ) s 5 434 M ( READ statements contained in the user defined I/O) s 5 423 M ( routine for read will "pick up" in the current record, where) s 5 412 M ( the last edit descriptor from the original I/O statement) s 5 401 M ( left off. Multiple records can be read, and the current) s 5 390 M ( position can be left within a record by the READ statement) s 5 379 M ( in the user defined I/O routine, thru the use of non-) s 5 368 M ( advancing i/o.) s 5 357 M ( ) s 5 346 M ( A very robust user defined I/O routine may need to use INQUIRE to) s 5 335 M ( determine what BLANK=, PAD= and DELIM= are for the specified) s 5 324 M ( unit.) s 5 313 M ( ) s 5 302 M ( Edit descriptors such as BN, BZ, P, etc., are permitted in) s 5 291 M ( FORMATs in user defined I/O routines, and have the) s 5 280 M ( same effect as if they had been present in the original) s 5 269 M ( FORMAT.) s 5 247 M ( | READ and WRITE statements executed in a user defined I/O) s 5 236 M ( | routine, or executed in a routine called \(directly or) s 5 225 M ( | indirectly\) from a user defined I/O routine shall not) s 5 214 M ( | have an ASYNCHRONOUS specifier.) s _R S %%Page: (8) 8 %%BeginPageSetup _S 24 24 translate /pagenum 8 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 8 of 10) s 5 687 M ( | --------------------------------------------------------------) s 5 676 M ( | Rationale) s 5 654 M ( | The desire to allow users to implement new data types in a) s 5 643 M ( | MODULE requires additional language features, including I/O) s 5 632 M ( | support. The provider of a module which implements a new) s 5 621 M ( | datatype needs to be able to also provide I/O support.) s 5 610 M ( | The approach chosen extends existing Fortran features to) s 5 599 M ( | support derived types, is fairly easy to use, bypasses the) s 5 588 M ( | restrictions on derived type I/O present in Fortran 90, and) s 5 577 M ( | allows the I/O support to be bundled with the MODULE which) s 5 566 M ( | supplies the derived type definition and implements the) s 5 555 M ( | operations thereon. This also provides the ability to) s 5 544 M ( | protect these I/O operations.) s 5 522 M ( | The use of visible interfaces to trigger this functionality) s 5 511 M ( | helps preserve Fortran 90 compatability, since no Fortran) s 5 500 M ( | program can specify such an interface.) s 5 478 M ( | --------------------------------------------------------------) s 5 467 M ( | Conceptual Model) s 5 445 M ( | The key concept is that the user defined I/O routines can,) s 5 434 M ( | more or less, be viewed as adding individual components into) s 5 423 M ( | the middle of the original item list, and edit desciptors into) s 5 412 M ( | the middle of the original format-specification \(if any\). They) s 5 401 M ( | also have full control over how input values are processed,) s 5 390 M ( | and how values are represented on output.) s 5 379 M ( | They can do so in an intelligent, dynamic, and arbitrarily) s 5 368 M ( | complex manner. They can also avoid the restrictions on) s 5 357 M ( | F90 derived type I/O \(pointers, etc.\), handle nested) s 5 346 M ( | derived types, and support complex data structures) s 5 335 M ( | \(such as linked lists\).) s 5 313 M ( | The user defined I/O routines provide a familar mechanism,) s 5 302 M ( | Fortran I/O statements, to insert data into an output record,) s 5 291 M ( | and to retrieve values from an input record.) s 5 269 M ( | The user of a derived type uses familiar Fortran syntax) s 5 258 M ( | to activate this capability. Usually, the user only needs) s 5 247 M ( | to "USE" the appropriate module, and possibly insert some) s 5 236 M ( | "DT" edit descriptors into their format-specifications.) s 5 214 M ( | All of the hard work is done by the provider/writer of the) s 5 203 M ( | derived type. Once that hard work is done, many users can) s 5 192 M ( | easily adapt their programs to use it.) s 5 170 M ( | The interface provides all the information necessary to) s 5 159 M ( | accomadate all types of Fortran I/O. A robust user defined) s 5 148 M ( | I/O routine will be quite large, but not necessarily very) s 5 137 M ( | complicated. A simple user-defined I/O routine can be) s 5 126 M ( | written quickly, and extended later to handle all the) s 5 115 M ( | possible forms of Fortran I/O.) s 5 93 M ( ) s _R S %%Page: (9) 9 %%BeginPageSetup _S 24 24 translate /pagenum 9 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 9 of 10) s 5 687 M ( | --------------------------------------------------------------) s 5 676 M ( | Example: \( this has not been syntax checked yet \)) s 5 654 M ( | TYPE linkedList) s 5 643 M ( | TYPE \(linkedList\), POINTER :: next) s 5 632 M ( | INTEGER :: value) s 5 621 M ( | END TYPE linkedList) s 5 599 M ( | RECURSIVE SUBROUTINE my_write_routine \(unit,) s 5 588 M ( | ifu,) s 5 577 M ( | dtv,) s 5 566 M ( | iotype, w, d, m,) s 5 555 M ( | rec, err\)) s 5 544 M ( | INTEGER, OPTIONAL :: unit) s 5 533 M ( | CHARACTER \(LEN=*\), OPTIONAL :: ifu) s 5 522 M ( | TYPE \(linkedList\), TARGET:: dtv ! the derived type value) s 5 511 M ( | CHARACTER \(*\) iotype ! the edit descriptor string) s 5 500 M ( | INTEGER, OPTIONAL :: w,d,m) s 5 489 M ( | INTEGER, OPTIONAL :: rec) s 5 467 M ( | TYPE \(linkedList\), POINTER :: ptr) s 5 456 M ( | INTEGER :: ww, dd ! local copies of w,d) s 5 445 M ( | CHARACTER \(LEN=20\) :: fmt ! format specification) s 5 434 M ( | ) s 5 423 M ( | err = .FALSE.) s 5 401 M ( | IF \( iotype == "NAMELIST" \) THEN) s 5 390 M ( | ! namelist I/O not supported yet) s 5 379 M ( | err = .TRUE.) s 5 368 M ( | RETURN) s 5 357 M ( | END IF) s 5 335 M ( | ! handle the optional "w" and "d" arguments) s 5 324 M ( | IF \( present \( w \) \) THEN) s 5 313 M ( | ww = w) s 5 302 M ( | ELSE) s 5 291 M ( | ww = 10) s 5 280 M ( | END IF) s 5 258 M ( | IF \( present \( d \) \) THEN) s 5 247 M ( | dd = d) s 5 236 M ( | ELSE) s 5 225 M ( | dd = 1) s 5 214 M ( | END IF) s 5 192 M ( | ! if we will need a format-spec, build it now) s 5 181 M ( | IF \( iotype\(1:2\) == "DT" \) THEN) s 5 170 M ( | ! build a Format string for use later) s 5 159 M ( | write\(fmt, "'\(I',I4,1x,I4,'\)'" \) ww, dd ! \(Iw.d\)) s 5 148 M ( | END IF) s 5 126 M ( | ptr => dtv) s _R S %%Page: (10) 10 %%BeginPageSetup _S 24 24 translate /pagenum 10 def /fname (97-101.txt) def /fdir () def /ftail (97-101.txt) def %%EndPageSetup 5 720 M ( ISO/IEC JTC1/SC22/WG5 N1246) s 5 709 M ( X3J3/97-101) s 5 698 M ( page 10 of 10) s 5 676 M ( | DO ! main loop down the linked list) s 5 654 M ( | IF \( PRESENT \( unit \) \) THEN) s 5 643 M ( | ! external I/O) s 5 632 M ( | IF \( iotype == "UNFORMATTED"\) THEN) s 5 621 M ( | IF \( PRESENT \( rec \) \) THEN) s 5 610 M ( | WRITE \(unit, REC=rec, ERR=99\) ptr%value) s 5 599 M ( | ELSE) s 5 588 M ( | WRITE \(unit, ERR=99\) ptr%value) s 5 577 M ( | END IF) s 5 566 M ( | ELSE IF \( iotype == "LISTDIRECTED" \) THEN) s 5 555 M ( | WRITE \(unit, *, ADVANCE="NO", ERR=99\) ptr%value) s 5 544 M ( | ELSE IF \( iotype\(1:2\) == "DT" \) THEN) s 5 533 M ( | IF \( PRESENT \( rec \) \) THEN) s 5 522 M ( | write\(unit, fmt, REC=rec, ERR=99\) ptr%value) s 5 511 M ( | ELSE) s 5 500 M ( | write\(unit, fmt, ADVANCE="NO", ERR=99\) ptr%value) s 5 489 M ( | END IF) s 5 478 M ( | ELSE) s 5 467 M ( | ! unrecognized i/o type) s 5 456 M ( | GO TO 99) s 5 445 M ( | END IF) s 5 434 M ( | ELSE) s 5 423 M ( | ! assume internal I/O) s 5 412 M ( | ! remember, direct access \(rec=\) is prohibited on) s 5 401 M ( | ! internal files, simplifies the stuff below) s 5 390 M ( | IF \( iotype == "UNFORMATTED"\) THEN) s 5 379 M ( | WRITE \(ifu, ERR=99\) ptr%value) s 5 368 M ( | ELSE IF \( iotype == "LISTDIRECTED" \) THEN) s 5 357 M ( | WRITE \(ifu, *, ADVANCE="NO", ERR=99\) ptr%value) s 5 346 M ( | ELSE IF \( iotype\(1:2\) == "DT" \) THEN) s 5 335 M ( | write\(ifu, fmt, ADVANCE="NO", ERR=99\) ptr%value) s 5 324 M ( | ELSE) s 5 313 M ( | ! unrecognized i/o type) s 5 302 M ( | GO TO 99) s 5 291 M ( | END IF) s 5 280 M ( | END IF) s 5 269 M ( | IF \( ASSOCIATED \(ptr%next\) \) EXIT) s 5 258 M ( | END DO) s 5 247 M ( | RETURN ! normal exit) s 5 225 M ( |99 err = .TRUE.) s 5 214 M ( | RETURN ! error exit) s 5 203 M ( END) s _R S %%Trailer %%Pages: 10 %%DocumentNeededResources: font Courier-Bold Courier %%EOF --------------718C5BC2341E--