1: @node Programming in Gauche, Core syntax, Concepts, Top
    2: @chapter  Programming in Gauche
    3: @c NODE Gauche?Ç¤Î¥×¥í¥°????
    4: @menu
    5: * Invoking Gosh::               
    6: * Interactive development::     
    7: * Writing Scheme scripts::      
    8: * Debugging::                   
    9: * Platform-dependent features::  
   10: * Profiling and tuning::        
   11: * Writing Gauche modules::      
   12: * Using extension packages::    
   13: @end menu
   14: 
   15: @node Invoking Gosh, Interactive development, Programming in Gauche, Programming in Gauche
   16: @section Invoking Gosh
   17: @c NODE Gauche???????@c EN
   18: Gauche can be used either as an independent Scheme interpreter
   19: or as an embedded Scheme library.   The interpreter
   20: which comes with Gauche distribution is a program named @code{gosh}.
   21: @c JP
   22: Gauche????????Scheme???󥿥ץ꥿?Ȥ??Ƥ⡢??߹??ߤ?cheme?饤?֥??Ȥ??Ƥ?Ȥ????Ȥ??Ǥ??ޤ???Gauche?Υǥ????ȥ??塼?????ˤϡ?@code{gosh}?Ȥ???
   23: ???󥿥ץ꥿???°???Ƥ??ޤ???
   24: @c COMMON
   25: 
   26: @deftp {Program} gosh [options] [scheme-file arg @dots{}]
   27: @c EN
   28: Gauche's interpreter.   Without @var{scheme-file}, @code{gosh} works
   29: interactively, i.e. it reads a Scheme expression from the standard input,
   30: evaluates it, and prints the result, and repeat that until it reads EOF or
   31: is terminated.
   32: @c JP
   33: Gauche?Υ??󥿥ץ꥿?Ǥ???  @var{scheme-file}??Ϳ?????ʤ?????
   34: @code{gosh}?ϥ??󥿥饯?ƥ??֤????ޤ??????ʤ???ɸ???????heme????߹??ߡ?
   35: ????ɾ????Ʒ?????Ȥ???????ư????EOF??फ???Ū?˽?λ??????????³???ޤ???
   36: @c COMMON
   37: 
   38: @c EN
   39: If @code{gosh} is invoked without @var{scheme-file}, but the input
   40: is not a terminal, it enters read-eval-print loop but not writes
   41: out a prompt while waiting input form.  This is useful when you
   42: pipe Scheme program into @code{gosh}.  You can force this behavior
   43: or suppress this behavior by @code{-b} and @code{-i} options.
   44: @c JP
   45: ?⤷@var{scheme-file}??Ϳ?????Ƥ??餺????????????ü??Ǥʤ?????
   46: @code{gosh}??ead-eval-print?롼?פ???????????????κݤ˥ץ??ץȤ??????ޤ??󡣤???Scheme??????פ?var{gosh}?˽????????????Ǥ???
   47: @code{-b}?ޤ???code{-i}???ץ????Ǥ?????????Ū??n?ޤ???ff?Ǥ??ޤ???
   48: @c COMMON
   49: 
   50: @c EN
   51: If @var{scheme-file} is specified, @code{gosh} runs it as a
   52: Scheme program and exit.
   53: @xref{Writing Scheme scripts}, for details.
   54: @c JP
   55: @var{scheme-file}??Í¿??????????@code{gosh}?Ϥ???Scheme?×¥í¥°???Ȥ????í¡¼?ɤ?????λ???Þ¤???????????ؤ??Ƥ?ref{Writing Scheme scripts}?ò»²¾È¤???????????
   56: @c COMMON
   57: @end deftp
   58: 
   59: @c EN
   60: @subheading Command-line options
   61: @c JP
   62: @subheading ???ޥ?饤?󥪥ץ???
   63: @c COMMON
   64: 
   65: @c EN
   66: The following command line options are recognized by @code{gosh}.
   67: The first command line argument which doesn't begin with `@minus{}'
   68: is recognized as the script file.  If you want to specify a file
   69: that begins with a minus sign, use a dummy option `@code{--}'.
   70: @c JP
   71: @code{gosh}?ˤϰʲ??Τ褦?ʥ??ޥ?饤?󥪥ץ?????????????
   72: `@minus{}' ?ǻϤޤ????ǽ????Þ¥?饤??ô¤¬¥??????È¥Õ¥?????ǧ??????????
   73: ???????ȥե??????? `@minus{}' ?ǻϤޤäƤ???ǽ?????????????ߡ????ץ???
   74: `@code{--}' ?򥹥????ȥե??????????֤??Ʋ???????
   75: @c COMMON
   76: 
   77: @deftp {Command Option} -I path
   78: @c EN
   79: Prepends @var{path} to the load path list.
   80: You can specify this option more than once to add multiple paths.
   81: @c JP
   82: @var{path}????ɥѥ??Υꥹ?Ȥκǽ??ä??ޤ??????Υ??ץ????????????ޤ???
   83: @c COMMON
   84: @end deftp
   85: 
   86: @deftp {Command Option} -A path
   87: @c EN
   88: Appends @var{path} to the tail of the load path list.
   89: You can specify this option more than once to add multiple paths.
   90: @c JP
   91: @var{path}????ɥѥ??Υꥹ?Ȥ??˲ä??ޤ??????Υ??ץ????????????ޤ???
   92: @c COMMON
   93: @end deftp
   94: 
   95: @deftp {Command Option} -q
   96: @c EN
   97: Makes @code{gosh} not to load the default initialization file.
   98: @c JP
   99: @code{gosh}????Æ°???Ë¥????Æ¥??????Õ¥??????í¡¼?ɤ??ʤ??褦?ˤ??Þ¤???
  100: @c COMMON
  101: @end deftp
  102: 
  103: @deftp {Command Option} -V
  104: @c EN
  105: Prints the @code{gosh} version and exits.
  106: @c JP
  107: @code{gosh}?ΥС???????????ƽ?λ???ޤ???
  108: @c COMMON
  109: @end deftp
  110: 
  111: @deftp {Command Option} -u module
  112: @c EN
  113: Use @var{module}.  Before starting execution of @var{scheme-file} or entering
  114: the read-eval-print loop, the specified module is @var{use}d, i.e.
  115: it is loaded and imported (@xref{Defining and selecting modules}, for details of @code{use}).
  116: You can specify this option more than once to use multiple modules.
  117: @c JP
  118: ??ư?塢???󥿥饯?ƥ??֤?ead-eval-print?롼?פ???????⤷????var{scheme-file}
  119: ????ɤ?????var{module}??se''???Þ¤????Ĥޤꤽ?Υ⥸?塼?뤬?í¡¼?ɤ????????Ȥ???????(@code{use}?ξܺ٤ˤĤ??Ƥ?ref{Defining and selecting modules}?ò»²¾È¤??Ʋ???????)
  120: ???Î¥??×¥????????????Þ¤???
  121: @c COMMON
  122: @end deftp
  123: 
  124: @deftp {Command Option} -l file
  125: @c EN
  126: Load @var{file} before starting execution of @var{scheme-file} or entering
  127: the read-eval-print loop.   The file is loaded in the same way as
  128: @code{load} (@xref{Loading Scheme file}).
  129: You can specify this option more than once to load multiple files.
  130: @c JP
  131: ??ư?塢???󥿥饯?ƥ??֤?ead-eval-print?롼?פ???????⤷????var{scheme-file}
  132: ????ɤ?????var{file}????ɤ??Þ¤????í¡¼?ɤξܺ٤ˤĤ??Ƥ?ref{Loading Scheme file}
  133: ?򻲾Ȥ??Ʋ??????????Υ??ץ????????????ޤ???
  134: @c COMMON
  135: @end deftp
  136: 
  137: @deftp {Command Option} -e scheme-expression
  138: @c EN
  139: Evaluate @var{scheme-expression}
  140: before starting execution of @var{scheme-file} or entering
  141: the read-eval-print loop.   Evaluation is done in the
  142: @var{interaction-environment} (@xref{Eval and repl}).
  143: You can specify this option more than once to evaluate multiple expressions.
  144: @c JP
  145: ??ư?塢???󥿥饯?ƥ??֤?ead-eval-print?롼?פ???????⤷????var{scheme-file}
  146: ????ɤ?????var{scheme-expression}?????ޤ???ɾ???@var{interaction-environment}??ǹԤ??ޤ?(@ref{Eval and repl}??????
  147: ???Î¥??×¥????????????Þ¤???
  148: @c COMMON
  149: @end deftp
  150: 
  151: @deftp {Command Option} -E scheme-expression
  152: @c EN
  153: Same as -e, except the @var{scheme-expression} is read
  154: as if it is surrounded by parenthesis.  For example:
  155: @c JP
  156: ???ץ???-e?Ȥۤ?????Ǥ?????@var{scheme-expression}?????줬???ǰϤޤ????뤫?Τ褦??ɤޤ?????
  157: ???Î¥??×¥????????????Þ¤??????
  158: @c COMMON
  159: @example
  160: % gosh -umath.const -E"print (sin (* pi/180 15))" -Eexit
  161: 0.25881904510252074
  162: @end example
  163: @end deftp
  164: 
  165: @deftp {Command Option} -b
  166: @c EN
  167: Batch. Does not print prompts even if the input is a terminal.
  168: @c JP
  169: ?Хå??????ü??Ǥ??äƤ????ץȤ???ʤ??褦?ˤ??ޤ???
  170: @c COMMON
  171: @end deftp
  172: 
  173: @deftp {Command Option} -i
  174: @c EN
  175: Interactive. Print prompts even if the input is not a terminal.
  176: @c JP
  177: ???󥿥饯?ƥ??֡?????ü???????Ƥ????ץȤ???褦?ˤ??ޤ???
  178: @c COMMON
  179: @end deftp
  180: 
  181: @deftp {Command Option} -f compiler-option
  182: @c EN
  183: This option controls compiler and runtime behavior.  For now we have
  184: following options available:
  185: @table @asis
  186: @item no-inline
  187: Prohibits the compiler from inlining procedures and constants. Equivalent to
  188: no-inline-globals, no-inline-locals and no-inline constants combined.
  189: @item no-inline-globals
  190: Prohibits the compiler from inlining global procedures.
  191: @item no-inline-locals
  192: Prohibits the compiler from inlining local procedures.
  193: @item no-inline-constants
  194: Prohibits the compiler from inlining constants.
  195: @item load-verbose
  196: Reports whenever a file is loaded.
  197: @item no-source-info
  198: Don't keep source information for debugging.  Consumes less memory.
  199: @item case-fold
  200: Ignore case for symbols as specified in R5RS.
  201: (It is distinguished by default).  @xref{Case-sensitivity}.
  202: @item test
  203: Adds "@code{../src}" and "@code{../lib}" to the load path before loading 
  204: initialization file.  This is useful when you want to test the
  205: compiled @code{gosh} interpreter inside source tree, without installing it.
  206: @end table
  207: @c JP
  208: ???Υ??ץ????ϥ??????????????ư???ƶ????ޤ???
  209: ???ΤȤ??í¡¢???Î¥??×¥????Τߤ?@var{compiler-option}?Ȥ????????
  210: @table @asis
  211: @item no-inline
  212: ???Υ???????????ޤ??󡣤??Υ??ץ????ϰʲ???no-inline-globals
  213: no-inline-locals ???? no-inline-constants ????˻?ꤷ???Τ??????
  214: @item no-inline-globals
  215: ???lobal)?ؿ?????????????ʤ??ޤ???@item no-inline-locals
  216: ?ɽ?ocal)?ؿ?????????????ʤ??ޤ???@item no-inline-constants
  217: ????????????ʤ??ޤ???@item no-source-info
  218: ?ǥХå??Τ??????????ե???????????󡣥??????̤Ͼ??????ʤ?????
  219: @item load-verbose
  220: ?Õ¥????뤬?í¡¼?ɤ??????ˤ?????𤷤ޤ???
  221: @item case-fold
  222: R5RS?˼???????ꡢ??????ʸ????????ޤ???(?ǥե????ǤϤ????϶???????)?? @ref{Case-sensitivity} ?򻲾Ȥ??Ʋ???????
  223: @item test
  224: "@code{../src}" ??"@code{../lib}" ?ò¡¢½????Õ¥???????????í¡¼?ɥѥ??˲ä??Þ¤??????????????줿@code{gosh}?ò¥¤¥ó¥¹¥È¡??뤻???????????ĥ꡼????¹Ԥ??Ƥߤ???????
  225: @end table
  226: @c COMMON
  227: @end deftp
  228: 
  229: @deftp {Command Option} -p profiler-option
  230: @c EN
  231: Turn on the profiler.  The following @var{profiler-option} is recognized:
  232: @c JP
  233: ?ץ???????ͭ???ޤ????ʲ??Τ褦??var{profiler-option}??
  234: ???ΤȤ??í¥µ?Ý¡??Ȥ??????Þ¤???
  235: @c COMMON
  236: 
  237: @table @code
  238: @item time
  239: @c EN
  240: Records and reports time spent on function calls and number of times
  241: each function is called.
  242: @c JP
  243: ?Ø¿??ñ¤µ¤ì¤¿???֤ȡ??Æ´Ø¿ô¤¬¸Æ¤Ð¤ì¤¿???????????Þ¤???
  244: @c COMMON
  245: @item load
  246: @c EN
  247: Records and reports time spent on loading each modules.
  248: Useful to tune start-up time of the scripts.
  249: (Results are in elapsed time).
  250: @c JP
  251: ?ƥ⥸?塼???í¡¼?ɤ????ˤ????ä????Ö¤?????????Þ¤???
  252: ???????Ȥε?ư???֤?塼?󤹤?????
  253: (?·в??֤???𤵤???)??
  254: @c COMMON
  255: @end table
  256: 
  257: @c EN
  258: See @ref{Using profiler} for the details of the profiler.
  259: @c JP
  260: ?ܤ?????ref{Using profiler}?򻲾Ȥ??Ʋ???????
  261: @c COMMON
  262: @end deftp
  263: 
  264: 
  265: @deftp {Command Option} @code{--}
  266: @c EN
  267: When @code{gosh} sees this option, it stops processing the options
  268: and takes next command line argument as a script file.  It is useful
  269: in case if you have a script file that begins with a minus sign,
  270: although it is not generally recommended.
  271: @c JP
  272: ???Υ??ץ????˽в񤦤ȡ?@code{gosh}?ϥ??ץ????β????????μ??ΰ?
  273: ̵???var{scheme-file}?Ǥ?????????ޤ???@var{scheme-file}???ޥ??ʥ?????
  274: ?ϤޤäƤ?????ɬ??Ǥ???
  275: @c COMMON
  276: @end deftp
  277: 
  278: @c EN
  279: The options -I, -A, -l, -u, -e and -E are processes in the order
  280: of appearance.  For example, adding a load path by -I affects the
  281: -l and -u option after it but not before it.
  282: @c JP
  283: ???×¥???-I, -A, -l, -u, -e ?Ú¤?-E ?Ï¡??????????Þ¥?饤???????и?????????????????????С?-I?ˤ???ä????í¡¼?ɥѥ????????ߤ?l?????×¥????˱ƶ????Þ¤???????????Τ??ˤϱƶ?????Þ¤???@c COMMON
  284: 
  285: @c EN
  286: @subheading Environment variables
  287: @c JP
  288: @subheading ?Ķ???? COMMON
  289: 
  290: @c EN
  291: The following environment variables are recognized:
  292: @c JP
  293: ?ʲ??δĶ??????????ޤ???
  294: @c COMMON
  295: 
  296: @deftp {Environment variable} GAUCHE_LOAD_PATH
  297: @c EN
  298: You can specify additional load paths by this environment
  299: variable, delimiting the paths by '@code{:}'.
  300: The paths are appended before the system default load paths.
  301: @c JP
  302: ???δĶ??????ơ???ä??????ɥѥ???????ޤ???
  303: ?ѥ???'@code{:}' ?Ƕ???????
  304: ????Ñ¿???Æ»?ꤵ?줿?Ñ¥??Ï¥????Æ¥??Ç¥Õ¥????Î¥í¡¼?ɥѥ??????Ï¢?뤵??????
  305: @c COMMON
  306: @end deftp
  307: 
  308: @deftp {Environment variable} GAUCHE_DYNLOAD_PATH
  309: @c EN
  310: You can specify additional load paths for dynamically loaded
  311: objects by this environment variable, delimiting the paths by '@code{:}'.
  312: The paths are appended before the system default load paths.
  313: @c JP
  314: ????Ñ¿???Æ¡?ưŪ?Ë¥í¡¼?ɤ??륪?Ö¥???????Ѥ?É²Ã¥í¡¼?ɥѥ?????Ǥ??Þ¤????Ñ¥???'@code{:}' ?Ƕ???????
  315: ????Ñ¿???Æ»?ꤵ?줿?Ñ¥??Ï¥????Æ¥??Ç¥Õ¥????Î¥í¡¼?ɥѥ??????Ï¢?뤵??????
  316: @c COMMON
  317: @end deftp
  318: 
  319: @c ----------------------------------------------------------------------
  320: @node Interactive development, Writing Scheme scripts, Invoking Gosh, Programming in Gauche
  321: @section Interactive development
  322: @c NODE  ???󥿥饯?ƥ??֤ʳ?ȯ
  323: 
  324: @c EN
  325: When @code{gosh} is invoked without any script files,
  326: it goes into interactive read-eval-print loop.
  327: @c JP
  328: ???????ȥե????뤬Ϳ?????ʤ??ä?????
  329: @code{gosh}?ϥ??󥿥饯?ƥ??֤?ead-eval-print?롼?פ????????
  330: @c COMMON
  331: 
  332: @c EN
  333: To exit the interpreter, type EOF (usually Control-D in Unix terminals)
  334: or evaluate @code{(exit)}.
  335: @c JP
  336: ???󥿥ץ꥿????????ϡ?EOFʸ??xü??Ǥ?̾?ntrol-D)?򥿥??פ??뤫??
  337: @code{(exit)}?????Þ¤???
  338: @c COMMON
  339: 
  340: @c EN
  341: In interactive session, @code{gosh} loads @code{gauche.interactive}
  342: module (@xref{Interactive session}) for the
  343: convenience.  The module also loads a file @file{.gaucherc} under
  344: the user's home directory if it exists.
  345: You may put settings there that would help interactive debugging.
  346: (As of Gauche release 0.7.3,
  347: @file{.gaucherc} is no longer loaded when @code{gosh} is run
  348: in script mode.)
  349: @c JP
  350: ???󥿥饯?Æ¥??Ö¥??Ã¥????Ǥϡ?@code{gosh}??@code{gauche.interactive}?⥸?塼???í¡¼?ɤ??Þ¤?
  351: (@ref{Interactive session}??????
  352: ???Υ⥸?塼???ޤ????桼?????Υۡ??????쥯?ȥ?@file{.gaucherc}?Ȥ???
  353: ?ե????뤬?????????ɤ??ޤ???
  354: ???󥿥饯?ƥ??֥ǥХå???????򤽤??˽񤤤Ƥ??????Ȥ??Ǥ??ޤ???
  355: (Gauche release 0.7.3???顢@file{.gaucherc}??osh?????????ȥ⡼?ɤ???ư???줿????ɤޤ????ʤ???????)
  356: @c COMMON
  357: 
  358: @c EN
  359: I recommend you to run @code{gosh} inside Emacs, for it has
  360: rich features useful to interact with internal Scheme process.
  361: Put the following line to your @file{.emacs} file:
  362: @example
  363: (setq scheme-program-name "gosh -i")
  364: @end example
  365: And you can run @code{gosh} by @key{M-x run-scheme}.
  366: @c JP
  367: @code{gosh}??cs???????뤳?Ȥ򤪴??ᤷ?ޤ???
  368: Emacs??cheme???Ö¥×¥í¥»?????뤿??Ë­??ʵ?ǽ??äƤ??Þ¤???
  369: ???ιԤ?le{.emacs}?˲ä??Ƥ????ȡ?@key{M-x run-scheme} ??Emacs?ΥХåե????code{gosh}?????????
  370: @example
  371: (setq scheme-program-name "gosh -i")
  372: @end example
  373: @c COMMON
  374: 
  375: @c EN
  376: If you want to use multibyte characters in the interaction,
  377: make sure your terminal's settings is in sync with @code{gosh}'s
  378: internal character encodings.
  379: @c JP
  380: ???Ķ??ǥޥ??Х???????????ϡ?ü???????????ǥ??󥰤?de{gosh}???????󥳡??ǥ??󥰤ȹ????????ˤ??Ʋ???????
  381: @c COMMON
  382: 
  383: @c EN
  384: Currently @code{gosh} has no fancy features such as
  385: line-editing or command history.   They'll be added in future.
  386: @c JP
  387: ???ΤȤ??í¡¢@code{gosh}?Ϲ?Ô½??䥳?Þ¥?Ò¥??È¥??ɤ???ǽ?????Ƥ??Þ¤??ó¡£¾???Ϥ??Τؤ???¤??Ƥ椯?Ǥ??礦??
  388: @c COMMON
  389: 
  390: @c ----------------------------------------------------------------------
  391: @node Writing Scheme scripts, Debugging, Interactive development, Programming in Gauche
  392: @section Writing Scheme scripts
  393: @c NODE Scheme???????Ȥ??
  394: 
  395: @c EN
  396: When a Scheme program file is given to @code{gosh}, it
  397: bounds a global variable @code{*argv*} to the list of the remaining
  398: command-line arguments, then loads the Scheme program.
  399: If the first line of @var{scheme-file} begins with two character
  400: sequence ``@code{#!}'', the entire line is ignored by @code{gosh}.
  401: This is useful to write a Scheme program that works as an executable
  402: script in unix-like systems.
  403: @c JP
  404: @code{gosh}?Î¥??Þ¥?饤??cheme?×¥í¥°???Î¥Õ¥???????????줿????
  405: @code{gosh}?Ϥ????ߤΥ??Þ¥?饤???ꥹ?Ȥò¥°¥í¡¼?Ð¥???de{*argv*}????????
  406: Scheme?×¥í¥°??????ɤ??Þ¤????⤷@var{scheme-file}?κǽ??Ô¤?``@code{#!}''?ǻϤޤä??????é¡¢???ιԤ???뤵??????????????Unix?ϤΥ????Æ¥??¹Բ????cheme??????????????Ȥ????????
  407: @c COMMON
  408: 
  409: @c EN
  410: Typical Gauche script has the first
  411: line like these
  412: @example
  413: #!/usr/local/bin/gosh
  414:   @r{or,}
  415: #!/usr/bin/env gosh
  416:   @r{or,}
  417: #!/bin/sh
  418: :; exec gosh -- $0 "$@@"
  419: @end example
  420: The second and third form uses a ``shell trampoline'' technique
  421: so that the script works as far as @code{gosh} is in the PATH.
  422: The third form is useful when you want to pass extra arguments
  423: to @code{gosh}, for typically @code{#!}-magic of executable scripts
  424: has limitations for the number of arguments to pass the interpreter.
  425: @c JP
  426: ŵ??Ū??auche???????Ȥκǽ??Ԥϼ??Τ褦?ʤ??Ǥ???
  427: @example
  428: #!/usr/local/bin/gosh
  429:   @r{?Þ¤???}
  430: #!/usr/bin/env gosh
  431:   @r{?Þ¤???}
  432: #!/bin/sh
  433: :; exec gosh -- $0 "$@@"
  434: @end example
  435: ??2?Ĥϡ֥????????ݥ??ץƥ??˥å?????ơ?@code{gosh}??PATH?ˤ??????쥯?ȥ?
  436: ?ɤ????ˤ?????ư?Ǥ??????ˤ??Ƥ??ޤ???3??????
  437: @code{gosh}?ˤ????Ĥ????ޥ?饤?󥪥ץ??????????????????
  438: @c COMMON
  439: 
  440: @c EN
  441: After the file is successfully loaded, @code{gosh} calls a
  442: procedure named `@code{main}' if it is defined in the user module.
  443: @code{Main} receives a single argument, a list of command line
  444: arguments.  Its first element is the script name itself.
  445: 
  446: When @code{main} returns, and its value is an integer, @code{gosh}
  447: uses it for exit code of the program.
  448: Otherwise, @code{gosh} exits with exit code 70 (@code{EX_SOFTWARE}).
  449: This behavior is compatible with the SRFI-22.
  450: 
  451: If the @code{main} procedure is not defined, @code{gosh} exits
  452: after loading the script file.
  453: @c JP
  454: ?Õ¥????뤬????í¡¼?ɤ??줿?é¡¢@code{gosh}??user?⥸?塼?? `@code{main}' ?Ȥ??????????????????뤫?ɤ???Ä´?Ù¡?
  455: ???????????????ƤӤޤ???@code{main}?ˤϡ????????Ȥؤΰ??ꥹ?Ȥ?
  456: ͣ????????Ϥ????????ꥹ?Ȥκǽ????ϥ??????ȥե??????Ǥ???
  457: 
  458: @code{main}?????ͤ?????顢@code{gosh}?Ϥ???ͤ?????ơ??????Ȥ??ƽ?λ???ޤ???
  459: @code{main}????????ͤ????????code{gosh}?Ͻ?λ???ơ?????70
  460: (@code{EX_SOFTWARE})?ǽ?λ???ޤ??????Τդ?????RFI-22?ȸߴ??Ǥ???
  461: 
  462: @code{main}???????????ʤ???@code{gosh}?Ï¥í¡¼?ɸ????Τޤޥ??Æ¡?????0????λ???Þ¤???
  463: @c COMMON
  464: 
  465: @c EN
  466: Although you can still write the program
  467: main body as toplevel expressions, like shell scripts or Perl scripts,
  468: it is much convenient to use this `@code{main}' convention, for
  469: you can load the script file interactively to debug.
  470: @c JP
  471: ?????륹?????Ȥ?rl???????Ȥ?????褦?ˡ????????ȤΥܥǥ?????
  472: ?¹Ԥ???????????Ȥ????Þ¤??????ʤ??? `@code{main}' ??ä??Ë¡???????Ȥ???ᤷ?Þ¤????????????????????Ȥò¥¤¥ó¥¿¥×¥ê¥¿?Ë¥??󥿥饯?Æ¥??Ö¤??í¡¼?ɤ??ƥǥХå????뤳?Ȥ????Þ¤???
  473: @c COMMON
  474: 
  475: 
  476: @defvar *argv*
  477: @c EN
  478: The program arguments passed to the Scheme script is bound to this
  479: variable.  If @code{gosh} is invoked in an interactive mode, this
  480: variable always contains @code{()}.
  481: 
  482: STk uses this variable to pass the command line argument as well,
  483: but other Scheme implementations use different ways.  It is better
  484: to define @code{main} procedure and uses its argument to receive
  485: command line arguments, for it is expected to be more portable.
  486: @c JP
  487: Scheme???????ȰʹߤΥ??Þ¥?饤???ꥹ?Ȥϡ????????È¤Î¥í¡¼?ɤ????????Ñ¿???????????@code{gosh}?????󥿥饯?Æ¥??֥⡼?ɤǵ?Æ°???줿????????Ñ¿?code{()}?Ȥʤ?????
  488: 
  489: ????ѿ?Tk?ȸߴ??????????????¾??cheme???????ˡ??äƥ??ޥ?饤?????ޤ????ݡ????֥????????Ȥ???ˤϡ?@code{main}????????ˡ????ᤷ?ޤ???
  490: @c COMMON
  491: @end defvar
  492: 
  493: @defvar *program-name*
  494: @c EN
  495: This variable is bound to the script file name passed to @code{gosh}.
  496: If @code{gosh} is invoked in the interactive mode, this variable
  497: contains the pathname of @code{gosh} itself.
  498: 
  499: STk uses the same variable to access the program/script name.
  500: Other Scheme implementations use different ways.
  501: @c JP
  502: ????ѿ???????ȥե????????????????????󥿥饯?ƥ??֥⡼?ɤǤ?????ѿ?code{gosh}???Ȥ?????äƤ??ޤ???
  503: 
  504: ????ѿ?Tk?ȸߴ??????????????¾?μ??????ˡ????ޤ???
  505: @c COMMON
  506: @end defvar
  507: 
  508: @c EN
  509: Now I show several simple examples below.
  510: First, this script works like @code{cat(1)}, without any command-line
  511: option processing and error handling.
  512: @c JP
  513: ?????Ĥ????????????ޤ????ǽ????nix??code{cat(1)}???ޥ??????ΤǤ???
  514: ???顼???䥳?ޥ?饤?󥪥ץ????ν??ϹԤäƤ??ޤ???@c COMMON
  515: 
  516: @example
  517: #!/usr/bin/env gosh
  518: 
  519: (define (main args)   ;@r{entry point}
  520:   (if (null? (cdr args))
  521:       (copy-port (current-input-port) (current-output-port))
  522:       (for-each (lambda (file)
  523:                   (call-with-input-file file
  524:                     (lambda (in)
  525:                       (copy-port in (current-output-port)))))
  526:                 (cdr args)))
  527:   0)
  528: @end example
  529: 
  530: @c EN
  531: The following script is a simple grep command.
  532: @c JP
  533: ???Υ??????Ȥϴ????rep???ޥ?Ǥ???
  534: @c COMMON
  535: 
  536: @example
  537: #!/usr/bin/env gosh
  538: 
  539: (define (usage)
  540:   (format (current-error-port)
  541:           "Usage: ~a regexp file ...\n" *program-name*)
  542:   (exit 2))
  543: 
  544: (define (grep rx port)
  545:   (with-input-from-port port
  546:     (lambda ()
  547:       (port-for-each
  548:        (lambda (line)
  549:          (when (rxmatch rx line)
  550:            (format #t "~a:~a: ~a\n"
  551:                    (port-name port)
  552:                    (- (port-current-line port) 1)
  553:                    line)))
  554:        read-line))))
  555: 
  556: (define (main args)
  557:   (if (null? (cdr args))
  558:       (usage)
  559:       (let ((rx (string->regexp (cadr args))))
  560:         (if (null? (cddr args))
  561:             (grep rx (current-input-port))
  562:             (for-each (lambda (f)
  563:                         (call-with-input-file f
  564:                           (lambda (p) (grep rx p))))
  565:                       (cddr args)))))
  566:   0)
  567: @end example
  568: 
  569: @c EN
  570: See also @ref{Parsing command-line options}, for a convenient way to
  571: parse command-line options.
  572: @c JP
  573: ?ޤ???@ref{Parsing command-line options}????ȼ??˥??ޥ?饤?󥪥ץ???
  574: ?????Ȥ??Ǥ??ޤ???
  575: @c COMMON
  576: 
  577: @c ----------------------------------------------------------------------
  578: @node Debugging, Platform-dependent features, Writing Scheme scripts, Programming in Gauche
  579: @section Debugging
  580: @c NODE ?ǥХå?
  581: 
  582: @c EN
  583: Gauche doesn't have much support for debugging yet.
  584: The idea of good debugging interfaces are welcome.
  585: @c JP
  586: Gauche?ˤϤޤ?ǥХå??򥵥ݡ??Ȥ??뵡ǽ?????ޤ?????????ޤ????ǥХå??󥰤Υ??󥿥ե??????˴ؤ???ɤ??????ǥ????????????󤻤????????
  587: @c COMMON
  588: 
  589: @c EN
  590: For now, the author uses the classic 'debug print stub' technique
  591: when necessary.  A special reader syntax @code{#?=@var{expr}} is
  592: defined, which is read as @code{(debug-print @var{expr})}.
  593: The macro @code{debug-print} evaluates and returns the result(s),
  594: printing messages before and after evaluation of @var{expr}.
  595: @c JP
  596: ???ΤȤ??í¡¢???????Ê»??ϸ??Ū?Ê¡Ö¥×¥??È¥????Ö¡??ȤäƤ??Þ¤???
  597: ???Τ????꡼????ޥ???code{#?=@var{expr}} ???????????ޤ???
  598: ???? @code{(debug-print @var{expr})} ?Τ褦??ɤޤ졢
  599: ?ޥ???code{debug-print} ??var{expr}?????Ƥ???ͤ???ޤ?????
  600: ɾ???????????????????Ϥ??ޤ???
  601: @c COMMON
  602: 
  603: @example
  604: gosh> #?=(+ 2 3)
  605: #?="(stdin)":1:(+ 2 3)
  606: #?-    5
  607: 5
  608: gosh> #?=(begin (print "foo") (values 'a 'b 'c))
  609: #?="(stdin)":2:(begin (print "foo") (values 'a 'b 'c))
  610: foo
  611: #?-    a
  612: #?+    b
  613: #?+    c
  614: a
  615: b
  616: c
  617: gosh> (define (fact n)
  618:         (if (zero? n)
  619:             1
  620:             (* n #?=(fact (- n 1)))))
  621: fact
  622: gosh> (fact 5)
  623: #?="(stdin)":6:(fact (- n 1))
  624: #?="(stdin)":6:(fact (- n 1))
  625: #?="(stdin)":6:(fact (- n 1))
  626: #?="(stdin)":6:(fact (- n 1))
  627: #?="(stdin)":6:(fact (- n 1))
  628: #?-    1
  629: #?-    1
  630: #?-    2
  631: #?-    6
  632: #?-    24
  633: 120
  634: @end example
  635: 
  636: @c EN
  637: You can also use trace/untrace macros in Gauche, written by Shigenobu Kimura:
  638: @url{http://homepage.mac.com/skimu/ggc/}.
  639: @c JP
  640: ?ޤ????¼?ɿ?????auche???race/untrace?ޥ????񤤤Ƥ?????????
  641: @url{http://homepage.mac.com/skimu/ggc/}.
  642: @c COMMON
  643: 
  644: @c ----------------------------------------------------------------------
  645: @node Platform-dependent features, Profiling and tuning, Debugging, Programming in Gauche
  646: @section Using platform-dependent features
  647: @c NODE ?ץ??ȥե?????¸?ε?ǽ
  648: 
  649: @c EN
  650: Gauche tries to provide low-level APIs close to what the underlying
  651: system provides, but sometimes they vary among systems.  For example,
  652: POSIX does not require @code{symlink}, so some systems may lack
  653: @code{sys-symlink} (@xref{Directory manipulation}).  Quite a few
  654: unix-specific system functions are not available on Windows platform.
  655: @c JP
  656: Gauche?Ǥ?S?????????I?˶ᤤ?????I??????????ˤ??Ƥ??ޤ???
  657: ?????????????ƥऴ?Ȥ˰????ΰ㤦???????????????Ȥ??С?POSIX?Ǥ?@code{symlink}????ܤǤϤ???????ǡ??????ƥ????Ƥ?@code{sys-symlink} (@ref{Directory manipulation}??????????????UNIX?ϤΥ????ƥ?????ʤ??餺Windows?ǤϻȤ??ޤ???
  658: @c EN
  659: To allow writing a portable program across those platforms, Gauche
  660: uses @code{cond-expand} (@xref{Feature conditional}) extensively.
  661: A set of extended @emph{feature-identifier}s is provided to check
  662: availability of specific features.  For example, on systems that
  663: has @code{symlink}, a feature identifier @code{gauche.sys.symlink}
  664: is defined.   So you can write a code that can switch based on
  665: the availability of @code{sys-symlink} as follows:
  666: @c JP
  667: ?×¥??È¥Õ¥??????ǥݡ????Ö¥??×¥í¥°???????????Gauche?Ǥ?????code{cond-expand} ????Þ¤?(@ref{Feature conditional}??????
  668: ??????줿@emph{??ǽ?????feature-identifier)}????????????ꡢ?????ä?????ǽ??????????ɤ???????å??Ǥ??ޤ??????Ȥ??С?
  669: @code{symlink}?????륷???ƥ??ϵ?ǽ?????code{gauche.sys.symlink}??
  670: ?????????????????äơ??ʲ??Τ褦??code{sys-symlink}?????Ǥ??뤫
  671: ?ɤ????ˤ??Æ¡??????ɤò¥¹¥??Ã¥???????Ê¥×¥í¥°??????Þ¤???
  672: @c COMMON
  673: 
  674: @example
  675: (cond-expand
  676:  (gauche.sys.symlink
  677:    ... code that uses sys-symlink ...)
  678:  (else
  679:    ... alternative code ...)
  680:  )
  681: @end example
  682: 
  683: @c EN
  684: If you're familiar with system programming in C, you can think
  685: it equivalent to the following C idiom:
  686: @c JP
  687: C?Î¥????Æ¥??í¥°???󥰤˾ܤ????ʤ顢???????ɤϰʲ????Î¥??Ç¥???????????Ȥߤʤ??Þ¤???
  688: @c COMMON
  689: 
  690: @example
  691: #if defined(HAVE_SYMLINK)
  692: ... code that uses symlink ...
  693: #else
  694: ... alternative code ...
  695: #endif
  696: @end example
  697: 
  698: @c EN
  699: There are quite a few such feature identifiers; each identifier is
  700: explained in the maunal entry of the procedures that depend on the feature.
  701: Here we list a few important ones:
  702: @c JP
  703: ???Τ褦?ʵ?ǽ????ҤϤ??????󤢤ꡢ???줾??????ҤˤĤ??ƤϤ??Υޥ˥?????Τ??ε?ǽ?˰???????????ι???????Ƥ??ޤ?????˽?פʤ?
  704: ????˥ꥹ?ȥ??åפ??Ƥ????ޤ???
  705: @c COMMON
  706: 
  707: @table @code
  708: @item gauche
  709: @c EN
  710: This feature identifier is always defined.  It is useful when you
  711: write Scheme code portable across multiple implementations.
  712: @c JP
  713: ???ε?ǽ????ҤϾ??????????ޤ???Gauche?ʳ???cheme?μ?????
  714: ??Τ??륳???ɤ???Ȥ??˻Ȥ??ޤ???
  715: @c COMMON
  716: @item gauche.os.windows
  717: @c EN
  718: Defined on Windows native platform (currently using MinGW, but we'll
  719: have VC++ version in future).  Note that cygwin is considered unix.
  720: @c JP
  721: Windows?ͥ??ƥ??֥ץ??ȥե???????????????(??????Ǥϡ?MinGW???äƤ??ޤ????????VC++??򥵥ݡ??Ȥ?????Ǥ???) cygwin??NIX?Ȥߤ??????Ȥ?????Ƥ????????
  722: @c COMMON
  723: @item gauche.sys.pthreads
  724: @c EN
  725: Defined if Gauche is compiled with pthread support.
  726: @c JP
  727: Gauche??pthread?򥵥ݡ??Ȥ??????˥?????뤵??????????????????
  728: @c COMMON
  729: @item gauche.net.ipv6
  730: @c EN
  731: Defined if Gauche is compiled with IPv6 support.
  732: @c JP
  733: Gauche??IPv6?򥵥ݡ??Ȥ??????˥?????뤵??????????????????
  734: @c COMMON
  735: @end table
  736: 
  737: @c EN
  738: Because @code{cond-expand} is a macro, the body of clauses
  739: are expanded into toplevel if @code{cond-expand} itself is in
  740: toplevel.  That means you can switch toplevel definitions:
  741: @c JP
  742: @code{cond-expand}?ϥޥ????Τǡ?@code{cond-expand}???Ȥ??ȥåץ???ˤ?????????Τϥȥåץ???Ÿ???????????????ȥåץ????
  743: ??򥹥??å?Ǥ??????????ȤǤ???
  744: @c COMMON
  745: 
  746: @example
  747: (cond-expand
  748:  (gauche.os.windows
  749:   (define (get-current-user)
  750:     ... get current username ...))
  751:  (else
  752:   (define (get-current-user)
  753:     (sys-uid->user-name (sys-getuid)))))
  754: @end example
  755: 
  756: @c EN
  757: Or even conditionally "use" the modules:
  758: @c JP
  759: ???뤤?Ͼ?ˤ??ƥ⥸?塼???Ȥ??櫓???ޤ???
  760: @c COMMON
  761: 
  762: @example
  763: (cond-expand
  764:  (gauche.os.windows
  765:    (use "my-windows-compatibility-module"))
  766:  (else))
  767: @end example
  768: 
  769: