<li><a href="#EXAMPLES">EXAMPLES</a></li>
<li><a href="#OPTIONS---OVERVIEW">OPTIONS - OVERVIEW</a>
<ul>
- <li><a href="#I-O-control">I/O control</a></li>
+ <li><a href="#I-O-Control">I/O Control</a></li>
</ul>
</li>
<li><a href="#FORMATTING-OPTIONS">FORMATTING OPTIONS</a>
<li><a href="#Comment-Controls">Comment Controls</a></li>
<li><a href="#Skipping-Selected-Sections-of-Code">Skipping Selected Sections of Code</a></li>
<li><a href="#Line-Break-Control">Line Break Control</a></li>
+ <li><a href="#Controlling-Breaks-at-Braces-Parens-and-Square-Brackets">Controlling Breaks at Braces, Parens, and Square Brackets</a></li>
+ <li><a href="#Welding">Welding</a></li>
+ <li><a href="#Breaking-Before-or-After-Operators">Breaking Before or After Operators</a></li>
<li><a href="#Controlling-List-Formatting">Controlling List Formatting</a></li>
+ <li><a href="#Adding-and-Deleting-Commas">Adding and Deleting Commas</a></li>
<li><a href="#Retaining-or-Ignoring-Existing-Line-Breaks">Retaining or Ignoring Existing Line Breaks</a></li>
<li><a href="#Blank-Line-Control">Blank Line Control</a></li>
<li><a href="#Styles">Styles</a></li>
+ <li><a href="#One-Line-Blocks">One-Line Blocks</a></li>
<li><a href="#Controlling-Vertical-Alignment">Controlling Vertical Alignment</a></li>
+ <li><a href="#Extended-Syntax">Extended Syntax</a></li>
<li><a href="#Other-Controls">Other Controls</a></li>
</ul>
</li>
<h1 id="DESCRIPTION">DESCRIPTION</h1>
-<p>Perltidy reads a perl script and writes an indented, reformatted script. This document describes the parameters available for controlling this formatting.</p>
+<p>Perltidy reads a perl script and writes an indented, reformatted script. The formatting process involves converting the script into a string of tokens, removing any non-essential whitespace, and then rewriting the string of tokens with whitespace using whatever rules are specified, or defaults. This happens in a series of operations which can be controlled with the parameters described in this document.</p>
<p>Perltidy is a commandline frontend to the module Perl::Tidy. For documentation describing how to call the Perl::Tidy module from other applications see the separate documentation for Perl::Tidy. It is the file Perl::Tidy.pod in the source distribution.</p>
<p>Option names may be terminated early as long as they are uniquely identified. For example, instead of <b>--dump-token-types</b>, it would be sufficient to enter <b>--dump-tok</b>, or even <b>--dump-t</b>, to uniquely identify this command.</p>
-<h2 id="I-O-control">I/O control</h2>
+<h2 id="I-O-Control">I/O Control</h2>
<p>The following parameters concern the files which are read and written.</p>
<p>Modify the input file or files in-place and save the original with the extension <i>.bak</i>. Any existing <i>.bak</i> file will be deleted. See next item for changing the default backup extension, and for eliminating the backup file altogether.</p>
+<p><b>Please Note</b>: Writing back to the input file increases the risk of data loss or corruption in the event of a software or hardware malfunction. Before using the <b>-b</b> parameter please be sure to have backups and verify that it works correctly in your environment and operating system.</p>
+
<p>A <b>-b</b> flag will be ignored if input is from standard input or goes to standard output, or if the <b>-html</b> flag is set.</p>
<p>In particular, if you want to use both the <b>-b</b> flag and the <b>-pbp</b> (--perl-best-practices) flag, then you must put a <b>-nst</b> flag after the <b>-pbp</b> flag because it contains a <b>-st</b> flag as one of its components, which means that output will go to the standard output stream.</p>
<-bext='/backup'> F<.backup> Delete if no errors
<-bext='original/'> F<.original> Delete if no errors</code></pre>
+</dd>
+<dt id="bm-s---backup-method-s"><b>-bm=s</b>, <b>--backup-method=s</b></dt>
+<dd>
+
+<p>This parameter should not normally be used but is available in the event that problems arise as a transition is made from an older implementation of the backup logic to a newer implementation. The newer implementation is the default and is specified with <b>-bm='copy'</b>. The older implementation is specified with <b>-bm='move'</b>. The difference is that the older implementation made the backup by moving the input file to the backup file, and the newer implementation makes the backup by copying the input file. The newer implementation preserves the file system <b>inode</b> value. This may avoid problems with other software running simultaneously. This change was made as part of issue <b>git #103</b> at github.</p>
+
</dd>
<dt id="w---warning-output"><b>-w</b>, <b>--warning-output</b></dt>
<dd>
<p>This flag asserts that the input and output code streams are different, or in other words that the input code is 'untidy' according to the formatting parameters. If this is not the case, an error message noting this is produced. This flag has no other effect on the functioning of perltidy.</p>
-</dd>
-<dt id="sal-s---sub-alias-list-s"><b>-sal=s</b>, <b>--sub-alias-list=s</b></dt>
-<dd>
-
-<p>This flag causes one or more words to be treated the same as if they were the keyword 'sub'. The string <b>s</b> contains one or more alias words, separated by spaces or commas.</p>
-
-<p>For example,</p>
-
-<pre><code> perltidy -sal='method fun _sub M4'</code></pre>
-
-<p>will cause the perltidy to treat the words 'method', 'fun', '_sub' and 'M4' the same as if they were 'sub'. Note that if the alias words are separated by spaces then the string of words should be placed in quotes.</p>
-
-<p>Note that several other parameters accept a list of keywords, including 'sub' (see <a href="#Specifying-Block-Types">"Specifying Block Types"</a>). You do not need to include any sub aliases in these lists. Just include keyword 'sub' if you wish, and all aliases are automatically included.</p>
-
-</dd>
-<dt id="gal-s---grep-alias-list-s"><b>-gal=s</b>, <b>--grep-alias-list=s</b></dt>
-<dd>
-
-<p>This flag allows a code block following an external 'list operator' function to be formatted as if it followed one of the built-in keywords <b>grep</b>, <b>map</b> or <b>sort</b>. The string <b>s</b> contains the names of one or more such list operators, separated by spaces or commas.</p>
-
-<p>By 'list operator' is meant a function which is invoked in the form</p>
-
-<pre><code> word {BLOCK} @list</code></pre>
-
-<p>Perltidy tries to keep code blocks for these functions intact, since they are usually short, and does not automatically break after the closing brace since a list may follow. It also does some special handling of continuation indentation.</p>
-
-<p>For example, the code block arguments to functions 'My_grep' and 'My_map' can be given formatting like 'grep' with</p>
-
-<pre><code> perltidy -gal='My_grep My_map'</code></pre>
-
-<p>By default, the following list operators in List::Util are automatically included:</p>
-
-<pre><code> all any first none notall reduce reductions</code></pre>
-
-<p>Any operators specified with <b>--grep-alias-list</b> are added to this list. The next parameter can be used to remove words from this default list.</p>
-
-</dd>
-<dt id="gaxl-s---grep-alias-exclusion-list-s"><b>-gaxl=s</b>, <b>--grep-alias-exclusion-list=s</b></dt>
-<dd>
-
-<p>The <b>-gaxl=s</b> flag provides a method for removing any of the default list operators given above by listing them in the string <b>s</b>. To remove all of the default operators use <b>-gaxl='*'</b>.</p>
-
</dd>
</dl>
</dd>
</dl>
-</dd>
-<dt id="xs---extended-syntax"><b>-xs</b>, <b>--extended-syntax</b></dt>
-<dd>
-
-<p>A problem with formatting Perl code is that some modules can introduce new syntax. This flag allows perltidy to handle certain common extensions to the standard syntax without complaint.</p>
-
-<p>For example, without this flag a structure such as the following would generate a syntax error and the braces would not be balanced:</p>
-
-<pre><code> method deposit( Num $amount) {
- $self->balance( $self->balance + $amount );
- }</code></pre>
-
-<p>For one of the extensions, module Switch::Plain, colons are marked as labels. If you use this module, you may want to also use the <b>--nooutdent-labels</b> flag to prevent lines such as 'default:' from being outdented.</p>
-
-<p>This flag is enabled by default but it can be deactivated with <b>-nxs</b>. Probably the only reason to deactivate this flag is to generate more diagnostic messages when debugging a script.</p>
-
-<p>For another method of handling extended syntax see the section <a href="#Skipping-Selected-Sections-of-Code">"Skipping Selected Sections of Code"</a>.</p>
-
</dd>
<dt id="io---indent-only"><b>-io</b>, <b>--indent-only</b></dt>
<dd>
fixit($i);
}</code></pre>
-<p>Use <b>-nola</b> to not outdent labels. To control line breaks after labels see <a href="#bal-n---break-after-labels-n">"bal=n, --break-after-labels=n"</a>.</p>
+<p>Use <b>-nola</b> to not outdent labels. To control line breaks after labels see <a href="#bal-n---break-after-labels-n">"-bal=n, --break-after-labels=n"</a>.</p>
</dd>
<dt id="Outdenting-Keywords"><b>Outdenting Keywords</b></dt>
<p>You will probably also want to use the flag <b>-skp</b> (previous item) too.</p>
-<p>The reason this is not recommended is that spacing a function paren can make a program vulnerable to parsing problems by Perl. For example, the following two-line program will run as written but will have a syntax error if reformatted with -sfp:</p>
+<p>The parameter is not recommended because spacing a function paren can make a program vulnerable to parsing problems by Perl. For example, the following two-line program will run as written but will have a syntax error if reformatted with -sfp:</p>
<pre><code> if ( -e filename() ) { print "I'm here\n"; }
sub filename { return $0 }</code></pre>
<h2 id="Line-Break-Control">Line Break Control</h2>
-<p>The parameters in this
section control breaks after non-blank lines of code. Blank lines are controlled separately by parameters in the section <a href="#Blank-Line-Control">"Blank Line Control"</a>.</p>
+<p>The parameters in this
and the next sections control breaks after non-blank lines of code. Blank lines are controlled separately by parameters in the section <a href="#Blank-Line-Control">"Blank Line Control"</a>.</p>
<dl>
+<dt id="dnl---delete-old-newlines"><b>-dnl</b>, <b>--delete-old-newlines</b></dt>
+<dd>
+
+<p>By default, perltidy first deletes all old line break locations, and then it looks for good break points to match the desired line length. Use <b>-ndnl</b> or <b>--nodelete-old-newlines</b> to force perltidy to retain all old line break points.</p>
+
+</dd>
+<dt id="anl---add-newlines"><b>-anl</b>, <b>--add-newlines</b></dt>
+<dd>
+
+<p>By default, perltidy will add line breaks when necessary to create continuations of long lines and to improve the script appearance. Use <b>-nanl</b> or <b>--noadd-newlines</b> to prevent any new line breaks.</p>
+
+<p>This flag does not prevent perltidy from eliminating existing line breaks; see <b>--freeze-newlines</b> to completely prevent changes to line break points.</p>
+
+</dd>
<dt id="fnl---freeze-newlines"><b>-fnl</b>, <b>--freeze-newlines</b></dt>
<dd>
<p>Note: If you also want to keep your blank lines exactly as they are, you can use the <b>-fbl</b> flag which is described in the section <a href="#Blank-Line-Control">"Blank Line Control"</a>.</p>
</dd>
+</dl>
+
+<h2 id="Controlling-Breaks-at-Braces-Parens-and-Square-Brackets">Controlling Breaks at Braces, Parens, and Square Brackets</h2>
+
+<dl>
+
<dt id="ce---cuddled-else"><b>-ce</b>, <b>--cuddled-else</b></dt>
<dd>
<dt id="cblx---cuddled-block-list-exclusive"><b>-cblx</b>, <b>--cuddled-block-list-exclusive</b></dt>
<dd>
-<p>When cuddled else formatting is selected with <b>-ce</b>, setting this flag causes perltidy to ignore its built-in defaults and rely exclusively on the block types specified on the <b>-cbl</b> flag described in the previous section. For example, to avoid using cuddled <b>catch</b> and <b>finally</b>, which among in the defaults, the following set of parameters could be used:</p>
+<p>When cuddled else formatting is selected with <b>-ce</b>, setting this flag causes perltidy to ignore its built-in defaults and rely exclusively on the block types specified on the <b>-cbl</b> flag described in the previous section. For example, to avoid using cuddled <b>catch</b> and <b>finally</b>, which are among the defaults, the following set of parameters could be used:</p>
<pre><code> perltidy -ce -cbl='else elsif continue' -cblx</code></pre>
-bbpi=2 indent one full indentation level</code></pre>
</dd>
+</dl>
+
+<h2 id="Welding">Welding</h2>
+
+<dl>
+
<dt id="wn---weld-nested-containers"><b>-wn</b>, <b>--weld-nested-containers</b></dt>
<dd>
next if $x == $y;
} } until $x++ > $z;</code></pre>
-<p>When this flag is set perltidy makes a preliminary pass through the file and identifies all nested pairs of containers. To qualify as a nested pair, the closing container symbols must be immediately adjacent and the opening symbols must either (1) be adjacent as in the above example, or (2) have an anonymous sub declaration following an outer opening container symbol which is not a code block brace, or (3) have an outer opening paren separated from the inner opening symbol by any single non-container symbol or something that looks like a function evaluation, as illustrated in the next examples.</p>
+<p>When this flag is set perltidy makes a preliminary pass through the file and identifies all nested pairs of containers. To qualify as a nested pair, the closing container symbols must be immediately adjacent and the opening symbols must either (1) be adjacent as in the above example, or (2) have an anonymous sub declaration following an outer opening container symbol which is not a code block brace, or (3) have an outer opening paren separated from the inner opening symbol by any single non-container symbol or something that looks like a function evaluation, as illustrated in the next examples. An additional option (4) which can be turned on with the flag <b>--weld-fat-comma</b> is when the opening container symbols are separated by a hash key and fat comma (=>).</p>
<p>Any container symbol may serve as both the inner container of one pair and as the outer container of an adjacent pair. Consequently, any number of adjacent opening or closing symbols may join together in weld. For example, here are three levels of wrapped function calls:</p>
<p>Finally, the stacking of containers defined by this flag have priority over any other container stacking flags. This is because any welding is done first.</p>
+</dd>
+<dt id="wfc---weld-fat-comma"><b>-wfc</b>, <b>--weld-fat-comma </b></dt>
+<dd>
+
+<p>When the <b>-wfc</b> flag is set, along with <b>-wn</b>, perltidy is allowed to weld an opening paren to an inner opening container when they are separated by a hash key and fat comma (=>). for example</p>
+
+<pre><code> # perltidy -wn -wfc
+ elf->call_method( method_name_foo => {
+ some_arg1 => $foo,
+ some_other_arg3 => $bar->{'baz'},
+ } );</code></pre>
+
+<p>This option is off by default.</p>
+
</dd>
<dt id="wnxl-s---weld-nested-exclusion-list"><b>-wnxl=s</b>, <b>--weld-nested-exclusion-list</b></dt>
<dd>
<pre><code> -wnxl='[ { q'</code></pre>
-<p>means do <b>NOT</b> include square-bracets, braces, or quotes in any welds. The only unspecified container is '(', so this string means that only welds involving parens will be made.</p>
+<p>means do <b>NOT</b> include square-brackets, braces, or quotes in any welds. The only unspecified container is '(', so this string means that only welds involving parens will be made.</p>
<p>To illustrate, following welded snippet consists of a chain of three welded containers with types '(' '[' and 'q':</p>
<p>Please note that if both opening and closing tokens are to be stacked, then the newer flag <b>-weld-nested-containers</b> may be preferable because it insures that stacking is always done symmetrically. It also removes an extra level of unnecessary indentation within welded containers. It is able to do this because it works on formatting globally rather than locally, as the <b>-sot</b> and <b>-sct</b> flags do.</p>
</dd>
-<dt id="dnl---delete-old-newlines"><b>-dnl</b>, <b>--delete-old-newlines</b></dt>
-<dd>
-
-<p>By default, perltidy first deletes all old line break locations, and then it looks for good break points to match the desired line length. Use <b>-ndnl</b> or <b>--nodelete-old-newlines</b> to force perltidy to retain all old line break points.</p>
-
-</dd>
-<dt id="anl---add-newlines"><b>-anl</b>, <b>--add-newlines</b></dt>
-<dd>
-
-<p>By default, perltidy will add line breaks when necessary to create continuations of long lines and to improve the script appearance. Use <b>-nanl</b> or <b>--noadd-newlines</b> to prevent any new line breaks.</p>
-
-<p>This flag does not prevent perltidy from eliminating existing line breaks; see <b>--freeze-newlines</b> to completely prevent changes to line break points.</p>
+</dl>
-</dd>
-<dt id="Controlling-whether-perltidy-breaks-before-or-after-operators"><b>Controlling whether perltidy breaks before or after operators</b></dt>
-<dd>
+<h2 id="Breaking-Before-or-After-Operators">Breaking Before or After Operators</h2>
<p>Four command line parameters provide some control over whether a line break should be before or after specific token types. Two parameters give detailed control:</p>
<p>and the <b>-bbao</b> flag sets the default to break before all of these operators. These can be used to define an initial break preference which can be fine-tuned with the <b>-wba</b> and <b>-wbb</b> flags. For example, to break before all operators except an <b>=</b> one could use --bbao -wba='=' rather than listing every single perl operator except <b>=</b> on a -wbb flag.</p>
-</dd>
-<dt id="bal-n---break-after-labels-n"><b>bal=n, --break-after-labels=n</b></dt>
+<dl>
+
+<dt id="bal-n---break-after-labels-n"><b>-bal=n, --break-after-labels=n</b></dt>
<dd>
<p>This flag controls whether or not a line break occurs after a label. There are three possible values for <b>n</b>:</p>
<dt id="mft-n---maximum-fields-per-table-n"><b>-mft=n</b>, <b>--maximum-fields-per-table=n</b></dt>
<dd>
-<p>If the computed number of fields for any table exceeds <b>n</b>, then it will be reduced to <b>n</b>. The default value for <b>n</b> is a large number, 40. While this value should probably be left unchanged as a general rule, it might be used on a small section of code to force a list to have a particular number of fields per line, and then either the <b>-boc</b> flag could be used to retain this formatting, or a single comment could be introduced somewhere to freeze the formatting in future applications of perltidy.</p>
+<p>If <b>n</b> is a positive number, and the computed number of fields for any table exceeds <b>n</b>, then it will be reduced to <b>n</b>. This parameter might be used on a small section of code to force a list to have a particular number of fields per line, and then either the <b>-boc</b> flag could be used to retain this formatting, or a single comment could be introduced somewhere to freeze the formatting in future applications of perltidy. For example</p>
<pre><code> # perltidy -mft=2
@month_of_year = (
'Nov', 'Dec'
);</code></pre>
+<p>The default value is <b>n=0</b>, which does not place a limit on the number of fields in a table.</p>
+
</dd>
<dt id="cab-n---comma-arrow-breakpoints-n"><b>-cab=n</b>, <b>--comma-arrow-breakpoints=n</b></dt>
<dd>
</dd>
</dl>
+<h2 id="Adding-and-Deleting-Commas">Adding and Deleting Commas</h2>
+
+<dl>
+
+<dt id="drc---delete-repeated-commas"><b>-drc</b>, <b>--delete-repeated-commas</b></dt>
+<dd>
+
+<p>Repeated commas in a list are undesirable and can be removed with this flag. For example, given this list with a repeated comma</p>
+
+<pre><code> ignoreSpec( $file, "file",, \%spec, \%Rspec );</code></pre>
+
+<p>we can remove it with -drc</p>
+
+<pre><code> # perltidy -drc:
+ ignoreSpec( $file, "file", \%spec, \%Rspec );</code></pre>
+
+<p>Since the default is not to add or delete commas, this feature is off by default and must be requested.</p>
+
+</dd>
+<dt id="want-trailing-commas-s-or--wtc-s---add-trailing-commas-or--atc-and---delete-trailing-commas-or--dtc"><b>--want-trailing-commas=s</b> or <b>-wtc=s</b>, <b>--add-trailing-commas</b> or <b>-atc</b>, and <b>--delete-trailing-commas</b> or <b>-dtc</b></dt>
+<dd>
+
+<p>A trailing comma is a comma following the last item of a list. Perl allows trailing commas but they are not required. By default, perltidy does not add or delete trailing commas, but it is possible to manipulate them with the following set of three related parameters:</p>
+
+<pre><code> --want-trailing-commas=s, -wtc=s - defines where trailing commas are wanted
+ --add-trailing-commas, -atc - gives permission to add trailing commas to match the style wanted
+ --delete-trailing-commas, -dtc - gives permission to delete trailing commas which do not match the style wanted</code></pre>
+
+<p>The parameter <b>--want-trailing-commas=s</b>, or <b>-wtc=s</b>, defines a preferred style. The string <b>s</b> indicates which lists should get trailing commas, as follows:</p>
+
+<pre><code> s=0 : no list should have a trailing comma
+ s=1 or * : every list should have a trailing comma
+ s=m a multi-line list should have a trailing commas
+ s=b trailing commas should be 'bare' (comma followed by newline)
+ s=h lists of key=>value pairs, with about one one '=>' and one ',' per line,
+ with a bare trailing comma
+ s=i lists with about one comma per line, with a bare trailing comma
+ s=' ' or -wtc not defined : leave trailing commas unchanged [DEFAULT].</code></pre>
+
+<p>This parameter by itself only indicates the where trailing commas are wanted. Perltidy only adds these trailing commas if the flag <b>--add-trailing-commas</b>, or <b>-atc</b> is set. And perltidy only removes unwanted trailing commas if the flag <b>--delete-trailing-commas</b>, or <b>-dtc</b> is set.</p>
+
+<p>Here are some example parameter combinations and their meanings</p>
+
+<pre><code> -wtc=0 -dtc : delete all trailing commas
+ -wtc=1 -atc : all lists get trailing commas
+ -wtc=m -atc : all multi-line lists get trailing commas, but
+ single line lists remain unchanged.
+ -wtc=m -dtc : multi-line lists remain unchanged, but
+ any trailing commas on single line lists are removed.
+ -wtc=m -atc -dtc : all multi-line lists get trailing commas, and
+ any trailing commas on single line lists are removed.</code></pre>
+
+<p>For example, given the following input without a trailing comma</p>
+
+<pre><code> bless {
+ B => $B,
+ Root => $Root
+ } => $package;</code></pre>
+
+<p>we can add a trailing comma after the variable <code>$Root</code> using</p>
+
+<pre><code> # perltidy -wtc=m -atc
+ bless {
+ B => $B,
+ Root => $Root,
+ } => $package;</code></pre>
+
+<p>This could also be achieved in this case with <b>-wtc=b</b> instead of <b>-wtc=m</b> because the trailing comma here is bare (separated from its closing brace by a newline). And it could also be achieved with <b>-wtc=h</b> because this particular list is a list of key=>value pairs.</p>
+
+<p>The above styles should cover the main of situations of interest, but it is possible to apply a different style to each type of container token by including an opening token ahead of the style character in the above table. For example</p>
+
+<pre><code> -wtc='(m [b'</code></pre>
+
+<p>means that lists within parens should have multi-line trailing commas, and that lists within square brackets have bare trailing commas. Since there is no specification for curly braces in this example, their trailing commas would remain unchanged.</p>
+
+<p>For parentheses, an additional item of information which can be given is an alphanumeric letter which is used to limit the selection further depending on the type of token immediately before the opening paren. The possible letters are currently 'k', 'K', 'f', 'F', 'w', and 'W', with these meanings for matching whatever precedes an opening paren:</p>
+
+<pre><code> 'k' matches if the previous nonblank token is a perl built-in keyword (such as 'if', 'while'),
+ 'K' matches if 'k' does not, meaning that the previous token is not a keyword.
+ 'f' matches if the previous token is a function other than a keyword.
+ 'F' matches if 'f' does not.
+ 'w' matches if either 'k' or 'f' match.
+ 'W' matches if 'w' does not.</code></pre>
+
+<p>These are the same codes used for <b>--line-up-parentheses-inclusion-list</b>. For example,</p>
+
+<pre><code> -wtc = 'w(m'</code></pre>
+
+<p>means that trailing commas are wanted for multi-line parenthesized lists following a function call or keyword.</p>
+
+<p>Here are some points to note regarding adding and deleting trailing commas:</p>
+
+<ul>
+
+<li><p>For the implementation of these parameters, a <b>list</b> is basically taken to be a container of items (parens, square brackets, or braces), which is not a code block, with one or more commas. These parameters only apply to something that fits this definition of a list.</p>
+
+<p>Note that a paren-less list of parameters is not a list by this definition, so these parameters have no effect on a peren-less list.</p>
+
+<p>Another consequence is that if the only comma in a list is deleted, then it cannot later be added back with these parameters because the container no longer fits this definition of a list. For example, given</p>
+
+<pre><code> my ( $self, ) = @_;</code></pre>
+
+<p>and if we remove the comma with</p>
+
+<pre><code> # perltidy -wtc=m -dtc
+ my ( $self ) = @_;</code></pre>
+
+<p>then we cannot use these trailing comma controls to add this comma back.</p>
+
+</li>
+<li><p>By <b>multiline</b> list is meant a list for which the first comma and trailing comma are on different lines.</p>
+
+</li>
+<li><p>A <b>bare</b> trailing comma is a comma which is at the end of a line. That is, the closing container token follows on a different line. So a list with a bare trailing comma is a special case of a multi-line list.</p>
+
+</li>
+<li><p>The decision regarding whether or not a list is multi-line or bare is made based on the <b>input</b> stream. In some cases it may take an iteration or two to reach a final state.</p>
+
+</li>
+<li><p>When using these parameters for the first time it is a good idea to practice on some test scripts and verify that the results are as expected.</p>
+
+</li>
+<li><p>Since the default behavior is not to add or delete commas, these parameters can be useful on a temporary basis for reformatting a script.</p>
+
+</li>
+</ul>
+
+</dd>
+<dt id="dwic---delete-weld-interfering-commas"><b>-dwic</b>, <b>--delete-weld-interfering-commas</b></dt>
+<dd>
+
+<p>If the closing tokens of two nested containers are separated by a comma, then welding requested with <b>--weld-nested-containers</b> cannot occur. Any commas in this situation are optional trailing commas and can be removed with <b>-dwic</b>. For example, a comma in this script prevents welding:</p>
+
+<pre><code> # perltidy -wn
+ skip_symbols(
+ [ qw(
+ Perl_dump_fds
+ Perl_ErrorNo
+ Perl_GetVars
+ PL_sys_intern
+ ) ],
+ );</code></pre>
+
+<p>Using <b>-dwic</b> removes the comma and allows welding:</p>
+
+<pre><code> # perltidy -wn -dwic
+ skip_symbols( [ qw(
+ Perl_dump_fds
+ Perl_ErrorNo
+ Perl_GetVars
+ PL_sys_intern
+ ) ] );</code></pre>
+
+<p>Since the default is not to add or delete commas, this feature is off by default. Here are some points to note about the <b>-dwic</b> parameter</p>
+
+<ul>
+
+<li><p>This operation is not reversible, so please check results of using this parameter carefully.</p>
+
+</li>
+<li><p>Removing this type of isolated trailing comma is necessary for welding to be possible, but not sufficient. So welding will not always occur where these commas are removed.</p>
+
+</li>
+</ul>
+
+</dd>
+</dl>
+
<h2 id="Retaining-or-Ignoring-Existing-Line-Breaks">Retaining or Ignoring Existing Line Breaks</h2>
<p>Several additional parameters are available for controlling the extent to which line breaks in the input script influence the output script. In most cases, the default parameter values are set so that, if a choice is possible, the output style follows the input style. For example, if a short logical container is broken in the input script, then the default behavior is for it to remain broken in the output script.</p>
<dt id="bom---break-at-old-method-breakpoints"><b>-bom</b>, <b>--break-at-old-method-breakpoints</b></dt>
<dd>
-<p>By default, a method call arrow <code>-></code> is considered a candidate for a breakpoint, but method chains will fill to the line width before a break is considered. With <b>-bom</b>, breaks before the arrow are preserved, so if you have preformatted a method chain:</p>
+<p>By default, a method call arrow <code>-></code> is considered a candidate for a breakpoint, but method chains will fill to the line width before a break is considered. With <b>-bom</b>, breaks before the arrow are preserved, so if you have pre-formatted a method chain:</p>
<pre><code> my $q = $rs
->related_resultset('CDs')
<p>Please note that this parameter set includes -st and -se flags, which make perltidy act as a filter on one file only. These can be overridden by placing <b>-nst</b> and/or <b>-nse</b> after the -pbp parameter.</p>
-<p>Also note that the value of continuation indentation, -ci=4, is equal to the value of the full indentation, -i=4. It is recommended that the either (1) the parameter <b>-ci=2</b> be used instead, or the flag <b>-xci</b> be set. This will help show structure, particularly when there are ternary statements. The following snippet illustrates these options.</p>
+<p>Also note that the value of continuation indentation, -ci=4, is equal to the value of the full indentation, -i=4. It is recommended that the either (1) the parameter <b>-ci=2</b> be used instead, or (2) the flag <b>-xci</b> be set. This will help show structure, particularly when there are ternary statements. The following snippet illustrates these options.</p>
<pre><code> # perltidy -pbp
$self->{_text} = (
<p>The <b>-xci</b> flag was developed after the <b>-pbp</b> parameters were published so you need to include it separately.</p>
</dd>
-<dt id="One-line-blocks"><b>One-line blocks</b></dt>
-<dd>
+</dl>
-<p>There are a few points to note regarding one-line blocks. A one-line block is something like this,</p>
+<h2 id="One-Line-Blocks">One-Line Blocks</h2>
+
+<p>A one-line block is a block of code where the contents within the curly braces is short enough to fit on a single line. For example,</p>
<pre><code> if ( -e $file ) { print "'$file' exists\n" }</code></pre>
-<p>where the contents within the curly braces is short enough to fit on a single line.</p>
+<p>The alternative, a block which spans multiple lines, is said to be a broken block. With few exceptions, perltidy retains existing one-line blocks, if it is possible within the line-length constraint, but it does not attempt to form new ones. In other words, perltidy will try to follow the input file regarding broken and unbroken blocks.</p>
+
+<p>The main exception to this rule is that perltidy will attempt to form new one-line blocks following the keywords <code>map</code>, <code>eval</code>, and <code>sort</code>, <code>eval</code>, because these code blocks are often small and most clearly displayed in a single line. This behavior can be controlled with the flag <b>--one-line-block-exclusion-list</b> described below.</p>
-<p>With few exceptions, perltidy retains existing one-line blocks, if it is possible within the line-length constraint, but it does not attempt to form new ones. In other words, perltidy will try to follow the one-line block style of the input file.</p>
+<p>When the <b>cuddled-else</b> style is used, the default treatment of one-line blocks may interfere with the cuddled style. In this case, the default behavior may be changed with the flag <b>--cuddled-break-option=n</b> described elsehwere.</p>
-<p>If an existing one-line block is longer than the maximum line length, however, it will be broken into multiple lines. When this happens, perltidy checks for and adds any optional terminating semicolon (unless the <b>-nasc</b> option is used) if the block is a code block.</p>
+<p>When an existing one-line block is longer than the maximum line length, and must therefore be broken into multiple lines, perltidy checks for and adds any optional terminating semicolon (unless the <b>-nasc</b> option is used) if the block is a code block.</p>
-<p>The main exception is that perltidy will attempt to form new one-line blocks following the keywords <code>map</code>, <code>eval</code>, and <code>sort</code>, because these code blocks are often small and most clearly displayed in a single line.</p>
+<dl>
-<p>One-line block rules can conflict with the cuddled-else option. When the cuddled-else option is used, perltidy retains existing one-line blocks, even if they do not obey cuddled-else formatting.</p>
+<dt id="olbxl-s---one-line-block-exclusion-list-s"><b>-olbxl=s</b>, <b>--one-line-block-exclusion-list=s</b></dt>
+<dd>
-<p>Occasionally, when one-line blocks get broken because they exceed the available line length, the formatting will violate the requested brace style. If this happens, reformatting the script a second time should correct the problem.</p>
+<p>As noted above, perltidy will, by default, attempt to create new one-line blocks for certain block types. This flag allows the user to prevent this behavior for the block types listed in the string <b>s</b>. The list <b>s</b> may include any of the words <code>sort</code>, <code>map</code>, <code>grep</code>, <code>eval</code>, or it may be <code>*</code> to indicate all of these.</p>
-<p>Sometimes it might be desirable to convert a script to have one-line blocks whenever possible. Although there is currently no flag for this, a simple workaround is to execute perltidy twice, once with the flag <b>-noadd-newlines</b> and then once again with normal parameters, like this:</p>
+<p>So for example to prevent multi-line <b>eval</b> blocks from becoming one-line blocks, the command would be <b>-olbxl='eval'</b>. In this case, existing one-line <b>eval</b> blocks will remain on one-line if possible, and existing multi-line <b>eval</b> blocks will remain multi-line blocks.</p>
-<pre><code> cat infile | perltidy -nanl | perltidy >outfile</code></pre>
+</dd>
+<dt id="olbn-n---one-line-block-nesting-n"><b>-olbn=n</b>, <b>--one-line-block-nesting=n</b></dt>
+<dd>
-<p>When executed on this snippet</p>
+<p>Nested one-line blocks are lines with code blocks which themselves contain code blocks. For example, the following line is a nested one-line block.</p>
-<pre><code> if ( $? == -1 ) {
- die "failed to execute: $!\n";
- }
- if ( $? == -1 ) {
- print "Had enough.\n";
- die "failed to execute: $!\n";
- }</code></pre>
+<pre><code> foreach (@list) { if ($_ eq $asked_for) { last } ++$found }</code></pre>
-<p>the result is</p>
+<p>The default behavior is to break such lines into multiple lines, but this behavior can be controlled with this flag. The values of n are:</p>
-<pre><code> if ( $? == -1 ) { die "failed to execute: $!\n"; }
- if ( $? == -1 ) {
- print "Had enough.\n";
- die "failed to execute: $!\n";
+<pre><code> n=0 break nested one-line blocks into multiple lines [DEFAULT]
+ n=1 stable: keep existing nested-one line blocks intact</code></pre>
+
+<p>For the above example, the default formatting (<b>-olbn=0</b>) is</p>
+
+<pre><code> foreach (@list) {
+ if ( $_ eq $asked_for ) { last }
+ ++$found;
}</code></pre>
-<p>This shows that blocks with a single statement become one-line blocks.</p>
+<p>If the parameter <b>-olbn=1</b> is given, then the line will be left intact if it is a single line in the source, or it will be broken into multiple lines if it is broken in multiple lines in the source.</p>
</dd>
<dt id="olbs-n---one-line-block-semicolons-n"><b>-olbs=n</b>, <b>--one-line-block-semicolons=n</b></dt>
<p>Note that the <b>n=2</b> option has no effect if adding semicolons is prohibited with the <b>-nasc</b> flag. Also not that while <b>n=2</b> adds missing semicolons to all one-line blocks, regardless of complexity, the <b>n=0</b> option only removes ending semicolons which terminate one-line blocks containing just one semicolon. So these two options are not exact inverses.</p>
</dd>
-<dt id="olbn-n---one-line-block-nesting-n"><b>-olbn=n</b>, <b>--one-line-block-nesting=n</b></dt>
+<dt id="Forming-new-one-line-blocks"><b>Forming new one-line blocks</b></dt>
<dd>
-<p>Nested one-line blocks are lines with code blocks which themselves contain code blocks. For example, the following line is a nested one-line block.</p>
+<p>Sometimes it might be desirable to convert a script to have one-line blocks whenever possible. Although there is currently no flag for this, a simple workaround is to execute perltidy twice, once with the flag <b>-noadd-newlines</b> and then once again with normal parameters, like this:</p>
-<pre><code> foreach (@list) { if ($_ eq $asked_for) { last } ++$found }</code></pre>
+<pre><code> cat infile | perltidy -nanl | perltidy >outfile</code></pre>
-<p>The default behavior is to break such lines into multiple lines, but this behavior can be controlled with this flag. The values of n are:</p>
+<p>When executed on this snippet</p>
-<pre><code> n=0 break nested one-line blocks into multiple lines [DEFAULT]
- n=1 stable: keep existing nested-one line blocks intact</code></pre>
+<pre><code> if ( $? == -1 ) {
+ die "failed to execute: $!\n";
+ }
+ if ( $? == -1 ) {
+ print "Had enough.\n";
+ die "failed to execute: $!\n";
+ }</code></pre>
-<p>For the above example, the default formatting (<b>-olbn=0</b>) is</p>
+<p>the result is</p>
-<pre><code> foreach (@list) {
- if ( $_ eq $asked_for ) { last }
- ++$found;
+<pre><code> if ( $? == -1 ) { die "failed to execute: $!\n"; }
+ if ( $? == -1 ) {
+ print "Had enough.\n";
+ die "failed to execute: $!\n";
}</code></pre>
-<p>If the parameter <b>-olbn=1</b> is given, then the line will be left intact if it is a single line in the source, or it will be broken into multiple lines if it is broken in multiple lines in the source.</p>
+<p>This shows that blocks with a single statement become one-line blocks.</p>
+
+</dd>
+<dt id="Breaking-existing-one-line-blocks"><b>Breaking existing one-line blocks</b></dt>
+<dd>
+
+<p>There is no automatic way to break existing long one-line blocks into multiple lines, but this can be accomplished by processing a script, or section of a script, with a short value of the parameter <b>maximum-line-length=n</b>. Then, when the script is reformatted again with the normal parameters, the blocks which were broken will remain broken (with the exceptions noted above).</p>
+
+<p>Another trick for doing this for certain block types is to format one time with the <b>-cuddled-else</b> flag and <b>--cuddled-break-option=2</b>. Then format again with the normal parameters. This will break any one-line blocks which are involved in a cuddled-else style.</p>
</dd>
</dl>
</dd>
</dl>
+<h2 id="Extended-Syntax">Extended Syntax</h2>
+
+<p>This section describes some parameters for dealing with extended syntax.</p>
+
+<p>For another method of handling extended syntax see the section <a href="#Skipping-Selected-Sections-of-Code">"Skipping Selected Sections of Code"</a>.</p>
+
+<p>Also note that the module <i>Perl::Tidy</i> supplies a pre-filter and post-filter capability. This requires calling the module from a separate program rather than through the binary <i>perltidy</i>.</p>
+
+<dl>
+
+<dt id="xs---extended-syntax"><b>-xs</b>, <b>--extended-syntax</b></dt>
+<dd>
+
+<p>This flag allows perltidy to handle certain common extensions to the standard syntax without complaint.</p>
+
+<p>For example, without this flag a structure such as the following would generate a syntax error:</p>
+
+<pre><code> Method deposit( Num $amount) {
+ $self->balance( $self->balance + $amount );
+ }</code></pre>
+
+<p>This flag is enabled by default but it can be deactivated with <b>-nxs</b>. Probably the only reason to deactivate this flag is to generate more diagnostic messages when debugging a script.</p>
+
+</dd>
+<dt id="sal-s---sub-alias-list-s"><b>-sal=s</b>, <b>--sub-alias-list=s</b></dt>
+<dd>
+
+<p>This flag causes one or more words to be treated the same as if they were the keyword <b>sub</b>. The string <b>s</b> contains one or more alias words, separated by spaces or commas.</p>
+
+<p>For example,</p>
+
+<pre><code> perltidy -sal='method fun _sub M4'</code></pre>
+
+<p>will cause the perltidy to treat the words 'method', 'fun', '_sub' and 'M4' the same as if they were 'sub'. Note that if the alias words are separated by spaces then the string of words should be placed in quotes.</p>
+
+<p>Note that several other parameters accept a list of keywords, including 'sub' (see <a href="#Specifying-Block-Types">"Specifying Block Types"</a>). You do not need to include any sub aliases in these lists. Just include keyword 'sub' if you wish, and all aliases are automatically included.</p>
+
+</dd>
+<dt id="gal-s---grep-alias-list-s"><b>-gal=s</b>, <b>--grep-alias-list=s</b></dt>
+<dd>
+
+<p>This flag allows a code block following an external 'list operator' function to be formatted as if it followed one of the built-in keywords <b>grep</b>, <b>map</b> or <b>sort</b>. The string <b>s</b> contains the names of one or more such list operators, separated by spaces or commas.</p>
+
+<p>By 'list operator' is meant a function which is invoked in the form</p>
+
+<pre><code> word {BLOCK} @list</code></pre>
+
+<p>Perltidy tries to keep code blocks for these functions intact, since they are usually short, and does not automatically break after the closing brace since a list may follow. It also does some special handling of continuation indentation.</p>
+
+<p>For example, the code block arguments to functions 'My_grep' and 'My_map' can be given formatting like 'grep' with</p>
+
+<pre><code> perltidy -gal='My_grep My_map'</code></pre>
+
+<p>By default, the following list operators in List::Util are automatically included:</p>
+
+<pre><code> all any first none notall reduce reductions</code></pre>
+
+<p>Any operators specified with <b>--grep-alias-list</b> are added to this list. The next parameter can be used to remove words from this default list.</p>
+
+</dd>
+<dt id="gaxl-s---grep-alias-exclusion-list-s"><b>-gaxl=s</b>, <b>--grep-alias-exclusion-list=s</b></dt>
+<dd>
+
+<p>The <b>-gaxl=s</b> flag provides a method for removing any of the default list operators given above by listing them in the string <b>s</b>. To remove all of the default operators use <b>-gaxl='*'</b>.</p>
+
+</dd>
+<dt id="uf-s---use-feature-s"><b>-uf=s</b>, <b>--use-feature=s</b></dt>
+<dd>
+
+<p>This flag tells perltidy to allow the syntax associated a pragma in string <b>s</b>. Currently only the recognized values for the string are <b>s='class'</b> or string <b>s=' '</b>. The default is <b>--use-feature='class'</b>. This enables perltidy to recognized the special words <b>class</b>, <b>method</b>, <b>field</b>, and <b>ADJUST</b>. If this causes a conflict with other uses of these words, the default can be turned off with <b>--use-feature=' '</b>.</p>
+
+</dd>
+</dl>
+
<h2 id="Other-Controls">Other Controls</h2>
<dl>
<p><b>-DEBUG</b> will write a file with extension <i>.DEBUG</i> for each input file showing the tokenization of all lines of code.</p>
+</dd>
+<dt id="Making-a-table-of-information-on-code-blocks"><b>Making a table of information on code blocks</b></dt>
+<dd>
+
+<p>A table listing information about the blocks of code in a file can be made with <b>--dump-block-summary</b>, or <b>-dbs</b>. This causes perltidy to read and parse the file, write a table of comma-separated values for selected code blocks to the standard output, and then exit. This parameter must be on the command line, not in a <i>.perlticyrc</i> file, and it requires a single file name on the command line. For example</p>
+
+<pre><code> perltidy -dbs somefile.pl >blocks.csv</code></pre>
+
+<p>produces an output file <i>blocks.csv</i> whose lines hold these parameters:</p>
+
+<pre><code> filename - the name of the file
+ line - the line number of the opening brace of this block
+ line_count - the number of lines between opening and closing braces
+ code_lines - the number of lines excluding blanks, comments, and pod
+ type - the block type (sub, for, foreach, ...)
+ name - the block name if applicable (sub name, label, asub name)
+ depth - the nesting depth of the opening block brace
+ max_change - the change in depth to the most deeply nested code block
+ block_count - the total number of code blocks nested in this block
+ mccabe_count - the McCabe complexity measure of this code block</code></pre>
+
+<p>This feature was developed to help identify complex sections of code as an aid in refactoring. The McCabe complexity measure follows the definition used by Perl::Critic. By default the table contains these values for subroutines, but the user may request them for any or all blocks of code or packages. For blocks which are loops nested within loops, a postfix '+' to the <code>type</code> is added to indicate possible code complexity. Although the table does not otherwise indicate which blocks are nested in other blocks, this can be determined by computing and comparing the block ending line numbers.</p>
+
+<p>By default the table lists subroutines with more than 20 <code>code_lines</code>, but this can be changed with the following two parameters:</p>
+
+<p><b>--dump-block-minimum-lines=n</b>, or <b>-dbl=n</b>, where <b>n</b> is the minimum number of <code>code_lines</code> to be included. The default is <b>-n=20</b>. Note that <code>code_lines</code> is the number of lines excluding and comments, blanks and pod.</p>
+
+<p><b>--dump-block-types=s</b>, or <b>-dbt=s</b>, where string <b>s</b> is a list of block types to be included. The type of a block is either the name of the perl builtin keyword for that block (such as <b>sub if elsif else for foreach ..</b>) or the word immediately before the opening brace. In addition, there are a few symbols for special block types, as follows:</p>
+
+<pre><code> if elsif else for foreach ... any keyword introducing a block
+ sub - any sub or anynomous sub
+ asub - any anonymous sub
+ * - any block except nameless blocks
+ + - any nested inner block loop
+ package - any package or class
+ closure - any nameless block</code></pre>
+
+<p>In addition, specific block loop types which are nested in other loops can be selected by adding a <b>+</b> after the block name. (Nested loops are sometimes good candidates for restructuring).</p>
+
+<p>The default is <b>-dbt='sub'</b>.</p>
+
+<p>In the following examples a table <code>block.csv</code> is created for a file <code>somefile.pl</code>:</p>
+
+<ul>
+
+<li><p>This selects both <code>subs</code> and <code>packages</code> which have 20 or more lines of code. This can be useful in code which contains multiple packages.</p>
+
+<pre><code> perltidy -dbs -dbt='sub package' somefile.pl >blocks.csv</code></pre>
+
+</li>
+<li><p>This selects block types <code>sub for foreach while</code> with 10 or more code lines.</p>
+
+<pre><code> perltidy -dbs -dbl=10 -dbt='sub for foreach while' somefile.pl >blocks.csv</code></pre>
+
+</li>
+<li><p>This selects blocks with 2 or more code lines which are type <code>sub</code> or which are inner loops.</p>
+
+<pre><code> perltidy -dbs -dbl=2 -dbt='sub +' somefile.pl >blocks.csv</code></pre>
+
+</li>
+<li><p>This selects every block and package.</p>
+
+<pre><code> perltidy -dbs -dbl=1 -dbt='* closure' somefile.pl >blocks.csv</code></pre>
+
+</li>
+</ul>
+
</dd>
<dt id="Working-with-MakeMaker-AutoLoader-and-SelfLoader"><b>Working with MakeMaker, AutoLoader and SelfLoader</b></dt>
<dd>
<p>The following list shows all short parameter names which allow a prefix 'n' to produce the negated form:</p>
-<pre><code> D anl asbl asc ast asu atnl aws b baa
- baao bar bbao bbb bbc bbs bl bli boa boc
- bok bol bom bos bot cblx ce conv cs csc
- cscb cscw dac dbc dcbl dcsc ddf dln dnl dop
- dp dpro dsc dsm dsn dtt dwls dwrs dws eos
- f fll fpva frm fs fso gcs hbc hbcm hbco
- hbh hbhh hbi hbj hbk hbm hbn hbp hbpd hbpu
- hbq hbs hbsc hbv hbw hent hic hicm hico hih
- hihh hii hij hik him hin hip hipd hipu hiq
- his hisc hiv hiw hsc html ibc icb icp iob
- isbc iscl kgb kgbd kgbi kis lal log lop lp
- lsl mem nib ohbr okw ola olc oll olq opr
- opt osbc osbr otr ple pod pvl q sac sbc
- sbl scbb schb scp scsb sct se sfp sfs skp
- sob sobb sohb sop sosb sot ssc st sts t
- tac tbc toc tp tqw trp ts tsc tso vbc
- vc vmll vsc w wn x xci xlp xs</code></pre>
+<pre><code> D anl asbl asc ast asu atc atnl aws b
+ baa baao bar bbao bbb bbc bbs bl bli boa
+ boc bok bol bom bos bot cblx ce conv cpb
+ cs csc cscb cscw dac dbc dbs dcbl dcsc ddf
+ dln dnl dop dp dpro drc dsc dsm dsn dtc
+ dtt dwic dwls dwrs dws eos f fll fpva frm
+ fs fso gcs hbc hbcm hbco hbh hbhh hbi hbj
+ hbk hbm hbn hbp hbpd hbpu hbq hbs hbsc hbv
+ hbw hent hic hicm hico hih hihh hii hij hik
+ him hin hip hipd hipu hiq his hisc hiv hiw
+ hsc html ibc icb icp iob isbc iscl kgb kgbd
+ kgbi kis lal log lop lp lsl mem nib ohbr
+ okw ola olc oll olq opr opt osbc osbr otr
+ ple pod pvl q sac sbc sbl scbb schb scp
+ scsb sct se sfp sfs skp sob sobb sohb sop
+ sosb sot ssc st sts t tac tbc toc tp
+ tqw trp ts tsc tso vbc vc vmll vsc w
+ wfc wn x xci xlp xs</code></pre>
<p>Equivalently, the prefix 'no' or 'no-' on the corresponding long names may be used.</p>
<h1 id="VERSION">VERSION</h1>
-<p>This man page documents perltidy version 20220613</p>
+<p>This man page documents perltidy version 20230309</p>
<h1 id="BUG-REPORTS">BUG REPORTS</h1>
projects / perltidy.git / blobdiff