| '\" |
| '\" Copyright (c) 1993-1998 Lucent Technologies, Inc. |
| '\" |
| '\" See the file "license.terms" for information on usage and redistribution |
| '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
| '\" |
| '\" RCS: $Id: ensemble.n,v 1.1 1998/07/27 18:42:00 stanton Exp $ |
| '\" |
| '\" The definitions below are for supplemental macros used in Tcl/Tk |
| '\" manual entries. |
| '\" |
| '\" .AP type name in/out ?indent? |
| '\" Start paragraph describing an argument to a library procedure. |
| '\" type is type of argument (int, etc.), in/out is either "in", "out", |
| '\" or "in/out" to describe whether procedure reads or modifies arg, |
| '\" and indent is equivalent to second arg of .IP (shouldn't ever be |
| '\" needed; use .AS below instead) |
| '\" |
| '\" .AS ?type? ?name? |
| '\" Give maximum sizes of arguments for setting tab stops. Type and |
| '\" name are examples of largest possible arguments that will be passed |
| '\" to .AP later. If args are omitted, default tab stops are used. |
| '\" |
| '\" .BS |
| '\" Start box enclosure. From here until next .BE, everything will be |
| '\" enclosed in one large box. |
| '\" |
| '\" .BE |
| '\" End of box enclosure. |
| '\" |
| '\" .CS |
| '\" Begin code excerpt. |
| '\" |
| '\" .CE |
| '\" End code excerpt. |
| '\" |
| '\" .VS ?version? ?br? |
| '\" Begin vertical sidebar, for use in marking newly-changed parts |
| '\" of man pages. The first argument is ignored and used for recording |
| '\" the version when the .VS was added, so that the sidebars can be |
| '\" found and removed when they reach a certain age. If another argument |
| '\" is present, then a line break is forced before starting the sidebar. |
| '\" |
| '\" .VE |
| '\" End of vertical sidebar. |
| '\" |
| '\" .DS |
| '\" Begin an indented unfilled display. |
| '\" |
| '\" .DE |
| '\" End of indented unfilled display. |
| '\" |
| '\" .SO |
| '\" Start of list of standard options for a Tk widget. The |
| '\" options follow on successive lines, in four columns separated |
| '\" by tabs. |
| '\" |
| '\" .SE |
| '\" End of list of standard options for a Tk widget. |
| '\" |
| '\" .OP cmdName dbName dbClass |
| '\" Start of description of a specific option. cmdName gives the |
| '\" option's name as specified in the class command, dbName gives |
| '\" the option's name in the option database, and dbClass gives |
| '\" the option's class in the option database. |
| '\" |
| '\" .UL arg1 arg2 |
| '\" Print arg1 underlined, then print arg2 normally. |
| '\" |
| '\" SCCS: @(#) man.macros 1.9 97/08/22 18:50:59 |
| '\" |
| '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. |
| .if t .wh -1.3i ^B |
| .nr ^l \n(.l |
| .ad b |
| '\" # Start an argument description |
| .de AP |
| .ie !"\\$4"" .TP \\$4 |
| .el \{\ |
| . ie !"\\$2"" .TP \\n()Cu |
| . el .TP 15 |
| .\} |
| .ie !"\\$3"" \{\ |
| .ta \\n()Au \\n()Bu |
| \&\\$1 \\fI\\$2\\fP (\\$3) |
| .\".b |
| .\} |
| .el \{\ |
| .br |
| .ie !"\\$2"" \{\ |
| \&\\$1 \\fI\\$2\\fP |
| .\} |
| .el \{\ |
| \&\\fI\\$1\\fP |
| .\} |
| .\} |
| .. |
| '\" # define tabbing values for .AP |
| .de AS |
| .nr )A 10n |
| .if !"\\$1"" .nr )A \\w'\\$1'u+3n |
| .nr )B \\n()Au+15n |
| .\" |
| .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n |
| .nr )C \\n()Bu+\\w'(in/out)'u+2n |
| .. |
| .AS Tcl_Interp Tcl_CreateInterp in/out |
| '\" # BS - start boxed text |
| '\" # ^y = starting y location |
| '\" # ^b = 1 |
| .de BS |
| .br |
| .mk ^y |
| .nr ^b 1u |
| .if n .nf |
| .if n .ti 0 |
| .if n \l'\\n(.lu\(ul' |
| .if n .fi |
| .. |
| '\" # BE - end boxed text (draw box now) |
| .de BE |
| .nf |
| .ti 0 |
| .mk ^t |
| .ie n \l'\\n(^lu\(ul' |
| .el \{\ |
| .\" Draw four-sided box normally, but don't draw top of |
| .\" box if the box started on an earlier page. |
| .ie !\\n(^b-1 \{\ |
| \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| .\} |
| .el \}\ |
| \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| .\} |
| .\} |
| .fi |
| .br |
| .nr ^b 0 |
| .. |
| '\" # VS - start vertical sidebar |
| '\" # ^Y = starting y location |
| '\" # ^v = 1 (for troff; for nroff this doesn't matter) |
| .de VS |
| .if !"\\$2"" .br |
| .mk ^Y |
| .ie n 'mc \s12\(br\s0 |
| .el .nr ^v 1u |
| .. |
| '\" # VE - end of vertical sidebar |
| .de VE |
| .ie n 'mc |
| .el \{\ |
| .ev 2 |
| .nf |
| .ti 0 |
| .mk ^t |
| \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' |
| .sp -1 |
| .fi |
| .ev |
| .\} |
| .nr ^v 0 |
| .. |
| '\" # Special macro to handle page bottom: finish off current |
| '\" # box/sidebar if in box/sidebar mode, then invoked standard |
| '\" # page bottom macro. |
| .de ^B |
| .ev 2 |
| 'ti 0 |
| 'nf |
| .mk ^t |
| .if \\n(^b \{\ |
| .\" Draw three-sided box if this is the box's first page, |
| .\" draw two sides but no top otherwise. |
| .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| .\} |
| .if \\n(^v \{\ |
| .nr ^x \\n(^tu+1v-\\n(^Yu |
| \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c |
| .\} |
| .bp |
| 'fi |
| .ev |
| .if \\n(^b \{\ |
| .mk ^y |
| .nr ^b 2 |
| .\} |
| .if \\n(^v \{\ |
| .mk ^Y |
| .\} |
| .. |
| '\" # DS - begin display |
| .de DS |
| .RS |
| .nf |
| .sp |
| .. |
| '\" # DE - end display |
| .de DE |
| .fi |
| .RE |
| .sp |
| .. |
| '\" # SO - start of list of standard options |
| .de SO |
| .SH "STANDARD OPTIONS" |
| .LP |
| .nf |
| .ta 4c 8c 12c |
| .ft B |
| .. |
| '\" # SE - end of list of standard options |
| .de SE |
| .fi |
| .ft R |
| .LP |
| See the \\fBoptions\\fR manual entry for details on the standard options. |
| .. |
| '\" # OP - start of full description for a single option |
| .de OP |
| .LP |
| .nf |
| .ta 4c |
| Command-Line Name: \\fB\\$1\\fR |
| Database Name: \\fB\\$2\\fR |
| Database Class: \\fB\\$3\\fR |
| .fi |
| .IP |
| .. |
| '\" # CS - begin code excerpt |
| .de CS |
| .RS |
| .nf |
| .ta .25i .5i .75i 1i |
| .. |
| '\" # CE - end code excerpt |
| .de CE |
| .fi |
| .RE |
| .. |
| .de UL |
| \\$1\l'|0\(ul'\\$2 |
| .. |
| .TH ensemble n 3.0 itcl "[incr\ Tcl]" |
| .BS |
| '\" Note: do not modify the .SH NAME line immediately below! |
| .SH NAME |
| ensemble \- create or modify a composite command |
| .SH SYNOPSIS |
| \fBensemble \fIensName\fR ?\fIcommand arg arg...\fR? |
| .br |
| or |
| .br |
| \fBensemble \fIensName\fR { |
| .br |
| \fBpart \fIpartName args body\fR |
| .br |
| \fI...\fR |
| .br |
| \fBensemble \fIpartName\fR { |
| .br |
| \fBpart \fIsubPartName args body\fR |
| .br |
| \fBpart \fIsubPartName args body\fR |
| .br |
| \fI...\fR |
| } |
| .br |
| } |
| .BE |
| |
| .SH DESCRIPTION |
| .PP |
| The \fBensemble\fR command is used to create or modify a composite |
| command. See the section \fBWHAT IS AN ENSEMBLE?\fR below for a |
| brief overview of ensembles. |
| .PP |
| If the \fBensemble\fR command finds an existing ensemble called |
| \fIensName\fR, it updates that ensemble. Otherwise, it creates an |
| ensemble called \fIensName\fR. If the \fIensName\fR is a simple name |
| like "foo", then an ensemble command named "foo" is added to the |
| current namespace context. If a command named "foo" already exists |
| in that context, then it is deleted. If the \fIensName\fR contains |
| namespace qualifiers like "a::b::foo", then the namespace path is |
| resolved, and the ensemble command is added that namespace context. |
| Parent namespaces like "a" and "b" are created automatically, as needed. |
| .PP |
| If the \fIensName\fR contains spaces like "a::b::foo bar baz", then |
| additional words like "bar" and "baz" are treated as sub-ensembles. |
| Sub-ensembles are merely parts within an ensemble; they do not have |
| a Tcl command associated with them. An ensemble like "foo" can |
| have a sub-ensemble called "foo bar", which in turn can have a |
| sub-ensemble called "foo bar baz". In this case, the sub-ensemble |
| "foo bar" must be created before the sub-ensemble "foo bar baz" |
| that resides within it. |
| .PP |
| If there are any arguments following \fIensName\fR, then they are |
| treated as commands, and they are executed to update the ensemble. |
| The following commands are recognized in this context: \fBpart\fR |
| and \fBensemble\fR. |
| .PP |
| The \fBpart\fR command defines a new part for the ensemble. |
| Its syntax is identical to the usual \fBproc\fR command, but |
| it defines a part within an ensemble, instead of a Tcl command. |
| If a part called \fIpartName\fR already exists within the ensemble, |
| then the \fBpart\fR command returns an error. |
| .PP |
| The \fBensemble\fR command can be nested inside another \fBensemble\fR |
| command to define a sub-ensemble. |
| |
| .SH "WHAT IS AN ENSEMBLE?" |
| The usual "info" command is a composite command--the command name |
| \fBinfo\fR must be followed by a sub-command like \fBbody\fR or \fBglobals\fR. |
| We will refer to a command like \fBinfo\fR as an \fIensemble\fR, and to |
| sub-commands like \fBbody\fR or \fBglobals\fR as its \fIparts\fR. |
| .PP |
| Ensembles can be nested. For example, the \fBinfo\fR command has |
| an ensemble \fBinfo namespace\fR within it. This ensemble has parts |
| like \fBinfo namespace all\fR and \fBinfo namespace children\fR. |
| .PP |
| With ensembles, composite commands can be created and extended |
| in an automatic way. Any package can find an existing ensemble |
| and add new parts to it. So extension writers can add their |
| own parts, for example, to the \fBinfo\fR command. |
| .PP |
| The ensemble facility manages all of the part names and keeps |
| track of unique abbreviations. Normally, you can abbreviate |
| \fBinfo complete\fR to \fBinfo comp\fR. But if an extension adds the |
| part \fBinfo complexity\fR, the minimum abbreviation for \fBinfo complete\fR |
| becomes \fBinfo complet\fR. |
| .PP |
| The ensemble facility not only automates the construction of |
| composite commands, but it automates the error handling as well. |
| If you invoke an ensemble command without specifying a part name, |
| you get an automatically generated error message that summarizes |
| the usage information. For example, when the \fBinfo\fR command |
| is invoked without any arguments, it produces the following error |
| message: |
| .CS |
| wrong # args: should be one of... |
| info args procname |
| info body procname |
| info cmdcount |
| info commands ?pattern? |
| info complete command |
| info context |
| info default procname arg varname |
| info exists varName |
| info globals ?pattern? |
| info level ?number? |
| info library |
| info locals ?pattern? |
| info namespace option ?arg arg ...? |
| info patchlevel |
| info procs ?pattern? |
| info protection ?-command? ?-variable? name |
| info script |
| info tclversion |
| info vars ?pattern? |
| info which ?-command? ?-variable? ?-namespace? name\fR |
| .CE |
| You can also customize the way an ensemble responds to errors. |
| When an ensemble encounters an unspecified or ambiguous part |
| name, it looks for a part called \fB@error\fR. If it exists, |
| then it is used to handle the error. This part will receive all |
| of the arguments on the command line starting with the offending |
| part name. It can find another way of resolving the command, |
| or generate its own error message. |
| |
| .SH EXAMPLE |
| We could use an ensemble to clean up the syntax of the various |
| "wait" commands in Tcl/Tk. Instead of using a series of |
| strange commands like this: |
| .CS |
| vwait x |
| tkwait visibility .top |
| tkwait window . |
| .CE |
| we could use commands with a uniform syntax, like this: |
| .CS |
| wait variable x |
| wait visibility .top |
| wait window . |
| .CE |
| The Tcl package could define the following ensemble: |
| .CS |
| ensemble wait part variable {name} { |
| uplevel vwait $name |
| } |
| .CE |
| The Tk package could add some options to this ensemble, with a |
| command like this: |
| .CS |
| ensemble wait { |
| part visibility {name} { |
| tkwait visibility $name |
| } |
| part window {name} { |
| tkwait window $name |
| } |
| } |
| .CE |
| Other extensions could add their own parts to the \fBwait\fR command |
| too. |
| |
| .SH KEYWORDS |
| ensemble, part, info |