NAME<\/a> ______________________________________________________________________________<\/p>\n apply \u2212 Apply an anonymous function<\/p>\n apply<\/b> func<\/i> ?arg1 arg2 …<\/i>? ______________________________________________________________________________<\/p>\n The command apply<\/b> applies the function func<\/i> to the arguments arg1 arg2 …<\/i> and returns the result.<\/p>\n The function func<\/i> is a two element list {args body}<\/i> or a three element list {args body namespace}<\/i> (as if the list<\/b> command had been used). The first element args<\/i> specifies the formal arguments to func<\/i>. The specification of the formal arguments args<\/i> is shared with the proc<\/b> command, and is described in detail in the corresponding manual page.<\/p>\n The contents of body<\/i> are executed by the Tcl interpreter after the local variables corresponding to the formal arguments are given the values of the actual parameters arg1 arg2 …<\/i>. When body<\/i> is being executed, variable names normally refer to local variables, which are created automatically when referenced and deleted when apply<\/b> returns. One local variable is automatically created for each of the function\u2019s arguments. Global variables can only be accessed by invoking the global<\/b> command or the upvar<\/b> command. Namespace variables can only be accessed by invoking the variable<\/b> command or the upvar<\/b> command.<\/p>\n The invocation of apply<\/b> adds a call frame to Tcl\u2019s evaluation stack (the stack of frames accessed via uplevel<\/b>). The execution of body<\/i> proceeds in this call frame, in the namespace given by namespace<\/i> or in the global namespace if none was specified. If given, namespace<\/i> is interpreted relative to the global namespace even if its name does not start with \u201c::\u201d.<\/p>\n The semantics of apply<\/b> can also be described by:<\/p>\n proc apply {fun args} { This shows how to make a simple general command that applies a transformation to each element of a list.<\/p>\n proc map {lambda list} { The apply<\/b> command is also useful for defining callbacks for use in the trace<\/b> command:<\/p>\n set vbl “123abc” proc(n), uplevel(n)<\/p>\n anonymous function, argument, lambda, procedure,<\/p>\n apply \u2212 Apply an anonymous function <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3783,1],"tags":[2895,2635],"class_list":["post-6293","post","type-post","status-publish","format-standard","hentry","category-n-comandos-tcl-tk","category-sin-categoria","tag-apply","tag-mann"],"gutentor_comment":0,"_links":{"self":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/6293","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/comments?post=6293"}],"version-history":[{"count":0,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/6293\/revisions"}],"wp:attachment":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/media?parent=6293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/categories?post=6293"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/tags?post=6293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
SYNOPSIS<\/a>
DESCRIPTION<\/a>
EXAMPLES<\/a>
SEE ALSO<\/a>
KEYWORDS<\/a> <\/p>\n
\nNAME <\/a> <\/h2>\n
SYNOPSIS <\/a> <\/h2>\n
DESCRIPTION <\/a> <\/h2>\n
set len [llength $fun]
if {($len < 2) || ($len > 3)} {
error “can\u2019t interpret “$fun” as anonymous function”
}
lassign $fun argList body ns
set name ::$ns::[getGloballyUniqueName]
set body0 {
rename [lindex [info level 0] 0] {}
}
proc $name $argList ${body0}$body
set code [catch {uplevel 1 $name $args} res opt]
return -options $opt $res
}<\/p>\nEXAMPLES <\/a> <\/h2>\n
set result {}
foreach item $list {
lappend result [apply<\/b> $lambda $item]
}
return $result
}
map {x {return [string length $x]:$x}} {a bb ccc dddd}
\u2192 1:a 2:bb 3:ccc 4:dddd<\/i>
map {x {expr {$x**2 + 3*$x – 2}}} {-4 -3 -2 -1 0 1 2 3 4}
\u2192 2 -2 -4 -4 -2 2 8 16 26<\/i><\/p>\n
trace add variable vbl write {apply<\/b> {{v1 v2 op} {
upvar 1 $v1 v
puts “updated variable to “$v””
}}}
set vbl 123
set vbl abc<\/p>\nSEE ALSO <\/a> <\/h2>\n
KEYWORDS <\/a> <\/h2>\n
\n","protected":false},"excerpt":{"rendered":"