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diff --git a/tcl8.6/doc/apply.n b/tcl8.6/doc/apply.n deleted file mode 100644 index aeb2227..0000000 --- a/tcl8.6/doc/apply.n +++ /dev/null @@ -1,102 +0,0 @@ -'\" -'\" Copyright (c) 2006 Miguel Sofer -'\" Copyright (c) 2006 Donal K. Fellows -'\" -.TH apply n "" Tcl "Tcl Built-In Commands" -.so man.macros -.BS -'\" Note: do not modify the .SH NAME line immediately below! -.SH NAME -apply \- Apply an anonymous function -.SH SYNOPSIS -\fBapply \fIfunc\fR ?\fIarg1 arg2 ...\fR? -.BE -.SH DESCRIPTION -.PP -The command \fBapply\fR applies the function \fIfunc\fR to the arguments -\fIarg1 arg2 ...\fR and returns the result. -.PP -The function \fIfunc\fR is a two element list \fI{args body}\fR or a three -element list \fI{args body namespace}\fR (as if the -\fBlist\fR command had been used). -The first element \fIargs\fR specifies the formal arguments to -\fIfunc\fR. The specification of the formal arguments \fIargs\fR -is shared with the \fBproc\fR command, and is described in detail in the -corresponding manual page. -.PP -The contents of \fIbody\fR are executed by the Tcl interpreter -after the local variables corresponding to the formal arguments are given -the values of the actual parameters \fIarg1 arg2 ...\fR. -When \fIbody\fR is being executed, variable names normally refer to -local variables, which are created automatically when referenced and -deleted when \fBapply\fR returns. One local variable is automatically -created for each of the function's arguments. -Global variables can only be accessed by invoking -the \fBglobal\fR command or the \fBupvar\fR command. -Namespace variables can only be accessed by invoking -the \fBvariable\fR command or the \fBupvar\fR command. -.PP -The invocation of \fBapply\fR adds a call frame to Tcl's evaluation stack -(the stack of frames accessed via \fBuplevel\fR). The execution of \fIbody\fR -proceeds in this call frame, in the namespace given by \fInamespace\fR or -in the global namespace if none was specified. If given, \fInamespace\fR is -interpreted relative to the global namespace even if its name does not start -with -.QW :: . -.PP -The semantics of \fBapply\fR can also be described by: -.PP -.CS -proc apply {fun args} { - set len [llength $fun] - if {($len < 2) || ($len > 3)} { - error "can't interpret \e"$fun\e" 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 -} -.CE -.SH EXAMPLES -.PP -This shows how to make a simple general command that applies a transformation -to each element of a list. -.PP -.CS -proc map {lambda list} { - set result {} - foreach item $list { - lappend result [\fBapply\fR $lambda $item] - } - return $result -} -map {x {return [string length $x]:$x}} {a bb ccc dddd} - \fI\(-> 1:a 2:bb 3:ccc 4:dddd\fR -map {x {expr {$x**2 + 3*$x - 2}}} {-4 -3 -2 -1 0 1 2 3 4} - \fI\(-> 2 -2 -4 -4 -2 2 8 16 26\fR -.CE -.PP -The \fBapply\fR command is also useful for defining callbacks for use in the -\fBtrace\fR command: -.PP -.CS -set vbl "123abc" -trace add variable vbl write {\fBapply\fR {{v1 v2 op} { - upvar 1 $v1 v - puts "updated variable to \e"$v\e"" -}}} -set vbl 123 -set vbl abc -.CE -.SH "SEE ALSO" -proc(n), uplevel(n) -.SH KEYWORDS -anonymous function, argument, lambda, procedure, -'\" Local Variables: -'\" mode: nroff -'\" End: |