[Richard Suchenwirth] 2005-04-02 - [lmap] is a "collecting [foreach]" which returns a list of its results. In [Jim] it is built in, but it can be easily had in pure Tcl:
 proc lmap {_var list body} {
    upvar 1 $_var var
    set res {}
    foreach var $list {lappend res [uplevel 1 $body]}
    set res
 }
Several usage examples are at [Multiplication tables]. [Lmap] is a compromise between Tcl and the classical [functional programming] function [map], in that it takes a "quasi-[lambda]" which is split up into the ''_var'' name and the ''body'' arguments. However, this style is well-known from [foreach], and somehow reads better:
 lmap i {1 2 3 4 5} {expr $i*$i}
vs.
 map [lambda i {expr $i*$i}] {1 2 3 4 5}

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[Category Functional Programming]