Print multiple tcl lists in a uniform manner - tcl

Question

I have a group of lists some with strings, some with numbers and some with both. All these lists have variable lengths. I would like to know what would be the best way to print it to a file so that they all have equal spacing between them.
For example, I use,
set numbers {0 1 2 3 4}
set type {dog reallybigbaddog thisisaevenlargersentence cat bird}
set paths {aaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb ccc ddddddddddddddddd efgh}
puts $fid "NUMBERS\t\tTYPE\tPATHS"
foreach numbersval $numbers typeval $type pathsval $paths {
puts $fid "$numbersval\t\t$typeval\t$pathsval"
}
The result was,
NUMBERS TYPE PATHS
0 dog AAA
1 reallybigbaddog bbbbbbbbbbbbbbbbbbbbbbbb
2 thisisaevenlargersentence ccc
3 cat ddddddddddddddddd
4 bird efgh
I Tried using "format" based on one of the suggestions on this site but that resulted in a similar output, I guess we need a way to determining what the longest string is and cant arbitrarily use "\t"? Would appreciate any better suggestions.

Answer 1

For reference, this is how you could do it with struct::matrix and report:
package require struct::matrix
package require report
set nrows 5
set ncols 3
set npads [expr {$ncols + 1}]
struct::matrix m
m add rows $nrows
m add column {0 1 2 3 4}
m add column {dog reallybigbaddog thisisaevenlargersentence cat bird}
m add column {aaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb ccc ddddddddddddddddd efgh}
m insert row 0 {NUMBERS TYPE PATHS}
report::report r $ncols
r data set [lrepeat $npads \t]
m format 2string r
(This uses only a fraction of the formatting power of report.) This method can handle values with spaces in them.
Result (there is a tab character to the left of the first column on each row, but it's lost in the formatting here.):
NUMBERS TYPE PATHS
0 dog aaa
1 reallybigbaddog bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2 thisisaevenlargersentence ccc
3 cat ddddddddddddddddd
4 bird efgh
Documentation: expr, lrepeat, package, report package, set, struct::matrix package

Answer 2

In this case, I'd call out to column -t to do the work for me:
set all "NUMBERS TYPE PATHS\n"
foreach n $numbers t $type p $paths {
append all "$n $t $p\n"
}
set formatted [exec column -t << $all]
puts $formatted
NUMBERS TYPE PATHS
0 dog aaa
1 reallybigbaddog bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2 thisisaevenlargersentence ccc
3 cat ddddddddddddddddd
4 bird efgh
A pure Tcl way to do this:
array set maxl {numbers 0 type 0 paths 0}
foreach l {numbers type paths} {
foreach e [concat $l [set $l]] {
if {[set len [string length $e]] > $maxl($l)} {
set maxl($l) $len
}
}
}
puts [format "%-*s %-*s %-*s" $maxl(numbers) NUMBERS $maxl(type) TYPE $maxl(paths) "PATH LISTS"]
foreach n $numbers t $type p $paths {
puts [format "%-*s %-*s %-*s" $maxl(numbers) $n $maxl(type) $t $maxl(paths) $p]
}