TABLE OF CONTENTS

::pwtk::parseIndex1

SYNOPSIS

proc ::pwtk::parseIndex1 {index lastIndex} {

PURPOSE

Tranform symbolic index to numeric index. The first index has the value of 1 (hence the prefix 1 in the name), i.e.: 

     begin, first, 1st       --> 1
     begin+N, first+N, 1st+N --> 1+N
     end, last               --> $lastIndex
     end-N, last-N,          --> $lastIndex-N

First index can have symbolic values of: 

     first, begin, 1st

Last index can have symbolic values of: 

     end, last

If index is given as math expression, it is evaluated. For example: 

     parseIndex1 end-1 3

returns 2.

ARGUMENTS

SOURCE

    set ind [regsub -nocase {(^begin|^first|^1st)} $index 1]
    set ind [regsub -nocase {(^end|^last)} $ind $lastIndex]
    try {
        set index [expr $ind]
    } on error err {
        set index $ind
    }
    #
    if { ! [string is integer -strict $index] } {
        uplevel 1 [list ::pwtk::error "expected integer for index, but got $index" 1]
    }
    return $index
}