Abbrev   built-in function

The Abbrev function determines whether one string info is a leading substring of another string information. An optional minimum length can be specified. The function returns 1 when the test string is a leading abbreviation of the reference string, and 0 otherwise. If the test string is shorter than the minimal length, then 0 is returned.

result = Abbrev( information, info [, length ] ] )

information -- reference string

The string that may start with the abbreviated text value.

info -- test substring

The abbreviated text value.

length -- minimal substring length

The minimal required length of the test substring -- the default minimum length is 0 !

Please observe:

1. Character case is significant during the substring comparison. You must convert the information and info values to uppercase in order to match mixed case abbreviations.

2. When the info value is received from a user interface, or a console, an unexpected surprise can occur if the length option is not specified. When nothing is entered, it matches anything ! You must specify a minimum length of 1, to circumvent this problem. Consider for example:

   say 'Do you want to use the force (but only when necessary) ?' inputValue = linein() if abbrev( 'PERFORCE', inputValue ) then say 'The force is with you !'

   The above will show the forceful message when inputValue is the empty string. This error is corrected as follows:

   say 'Do you want to use the force (but only when necessary) ?' inputValue = linein() if abbrev( 'PERFORCE', inputValue, 1 ) then say 'The force is with you !' else say 'Proceed carefully -- you lack the force...'

Examples: say Abbrev( 'Print', 'Pri' ) -- shows 1 -- 'Pri' is a leading substring of 'Print' say Abbrev( 'PRINT', 'Pri' ) -- shows 0 -- character case is incorrect say Abbrev( 'Print', 'Pr', 3 ) -- shows 0 -- 'Pr' is too short say Abbrev( 'Print', '' ) -- shows 1 -- the empty string is a leading substring of 'Print' !! say Abbrev( 'Print', '', 1 ) -- shows 0 -- the empty string is too short