upper & lower case

Sometimes in writing QUEST logics, especially those that deal with user input or reading from text files, I've had to compare two pieces of text for equality where the case of the text wasn't an issue.  The thing with SCL is that text comparisons are case sensitive, which meant I needed a way to convert a text string to either all caps or all lower case characters.  I never found anything for this in QUEST's SCL docs, so I made my own, and here they are.  The routines work by reading each character in a string individually, and seeing if it's already in the desired case.  If not, we just add or subtract 32 to/from its ASCII value to convert between upper and lower case characters in ASCII text.

Here's a download if you don't want to copy the text

routine is_lower( the_string : String ) : Integer

Const

   first_lower 97

   last_lower 122

   upper_to_lower 32

Var

   the_char : String  

   result : Integer

Begin

   the_char = leftstr( the_string , 1 )

   if( asc( the_char ) <= last_lower AND asc( the_char ) >= first_lower ) then

      result = true

   else

      result = false

   endif

   return result

End

routine is_upper( the_string : String ) : Integer

Const

   first_upper 65

   last_upper 90

   upper_to_lower 32

Var

   the_char : String  

   result : Integer

Begin

   the_char = leftstr( the_string , 1 )

   if( asc( the_char ) <= last_upper AND asc( the_char ) >= first_upper ) then

      result = true

   else

      result = false

   endif

   return result

End          

routine upper( the_string : String ) : String  

--Return upper case version of the_string

Const

   first_lower 97

   last_lower 122

   upper_to_lower 32

Var

   i : Integer

   result , check_char : String  

Begin

result = ''

for i = 1 to len( the_string ) do

   check_char = substr( the_string , i , 1 )

   if( is_lower( check_char ) ) then

      check_char = chr( asc( check_char ) - 32 )

   endif

   result = result + check_char

endfor

return result

End

routine lower( the_string : String ) : String  

--Return upper case version of the_string

Const

   first_lower 97

   last_lower 122

   upper_to_lower 32

Var

   i : Integer

   result , check_char : String  

Begin

result = ''

for i = 1 to len( the_string ) do

   check_char = substr( the_string , i , 1 )

   if( is_upper( check_char ) ) then

      check_char = chr( asc( check_char ) + 32 )

   endif

   result = result + check_char

endfor

return result

End