Library for 'autocomplete' feature

VARIABLE LW-LEN
Length of uncompleted word (last word in string, received by LastWord or 
AComplete)

: LastWord ( addr u -- addr1 u1 )
Return substring of string at addr u, which is the last word, delimited by 
char with code <=32.

: UCOMPARE ( addr u addr1 u1 -- 0 | -1 )
Compare strings without case-sensitivity. Return 0 if equal.

: ClosestW ( addr u -- addr1 u1 -1 | 0 )
Search for word in the current search order, beginning from the string at 
(addr u). Return 0 if not found, return  -1 and its address and length 
(addr1 u1). 

: AComplete ( addr1 u1 -- addr2 u2 true | false )
Return false if the string at (addr1 u1) cannot be autocompleted. Otherwise, 
return true and (addr2 u2), the word name for autocompletion. For example, 
define: 

create MyWord

and execute:

s" qwe asd zxc myw" AComplete . cr type cr lw-len @ . cr

you will get:

-1
MyWord
3

where -1 indicates whether the word was found, MyWord is its name, and 3 
is the length  of the incomplete part 'myw'.
