functions TRIM LTRIM and RTRIM.

[joreveur]

Hello
I look for the equivalent of functions TRIM LTRIM and RTRIM. :  trim
Thank you if see can help me
Cordially

[vovchik]

Dear joreveur,

You can probably do anything you want as regards trimming strings with CHOP$, which takes useful arguments. However, James C. Fuller did provide some functions way back in 2009, I think, that do what you are looking for (QB style):

' *********************
' LTRIM$
' *********************
' multiple entries in match$ are treated individually

' ------------------
FUNCTION LTRIM$(STRING main$, STRING match$)
' ------------------
LOCAL mlen, mtlen, i, j TYPE int
i = 0
j = 0
mlen = LEN(main$)
mtlen = LEN(match$)
IF (mlen = 0) OR (mtlen = 0) THEN
RETURN main$
END IF
FOR i = 1 TO mlen
IF INSTR(match$, MID$(main$, i, 1), 1) = 0 THEN
RETURN RIGHT$(main$, mlen - j)
ELSE
INCR j
END IF  
NEXT i
RETURN main$
END FUNCTION

' --------
' Example:
PRINT LTRIM$(" James Fuller", CONCAT$(" ",CHR$(9)))
' --------


' *********************
' RTRIM$
' *********************
' multiple entries in match$ are treated individually

' ------------------
FUNCTION RTRIM$(STRING main$, STRING match$)
' ------------------
LOCAL mlen, mtlen, i, j TYPE int
i = 0
mlen = LEN(main$)
j = mlen
mtlen = LEN(match$)
IF (mlen = 0) OR (mtlen = 0) THEN
RETURN main$
END IF
FOR i = mlen TO 1 STEP -1
IF INSTR(match$, MID$(main$, i, 1), 1) = 0 THEN
RETURN LEFT$(main$, j)
ELSE
DECR j
END IF  
NEXT i
RETURN main$
END FUNCTION

' --------
' Example:
PRINT RTRIM$("James Fuller ", CONCAT$(" ", CHR$(9)));
PRINT
' PRINT "More"
' --------


' *********************
' TRIM$
' *********************

' ------------------
FUNCTION TRIM$(STRING main$, STRING match$)
' ------------------
LOCAL mlen, mtlen TYPE int
LOCAL S1$ TYPE STRING
mlen = LEN(match$)
mtlen = LEN(match$)
IF (mlen = 0) OR (mtlen = 0) THEN
RETURN match$
END IF
S1$ = LTRIM$(main$, match$)
S1$ = RTRIM$(S1$, match$)
RETURN S1$
END FUNCTION

' --------
' Example:
PRINT "ABC", TRIM$(" James ", CONCAT$(" ", CHR$(9))), "EFG" FORMAT "%s%s%s\n"
' --------


' *********************
' EXTRACTSTR$
' *********************

' ------------------
FUNCTION EXTRACTSTR$(STRING main$, STRING delimiter$)
' ------------------
LOCAL i TYPE int
LOCAL sret$ TYPE STRING
sret$ = ""
IF (LEN(main$) = 0) OR (LEN(delimiter$) = 0) THEN
RETURN sret$
END IF
i = INSTR(main$, delimiter$, 1)
IF i = 0 THEN
RETURN main$
END IF
RETURN LEFT$(main$, i - 1)
END FUNCTION

' --------
' Example:
' EXTRACTSTR$(main$, delimiter$)
' Similar to LEFT$ but uses a delimiter rather the position
S1a$ = EXTRACTSTR$("James C. Fuller"," ")
PRINT S1a$
' --------


' *********************
' REMAINSTR$
' *********************

' ------------------
FUNCTION REMAINSTR$(STRING main$, STRING delimiter$)
' ------------------
LOCAL i, j, k, mlen, dlen TYPE int
LOCAL sret$ TYPE STRING
i = 0
j = 0
k = 0
mlen = LEN(main$)
dlen = LEN(delimiter$)
IF mlen = 0 THEN
RETURN sret$
END IF
IF dlen = 0 THEN
RETURN sret$
END IF
i = INSTR(main$, delimiter$, 1)
IF i = 0 THEN
RETURN main$
END IF
j = i
k = i + LEN(delimiter$)
WHILE TRUE DO
i = INSTR(main$, delimiter$, k)
IF i = 0 THEN
sret$ = MID$(main$, k, mlen)
RETURN sret$
ELSE
k = i + LEN(delimiter$)
END IF
WEND
END FUNCTION

' --------
' Example:
S10$ = REMAINSTR$("James C. Fuller", " ")
PRINT S10$
' --------


' *********************
' TOTAL
' *********************

' ------------------
FUNCTION TOTAL(STRING main$, STRING match$)
' ------------------
LOCAL i, j, k, mlen, matchlen TYPE int
mlen = LEN(main$)
matchlen = LEN(match$)
i = 1
j = 0
k = 0
IF (mlen = 0) OR (matchlen = 0) THEN
RETURN j
END IF  
WHILE TRUE DO
IF EQUAL(MID$(main$, i, matchlen), match$) THEN
INCR j
END IF
INCR i, matchlen
IF i > mlen THEN
BREAK
END IF
WEND
RETURN j
END FUNCTION

' --------
' Example:
PRINT TOTAL("one,two,three,,four,five,six", ",")
' --------

And analogous functions using CHOP$ are:

' ------------------
FUNCTION LTRIM$(STRING main$, STRING match$)
' ------------------
RETURN CHOP$(main$, match$, 1)
END FUNCTION

' ------------------
FUNCTION RTRIM$(STRING main$, STRING match$)
' ------------------
RETURN CHOP$(main$, match$, 2)
END FUNCTION

' ------------------
FUNCTION TRIM$(STRING main$, STRING match$)
' ------------------
RETURN CHOP$(main$, match$, 0)
END FUNCTION

With kind regards,
vovchik

[joreveur]

Hello vovchik
Thanks you  very much for your responses.

I checked your functions
I have a qustion withe TRIM

PRINT "ABC", TRIM$(" James is a    boy  ", CONCAT$(" ", CHR$(9))), "EFG" FORMAT "%s%s%s\n"

and the return is
ABCJames is a    boyEFG
there are more spaces between words. is it a error ?

Else do you have a another function to suppress all spaces (or other characters) ?

Example
PRINT
SUPR$("ABCJames is a    boyEFG) :' result will be ABCJamesisaboyEFG


With my best regards

[Pjot]

Jul 13, 2017 7:54:16 GMT 1 joreveur said:

Else do you have a another function to suppress all spaces (or other characters) ?

Example
PRINT
SUPR$("ABCJames is a    boyEFG) :' result will be ABCJamesisaboyEFG

With my best regards

Hi joreveur,

I think what you're looking for can be achieved with EXTRACT$:

PRINT EXTRACT$("ABCJames is a    boyEFG", " ")


If there are other types of white spaces to be deleted (like TAB or newline), then you can make use of the Regular Expression capability of EXTRACT$:

PRINT EXTRACT$("ABCJames is a    boyEFG", "[[:space:]]", TRUE)


Please consult 'man 7 regex' where you can find information about the predefined categories to use in situations like these:

alnum digit punct
alpha graph space
blank lower upper
cntrl print xdigit

Hope this helps,

Peter

[vovchik]

Dear Peter and joreveur,

Thanks... and here is a little example:

' ------------------
FUNCTION PURGE$(STRING txt$, int filter)
' ------------------
LOCAL f$ TYPE STRING
SELECT filter
CASE 0
f$ = "alnum"
CASE 1
f$ = "alpha"
CASE 2
f$ = "blank"
CASE 3
f$ = "cntrl"
CASE 4
f$ = "digit"
CASE 5
f$ = "graph"
CASE 6
f$ = "lower"
CASE 7
f$ = "print"
CASE 8
f$ = "punct"
CASE 9
f$ = "space"
CASE 10
f$ = "upper"
CASE 11
f$ = "xdigit"
DEFAULT
f$ = "space"
END SELECT
f$  = "[[:" & f$ & ":]]"
RETURN EXTRACT$(txt$, f$, TRUE) & " (" & f$ & ")"
END FUNCTION

FOR i = 0 TO 11
PRINT i, ". ", PURGE$("ABCJames ? x34 is a    boyEFG!", i)
NEXT i

With kind regards,
vovchik

PS. Mod the RETURN to RETURN EXTRACT$(txt$, f$, TRUE) for PURGE$ to be useful in a program.