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# Avoiding 'Redo From Start'

March 14 2012 at 4:06 PM
AlGoreIthm  (Login AlGoreIthm)

This Function accepts only a numeral as input: The Challenge - very open ended,
just submit the same thing in an improved form.
Also keep in mind this was whipped up by someone who couldn't possibly be more 'math-deficient'.

==============================================================================

DECLARE FUNCTION NUMERAL ()

s# = NUMERAL
PRINT s#

END

FUNCTION NUMERAL#

num\$ = "0123456789."
y% = 3
posi% = 1
PRINT "ENTER a numeral:"

DO
LOCATE y%, posi%: PRINT CHR\$(178)
LOCATE 1, 56: PRINT posi%

SLEEP
k\$ = INKEY\$

IF posi% = 1 AND k\$ = "-" OR INSTR(num\$, k\$) THEN inp\$ = inp\$ + k\$: posi% = posi% + 1
IF k\$ = "." THEN num\$ = LEFT\$(num\$, 10): nposi% = posi% - 1: LOCATE 2, 56: PRINT nposi%

IF k\$ = CHR\$(8) AND posi% > 1 THEN
posi% = posi% - 1
IF posi% = nposi% THEN num\$ = num\$ + ".": nposi% = 0
inp\$ = LEFT\$(inp\$, posi% - 1)
END IF

LOCATE y%, 1: PRINT inp\$; " "

LOOP WHILE k\$ <> CHR\$(13)

NUMERAL = VAL(inp\$)

END FUNCTION

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# This seems to do the same thing...

March 14 2012, 7:42 PM
 s = NUMERAL PRINT s FUNCTION NUMERAL cxx = CSRLIN cxy = POS(0) DO LOCATE cxx, cxy ky\$ = INKEY\$ IF ky\$ <> "" THEN SELECT CASE ky\$ CASE CHR\$(8) com\$ = LEFT\$(com\$, LEN(com\$) - 1) CASE ELSE com\$ = com\$ + ky\$ END SELECT END IF PRINT "Number of digits :"; LEN(com\$) PRINT com\$; CHR\$(178); SPACE\$(1) LOOP UNTIL ky\$ = CHR\$(13) NUMERAL = VAL(com\$) END FUNCTION
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AlGoreIthm
(Login AlGoreIthm)

# nope - not even close

March 16 2012, 3:36 PM
 The problem with your version is that it doesn't meet the challenge of improving the original submission, but also, it accepts the minus sign repeatedly and in any position and the same goes for the decimal point. It also accepts alpha characters while the original only accepts numbers which is the point of the exercise. Your program works very well 'as-is' but it doesn't prevent unacceptable numeric input from occuring. Please try again.
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# What about this?

March 16 2012, 4:00 PM
 s = NUMERAL PRINT s FUNCTION NUMERAL cxx = CSRLIN cxy = POS(0) DO LOCATE cxx, cxy ky\$ = INKEY\$ IF ky\$ <> "" THEN SELECT CASE ky\$ CASE CHR\$(8) com\$ = LEFT\$(com\$, LEN(com\$) - 1) CASE ELSE IF ky\$ >= CHR\$(48) AND ky\$ <= CHR\$(57) THEN com\$ = com\$ + ky\$ IF ky\$ = "." AND INSTR(com\$, ".") = 0 THEN com\$ = com\$ + ky\$ IF ky\$ = "-" AND LEN(com\$) = 0 THEN com\$ = com\$ + ky\$ END SELECT END IF PRINT "Number of digits :"; LEN(com\$) PRINT com\$; CHR\$(178); SPACE\$(1) LOOP UNTIL ky\$ = CHR\$(13) NUMERAL = VAL(com\$) END FUNCTION
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# More structured version...

March 16 2012, 4:12 PM
 s = NUMERAL PRINT s FUNCTION NUMERAL cxx = CSRLIN cxy = POS(0) DO _limit 60 LOCATE cxx, cxy ky\$ = INKEY\$ IF ky\$ <> "" THEN num = ASC(ky\$) SELECT CASE num CASE 8 com\$ = LEFT\$(com\$, LEN(com\$) - 1) CASE 48 TO 57 com\$ = com\$ + ky\$ CASE 46 IF INSTR(com\$, ".") = 0 THEN com\$ = com\$ + ky\$ CASE 45 IF LEN(com\$) = 0 THEN com\$ = com\$ + ky\$ END SELECT END IF PRINT "Number of digits :"; LEN(com\$) PRINT com\$; CHR\$(178); SPACE\$(1) LOOP UNTIL ky\$ = CHR\$(13) NUMERAL = VAL(com\$) END FUNCTION Also, how can you have multiple conditions with select case?
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(Login MCalkins)
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# Re: More structured version...

March 17 2012, 4:28 AM
 >Also, how can you have multiple conditions with select case? You mean on the same CASE? Use comma as a separator: CASE 1,3,5,7, is <=-5, 100 to 200, 205 Regards, Michael
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# *Oh Ok.. Thanks

March 17 2012, 5:30 AM
 *
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AlGoreIthm
(Login AlGoreIthm)

# Much better

March 17 2012, 1:28 PM
 this line com\$ = LEFT\$(com\$, LEN(com\$) - 1) gives an 'Illegal Function Call' Error when backspace tries to go back before the first digit - getting there ...
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# Re: Much better

March 17 2012, 2:10 PM
 I don't get that error but this should fix it : s = NUMERAL PRINT s FUNCTION NUMERAL cxx = CSRLIN cxy = POS(0) DO _LIMIT 60 LOCATE cxx, cxy ky\$ = INKEY\$ IF ky\$ <> "" THEN num = ASC(ky\$) SELECT CASE num CASE 8 IF LEN(com\$) > 0 THEN com\$ = LEFT\$(com\$, LEN(com\$) - 1) CASE 48 TO 57 com\$ = com\$ + ky\$ CASE 46 IF INSTR(com\$, ".") = 0 THEN com\$ = com\$ + ky\$ CASE 45 IF LEN(com\$) = 0 THEN com\$ = com\$ + ky\$ END SELECT END IF PRINT "Number of digits :"; LEN(com\$) PRINT com\$; CHR\$(178); SPACE\$(1) LOOP UNTIL ky\$ = CHR\$(13) NUMERAL = VAL(com\$) END FUNCTION
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AlGoreIthm
(Login AlGoreIthm)

# Final version..?

March 23 2012, 1:52 PM
 I admit to borrowing from pmarathe's early version - it was enough to inspire a change that helped get rid of variables posi% and nposi%. DECLARE FUNCTION NUMERAL# (x%, y%) ' x% and y% are coordinate values for screen location x% = 5: y% = 6: s# = NUMERAL#(x%, y%) 'LOCATE 15, 2: PRINT s# ' test line to validate that s# is identical to the input END FUNCTION NUMERAL# (x%, y%) LOCATE y%, x%: PRINT "ENTER a numeral:" num\$ = "0123456789" WHILE k\$ <> CHR\$(13) LOCATE y%, x% + 17: PRINT inp\$; CHR\$(178); " "; k\$ = INKEY\$ IF (LEN(inp\$) = 0 AND k\$ = "-") OR INSTR(num\$, k\$) OR (k\$ = "." AND INSTR(inp\$, k\$) = 0) THEN inp\$ = inp\$ + k\$ IF k\$ = CHR\$(8) AND LEN(inp\$) > 0 THEN inp\$ = LEFT\$(inp\$, LEN(inp\$) - 1) WEND LOCATE y%, x% + 17: PRINT inp\$; " " NUMERAL# = VAL(inp\$) END FUNCTION
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# When does 'redo from start' occur?

March 17 2012, 2:13 PM
 I've never seen this error.. what is it? I'm using QB64, by the way. Is that why I don't get that error?
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AlGoreIthm
(Login AlGoreIthm)

# Re: When does 'redo from start' occur?

March 17 2012, 2:29 PM
 It could be the reason - not familiar at all with QB64. 'Redo From Start' is an error message the user will get while running QBasic as they attempt to enter non-numeric input, when only numeric input is acceptable (ex: in a numeric variable). When this occurs, the Input fails and the user must re-enter his input from the beginning. The idea here is to set up a simple Input Function that will only accept properly formatted numeric input, and will never need to display an error message; if the input is all-numeric only and properly formatted, it is correct and can be processed.
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# Re: When does 'redo from start' occur?

March 17 2012, 2:38 PM
 In QB64 it only allows numeric input when a numeric variable is being used...
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(Login rpgfan3233)

# Re: When does 'redo from start' occur?

March 17 2012, 2:47 PM
 There are two situations in which I know it occurs for certain: - Using INPUT with a string containing a comma - Trying to INPUT a string when a numeric variable is used The last case is one that QB64 eliminates by limiting the characters you can type when trying to store a numeric value. The first case, however, is a bit more difficult. INPUT was designed to allow you to enter several items at once. For example, you could enter a name and age: INPUT "Enter your name and age, separated by a comma: ", name\$, age% The problem arises when you do something like this: INPUT "Enter your name (Last, First): ", name\$ Ideally you would use the comma in the string to separate the names later. This limits the number of reads you would need to do. In QBasic, this was definitely an issue due to limited system resources, and string operations may have taken less time. However, if you try to enter the name in the last case: Kitsune,Chrono You would end up getting a "Redo from start" message because there are two items there, not one. Ultimately, there is a rule: use LINE INPUT for strings and INPUT for numbers. And back in QBasic, you should have used LINE INPUT for numbers and parsed the string yourself actually. After all, how can you store 3.45 in an integer variable?
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# *Oh Ok.. Thanks

March 17 2012, 2:50 PM
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