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| Jason | Infix to RPN Expression Converter'+-----------------------------------+
'| iNFiX TO RPN EXPRESSiON CONVERTER |
'| --------------------------------- |
'| ORiGiNAL AUTHOR: DiCK |
'| MODiFiED BY: HORATiO |
'| --------------------------------- |
'| CREATED: 08APR12 |
'| LAST MODiFiED: 10APR12 |
'+-----------------------------------+
DEFINT A-Z
DECLARE FUNCTION convert$ (expression$)
DECLARE FUNCTION precedence% (operator$)
DECLARE FUNCTION pop$ ()
DECLARE SUB push (value$)
CONST stackMax% = 64
DIM SHARED stack$(stackMax%)
DIM SHARED size%
INPUT "", expression$
PRINT convert$(expression$)
FUNCTION convert$ (expression$)
FOR position% = 1 TO LEN(expression$)
byte$ = MID$(expression$, position%, 1)
flag% = 0
IF ASC(byte$) >= ASC("0") AND ASC(byte$) <= ASC("9") OR ASC(LCASE$(byte$)) >= ASC("a") AND
ASC(LCASE$(byte$)) <= ASC("z") OR byte$ = "." THEN
flag% = -1
output$ = output$ + byte$
END IF
IF byte$ = CHR$(34) THEN
flag% = -1
DO
output$ = output$ + byte$
byte$ = MID$(expression$, position%, 1)
position% = position% + 1
LOOP UNTIL byte$ = CHR$(34)
END IF
IF byte$ + MID$(expression$, position% + 1, 1) = "!=" THEN
byte$ = "!="
position% = position + 1
END IF
IF INSTR("<= >=", byte$ + MID$(expression$, position% + 1, 1)) THEN
byte$ = byte$ + "="
position% = position% + 1
END IF
IF byte$ = "!" THEN
flag% = -1
output$ = output$ + ", 255, ^"
END IF
IF NOT flag% THEN
SELECT CASE byte$
CASE "("
push byte$
CASE ")"
DO
byte$ = pop$
IF byte$ = "(" THEN EXIT DO
output$ = output$ + byte$
LOOP
CASE ELSE
output$ = output$ + ", "
o2$ = stack$(size%)
IF precedence%(byte$) <= precedence%(o2$) THEN
output$ = output$ + pop$ + ", "
END IF
push byte$
END SELECT
END IF
NEXT position%
FOR element% = 1 TO size%
output$ = output$ + ", " + pop$
NEXT element%
convert$ = output$
END FUNCTION
FUNCTION pop$
pop$ = stack$(size%)
size% = size% - 1
END FUNCTION
FUNCTION precedence% (operator$)
SELECT CASE operator$
CASE "*", "/", "\"
precedence% = 7
CASE "+", "-", "$"
precedence% = 6
CASE "<", "<=", ">", ">="
precedence% = 5
CASE "=", "!=", "<>"
precedence% = 4
CASE "&"
precedence% = 3
CASE "|"
precedence% = 2
CASE "^"
precedence% = 1
END SELECT
END FUNCTION
SUB push (value$)
size% = size% + 1
stack$(size%) = value$
END SUB | 2012-04-09 | 2:08 PM |
| HorvatM | Re:Infix to RPN Expression ConverterThe box with the credits at the top makes it demoscene-like. But it could use some ASCII art. :D | 2012-04-09 | 3:40 PM |
| Jason | Re:Infix to RPN Expression Converteri couldn't help myself. | 2012-04-10 | 4:30 AM |
Code
2021 Brandon Cornell
