formula solver 3/7

 BBS: Inland Empire Archive
Date: 03-13-93 (22:25)             Number: 336
From: QUINN TYLER JACKSON          Refer#: NONE
  To: ALL                           Recvd: NO  
Subj: formula solver 3/7             Conf: (2) Quik_Bas

'>>> Start of page 3.

' simple loop for testing
DO
    INPUT Test$
    PRINT funEvaluate(Test$)
LOOP

FUNCTION fqjFetchVar (VarName$)

    FOR i% = 1 TO VariPtr
        IF RTRIM$(VarMem(i%).Nom) = VarName$ THEN
            fqjFetchVar = VarMem(i%).Valu
            FLAG% = TRUE
            EXIT FOR
        END IF
    NEXT i%

END FUNCTION

FUNCTION fqjInOpList (OpTyp$, Op$)

SELECT CASE LEN(Op$)
    CASE 1

    FOR i% = 1 TO LEN(OpTyp$)
        IF MID$(OpTyp$, i%, 1) = Op$ THEN
            fqjInOpList = -1
            EXIT FUNCTION
        END IF
    NEXT i%

    CASE 2

    FOR i% = 1 TO LEN(OpTyp$)
        IF MID$(OpTyp$, i%, 2) = Op$ THEN
            fqjInOpList = -1
            EXIT FUNCTION
        END IF
    NEXT i%

END SELECT

END FUNCTION

FUNCTION funEvaluate (Exp$)

OPERATOR$ = ADDSUB + MULTDIV + POWER + LOGICAL
expression$ = LCASE$(Exp$)

Ptr = 1

AssignmentPtr% = INSTR(expression$, ASSIGNMENT)

IF AssignmentPtr% = 0 THEN ' just do a simple evaluation
    CALL sqjGetOp
    CALL sqjLevel1(r)
    funEvaluate = r
ELSE                       ' assign a variable!
    VariableName$ = LTRIM$(RTRIM$(LEFT$(expression$, AssignmentPtr% -_
 1)))
    Valu = funEvaluate(MID$(expression$, AssignmentPtr% + 2))

    CALL sqjAssignVar(VariableName$, Valu)

    funEvaluate = Valu
END IF
END FUNCTION

'>>> Continued on page 4.

--- Maximus/2 2.01wb
 * Origin: The Nibble's Roost, Richmond BC Canada 604-244-8009 (1:153/918)