1 line
3.5 KiB
Plaintext
1 line
3.5 KiB
Plaintext
|
;..............................................................................;
;
; EVAL - Evaluate word expression to A
;
; eval expression
;
; The first operand in an expression may or may not be present. If it is
; present then the accumulator will be loaded with its value before expression
; evaluation begins.
;
; Sample expressions:
;
; eval 'Var1.+Var2.-Var3.+#10'
; eval '.*Var3./Var4.%Var5'
;
; Note:
;
; Eleven operations are supported +,-,*,/,% (mod), ^ (and), | (or), x (eor), < (asl),
; > (lsr), i (inc), and d (dec). Each of these must be preceded by a '.' and no spaces
; can be present in the expression. The expression should be quoted. Also note that
; both immediate and variable word values may be operands.
;
;..............................................................................;
MACRO
&lab eval &exp
&lab
lclc &operand
lcla &opstart
lclc &newexp
IF (&substr(&exp,1,1) = '''') or (&substr(&exp,1,1) = '"') THEN
&newexp setc &substr(&exp,2,&len(&exp)-2)
ELSE
&newexp setc &exp
ENDIF
&operand setc &substr(&newexp,1,1)
IF &operand='.' GOTO .no1op
&opstart seta &pos('.',&newexp)
IF &opstart>0 GOTO .doexp
lda &newexp
mexit
.doexp
&operand setc &substr(&newexp,1,&opstart-1)
&newexp setc &substr(&newexp,&opstart,&len(&newexp)-&opstart+1)
lda &operand
.no1op
eval2 &newexp
mexit
MEND
;
; Eval2 is the heart of the eval macro
;
MACRO
&lab eval2 &exp
&lab ;
IF (&nbr(&syslist)=0) GOTO .done
lclc &op
lclc &operand
lclc &rest
lcla &restbegin
lclc &newexp
&newexp setc &exp
.start
&op setc &substr(&newexp,2,1)
&rest setc &substr(&newexp,3,&len(&newexp)-2)
&restbegin seta &pos('.',&rest)
IF &restbegin>0 GOTO .ok
&restbegin seta &len(&rest)+1
.ok
&operand setc &substr(&rest,1,&restbegin-1)
IF &op='+' GOTO .doadd
IF &op='-' GOTO .dosub
IF &op='*' GOTO .domul
IF &op='/' GOTO .dodiv
IF &op='%' GOTO .domod
IF &op='^' GOTO .doand
IF &op='|' GOTO .door
IF &op='x' GOTO .doxor
IF &op='<' GOTO .doasl
IF &op='>' GOTO .dolsr
IF &op='i' GOTO .doinc
IF &op='d' GOTO .dodec
.done
mexit
.doadd
clc
adc &operand
GOTO .dorest
.dosub
sec
sbc &operand
GOTO .dorest
.domul
pha
pha
pha
lda &operand
pha
_Multiply
pla
plx
GOTO .dorest
.dodiv
pha
pha
pha
lda &operand
pha
_SDivide
pla
plx
GOTO .dorest
.domod
pha
pha
pha
lda &operand
pha
_SDivide
plx
pla
GOTO .dorest
.doand
and &operand
GOTO .dorest
.door
ora &operand
GOTO .dorest
.doxor
eor &operand
GOTO .dorest
.doasl
asl a
GOTO .dorest
.dolsr
lsr a
GOTO .dorest
.doinc
inc a
GOTO .dorest
.dodec
dec a
GOTO .dorest
.dorest
&restbegin seta &pos('.',&rest)
IF &restbegin>0 GOTO .next
mexit
.next
&newexp setc &substr(&rest,&restbegin,&len(&rest)-&restbegin+1)
GOTO .start
mexit
MEND
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