CP/M/CPM_CDROM.iso/simtel/sigm/vols000/vol064/mid.src

Text File | 1984-04-29 | 2KB | 188 lines

;
;TYPE
;$STRING80=STRING 80;
;$STRING0 = STRING 0;
;$STRING255 = STRING 255;
;BYTE = 0..255;
;VAR
;DATA:$STRING255;
;START,STOP:INTEGER;
;
;
;FUNCTION LENGTH(X:$STRING255):INTEGER;EXTERNAL;
    EXTD    L168,LENGTH
;PROCEDURE SETLENGTH(VAR X:$STRING0;Y:INTEGER);EXTERNAL;
    EXTD    L169,SETLENGT
;
;{function to extract characters from within a string, starting at
;position "y" and ending at position "z"..
;corresponds to BASIC command  MID$(A$,X,Y) }
;
;FUNCTION MID(X:$STRING255; Y,Z:BYTE):$STRING255;
;
;{y = starting position and z = the ending position in string x}
;
;LABEL 1;
;VAR
;LEN,I:INTEGER;
;MIDDLE:$STRING255;
;
;BEGIN
L170
    NAME MID
    ENTRY MID
MID:
    ENTR    D,2,260
;SETLENGTH(MIDDLE,0);
    STMT    D,1
    PUSH    IX
    POP    H
    LXI    B,-4
    DADD    B
    PUSH    H
    MOV    H,A
    MOV    L,A
    PUSH    H
    CALL    L169
;LEN:=LENGTH(X);
    STMT    D,2
    PUSH    IX
    POP    H
    LXI    B,265
    DADD    B
    SPSH    S,255
    CALL    L168
    STMT    M,2
    MOV    -2(IX),D
    MOV    -3(IX),E
;
;IF (Y < 1) OR (Y > Z) OR ( Y > LEN) OR (LEN = 0) OR (Z > 255) THEN GOTO 1;
    STMT    D,3
    MOV    H,A
    MOV    L,9(IX)
    MOV    A,L
    CMPI    D,1
    MOV    A,H
    JC    L198
    MOV    H,A
    MOV    L,9(IX)
    MOV    D,A
    MOV    E,8(IX)
    GRET    D,0
    JC    L198
    MOV    H,A
    MOV    L,9(IX)
    MOV    E,-3(IX)
    MOV    D,-2(IX)
    GRET    D,0
    JC    L198
    MOV    L,-3(IX)
    MOV    H,-2(IX)
    MOV    D,A
    MOV    E,A
    DSB1    D,0
    JZ    L198
    MOV    H,A
    MOV    L,8(IX)
    MVI    A,255
    CMP    L
    MOV    A,H
    JNC    L197
L196
L198    EQU    L196
    STMT    D,4
    CTRL    M,4
    JMP    L171
L197
;IF Z > LEN THEN Z:=LEN;
    STMT    D,5
    MOV    H,A
    MOV    L,8(IX)
    MOV    E,-3(IX)
    MOV    D,-2(IX)
    GRET    D,0
    JNC    L239
    STMT    D,6
    MOV    L,-3(IX)
    MOV    H,-2(IX)
    RCHK    H,0,255
    MOV    8(IX),L
L239
;
;FOR I:= Y TO Z DO APPEND(MIDDLE,X[I]);
    STMT    D,7
    MOV    H,A
    MOV    L,9(IX)
    MOV    0(IX),H
    MOV    -1(IX),L
    XCHG
    PUSH    IX
    MOV    H,A
    MOV    L,8(IX)
    XTHL
L260
    MOV    D,M
    DCX    H
    MOV    E,M
    XTHL
    PUSH    H
    GE    D,0
    JNC    L261
    STMT    D,8
    PUSH    IX
    POP    H
    LXI    B,-4
    DADD    B
    PUSH    H
    LXI    H,255
    PUSH    H
    MOV    L,-1(IX)
    MOV    H,0(IX)
    RCHK    H,1,255
    XCHG
    LXI    H,265
    ADDR    IX
    MOV    D,A
    MOV    E,M
    INR    D
    PUSH    D
    LXI    H,2
    PUSH    H
    CALL    L137
    CTRL    M,8
    POP    H
    XTHL
    INR    M
    INX    H
    JRNZ    L286
    INR    M
    JV    L287
L286
    JMP    L260
L261
    POP    D
L287
    POP    D
;
;1:
    STMT    D,9
L171
;MID:=MIDDLE;
    STMT    D,10
    PUSH    IX
    POP    H
    LXI    B,-4
    DADD    B
    RCHK    S,255
    XCHG
    PUSH    IX
    POP    H
    LXI    B,521
    DADD    B
    XCHG
    LXI    B,256
    LDDR
;END;
    STMT    D,11
    EXIT    D,258