matinal：SAP ABAP 7.40及以上新语法REDUCE 运算符

*定义

… REDUCE type(
INIT result = start_value
           …
    FOR for_exp1
    FOR for_exp2
           …
    NEXT …
         result = iterated_value
    … )
 *案例1
 TYPES: BEGIN OF TY_LINE,
         COL1 TYPE I,
       END OF TY_LINE,
       TY_TAB TYPE STANDARD TABLE OF TY_LINE WITH EMPTY KEY.
 
DATA(GT_ITAB) = VALUE TY_TAB( FOR J = 1 THEN J + 1 UNTIL J > 10
                              ( COL1 = J  )
                            ).
 
DATA(LV_SUM) = REDUCE I( INIT X = 0 FOR LS_ITAB IN GT_ITAB NEXT X = X + LS_ITAB-COL1 ).
CL_DEMO_OUTPUT=>DISPLAY( LV_SUM ).
*案例2
YPES OUTREF TYPE REF TO IF_DEMO_OUTPUT.
 
DATA(OUTPUT) = REDUCE OUTREF( INIT OUT  = CL_DEMO_OUTPUT=>NEW( )
                                   TEXT = `Count up:`
                              FOR N = 1 THEN N + 2 UNTIL N > 11
                              NEXT OUT  = OUT->WRITE( TEXT )
                                   TEXT = |{ N }| ).
 
OUTPUT->DISPLAY( ).