Download RPG IV V5R1 Enhancements - Metro Midrange Systems Association

RPG IV V5R1 Enhancements
Presented by
Barry Diehl
At a Glance

Built-In Functions (BIFs)
 Free-format
 Runtime Control of Files and Members
 Improved Error Control
 Increased Java support
 Miscellaneous Changes
How did it happen?

George Farr of IBM Toronto surveys users
giving them a list of possible enhancements.
 Each enhancement is “priced”
 Survey participants can spend $100
What didn’t make it?
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Multiple dimension arrays
 Keylists in D specs
 More H-Spec Keywords
 Bitwise operations in expressions
Built-In Functions
Taking time
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%TIME{(expression{:time-format})}
%TIMESTAMP{(expression{:*ISO|*ISO0})}
%DATE{(expression{:date-format})}
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If no value specified, current system values are retrieved
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When the expression is *DATE, UDATE or a timestamp,
don’t use the format - the system knows the format
One More Time
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%SECONDS(number)
%MINUTES(number)
%HOURS(number)
%DAYS(number)
%MONTHS(number)
%YEARS(number)
Determine date in 3 years
newdate = date + %YEARS(3)
Determine date 6 months ago
loandate = date - %MONTHS(6)
What’s the Difference?
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%DIFF(op1:op2:*MS|*S|*MN|*H|*D|*M|*Y)
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Determine the number of days between 2 dates
NumDays = %Diff(LoanDate:DueDate:*D)
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Add number of minutes between the start and end
TotalTime = TotalTime + %Diff(StartTime:EndTime:*MN)
Parts Is Parts

Extract a subset of a date, time or timestamp with
%SUBDT
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%SUBDT(value:*MS|*S|*MN|*H|*D|*M|*Y)
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date = d’1999-02-17’;
time = t’01.23.45’;
num = %SubDt(date:*Y); // num = 1999
num = %SubDt(time:*MN); // num = 23
A Well-Defined Search

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%LOOKUPxx(arg:array{:startindex{:numelems}}) returns array index of the element in array that matches
Where xx =
– blank  an exact match
– LT  value closest to arg, but less than arg
– LE  an exact match or the value closest to arg, but less than arg
– GT  value closest to arg, but greater than arg
– GE  an exact match or the value closest to arg, but greater than
arg
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Zero is returned if no match found
%Found and %Equal don’t work on this function
Use %TLOOKUPxx for tables
Other Functions
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%ALLOC and %REALLOC
 %CHECK and %CHECKR
 %XLATE
 %SHTDN
 %SQRT
Free-Format RPG
Free-format Rules

/FREE and /END-FREE
 Write code between columns 8 and 80
 General form:
opcode(extenders) Factor 1 Factor 2 Result
 Statements end with semi-colon
 End-of-line comments marked with //
 Compiler directives can be used
 Can’t define fields or have result indicators
 Free and fixed can be mixed
Function Replacements
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ADDDUR  %YEARS, %MONTHS
ALLOC  %ALLOC
CHECK  %CHECK
CHECKR  %CHECKR
EXTRCT  %SUBDT
LOOKUP  %LOOKUPxx, %TLOOKUPxx
MVR  %REM
OCCUR  %OCCUR
REALLOC  %REALLOC
Function Replacements
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SCAN  %SCAN
SHTDN  %SHTDN
SQRT  %SQRT
SUBDUR  %DIFF or minus sign
SUBST  %SUBST
TIME  %DATE, %TIME, %TIMESTAMP
XFOOT  %XFOOT
XLATE  %XLATE
Operator Replacement
ADD  +
 CAT  +
 DIV  /
 MULT  *
 SUB  
Generalize
ANDxx  AND
 DOUxx  DOU
 DOWxx  DOW
 IFxx  IF
 ORxx  OR
 WHENxx  WHEN
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Social Engineering - Obsolete
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BITOFF  use MOVE
BITON  use MOVE
CABxx
CAS and ENDCS
COMP
GOTO
MHHZO
MHLZO
MLHZO
MLLZO
TAG
Social Engineering – Moving to New
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CALL and CALLB  CALLP
DEFINE  D spec – use LIKE or DTAARA keywords
DO  FOR
END  need to qualify the type now
MOVE  EVALR or built-in functions
MOVEA
MOVEL  EVAL or built-in functions
PARM and PLIST  use prototype definition
SETOFF and SETON  EVAL
TESTN and TESTZ
Z-ADD and Z-SUB
Free-Form Details
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KLIST and KFLD not included
EVAL is optional
Debug works fine
Most examples in Reference are free-form
Macro in CODE/400 performs one-way
conversion
Mix of Free and Fixed-formats is ok
Compiler directives ok - but no SQL
Fixed-format (page 1)
Free-format (page 1)
Fixed-format (page 2)
Free-format (page 2)
Fixed-format (page 3)
Free-format (page 3)
Fixed-format (page 4)
Free-format (page 4)
Runtime Control of Files and
Members
Runtime Control of Files and
Members

Use EXTFILE(file name) and
EXTMBR(member name) as keywords in F
Spec
 Need USROPN keyword too
 OVRDBF still has control
Improved Error Control
Current Checking
Error indicator or Extender (E) – doesn’t
handle all situations
 *PSSR or INFSR subroutines – can’t easily
return to the statement that caused the
problem
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Monitor Group
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MONITOR - marks beginning of code to trap errors
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ON-ERROR {exception-id1 {:exception-id2…}}
Begins the group for one or more status codes. Can also
use:
– *PROGRAM - all program errors
– *FILE - all file errors
– *ALL - all errors

ENDMON - marks the end of the group
Monitor Group Example
Monitor Group Example page 2
New Error Processing Order
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Statement indicators
 Opcode extenders, %STATUS, %ERROR
 MONITOR group
 INFSR
 *PSSR
Increased Java Support
(Many thanks to George Farr of IBM - these are his examples)
RPG Calling JAVA: 3 options
1.
2.
3.
Use QCMDEXC to launch the JVM for
the Java class
Use system C-APIs to instantiate Java
objects and call methods in them (Java
Native Invocation or JNI)
Use V5R1 RPG enhancements that mask
the JVN complexity
Calling Java from RPG

Declare Objects
 Prototype Java Methods
 Instantiate an Object
Declare Objects
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D Test
S
O
CLASS(*JAVA:’java.lang.String’)
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Must declare a field to hold the object reference
– First parameter must be *JAVA
– Fields of type ‘O’ cannot be DS subfields
– Arrays of objects are allowed
– Fields of type ‘O’ are NOT pointers, they only store
references to objects
Prototype Java Methods
EXTPROC(*JAVA:’java.lang.String’:’trim’)
CLASS(*JAVA:’java.lang.String’)
STATIC

D trimstring PR
D
D

EXTPROC accepts 3 parameters
O
– *JAVA keyword
– ‘package.class’ name of class containing method
– Name of method or *CONSTRUCTOR

Specify return type
– Use CLASS keyword if it returns a Java object (‘O’ type)
– Specify STATIC for static methods
Instantiate an Object
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D crtBigDec
D
D Parm1
D*
D refflt
D*
D DblField
PR O
8F
S
O
CLASS(*JAVA:’java.math.BigDecimal’)
S
8F
INZ(‘0’)
C* Instantiate the class
C*
C
EVAL
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EXTPROC(*JAVA:’java.math.BigDecimal’:*CONSTRUCTOR)
CLASS(*JAVA:’java.math.BigDecimal’)
VALUE
refflt = crtBigDec(dblField)
Prototype the desired constructor method
Declare the object reference variable
Call the constructor method, store result
Calling Methods Example
D fld
D str
D*
D makestring
D
D parm
D*
D makealpha
D*
D trimstring
D
C
C
C
S
S
PR
10A INZ(‘ Farr ‘)
O CLASS(*JAVA:’java.lang.String’)
O
EXTPROC(*JAVA:’java.lang.String’:*CONSTRUCTOR)
CLASS(*JAVA:’java.lang.String’)
10A
PR 10A EXTPROC(*JAVA:’java.lang.String’:’getBytes’)
PR
O EXTPROC(*JAVA:’java.lang.String’:’trim’)
CLASS(*JAVA:’java.lang.String’)
EVAL str = makestring(fld)
EVAL str = trimstring(str)
EVAL fld = makeslpha(str)
Miscellaneous Changes
ELSEIF
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Can combine an ELSE and IF together
If A = 1;
X = X + 1;
ElseIf A = 2;
X = X + 2;
ElseIf A = 3;
X = X + 3;
EndIf;
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Reduce number of ENDIFs and nesting
levels
 Don’t forget about SELECT
Qualified Data Structure
Names
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New keyword QUALIFIED - allows names
to be reused in the program
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Useful in prototyped parameter definitions
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New keyword LIKEDS(data structure) will have the same structure
Qualified Data Structures
Example
Summary

Built-In Functions (BIFs)
 Free-format
 Runtime Control of Files and Members
 Improved Error Control
 Increased Java support
 Miscellaneous Changes