ConvertBot: implements a foreach iteration loop within a macro

2020-04-27T22:05:08Z

implements a foreach iteration loop within a macro

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implements a foreach iteration loop within a macro
<pre>
<ITEM> Result label to hold item
<FUNC> Function type [INDF,INFILE,INLIST,INSIZE,INTABLE,INTF]
<IN> Variable containing input values

A FOREACH-ENDFOR combination is used in a macro to loop through each
value in a set defined by either a List, Table, or File.

Each pass through the loop, the result <ITEM> will contain the next
member of the set.

Modifiers may be added to the end of the <FUNC> name to modify behavior.
For example, INTABLE/V for key values instead of key names.

There are no restrictions nesting FOREACH loops.

Since 2.5.0 the generic IN function has been added that can iterate over
a large number of Java objects, including:
o java.util.Map (includes Table, Hashtable, HashMap, ...)
o java.util.Collection (includes List, Vector, LinkedList, ...)
o java.util.Iterator (any implementation of the Iterator interface)
o java.util.Enumeration (any implementation of the Enumeration interface)
o java.lang.Object[] (any generic Java array)
o nxm.sys.lib.Data (the values in a Data object via Data.toVector())

Notes:
o Using IN for a Map iterates over the keys in the Map, using IN/V
iterates over the values in the Map.
o The IN function only supports /REV when using an Object[].

FUNCTIONS:
INDF - Each element in a Midas data file
INFILE - Alias for INDF
INLIST - Each element in a comma separated list
INSIZE - Iterate for IN=<size>
INTABLE - Each key in a table or KeyVector
INTABLE/V - Each value in a table or KeyVector
INTF - Each line in a text file
INKW - Each keyword in a Midas file with scope
IN - Each item in a Java object (see above)
IN/V - Each value in a Java Map object (see above)

EXAMPLES:
1. Erase all files whose names are in a given data file
foreach name INDF mydatafile
erase name
endfor

2. Iterate through each item in a LIST
foreach area INLIST "MYOPT,SP,GEO,SYS"
configure c ^area
endfor

3. Iterate through each element in a FILE (0 to SIZE-1)
foreach offset INSIZE FILE(fftdemo).size
say "Data at ^offset is ^{FILE(fftdemo).data(offset)}"
endfor

4. Iterate through each KEY in a table
foreach key INTABLE msg.data
say "Key ^key = ^msg.data.^key"
endfor

5. Iterate through each KEY in a KeyVector. Produces values for layName of
GRID, WORLD and CITIES
plot/bg world|cities
foreach layName INTABLE reg.PLOT.layers
say "Layer name = ^layName"
endfor

6. Iterate through each VALUE (KEY=VALUE) in a table
foreach val INTABLE/V msg.data
say "Value = ^val"
endfor

7. Iterate through each line in a TEXT file
foreach line INTF mytextfile
say "Next Line is: ^line"
endfor

8. Iterate through each keyword in a Data file
foreach kwi INKW env.hwfile /scope=tag=alias
say "Next Key: ^kwi.name Value: ^kwi.value"
endfor

9. Iterates over a Java Vector
new java.util.Vector vect
...
foreach val IN vect
say "val = ^{val}"
endfor

Switches:
/REV - process elements in reverse order (not implemented)
/SCOPE - For INKW only. Sets the SCOPE. See KEYWORD command.
/SORT - process elements in sorted order (applies only to Tables)
/VAL - Same as INTABLE/V or IN/V

SEE ALSO: ENDFOR, BREAK, KEYWORD

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[[Category:NXM_Explain]]

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ConvertBot: implements a foreach iteration loop within a macro