SYNOPSIS

# Only add the 720 field to the authors when the $e subfield contains a 'promotor'
do marc_each()
if marc_match("720e","promotor")
marc_map("720ab",authors.$append)
end
end
# Delete all the 500 fields
do marc_each()
if marc_match("500",".*")
reject()
end
end

DESCRIPTION

The marc_each binder will iterate over each individual MARC field and execute the fixes only in context over each individual field.

If a MARC record contains:

    500  $aTest
    500  $aTest2$eskip
    500  $aTest3

then the fix

    do marc_each()
        marc_map("500",note.$append)
    end

will have the same effect as

    marc_map("500",note.$append)

because "marc_map" by default loops over all repeated MARC fields. But the "marc_each" bind has the advantage to process fields in context. E.g. to only map fields where the $e doesn't contain 'skip' you can write:

    do marc_each()
        unless marc_match("500e",skip)
            marc_map("500",note.$append)
        end
    end