To: J3                                                     J3/25-126r1
From: Steve Lionel
Subject: US-09 Allow I/O of Enumerator Names
Date: 2025-February-20

Reference: 23-151r1, 25-007

This paper specifies the edits to support F202Y work item US-09,
as described in paper 23-151r1. In summary, entities of
non-interoperable enumeration type (7.6.2) may now appear in
the I/O list of a formatted I/O statement when corresponding to
G format edit descriptor, list-directed or namelist-directed I/O.

Edits
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[xv] Introduction p2

Add under the Input/Output bullet:

"Entities of enumeration type (7.6.2) may now
appear in the I/O list of list-directed and namelist-directed
input/output statements, and when corresponding to a G format edit
descriptor in formatted input/output statements."

[299:19] 13.7.2.1p1 Data edit descriptors > General rules

In the sentence "The I, B, O, and Z edit descriptors can be used to specify
input/output of enumeration type data.", insert "G," in an appropriate
place in the list of edit descriptors."

[308:30] 13.7.5.1p1 Generalized editing Overview

After "enum type" insert ", enumeration type, "

so that the sentence reads:

The Gw, Gw.d and Gw.d Ee edit descriptors are used with an effective
item of enum type, enumeration type, or any intrinsic type.

[309:31+]

After 13.7.5.3 "Generalized logical editing", a new subclause:

13.7.5.x Generalized enumeration editing

For input with a Gw, Gw.d, or Gw.dEe edit descriptor, the character
string consists of a valid enumerator-name for the type of the input
list item, irrespective of case, with trailing blanks ignored. If the
input field does not contain such a name, an error condition occurs.
The value assigned to the effective item is the enumeration value
with that name.

For output, the field is the enumerator-name for the
output list value, in uppercase and padded with blanks to the right
if necessary to satisfy a nonzero w field. If w is nonzero but is
shorter than the width of the enumerator-name, the output field is
filled with asterisks. If w is zero, the output field is the exact
length of the enumerator-name.

NOTE
An enumerator name consists of the characters of the name in the
Fortran character set; the default character set is required to
include those characters.

[315:15+] 13.10.3.1p6+ List-directed input forms

Insert a new paragraph:

When the next effective item is of an enumeration type, the value
in the input record is interpreted as if a Gw edit descriptor
with a suitable value of w were used.

[317:27+] 13.10.4p7+ List-directed output

Insert a new paragraph:

Enumeration type output values are produced with the effect of
a G0 edit descriptor.

[320:7] 13.11.3.3p1 Namelist input values

In "where c is a literal constant" insert "or named " after
"literal".

so that the sentence reads:

Each value is either a null value (13.11.3.4), c, r*c, or r*,
where c is a literal or named constant, optionally signed if
8 integer or real, and r is an unsigned, nonzero, integer
literal constant.

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