To: J3                                                     J3/25-201r1
From: Steve Lionel
Subject: US-09 - Further edit for Allow I/O of Enumerator Names
Date: 2026-January-15

Reference: 25-126r1, 25-007r1

Van Snyder pointed out that paper 25-126r1, containing edits to
implement US-09 and passed at meeting 235, neglected to remove
constraint C8109 forbidding objects of enumeration-type or that contain
an enumeration type component, from appearing in a
namelist-group-object list. This paper removes that constraint.

Most of these edits are those from 25-126r1, but additional edits were
added in m238 to add clarity.

Edits
=====

[xv] Introduction p2

Add under the Input/Output bullet:

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

[140:11, C8109] 8.9 NAMELIST statement

Delete constraint C8109 which reads:

C8109 A namelist-group-object shall not be of enumeration type, or have
a direct component that is of enumeration type.

[300:19] 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."

[309:30] 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.

[310:31+]

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.

The enumerator name is the name in the enumeration definition. It need
not be accessible in the scope of the input/output statement.

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.

[316:15+] 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.

[318:27+] 13.10.4p7+ List-directed output

Insert a new paragraph:

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

[321:7] 13.11.3.3p1 Namelist input values

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

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 constant or enumerator name, optionally signed if
integer or real, and r is an unsigned, nonzero, integer literal constant.

--END--