codee-com/open-catalog

[Fortran] format strings may generate indistinguishable output

Open

#100 opened on Sep 11, 2025

View on GitHub
 (1 comment) (0 reactions) (0 assignees)Fortran (12 forks)auto 404
Fortrangood first issuehelp wantednew check

Repository metrics

Stars
 (105 stars)
PR merge metrics
 (PR metrics pending)

Description

Format strings like '(5I0)' will generate single long number. Most of time, it is undesired behaviour.

Example:

program main
  print '(3I0)', [11, 22, 33]
  print '(3I0)', [112, 23, 3]
end program main

The same issue is for real type. For logical type, it is not a problem.

Contributor guide

Research direction
Investigate how Fortran format strings are processed and identify why width specifiers like I0 can produce ambiguous output. Trace the code that formats integer output for edit descriptors.
Tech stack
None
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Fortran
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60