https://github.com/pdebuyl/fortran_hash_table

"<string,string>" hash table in Fortran 2008
https://github.com/pdebuyl/fortran_hash_table

fortran fortran2008 hashtable

Last synced: 20 days ago
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"<string,string>" hash table in Fortran 2008

• Host: GitHub
• URL: https://github.com/pdebuyl/fortran_hash_table
• Owner: pdebuyl
• License: bsd-3-clause
• Created: 2018-03-18T19:23:56.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-03-20T12:56:17.000Z (almost 7 years ago)
• Last Synced: 2024-11-13T20:42:50.337Z (3 months ago)
• Topics: fortran, fortran2008, hashtable
• Language: Fortran
• Homepage: https://pdebuyl.github.io/fortran_hash_table/
• Size: 174 KB
• Stars: 14
• Watchers: 4
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Fortran hash table {#mainpage}

The module `dictionary_m` implements a "" hash table based on the djb2 hash

function.

    program example_from_readme

      use dictionary_m

      implicit none

      type(dictionary_t) :: d

      call d%init(1024)

      call d%set('one', 'one')

      call d%set('pi', '3.14159')

      write(*,*) 'one', ' = ', d%get('one')

      write(*,*) 'pi', ' = ', d%get('pi')

    end program example_from_readme

**Author:** Pierre de Buyl

**License:** BSD

**Code repository:** [https://github.com/pdebuyl/fortran_hash_table/](https://github.com/pdebuyl/fortran_hash_table/)

## Project goals

- Demonstrate a hash table in Fortran.

- Use standard Fortran 2008.

- Single file implementation.

- No dependency.

- No preprocessing.

- Not design a generic container, `dictionary_m` just stores strings. It is of course

  possible to replace the "value" entry in the type `entry_t` for a single-datatype

  dictionary.

The hash table is based on plain allocatable arrays and the base data is stored in `(len=:),

allocatable` character variables. Buckets are extended arbitrarily by reallocation, thus

collisions will slow down this implementation with respect to others using better data

structures.

The goal is not to beat other implementations performance-wise but to provide the

convenience for Fortran programmers to store configuration settings, or other auxiliary data

easily.

## Installation

`dictionary_m` consists of a single Fortran file. You can just drop `src/dictionary_m.f90`

in your Fortran project.

The code requires Fortran 2008 support. For gfortran, I have tested version 6.3 and 7.2. For

Intel Fortran, I have tested version 16.0.3.

## Documentation and coverage

If you read this page from the "GitHub pages" doxygen-generated

[documentation](https://pdebuyl.github.io/fortran_hash_table/), you can access:

- The documentation of the module `dictionary_m`.

- The [list of files and test programs](files.html)

- The [coverage data](coverage/index.html) generated from lcov and genhtml.

## See also

I am neither the first or the only person having implemented a hash table in Fortran. While

the implementations below did not fit my design goals, they might suit you just fine.

- [HASTY](https://github.com/szaghi/HASTY) by Stefano Zaghi: *HASh Table fortran container exploting coarraY*.

- In [FLIBS](http://flibs.sourceforge.net/) by Arjen Markus, `dictionaries` is a *Generic

  source code for implementing a mapping of strings to data.*

- The Fortran Wiki has a [page on hash tables](http://fortranwiki.org/fortran/show/Hash+tables).