developers:coding_rules
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| developers:coding_rules [2021/08/31 20:31] – [Modules] Xavier Gonze | developers:coding_rules [2021/08/31 20:33] – [ABINIT style for Fortran programming] Xavier Gonze | ||
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| (revised many times from the original draft in 1991, BUT NOT REALLY UP_TO_DATE ... SHOULD BE REVISED ONCE MORE) | (revised many times from the original draft in 1991, BUT NOT REALLY UP_TO_DATE ... SHOULD BE REVISED ONCE MORE) | ||
| - | |||
| - | The following sections are covered: | ||
| - | |||
| - | * Foreword. | ||
| - | * Declarations. | ||
| - | * Variables | ||
| - | * File format | ||
| - | * Constructs for flow control | ||
| - | * Use of arrays | ||
| - | * Coding practice | ||
| - | * Exception handling, I/Os | ||
| - | * To be avoided. | ||
| - | * Use of BLAS and LAPACK subroutines. | ||
| - | * Modules | ||
| - | * Derived datatypes | ||
| - | * Other topics | ||
| - | * Useful links | ||
| - | |||
| ====== 1. Foreword ====== | ====== 1. Foreword ====== | ||
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| Be cautious when you introduce such a feature, and mention it to the ABINIT coordinator. | Be cautious when you introduce such a feature, and mention it to the ABINIT coordinator. | ||
| - | ====== Derived datatypes ====== | + | ====== |
| - | Derived datatypes should be declared in the adequate module (MG: And this rule is not followed in many places, e.g dataset_type, | + | 12.a. Derived datatypes should be declared in the adequate module (MG: And this rule is not followed in many places, e.g dataset_type, |
| These are powerful F90 constructs, but the information about them is not local to the subroutine | These are powerful F90 constructs, but the information about them is not local to the subroutine | ||
| where they are used, so they should be introduced in a controlled way, in order for the programmers to become sufficiently easily familiarized with them: the introduction of a new derived datatype must be made in agreement with the coordinator of ABINIT. | where they are used, so they should be introduced in a controlled way, in order for the programmers to become sufficiently easily familiarized with them: the introduction of a new derived datatype must be made in agreement with the coordinator of ABINIT. | ||
| The introduction of appropriate derived datatypes in ABINIT is one of the central issues of v3.2 and later versions. | The introduction of appropriate derived datatypes in ABINIT is one of the central issues of v3.2 and later versions. | ||
| - | 11.b. Suffix a type identifier with ' | + | 12.b. Suffix a type identifier with ' |
| TYPE ipe_type | TYPE ipe_type | ||
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| - | 11.c. Pros and cons. | + | 12.c. Pros and cons. |
| Grouping connected variables into structured types is interesting for readability (it avoids too long | Grouping connected variables into structured types is interesting for readability (it avoids too long | ||
| Line 723: | Line 705: | ||
| However, source code itself may become less readable. Also, remember that the use of structured types is never more efficient for CPU: complex declarations should be avoided. | However, source code itself may become less readable. Also, remember that the use of structured types is never more efficient for CPU: complex declarations should be avoided. | ||
| - | ====== | + | ====== |
| For the time being, pointers are only allowed when an array has to be allocated in a subprogram, and | For the time being, pointers are only allowed when an array has to be allocated in a subprogram, and | ||
developers/coding_rules.txt · Last modified: 2021/08/31 20:35 by Xavier Gonze