# fortls - Fortran Language Server
[](https://pepy.tech/project/fortls)
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`fortls` is an implementation of the [Language Server Protocol](https://github.com/Microsoft/language-server-protocol)
(LSP) for Fortran using Python (3.7+).
All code editors that support LSP can integrate with `fortls` see the section
[Editor Integration](https://gnikit.github.io/fortls/editor_integration.html#editor-integration) in the documentation.
Some supported code editors include:
[Visual Studio Code](https://gnikit.github.io/fortls/editor_integration.html#visual-studio-code),
[Atom](https://gnikit.github.io/fortls/editor_integration.html#atom),
[Sublime Text](https://gnikit.github.io/fortls/editor_integration.html#sublime-text),
[(Neo)Vim](https://gnikit.github.io/fortls/editor_integration.html#vim-neovim-gvim),
and [Emacs](https://gnikit.github.io/fortls/editor_integration.html#emacs).
## Features
- Project-wide and Document symbol detection and Renaming
- Hover support, Signature help and Auto-completion
- GoTo/Peek implementation and Find/Peek references
- Preprocessor support
- Documentation parsing ([Doxygen](http://www.doxygen.org/) and
[FORD](https://github.com/Fortran-FOSS-Programmers/ford) styles)
- Access to multiple intrinsic modules and functions
- `ISO_FORTRAN_ENV` GCC 11.2.0
- `IOS_C_BINDING` GCC 11.2.0
- `IEEE_EXCEPTIONS`, `IEEE_ARITHMETIC`, `IEEE_FEATURES` GCC 11.2.0
- OpenMP `OMP_LIB`, `OMP_LIB_KINDS` v5.0
- OpenACC `OPENACC`, `OPENACC_KINDS` v3.1
- Diagnostics
- Multiple definitions with the same variable name
- Variable definition masks definition from parent scope
- Missing subroutine/function arguments
- Unknown user-defined type used in `TYPE`/`CLASS` definition
(only if visible in project)
- Unclosed blocks/scopes
- Invalid scope nesting
- Unknown modules in `USE` statement
- Unimplemented deferred type-bound procedures
- Use of non-imported variables/objects in interface blocks
- Statement placement errors (`CONTAINS`, `IMPLICIT`, `IMPORT`)
- Code actions
- Generate type-bound procedures and implementation templates for
deferred procedures
### Notes/Limitations
- Signature help and hover does not handle elegantly overloaded functions i.e. interfaces
## `fortls` vs `fortran-language-server`
This project was originally based on `fortran-language-server` LSP implementation, but the two projects have since diverged.
`fortls` (this project) is now developed independently of the upstream `hansec/fortran-language-server` project and contains numerous new features and bug fixes
the original `fortran-language-server` does not.
For a complete and detailed list of the differences between the two Language Servers
see the Documentation section: [Unique fortls features (not in fortran-language-server)](https://gnikit.github.io/fortls/fortls_changes.html)
The name of executable for this project has been chosen to remain `fortls`
to allow for integration with pre-existing plugins and workflows, but it could
change in the future.
## Installation
### PyPi
```sh
pip install fortls
```
### Anaconda
```sh
conda install -c conda-forge fortls
```
for more information about the Anaconda installation [see](https://github.com/conda-forge/fortls-feedstock#about-fortls)
### Common installation problems
It is **NOT** recommended having `fortls` and `fortran-language-server`
simultaneously installed, since they use the same binary name. If you are having trouble
getting `fortls` to work try uninstalling `fortran-language-server` and reinstalling `fortls`.
With `pip`
```sh
pip uninstall fortran-language-server
pip install fortls --upgrade
```
or with Anaconda
```sh
conda uninstall fortran-language-server
conda install -c conda-forge fortls
```
## Settings
`fortls` can be configured through both the command line e.g.
`fortls --hover_signature` or through a Configuration json file.
The two interfaces are identical and a full list of the available options can
be found in the [Documentation](https://gnikit.github.io/fortls/options.html)
or through `fortls -h`
An example for a Configuration file is given below
```json
{
"incremental_sync": true,
"lowercase_intrinsics": true,
"hover_signature": true,
"use_signature_help": true,
"excl_paths": ["tests/**", "tools/**"],
"excl_suffixes": ["_skip.f90"],
"include_dirs": ["include/**"],
"pp_suffixes": [".F90", ".h"],
"pp_defs": { "HAVE_HDF5": "", "MPI_Comm": "integer" }
}
```
## Implemented server requests
| Request | Description |
| -------------------------------- | ------------------------------------------------------ |
| `workspace/symbol` | Get workspace-wide symbols |
| `textDocument/documentSymbol` | Get document symbols e.g. functions, subroutines, etc. |
| `textDocument/completion` | Suggested tab-completion when typing |
| `textDocument/signatureHelp` | Get signature information at a given cursor position |
| `textDocument/definition` | GoTo definition/Peek definition |
| `textDocument/references` | Find all/Peek references |
| `textDocument/documentHighlight` | Same as `textDocument/references` |
| `textDocument/hover` | Show messages and signatures upon hover |
| `textDocument/implementation` | GoTo implementation/Peek implementation |
| `textDocument/rename` | Rename a symbol across the workspace |
| `textDocument/didOpen` | Document synchronisation upon opening |
| `textDocument/didSave` | Document synchronisation upon saving |
| `textDocument/didClose` | Document synchronisation upon closing |
| `textDocument/didChange` | Document synchronisation upon changes to the document |
| `textDocument/codeAction` | **Experimental** Generate code |
## Acknowledgements
This project would not have been possible without the original work of [@hansec](https://github.com/hansec/)
in [`fortran-language-server`](https://github.com/hansec/fortran-language-server)
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## Bug reports
When [filing bugs](https://github.com/gnikit/fortls/issues/new)
please provide example code to reproduce the observed issue.
## Security Policy
To report a security vulnerability please follow the instructions in our
[Security page](https://github.com/gnikit/fortls/security/policy).
## License
This project is made available under the [MIT License](https://github.com/gnikit/fortls/blob/master/LICENSE).