Delivering comprehension features into source code editors through LSP

The maintenance of large, legacy software often results in higher development time and cost due to increasing size and complexity of the codebase and its documentation, their continuously eroding quality and fluctuation among developers. Code comprehension tools are designed to tackle this issue by providing various textual information, visualization views and source code metrics on multiple abstraction levels. These tools usually process not only the codebase, but also the build information, the version control repository and other available information sources. Meanwhile source code editors and integrated development environments (IDEs) are not performing well in the field of code comprehension as they are optimized for writing new code, not for effective browsing. This can easily result in frequent switching between environments during development, hindering effective programming and raising development cost. Language Server Protocol (LSP) is an open-source protocol to connect source code editors with servers that provide language-specific features. In this research we analyze how LSP can be utilized to improve the code comprehension experience inside code editors by integrating the features of such tools through remote procedure calls. As a prototype solution we showcase the integration of two open-source applications: Visual Studio Code and the Code Compass code comprehension tool.