iv Preface
All these projects are dependent on the TypeScript package (even the TypeScript
compiler is itself written in TypeScript). The dependency on other language projects
varies. None of the projects are dependent on Visual Studio Code. These projects only
need a code editor that can work with the TypeScript tsc compiler – and there are
many (see middle of main page at http://typescriptlang.org). Visual Studio Code is
one such editor, that is particularly good, open source, freely available for macOS,
Linux and Windows, and it too is written in TypeScript. But you may choose to use any
code editor to investigate the source trees of these projects.
Viewing Markdown Files
In addition to source in TypeScript, all these projects also contain documentation files
in markdown format (*.md). Markdown is a domain specific language (DSL) for
represent HTML documents. It is easier / quicker to manually author compared to
HTML. When transformed to HTML it provides professional documentation. One
question you might have is how to view them (as HTML, rather that as .md text). One
easy way to see them as html is just to view the .md files on Github, e.g.:
● https://github.com/angular/angular
Alternatively, on your own machine, most text editors have either direct markdown
support or it is available through extensions. When examining a source tree with .md
files, it is often useful when your code editor can also open markdown files and
transform them to HTML when requested. StackOverflow covers this issue here:
● http://stackoverflow.com/questions/9843609/view-markdown-files-offline
For example, Visual Studio Code supports Markdown natively and if you open a .md
file and select CTRL+SHIFT+V, you get to see nice HTML:
● https://code.visualstudio.com/docs/languages/markdown
Finally, if you want to learn markdown, try here:
● http://www.markdowntutorial.com
Benefits of Understanding The Source
There are many good reasons for intermediate- to advanced-developers to become
familiar with the source trees of the projects that provide the foundation for their daily
application development.
Enhanced Understanding - As in common with many software packages, descriptions
of software concepts and API documentation may or may not be present, and if
present may not be as comprehensive as required, and what is present may or may
not accurately reflect what the code currently does - the doc for a particular concept
may well once have been up-to-date, but code changes, the doc not necessarily so,
and certainly not in lock-step, and this applies to any fast evolving framework.
Advanced Debugging – When things go wrong, as they must assuredly will (and
usually just become an important presentation to potential customers), application
developers scrambling to fix problems will be much quicker when they have better
insight via knowing the source.
Optimization – for large-scale production applications with high data throughput,
knowing how your application’s substrate actually works can be really useful in
