“To run a JavaScript program, the source text needs to be processed so V8 can understand it. V8 starts out by parsing the source into an abstract syntax tree (AST), a set of objects that represent the program structure. That AST gets compiled to bytecode by Ignition. The performance of these parse + compile phases is important: V8 cannot run code before compilation is done. In this series of blog posts, we focus on parsing, and the work done in V8 to ship a blazingly fast parser.”

“All major browsers implement lazy parsing. Instead of generating an abstract syntax tree (AST) for each function and then compiling it to bytecode, the parser can decide to “pre-parse” functions it encounters instead of fully parsing them. It does so by switching to the preparser, a copy of the parser that does the bare minimum needed to be able to otherwise skip over the function. The preparser verifies that the functions it skips are syntactically valid, and produces all the information needed for the outer functions to be compiled correctly. When a preparsed function is later called, it is fully parsed and compiled on-demand.”

Fergus catalogues and briefly describes Google’s key software engineering practices.

“Technical debt tries to encapsulate many, often conflicting concepts in an easy-to-grasp explanation which can quickly become unhelpful. The idea of interest repayments affecting the ability to deliver to your customers becomes an excuse for missing deadlines, employee dissatisfaction, and user experience compromises.”

When and why to use hooks. Interesting retrospective.

Dive deep into the nitty gritty of animation performance profiling with Chloe.