Preface to the Revised Report

Over 16 years have passed since the publication of the Haskell 2010 language report, and the Haskell that we write today has evolved in many ways, some of which are incompatible with the language specified in the Haskell 2010 language report. In order to account for this change we saw the need to compile a revised version of the Haskell 2010 language report which does not add any novel language features but brings the report in line with the version of Haskell 2010 implemented by compilers and maintainers of the standard libraries. This revised report is the result of that effort.

Organization of the Revised Report

In distinction to the previous version of the Haskell 2010 language report, this revision separates out documentation of the standard libraries. These standard libraries are now available in the form of a zero-dependency Haskell package which makes the API specification machine readable and allows to generate documentation using standard Haskell tools like Haddock.

Changes to the Report

Forall as a keyword

The definition of the nonterminal $$ \text{𝑟𝑒𝑠𝑒𝑟𝑣𝑒𝑑𝑖𝑑}$$ has been changed to also include the terminal $\text{𝚏𝚘𝚛𝚊𝚕𝚕}$ as a reserved identifier.

Decimal characters in numeric literals

The definitions of the nonterminals $$ \text{𝑑𝑒𝑐𝑖𝑚𝑎𝑙}$$ and $$ \text{ℎ𝑒𝑥𝑖𝑡}$$ have been changed to exclude Unicode decimal digits other than $\mathrm{𝟶}$ to $\mathrm{𝟿}$.