Domain-Specific Languages in R

 This book introduces embedded domain-specific languages in R. The term domain-specific languages, or DSL, refers to programming languages specialized for a particular purpose, as opposed to general-purpose programming languages. Domain-specific languages ideally give you a precise way of specifying tasks you want to do and goals you want to achieve, within a specific context. Regular expressions are one example of a domain-specific language, where you have a specialized notation to express patterns of text. You can use this domain-specific language to define text strings to search for or specify rules to modify text. Regular expressions are often considered very hard to read, but they do provide a useful language for describing text patterns. Another example of a domain-specific language is SQL—a language specialized for extracting from and modifying a relational database. With SQL, you have an expressive domain-specific language in which you can specify rules as to which data points in a database you want to access or modify.