syntax

The Eiffel Software compiler provides a set of options, available in Project Settings, which allows users to select a variant of the Eiffel programming language syntax that best suits their needs. The meanings of these options, and in fact the options themselves, are subject to change from one version to the next. Below you will find a table that defines the meaning of the syntax level variants for each version.

The specification of the Eiffel programming language has remained largely static over its life, arguably due to its sound initial design. Still, on occasion there will be significant value in evolving Eiffel and adapting it to new challenges. To accommodate this evolution, the Eiffel Software compiler provides a set of compilation variants which offer a balance of syntax support. This starts with compatibility with previously valid syntax, moves through the latest standard, and forward to language features which are currently supported but not yet etched into the standard.

The syntax specification shown here is a less complete and less formal version of that which is in the Eiffel ISO/ECMA standard document. The format is BNF-E. The Language Specification section of the standard document includes an overview of BNF-E.

There are a few parts of the syntax that are either non-production or non-representable in BNF-E. Some of these have been omitted from the following specification. These omitted parts of the syntax definition add to the precision of the specification, but knowledge of them is not always vital for developers.

The Quick Reference to the Eiffel programming language provides an informal guide to the syntax and reserved words of the language. The Eiffel programming language is described in detail in the ISO/ECMA standard document, available online.

Sometimes there are differences between the language as defined by the standard and that which is implemented by Eiffel Software.