A modular specification of Oberon0 using the Silver attribute grammar system

• Silver, an extensible attribute grammar system, is used to specify the language Oberon0 for the LDTA'11 Tool Challenge.
• We highlight the modular nature of these specifications.
• We show how forwarding, a default attribute evaluation mechanism, simplifies the specification of language extensions.

This paper describes an implementation of Oberon0 using the Silver attribute grammar system for the Tool Challenge at the 2011 International Workshop on Language Descriptions, Tools, and Applications. Silver was developed to study how independently-developed language extension specifications can be imported into a host language specification to define a new custom extended language. Thus it contains many features useful in modular language specification, such as forwarding, higher-order attributes, reference/remote attributes, and a simplified form of collection attributes. These are discussed in the context of the Oberon0 specification presented here.