Enhancements in Dyalog v20.0: Arrays, Namespaces, Composition, and Inline Tracing

Asher presents some of the enhancements that were in introduced in Dyalog v20.0:

• Array notation introduces a literal syntax for most arrays – including nested and high-rank arrays – and namespaces, enabling direct construction and manipulation of complex structures.
• Namespace handling is streamlined with ⎕VGET, ⎕VSET, and extensions to ⎕NS. These are particularly useful when working with namespaces produced by ⎕JSON from web-service responses, allowing default values to mitigate missing members.
• The new compositional operator ⍛ (behind) captures the common patterns (f Y) g Y and (f X) g Y, improving clarity and reducing boilerplate.
• Inline tracing enables primitive-by-primitive evaluation with access to arguments and results, supporting debugging, teaching, and performance analysis.