Extensible Language One.
An extensible language by B. Wegbreit of Harvard ca 1974.
EL1 is internally somewhat Lisp
-like, but fully typed with record
s and pointers.
The external syntax
-like and extensible, supporting user-defined data structure
s, control structures and operations.
is table-driven, with a modifiable set of productions.
Used as the basis for the ECL operating system
["Studies in Extensible Programming Languages", B. Wegbreit, Garland.