J

The J programming language combines an ASCII encoding of APL as embodied by SHARP APL with functional techniques developed by John Backus for the FP and FL languages. J is characterized by its use of leading axis theory as a foundational design principle and its tacit programming capabilities. Function trains are a key J feature and were later adopted by Dyalog APL. J's primitives consist of a single ASCII character possibly followed by one or two periods or colons. It is also notable for its use of terms from English grammar to describe the language. For example, functions are called "verbs" while arrays are called "nouns".