Lineage

coeval takes each of its ideas from earlier work. This page names the sources.

Idea of coeval	Source
An evaluator gets its parts as documents	John Shutt, the Kernel language and the thesis of Shutt on fexprs: operatives get their operands without evaluation
An evaluator must not look inside its parts	Mitchell Wand, “The Theory of Fexprs is Trivial” (1998). A summary is in the article on fexprs.
Finite syntax, and meaning by observation	Turi and Plotkin, Towards a Mathematical Operational Semantics (1997): syntax is an algebra, behavior is a coalgebra
A program for the syntax, an interpreter for the behavior	The pair of a free monad and a cofree comonad, in this series on interpreters
Data that goes down and up a tree	Donald Knuth, Semantics of Context-Free Languages (1968): inherited and synthesized attributes
References sideways, and equations from an ancestor	Görel Hedin, reference attribute grammars, in JastAdd
A formula at a position, and dataflow	Uustalu and Vene, the comonadic view of dataflow and attribute grammars
Constraints go down, sizes go up	The layout of Flutter
A schedule is separate from the task	Mokhov, Mitchell and Peyton Jones, Build Systems à la Carte (2018)
Names for the results of earlier steps	The paths of the states of AWS Step Functions, and the outputs of the steps of GitHub Actions
New kinds against new operations	William Cook, On Understanding Data Abstraction, Revisited (2009)
A kind with aspects	The concepts and aspects of JetBrains MPS