Deml: The Directed Acyclic Graph Elevation Markup Language

Summary

DEML (DAG Elevation Markup Language) Languages designed to represent all types of graph data structures, such as Graphviz's DOT Language and Mermaid JS's flowchart syntax, don't take advantage of the properties specific to DAGs (Directed Acyclic Graphs). DAGs act like rivers. Water doesn't flow upstream (tides and floods being exceptions). Sections of a river at the same elevation can't be the inputs or outputs of each other, like the nodes C, D, and E in the image below. Their input is B. C outputs to F, while D and E output to G. DEML's goal is to use this ordering as part of the file syntax to make it easier for humans to parse. In DEML we represent an elevation marker with ---- on a new line. The order of elevation clusters is significant, but the order of nodes between two ---- elevation markers is not significant. UpRiver > A ---- A > B ---- B > C | D | E ---- C D E ---- F < C G < D | E > DownRiver ---- DownRiver < F Nodes are defined by the first word on a line. The defined node can point to its outputs with > and to its inputs with < . Inputs and outputs are separated by | . Dagrs Dagrs is a library for running multiple tasks with dependencies defined in a DAG. In DEML, shell commands can be assigned to a node with = . DEML files can be run via dag-rs with the comand deml run -i <filepath> . To compare the difference in readability, here is the Dagrs YAML example in both YAML and DEML YAML dagrs : a : name : " Task 1 " after : [ b, c ] cmd : echo a b : name : " Task 2 " after : [ c, f, g ] cmd : echo b c : name : " Task 3 " after : [ e, g ] cmd : echo c d : name : " Task 4 " after : [ c, e ] cmd : echo d e : name : " Task 5 " after : [ h ] cmd : echo e f : name : " Task 6 " after : [ g ] cmd : python3 ./tests/config/test.py g : name : " Task 7 " after : [ h ] cmd : node ./tests/config/test.js h : name : " Task 8 " cmd : echo h DEML H > E | G = echo h ---- G = node ./ tests / config / test . js E = echo e ---- F < G = python3 ./ tests / config / test . py C <...