Make Mode Design

NGS Make Mode Design (WIP)

This page describes the design of NGS make mode. In this mode, it will be possible to use NGS in a manner similar to make.

Requirements

• A way to describe build targets in NGS syntax
• A way to easily run a given target from the command line
• A way to easily run a given target from other NGS scripts (after they require() the file with the targets)
• Allow inclusion of additional targets using require()
• Easy way to pass positional and named parameters when running a target

Design

• Targets will be NGS methods (functions). This will allow calling the targets from other NGS scripts and from other targets().
• Targets will live in namespaces and hence must be defined using ns keyword.
  • Namespaces will allow easy lookup of targets when invoked from command line (as opposed to globals())
  • Namespaces allow restricting targets to a particular set of methods
  • Namespaces allow listing of targets
• For passing parameters from command line, factor out and re-use the parameters matching facility that is currently used to invoke main().

TODO / Open Issues

• Design dependencies handling
  • Simply call another method? No because of parallelism and dependency graph.
• Design Parallelism
• Design rules
• file target to make a file? Solves namespace issues and .PHONY of GNU Make.
• Running
  • Run using a command such as ngs-make or directly using the NGS file such as ./make.ngs TARGET
  • Not requiring additional binary/script in path should be a plus
  • ./make.ngs style also makes it obvious how to run alternate "make" files (think make.linux.ngs and make.macosx.ngs)
• A syntax to define additional constraints on the method arguments (such as ~ Sfx('.o'))
• Nested namespaces?
• Looks like too much boilerplate to support require()ing.
• Lists of files similar to Rake::FileList ?

Sample NGS make script (thoughts)

#!/usr/bin/env ngs

ns {

	doc Builds .o files
	F file(dst:Str) {
		guard dst ~ Sfx('.o')
		...
	}

	doc Removes all generated files
	F clean() {
		...
	}

}

Related Issues

• https://github.com/ngs-lang/ngs/issues/37 - Make mode