model

type Environment struct {
	// OutDir is the path where build outputs are located, relative to some base directory.
	OutDir string
}

type File struct {
	// RelPath is the relative path to the file.
	RelPath string

	// FromSourceDir marks the file as being from the source directory.
	FromSourceDir bool
}

type Filegroup []File

type Filegroups map[string]Filegroup

type Inputs map[string]OutputRefs

type OutputRef struct {
	// Target points to the target the output.
	Target *Target

	// FilegroupName refers to he file group.
	FilegroupName string
}

type OutputRefs []OutputRef

type Rule struct {
	// Description is a friendly name for the rule.
	Description string

	// Volatile rules are always rebuilt, regardless of their inputs changing or not.
	Volatile bool

	// Command returns command lines to run to generate outputs from inputs.
	Command func(inputPaths map[string][]string, outputPaths map[string][]string, annotations map[string]interface{}) (string, error)
}

type Target struct {
	// Rule that will map inputs to outputs.
	Rule *Rule

	// Inputs that will be provided to generate outputs.
	Inputs Inputs

	// Outputs that will be generated from inputs.
	Outputs Filegroups

	// Any additional annotations to consider during execution of the rule.
	Annotations map[string]interface{}
}