Rules
Targets
	Profiles
		Build
		Clean
		Install
		Package
		etc.
	Dependancies
	Force Ruleset / mode
	Input
	Produces / Output
Actions (functions)
	Execute
	Delete
	Download
	GetDependencies
	ExecuteTest
	RunTarget

Mode Variables - switch modes for a variety of things (debug/release, platforms)

Includes (including default includes)

Bash style variable replacements / execute / etc.

Functions?
	files() returns list (globbing)
	querySystemParam() 

if blocks can be anywhere.

semi-typed variables, default to string

variables in a target:  INPUT, OUTPUT (by default instead of target and match)

---- ast processing order ----
1) import all environment variables
2) import all cached data
3) set all variables specified on the command line
4) root level "script"
4.1) execute root level items, for target, rule, and non-auto, non-global config
		this means building the target, rule, and config tables.
		for global config and auto-config, run them as we hit them.
5) execute specified target(s) with specified profile

---- pseudo code -----

set CXXFLAGS += "param";   // ensure there are spaces so it works for a command
set CXXFLAGS << "param";   // append like you'd expect, no extra changes

unset PREFIX;			// may be handy to be able to unset things

include "otherbuild.h"; // oh yeah includes

notice "something good?"; // display a notice to the user, just info...
warning "yeah yeah yeah..."; // display a warning message, but don't exit
error "something or other"; // exit immediately with an error message

target "libbu++.a"
{
	input files("src/*.cpp");
	set CXXFLAGS="-ggdb";
	condition file;
	requires [];

	hidden;  // Hides this from the user, but still callable
}

target ["file a", files("src/*.cpp), files("src/*y")].replace("bob", "sam")...
{
	condition always;
}

auto config "X"
{
}

config "EXTRA_DEBUG"
{
	display "Debugging/Extra debugging";
	type int; (or string, or bool, or list, or version)
	default 0;
	allow ["0-5","6"];

}

rule "cpp"
{
	input glob("*.cpp"); // or just a string, pretend it's a glob
	output "${INPUT}".replace(".cpp",".o");
	requires getDeps("g++ ${CXXFLAGS} -M ${OUTPUT} ${INPUT}", "make");
	profile "build"
	{
		fnc1() tag "c++";
		fnc2();
	}
}