The new std.process is ready for review

[Lars T. Kyllingstad]

On Wednesday, 13 March 2013 at 20:26:44 UTC, Steven Schveighoffer 
wrote:
> I hate to have feature creep at this point, but one kind of 
> annoying thing
> is, if you want to *add* to the current environment, it is a 
> multi-step
> process:
>
> auto curenv = environment.toAA;
> curenv["x"] = "y";
> spawnProcess("helloworld", curenv);
>
> But with something similar to Dennis' idea, we have a possible 
> way to do
> that without making a copy of the current environment into an 
> AA and
> adding:
>
> struct EnvironmentArg
> {
>      this(string[string] env, bool useParent=false) { this.env 
> = env;
> this.useParent = useParent;}
>      this(bool useParent) {this.useParent = useParent;}
>      string[string] env;
>      bool useParent;
> }
>
> spawnProcess("helloworld", EnvironmentArg(["x":"y"], true)); // 
> use parent
> environment, add x=y
> spawnProcess("helloworld", EnvironmentArg(["x":"y"])); // 
> replace
> environment with x=y
> spawnProcess("helloworld", EnvironmentArg(false)); // use empty 
> environment
> spawnProcess("helloworld", EnvironmentArg(true)); // use parent
> environment exactly
>
> EnvironmentArg should probably have better name, and I would 
> recommend
> some global functions that make common things, like:
>
> EnvironmentArg emptyEnvironment() { return EnvironmentArg(null, 
> false);}
> EnvironmentArg parentEnvironment() { return 
> EnvironmentArg(null, true);}
>
> Like? Hate?

Hmm.. what if spawnProcess() takes a normal string[string] like 
it does now, but we add a flag to Config that determines whether 
it is merged with the parent's environment or not?

string[string] myEnv = [ "foo" : "bar" ];
spawnProcess("helloworld", null);     // Parent's env
spawnProcess("helloworld", myEnv);    // Parent's env + myEnv
spawnProcess("helloworld", null, ..., Config.clearEnv);  // Empty 
env
spawnProcess("helloworld", myEnv, ..., Config.clearEnv); // Only 
myEnv

Lars