* terraforn: refactor EvalRefresh
EvalRefresh.Eval(ctx) is now Refresh(evalRefreshReqest, ctx). While none
of the inner logic of the function has changed, it now returns a
states.ResourceInstanceObject instead of updating a pointer. This is a
human-centric change, meant to make the logic flow (in the calling
functions) easier to follow.
* terraform: refactor EvalReadDataPlan and Apply
This is a very minor refactor that removes the (currently) redundant
types EvalReadDataPlan and EvalReadDataApply in favor of using
EvalReadData with a Plan and Apply functions.
This is in effect an aesthetic change; since there is no longer an
Eval() abstraction we can rename functions to make their functionality
as obvious as possible.
* terraform: refactor EvalCheckPlannedChange
EvalCheckPlannedChange was only used by NodeApplyableResourceInstance
and has been refactored into a method on that type called
checkPlannedChange.
* terraform: refactor EvalDiff.Eval
EvalDiff.Eval is now a method on NodeResourceAbstracted called Plan
which takes as a parameter an EvalPlanRequest. Instead of updating
pointers it returns a new plan and state.
I removed as many redundant fields from the original EvalDiff struct as
possible.
* terraform: refactor EvalReduceDiff
EvalReduceDiff is now reducePlan, a regular function (without a method)
that returns a value.
* terraform: refactor EvalDiffDestroy
EvalDiffDestroy.Eval is now NodeAbstractResourceInstance.PlanDestroy
which takes ctx, state and optional DeposedKey and returns a change.
I've removed the state return value since it was only ever returning a
nil state.
* terraform: refactor EvalWriteDiff
EvalWriteDiff.Eval is now NodeAbstractResourceInstance.WriteChange.
* rename files to something more logical
* terrafrom: refresh refactor, continued!
I had originally made Refresh a stand-alone function since it was
(obnoxiously) called from a graphNodeImportStateSub, but after some
(greatly appreciated) prompting in the PR I instead made it a method on
the NodeAbstractResourceInstance, in keeping with the other refactored
eval nodes, and then built a NodeAbstractResourceInstance inside import.
Since I did that I could also remove my duplicated 'writeState' code
inside graphNodeImportStateSub and use n.writeResourceInstanceState, so
double thanks!
* unexport eval methods
* re-refactor Plan, it made more sense on NodeAbstractResourceInstance. Sorry
* Remove uninformative `Eval`s from EvalReadData, consolidate to a single
file, and rename file to match function names.
* manual rebase
