%%  SCHEMA:
    %%      specialization(Fn, Scope) - problem of what specialization of Fn should be picked up in Scope. 
    %%      resolution_dependency(Resolution, Dependency) - Dependency is necessary prerequisite for choosing Resolution.
    %%

true.

    %nested scope propagation:
bind_scope(Scope, Context, Info) :- bind_scope(ScopeParent, Context, Info), cfa_parent(Scope, scope(ScopeParent)).

    %strong/uniform inter-function propagation:
bind_scope(Scope, Context,Info) :- bind_scope(ScopeParent, Context, Info): cfa_call(ScopeParent, FnCurrent); cfa_parent(Scope, function(FnCurrent)); cfa_call(_, FnCurrent);   bind_scope(_, Context, Info); scope(Scope).
      
    %weak inter-function propagation
bind_scope(Scope, Context, weak(ScopeParent)):- not bind_scope(Scope, Context, strong), bind_scope(ScopeParent, Context, strong), cfa_call(ScopeParent, FnCurrent), cfa_parent(Scope, function(FnCurrent)).
bind_scope(Scope, Context, weak(ScopeParent, Info)):- Info<>strong, not bind_scope(Scope, Context, Info), bind_scope(ScopeParent, Context, Info), cfa_call(ScopeParent, FnCurrent), cfa_parent(Scope, function(FnCurrent)).


    %make decisions
%%%bind_scope_decision(Scope, loop(Subject), Scope):- cfa_contextloop(Scope, Subject), demand_dependency(loop(Subject), X), bind_scope(Scope, X, strong).*
%%%bind_scope_decision(Scope, loop(Subject), Scope):- cfa_call(Scope, FnChild), bind_function_demand(FnChild, loop(Subject)), demand_dependency(loop(Subject), X), bind_scope(Scope, X, strong).

    %on-site decision
%   ASSERT: ON-SITE DECISION SHOULD BE FIRST CLASS (checks at least one specialization exists)
bind_scope_decision(Scope, Subject, Resolution):- bind_scope(Scope, Resolution, strong), Subject = specialization(Fn, Scope), cfa_call(Scope, Fn), cfa_function_specializations(Fn, Resolution).
bind_scope_decision(ScopeSource, Subject, Resolution):- bind_scope(Scope, Resolution, weak(ScopeSource)), Subject = specialization(Fn, Scope), cfa_call(Scope, Fn), cfa_function_specializations(Fn, Resolution).
bind_scope_decision(ScopeSource, Subject, resolution_dependency(Resolution, Dependency)):- bind_scope(Scope, Resolution, weak(ScopeSource, Dependency)), Subject = specialization(Fn, Scope), cfa_call(Scope, Fn), cfa_function_specializations(Fn, Resolution).

    %dependent decisions
bind_scope_demand(Scope, dependency(Subject, Scope)) :- bind_scope_decision(Scope, Subject, resolution_dependency(_, Dependency)).
bind_scope_demand(ScopeSource, dependency(Subject, ScopeSource)) :- Dependency = weak(ScopeSource, DependencyTail), bind_scope_demand(Scope, dependency(Subject, Scope)), scope_dependencies(dependency(Subject, Scope), Dependency).

bind_scope_decision(ScopeSource, dependency(Subject, Scope), Dependency) :- Dependency = weak(ScopeSource), bind_scope_demand(Scope, dependency(Subject, Scope)), scope_dependencies(dependency(Subject, Scope), Dependency).
bind_scope_decision(ScopeSource, dependency(Subject, Scope), resolution_dependency(Dependency, DependencyTail)) :- Dependency = weak(ScopeSource, DependencyTail), bind_scope_demand(Scope, dependency(Subject, Scope)), scope_dependencies(dependency(Subject, Scope), Dependency).


    %dependent decision helpers:
scope_dependencies(dependency(Subject, Scope), Dependency) :- bind_scope_decision(Scope, Subject, resolution_dependency(_, Dependency)).    
scope_dependencies(dependency(Subject, ScopeSource), DependencyTail) :- Dependency = weak(ScopeSource, DependencyTail), bind_scope_demand(Scope, dependency(Subject, Scope)), scope_dependencies(dependency(Subject, Scope), Dependency).

    %on-site demand 
%   ASSERT: ON-SITE DEMAND SHOULD BE dependent OF on-site decision (check there are no specializations AT ALL)
%%%bind_scope_demand(Scope, Subject):- cfa_contextloop(Scope, Subject), not bind_scope_decision(Scope, loop(Subject), _).
bind_scope_demand(Scope, Subject):- Subject = specialization(FnCallee, Scope), cfa_call(Scope, FnCallee), cfa_function_specializations(FnCallee, _), not bind_scope_decision(Scope, Subject, _).

    %nested scope demand propagation
%ASSERT: NO DECISION CHECKS. because decisions linked to a leaf(function execution sites) scopes
bind_scope_demand(Scope, Subject):- bind_scope_demand(ScopeChild, Subject), cfa_parent(ScopeChild, scope(Scope)).
bind_function_demand(Fn, Subject):- bind_scope_demand(Scope, Subject), cfa_parent(Scope, function(Fn)).

    %inter-function propagation demand
bind_scope_demand(Scope, Subject):- cfa_call(Scope, FnChild), bind_function_demand(FnChild, Subject), not bind_scope_decision(Scope, Subject, _).