added is_valid methods and exceptions

Author: e-duar-do

docs/src/reference/dynamic_functions/dynamic_variables.md

@@ -10,4 +10,6 @@ supports_dynamic_variable
 UnsupportedDynamicVariable
 add_dynamic_variable
 AddDynamicVariableNotAllowed
+MOI.is_valid(::MOI.ModelLike, ::DynamicVariableIndex)
+InvalidDynamicVariableIndex
 ```

docs/src/reference/dynamic_functions/phases.md

@@ -10,4 +10,6 @@ supports_phase
 UnsupportedPhase
 AddPhaseNotAllowed
 add_phase
+MOI.is_valid(::MOI.ModelLike, ::PhaseIndex)
+InvalidPhaseIndex
 ```

src/dynamic_functions/dynamic_variables.jl

@@ -65,4 +65,20 @@ An [`AddDynamicVariableNotAllowed`](@ref) is thrown if a dynamic variable cannot
 to `model` in its current state.
 """
 add_dynamic_variable(::MOI.ModelLike, ::PhaseIndex) =
-    throw(AddDynamicVariableNotAllowed(""))
+    throw(AddDynamicVariableNotAllowed(""))
+
+"""
+    MOI.is_valid(model::MOI.ModelLike, index::DynamicVariableIndex)::Bool
+
+Return a `Bool` indicating whether `index` refers to a valid object in `model`.
+"""
+MOI.is_valid(model::MOI.ModelLike, index::DynamicVariableIndex)
+
+"""
+    InvalidDynamicVariableIndex(index::DynamicVariableIndex)
+
+An error indicating that the dynamic variable `index` is invalid.
+"""
+struct InvalidDynamicVariableIndex <: Exception
+    index::DynamicVariableIndex
+end

src/dynamic_functions/phases.jl

@@ -61,4 +61,20 @@ in its current state.
 """
 add_phase(::MOI.ModelLike) = throw(AddPhaseNotAllowed(""))
 
-MOI.operation_name(::AddPhaseNotAllowed) = "Adding a phase"
+MOI.operation_name(::AddPhaseNotAllowed) = "Adding a phase"
+
+"""
+    MOI.is_valid(model::MOI.ModelLike, index::PhaseIndex)::Bool
+
+Return a `Bool` indicating whether `index` refers to a valid object in `model`.
+"""
+MOI.is_valid(model::MOI.ModelLike, index::PhaseIndex)
+
+"""
+    InvalidPhaseIndex(index::PhaseIndex)
+
+An error indicating that the phase `index` is invalid.
+"""
+struct InvalidPhaseIndex <: Exception
+    index::PhaseIndex
+end