refactor: mark several variable metadata keys as public

Author: AayushSabharwal

docs/src/API/variables.md

@@ -56,6 +56,7 @@ help?> u
 ```@docs
 hasdescription
 getdescription
+ModelingToolkit.VariableDescription
 ```
 
 ## Connect
@@ -83,6 +84,7 @@ getconnect(k)
 ```@docs
 hasconnect
 getconnect
+ModelingToolkit.VariableConnectType
 ```
 
 ```@docs; canonical=false
@@ -112,6 +114,8 @@ isinput
 isoutput
 ModelingToolkit.setinput
 ModelingToolkit.setoutput
+ModelingToolkit.VariableInput
+ModelingToolkit.VariableOutput
 ```
 
 ## Bounds
@@ -144,6 +148,7 @@ hasbounds(x[2])
 ```@docs
 hasbounds
 getbounds
+ModelingToolkit.VariableBounds
 ```
 
 ## Guess
@@ -232,6 +237,7 @@ isirreducible(important_value)
 
 ```@docs
 isirreducible
+ModelingToolkit.VariableIrreducible
 ```
 
 ## State Priority
@@ -245,6 +251,7 @@ state_priority(important_dof)
 
 ```@docs
 state_priority
+ModelingToolkit.VariableStatePriority
 ```
 
 ## Units
@@ -261,6 +268,7 @@ getunit(speed)
 ```@docs
 hasunit
 getunit
+ModelingToolkit.VariableUnit
 ```
 
 ## Variable type
@@ -286,6 +294,7 @@ getmisc(y)
 ```@docs
 hasmisc
 getmisc
+ModelingToolkit.VariableMisc
 ```
 
 ## Dumping metadata

src/ModelingToolkit.jl

@@ -339,7 +339,9 @@ export DynamicOptSolution
 @public AbstractSystem, CheckAll, CheckNone, CheckComponents, CheckUnits
 @public t, D, t_nounits, D_nounits, t_unitful, D_unitful
 @public SymbolicContinuousCallback, SymbolicDiscreteCallback
-@public VariableType, MTKVariableTypeCtx
+@public VariableType, MTKVariableTypeCtx, VariableBounds, VariableConnectType
+@public VariableDescription, VariableInput, VariableIrreducible, VariableMisc
+@public VariableOutput, VariableStatePriority, VariableUnit
 
 for prop in [SYS_PROPS; [:continuous_events, :discrete_events]]
     getter = Symbol(:get_, prop)

src/variables.jl

@@ -1,10 +1,46 @@
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing the unit associated with a symbolic variable.
+"""
 struct VariableUnit end
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing the type of connector that a variable is.
+"""
 struct VariableConnectType end
 struct VariableNoiseType end
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing whether a symbolic variable is an input or not.
+"""
 struct VariableInput end
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing whether a symbolic variable is an output or not.
+"""
 struct VariableOutput end
+"""
+  $TYPEDEF
+
+Symbolic metadata key for storing whether a symbolic variable is irreducible or not.
+"""
 struct VariableIrreducible end
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing the priority a variable has for being selected during
+state selection.
+"""
 struct VariableStatePriority end
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing miscellaneous information about a symbolic variable.
+"""
 struct VariableMisc end
 # Metadata for renamed shift variables xₜ₋₁
 struct VariableUnshifted end
@@ -227,6 +263,11 @@ function default_toterm(x)
 end
 
 ## Bounds ======================================================================
+"""
+    $TYPEDEF
+
+Symbolic metadata key for specifying the bounds of a symbolic variable.
+"""
 struct VariableBounds end
 Symbolics.option_to_metadata_type(::Val{:bounds}) = VariableBounds
 
@@ -436,6 +477,11 @@ function getbounds(p::AbstractVector)
 end
 
 ## Description =================================================================
+"""
+    $TYPEDEF
+
+Symbolic metadata key for storing the description of a symbolic variable.
+"""
 struct VariableDescription end
 Symbolics.option_to_metadata_type(::Val{:description}) = VariableDescription