Aliases for the AST and model constructors, spelled the way the same type is
spelled in C++ and Python (Set("tech") rather than new_set("tech")).
They call the existing constructors and return the same objects; the
original names are unaffected.
Usage
Set(...)
Mapping(...)
Parameter(...)
Variable(...)
Equation(...)
SetRef(...)
MappingRef(...)
ParameterRef(...)
VariableRef(...)
Symbol(...)
Dims(...)
Constant(...)
Expression(...)
Unary(...)
When(...)
Func(...)
Sum(...)
Prod(...)
SetMin(...)
SetMax(...)
Shift(...)
Call(...)
Where(...)Details
Declarations take the bare name (Set(), Parameter(), Variable(),
Mapping(), Equation()); references take a Ref suffix (SetRef(),
ParameterRef(), VariableRef(), MappingRef()). The two are structurally
different objects - see ast_schema().
