Is the expression something that can be assigned to?
envin is an environment of bindings already seen.
envin is an environment of bindings already seen. Add a binding of i to e and return the complete set of bindings, unless i already has a binding in envin, in which case define i to be a multiply-defined entity.
Pre-defined exception numbers
The entity referred to by a declaration or a variable expression.
The entity referred to by a declaration or a variable expression. If a name has been used previously in a declaration then return an unknown entity which will trigger an error.
Attribute to consecutively number enumeration constants.
The environment containing all bindings visible at a particular node in the tree, not including any that are defined at that node.
The environment containing all bindings visible "after" a particular node in the tree.
The environment containing all bindings visible "after" a particular node in the tree. I.e., its the environment at the node plus any new bindings introduced by the node.
Visit all nodes to check for semantic errors.
Visit all nodes to check for semantic errors. Errors will be recorded using the Messaging module so that they can be reported to the user later.
Attribute to consecutively number exception constants
What is the expected type of an expression? I.
What is the expected type of an expression? I.e., what type does the context impose on it. Returns UnknownType () if any type will do.
Initial environment, pre-primed with predeclared identifiers like DivideByZero
Is this statement inside a LOOP statement? Used to check that EXIT statements are placed appropriately.
What is the type of an expression?