Typing Rules
- Abstruct syntax does not define well-formed programs only.
- Phrase "(0=1)+2" allowed.
- Cannot add boolean to integer.
- Refine abstract syntax definition.
- Integer and boolean expressions.
- Define two distinct syntax domains?
- Better: add typing annotations!
- Attributed syntax trees
- Type attributes to all phrase forms.
- Syntax tree is well typed if type attributes can be attached to
all of its nonterminals.
Inference rules used for describing type structures.
Author: Wolfgang Schreiner
Last Modification: March 26, 1998