PPT Slide
formation of visual sentences:
- conventional programming languages: textual tokens are concatenated to form a textual sentence (concatenation is implicit)
- visual programming languages: icons correspond to tokens; construction rules are explicit (part of the language):
- horizontal concatenation
- vertical concatenation
- spatial overlay
syntactic analysis:
- picture grammars, graph grammars, …
- result: good old parse tree
semantic analysis:
- similar to conventional programming languages (attribute grammars, etc.)
recently some effort went into formalizing VLs
- e.g. lambda-calculus (Citrin95), types & type inferences (Burnett93)