Topic:
attribute grammar
Topic:
formal methods and languages
Topic:
semantic grammar
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Summary
van Wijngaarden grammars specified ALGOL 68's syntax. They are two-level grammars which allow language statements, e.g., declarations, to modify the grammar. This could completely define the language's syntax and semantics. van Wijngaarden grammars are difficult to understand. (cbb 5/80)
Subtopic: 1-level Wijngaarden 
| QuoteRef: kostCH_1974a ;;148 1-level Wijngaarden grammars same as BNF but uses a different syntax
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Subtopic: 2-level Wijngaarden
| Quote: 2-level van Wijngaarden grammars define meta rules that generate BNF rules [»kostCH_1974a, OK]
| | QuoteRef: kostCH_1974a ;;150 in 2 level van Wijngaarden grammar most productions will fail
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Subtopic: declaration as rule
| Quote: the declarative statements of a program could define a context-free grammar for its imperative statement [»hanfKV_1973]
| | Quote: with van Wijngaarden grammars can specify that all variables in a declaration list have the given type
| | Quote: declarations define what variables can be used in a program's statement productions [»hanfKV_1973, OK]
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Subtopic: execution as rule
| Quote: a van Wijngaarden grammar generates all correct executions of a program as 'program input output' [»pagaFG3_1979]
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Subtopic: problems with van Wijngaarden grammar
| Quote: van Wijngaarden's approach may be too subtle and intricate to explain a programming language; highly recursive from simple rules [»wirtN1_1966]
| Quote: separate language definition from program definition; van Wijngaarden grammars mix the two
[»wirtN1_1966]
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Related Topics
Topic: attribute grammar (9 items)
Topic: formal methods and languages (53 items)
Topic: semantic grammar
(23 items)
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