32 lines
1.1 KiB
Markdown
32 lines
1.1 KiB
Markdown
---
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layout: page
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title: Term Table
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parent: language
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weight: 230
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permalink: :basename
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---
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### Term table
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Term table contains term declarations. A term is a simple recursive data type that is suitable for implementing unification. Also, terms can model any other data structure, in particular they are suitable for representing types in a programming language.
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A term is defined by its symbol and its features, which can be a child term, a list of children terms or any Java object[^obj].
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_(example of a term declaration)_
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An *open* term declaration can be *extended* by another term, which helps implement a structural subtyping on terms. A term extending another term can add new features.
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_(example of open term declaration)_
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A instance of `classifier()` can always be matched with a pattern `parameterized()`, because the former structurally extends the latter.
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A term table can extend another term table, in order to provide extensions to existing terms.
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_(example of a term table extension)_
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[^obj]: Java object conforming to equals/hashCode contract
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