40 lines
819 B
Markdown
40 lines
819 B
Markdown
% Glossary
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Not every Rustacean has a background in systems programming, nor in computer
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science, so we've added explanations of terms that might be unfamiliar.
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### Arity
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Arity refers to the number of arguments a function or operation takes.
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```rust
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let x = (2, 3);
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let y = (4, 6);
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let z = (8, 2, 6);
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```
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In the example above `x` and `y` have arity 2. `z` has arity 3.
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### Abstract Syntax Tree
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When a compiler is compiling your program, it does a number of different
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things. One of the things that it does is turn the text of your program into an
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‘abstract syntax tree’, or ‘AST’. This tree is a representation of the
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structure of your program. For example, `2 + 3` can be turned into a tree:
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```text
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+
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/ \
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2 3
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```
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And `2 + (3 * 4)` would look like this:
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```text
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+
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/ \
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2 *
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/ \
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3 4
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```
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