36 lines
1.2 KiB
Markdown
36 lines
1.2 KiB
Markdown
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# Problem
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## All these functions operate on a *parser value:
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+ `main.go`:
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+ `summarize(*p parser)`
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+ `parser.go`:
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+ `func parse(p *parser, line string) (r result)`
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+ `func update(p *parser, r result)`
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+ `func err(p *parser) error`
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## What is an object in Go?
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+ Object = A value of a type : `&parser{}` is an object.
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+ `type parser struct` is the definition (class/blueprint) of the object.
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### Methods are behaviors of objects:
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+ Parser needs to parse, update (analyse) the parsings, and report an error if any.
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+ Parser also needs to summarize the results.
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+ So, all these functions belong to a parser object.
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# Solution
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+ Attach the functions to the parser using methods.
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+ Methods are the behavior of the parser.
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+ Keep the methods that belong to a single type in the same file.
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1. Move the `summarize` into `parser.go`.
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2. `parser.go`: Use methods.
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3. `main()` : Use methods of the `parser`.
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# Convince
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+ `p.` shows the fields and methods belong to the `parser`.
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+ `p.` selects a method from the method set of the `parser`.
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+ `p.method` sends the `p` as the first parameter to the method.
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+ `p` is the receiver: `*pointer`. It's a pointer receiver.
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+ Receiver is copied to the method.
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