94 lines
1.5 KiB
Markdown
94 lines
1.5 KiB
Markdown
# Nasal Namespace
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## Introduction
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In this nasal interpreter,
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we use this way below to construct namespaces:
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- library is linked directly with the script
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- module is wraped by a function generated by linker, and return a hash
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## Library
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Library file is linked with script file directly, like this:
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In `std/lib.nas`:
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```nasal
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var a = 1;
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```
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In `example.nas`:
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```nasal
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var b = 1;
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```
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At the link stage,
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in fact we put the ast of two files together to make a new ast,
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so the result is equal to:
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```nasal
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var a = 1;
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var b = 1;
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```
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## Module
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Modules is wraped up by a function,
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and return a hash, for example:
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In `std/example_module.nas`:
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```nasal
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var a = 1;
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var _a = 1;
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```
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We analysed this file and generated the ast.
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Then we find all the global symbols.
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At last we use the information of all the globals symbols in this file to generate a hash to return.
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So the result is equal to:
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```nasal
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var example_module = func {
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# source code begin
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var a = 1;
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var _a = 1;
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# source code end
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return {
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a: a
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# _a begins with underscore so do not export
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};
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}();
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```
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## Import a Module
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Here is a module named `std/example_module.nas`:
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```nasal
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var a = 1;
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```
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Then there's a script file named `test.nas`, import module in this file using this way:
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```nasal
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use std.example_module;
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println(example_module.a); # 1
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```
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Or this way:
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```nasal
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import("std/example_module.nas");
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println(example_module.a); # 1
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```
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