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| author | ruki <waruqi@gmail.com> | 2018-11-08 00:38:48 +0800 |
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| committer | ruki <waruqi@gmail.com> | 2018-11-07 21:53:09 +0800 |
| commit | 26105034da4fcce7ac883c899d781f016559310d (patch) | |
| tree | c459a5dc4e3aa0972d9919033ece511ce76dd129 /node_modules/@webassemblyjs/floating-point-hex-parser/README.md | |
| parent | 2c77f00f1a7ecb6c8192f9c16d3b2001b254a107 (diff) | |
| download | xmake-docs-26105034da4fcce7ac883c899d781f016559310d.tar.gz xmake-docs-26105034da4fcce7ac883c899d781f016559310d.zip | |
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diff --git a/node_modules/@webassemblyjs/floating-point-hex-parser/README.md b/node_modules/@webassemblyjs/floating-point-hex-parser/README.md new file mode 100644 index 00000000..648e09bc --- /dev/null +++ b/node_modules/@webassemblyjs/floating-point-hex-parser/README.md @@ -0,0 +1,34 @@ +# Parser function for floating point hexadecimals + +[]() +[]() +[]() + +> A JavaScript function to parse floating point hexadecimals as defined by the [WebAssembly specification](https://webassembly.github.io/spec/core/text/values.html#text-hexfloat). + +## Usage + +```javascript +import parseHexFloat from '@webassemblyjs/floating-point-hex-parser' + +parseHexFloat('0x1p-1') // 0.5 +parseHexFloat('0x1.921fb54442d18p+2') // 6.283185307179586 +``` + +## Tests + +This module is tested in two ways. The first one is through a small set of test cases that can be found in [test/regular.test.js](https://github.com/maurobringolf/@webassemblyjs/floating-point-hex-parser/blob/master/test/regular.test.js). The second one is non-deterministic (sometimes called *fuzzing*): + +1. Generate a random IEEE754 double precision value `x`. +1. Compute its representation `y` in floating point hexadecimal format using the C standard library function `printf` since C supports this format. +1. Give both values to JS testcase and see if `parseHexFloat(y) === x`. + +By default one `npm test` run tests 100 random samples. If you want to do more, you can set the environment variable `FUZZ_AMOUNT` to whatever number of runs you'd like. Because it uses one child process for each sample, it is really slow though. For more details about the randomized tests see [the source](https://github.com/maurobringolf/@webassemblyjs/floating-point-hex-parser/tree/master/test/fuzzing). + +## Links + +* [maurobringolf.ch/2017/12/hexadecimal-floating-point-notation/](https://maurobringolf.ch/2017/12/hexadecimal-floating-point-notation/) + +* [github.com/xtuc/js-webassembly-interpreter/issues/32](https://github.com/xtuc/js-webassembly-interpreter/issues/32) + +* [github.com/WebAssembly/design/issues/292](https://github.com/WebAssembly/design/issues/292) |
