HCoop / hcoop / debian / mlton.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f918cf1 CE |
1 | <!DOCTYPE html>\r |
| 2 | <html lang="en">\r | |
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| 5 | <meta name="generator" content="AsciiDoc 8.6.9">\r | |
| 6 | <title>WarnUnusedAnomalies</title>\r | |
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| 16 | </script>\r | |
| 17 | <link rel="stylesheet" href="./mlton.css" type="text/css">\r | |
| 18 | </head>\r | |
| 19 | <body class="article">\r | |
| 20 | <div id="banner">\r | |
| 21 | <div id="banner-home">\r | |
| 22 | <a href="./Home">MLton 20180207</a>\r | |
| 23 | </div>\r | |
| 24 | </div>\r | |
| 25 | <div id="header">\r | |
| 26 | <h1>WarnUnusedAnomalies</h1>\r | |
| 27 | </div>\r | |
| 28 | <div id="content">\r | |
| 29 | <div id="preamble">\r | |
| 30 | <div class="sectionbody">\r | |
| 31 | <div class="paragraph"><p>The <span class="monospaced">warnUnused</span> <a href="MLBasisAnnotations">MLBasis annotation</a> can be used\r | |
| 32 | to report unused identifiers. This can be useful for catching bugs\r | |
| 33 | and for code maintenance (e.g., eliminating dead code). However, the\r | |
| 34 | <span class="monospaced">warnUnused</span> annotation can sometimes behave in counter-intuitive\r | |
| 35 | ways. This page gives some of the anomalies that have been reported.</p></div>\r | |
| 36 | <div class="ulist"><ul>\r | |
| 37 | <li>\r | |
| 38 | <p>\r | |
| 39 | Functions whose only uses are recursive uses within their bodies are\r | |
| 40 | not warned as unused:\r | |
| 41 | </p>\r | |
| 42 | <div class="listingblock">\r | |
| 43 | <div class="content"><div class="highlight"><pre><span class="k">local</span><span class="w"></span>\r | |
| 44 | <span class="k">fun</span><span class="w"> </span><span class="n">foo</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">foo</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 45 | <span class="k">val</span><span class="w"> </span><span class="n">bar</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">let</span><span class="w"> </span><span class="k">fun</span><span class="w"> </span><span class="n">baz</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">baz</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="n">baz</span><span class="w"> </span><span class="k">end</span><span class="w"></span>\r | |
| 46 | <span class="k">in</span><span class="w"></span>\r | |
| 47 | <span class="k">end</span><span class="w"></span>\r | |
| 48 | </pre></div></div></div>\r | |
| 49 | <div class="listingblock">\r | |
| 50 | <div class="content monospaced">\r | |
| 51 | <pre>Warning: z.sml 3.5.\r | |
| 52 | Unused variable: bar.</pre>\r | |
| 53 | </div></div>\r | |
| 54 | </li>\r | |
| 55 | <li>\r | |
| 56 | <p>\r | |
| 57 | Components of actual functor argument that are necessary to match\r | |
| 58 | the functor argument signature but are unused in the body of the\r | |
| 59 | functor are warned as unused:\r | |
| 60 | </p>\r | |
| 61 | <div class="listingblock">\r | |
| 62 | <div class="content"><div class="highlight"><pre><span class="k">functor</span><span class="w"> </span><span class="n">Warning</span><span class="w"> </span><span class="p">(</span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"></span>\r | |
| 63 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">y</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">x</span><span class="w"></span>\r | |
| 64 | <span class="k">end</span><span class="w"></span>\r | |
| 65 | <span class="k">structure</span><span class="w"> </span><span class="n">X</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Warning</span><span class="w"> </span><span class="p">(</span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">int</span><span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"></span>\r | |
| 66 | </pre></div></div></div>\r | |
| 67 | <div class="listingblock">\r | |
| 68 | <div class="content monospaced">\r | |
| 69 | <pre>Warning: z.sml 4.29.\r | |
| 70 | Unused type: t.</pre>\r | |
| 71 | </div></div>\r | |
| 72 | </li>\r | |
| 73 | <li>\r | |
| 74 | <p>\r | |
| 75 | No component of a functor result is warned as unused. In the\r | |
| 76 | following, the only uses of <span class="monospaced">f2</span> are to match the functor argument\r | |
| 77 | signatures of <span class="monospaced">functor G</span> and <span class="monospaced">functor H</span> and there are no uses of\r | |
| 78 | <span class="monospaced">z</span>:\r | |
| 79 | </p>\r | |
| 80 | <div class="listingblock">\r | |
| 81 | <div class="content"><div class="highlight"><pre><span class="k">functor</span><span class="w"> </span><span class="n">F</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">X</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="k">sig</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="k">end</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"></span>\r | |
| 82 | <span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">X</span><span class="p">.</span><span class="n">t</span><span class="w"></span>\r | |
| 83 | <span class="w"> </span><span class="k">fun</span><span class="w"> </span><span class="n">f1</span><span class="w"> </span><span class="p">(_</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">X</span><span class="p">.</span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="p">()</span><span class="w"></span>\r | |
| 84 | <span class="w"> </span><span class="k">fun</span><span class="w"> </span><span class="n">f2</span><span class="w"> </span><span class="p">(_</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">X</span><span class="p">.</span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="p">()</span><span class="w"></span>\r | |
| 85 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">z</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="p">()</span><span class="w"></span>\r | |
| 86 | <span class="k">end</span><span class="w"></span>\r | |
| 87 | <span class="k">functor</span><span class="w"> </span><span class="n">G</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">Y</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="k">sig</span><span class="w"></span>\r | |
| 88 | <span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"></span>\r | |
| 89 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">f1</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 90 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">f2</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 91 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">z</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 92 | <span class="w"> </span><span class="k">end</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"></span>\r | |
| 93 | <span class="w"> </span><span class="k">fun</span><span class="w"> </span><span class="n">g</span><span class="w"> </span><span class="p">(</span><span class="n">x</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">Y</span><span class="p">.</span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Y</span><span class="p">.</span><span class="n">f1</span><span class="w"> </span><span class="n">x</span><span class="w"></span>\r | |
| 94 | <span class="k">end</span><span class="w"></span>\r | |
| 95 | <span class="k">functor</span><span class="w"> </span><span class="n">H</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">Y</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="k">sig</span><span class="w"></span>\r | |
| 96 | <span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"></span>\r | |
| 97 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">f1</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 98 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">f2</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 99 | <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">z</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"></span>\r | |
| 100 | <span class="w"> </span><span class="k">end</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"></span>\r | |
| 101 | <span class="w"> </span><span class="k">fun</span><span class="w"> </span><span class="n">h</span><span class="w"> </span><span class="p">(</span><span class="n">x</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">Y</span><span class="p">.</span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Y</span><span class="p">.</span><span class="n">f1</span><span class="w"> </span><span class="n">x</span><span class="w"></span>\r | |
| 102 | <span class="k">end</span><span class="w"></span>\r | |
| 103 | <span class="k">functor</span><span class="w"> </span><span class="n">Z</span><span class="p">()</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"></span>\r | |
| 104 | <span class="w"> </span><span class="k">structure</span><span class="w"> </span><span class="n">S</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">F</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">X</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">unit</span><span class="w"> </span><span class="k">end</span><span class="p">)</span><span class="w"></span>\r | |
| 105 | <span class="w"> </span><span class="k">structure</span><span class="w"> </span><span class="n">SG</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">G</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">Y</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">S</span><span class="p">)</span><span class="w"></span>\r | |
| 106 | <span class="w"> </span><span class="k">structure</span><span class="w"> </span><span class="n">SH</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">H</span><span class="p">(</span><span class="k">structure</span><span class="w"> </span><span class="n">Y</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">S</span><span class="p">)</span><span class="w"></span>\r | |
| 107 | <span class="k">end</span><span class="w"></span>\r | |
| 108 | <span class="k">structure</span><span class="w"> </span><span class="n">U</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Z</span><span class="p">()</span><span class="w"></span>\r | |
| 109 | <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">U</span><span class="p">.</span><span class="n">SG</span><span class="p">.</span><span class="n">g</span><span class="w"> </span><span class="p">()</span><span class="w"></span>\r | |
| 110 | <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">U</span><span class="p">.</span><span class="n">SH</span><span class="p">.</span><span class="n">h</span><span class="w"> </span><span class="p">()</span><span class="w"></span>\r | |
| 111 | </pre></div></div></div>\r | |
| 112 | <div class="listingblock">\r | |
| 113 | <div class="content monospaced">\r | |
| 114 | <pre></pre>\r | |
| 115 | </div></div>\r | |
| 116 | </li>\r | |
| 117 | </ul></div>\r | |
| 118 | </div>\r | |
| 119 | </div>\r | |
| 120 | </div>\r | |
| 121 | <div id="footnotes"><hr></div>\r | |
| 122 | <div id="footer">\r | |
| 123 | <div id="footer-text">\r | |
| 124 | </div>\r | |
| 125 | <div id="footer-badges">\r | |
| 126 | </div>\r | |
| 127 | </div>\r | |
| 128 | </body>\r | |
| 129 | </html>\r |