HCoop / hcoop / debian / mlton.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Import Debian changes 20180207-1
[hcoop/debian/mlton.git] / doc / guide / localhost / MLBasisSyntaxAndSemantics
CommitLineData
7f918cf1
CE		 1<!DOCTYPE html>\r
2<html lang="en">\r
3<head>\r
4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">\r
5<meta name="generator" content="AsciiDoc 8.6.9">\r
6<title>MLBasisSyntaxAndSemantics</title>\r
7<link rel="stylesheet" href="./asciidoc.css" type="text/css">\r
8<link rel="stylesheet" href="./pygments.css" type="text/css">\r
9\r
10\r
11<script type="text/javascript" src="./asciidoc.js"></script>\r
12<script type="text/javascript">\r
13/*<![CDATA[*/\r
14asciidoc.install();\r
15/*]]>*/\r
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>MLBasisSyntaxAndSemantics</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>An <a href="MLBasis">ML Basis</a> (MLB) file should have the <span class="monospaced">.mlb</span> suffix and\r
32should contain a basis declaration.</p></div>\r
33</div>\r
34</div>\r
35<div class="sect1">\r
36<h2 id="_syntax">Syntax</h2>\r
37<div class="sectionbody">\r
38<div class="paragraph"><p>A basis declaration (<em>basdec</em>) must be one of the following forms.</p></div>\r
39<div class="ulist"><ul>\r
40<li>\r
41<p>\r
42<span class="monospaced">basis</span> <em>basid</em> <span class="monospaced">=</span> <em>basexp</em> (<span class="monospaced">and</span> <em>basid</em> <span class="monospaced">=</span> <em>basexp</em>)<sup>*</sup>\r
43</p>\r
44</li>\r
45<li>\r
46<p>\r
47<span class="monospaced">open</span> <em>basid<sub>1</sub></em> &#8230; <em>basid<sub>n</sub></em>\r
48</p>\r
49</li>\r
50<li>\r
51<p>\r
52<span class="monospaced">local</span> <em>basdec</em> <span class="monospaced">in</span> <em>basdec</em> <span class="monospaced">end</span>\r
53</p>\r
54</li>\r
55<li>\r
56<p>\r
57<em>basdec</em> [<span class="monospaced">;</span>] <em>basdec</em>\r
58</p>\r
59</li>\r
60<li>\r
61<p>\r
62<span class="monospaced">structure</span> <em>strid</em> [<span class="monospaced">=</span> <em>strid</em>] (<span class="monospaced">and</span> <em>strid</em>[<span class="monospaced">=</span> <em>strid</em>])<sup>*</sup>\r
63</p>\r
64</li>\r
65<li>\r
66<p>\r
67<span class="monospaced">signature</span> <em>sigid</em> [<span class="monospaced">=</span> <em>sigid</em>] (<span class="monospaced">and</span> <em>sigid</em> [<span class="monospaced">=</span> <em>sigid</em>])<sup>*</sup>\r
68</p>\r
69</li>\r
70<li>\r
71<p>\r
72<span class="monospaced">functor</span> <em>funid</em> [<span class="monospaced">=</span> <em>funid</em>] (<span class="monospaced">and</span> <em>funid</em> [<span class="monospaced">=</span> <em>funid</em>])<sup>*</sup>\r
73</p>\r
74</li>\r
75<li>\r
76<p>\r
77<em>path</em><span class="monospaced">.sml</span>, <em>path</em><span class="monospaced">.sig</span>, or <em>path</em><span class="monospaced">.fun</span>\r
78</p>\r
79</li>\r
80<li>\r
81<p>\r
82<em>path</em><span class="monospaced">.mlb</span>\r
83</p>\r
84</li>\r
85<li>\r
86<p>\r
87<span class="monospaced">ann</span> <span class="monospaced">"</span><em>ann</em><span class="monospaced">"</span> <span class="monospaced">in</span> <em>basdec</em> <span class="monospaced">end</span>\r
88</p>\r
89</li>\r
90</ul></div>\r
91<div class="paragraph"><p>A basis expression (<em>basexp</em>) must be of one the following forms.</p></div>\r
92<div class="ulist"><ul>\r
93<li>\r
94<p>\r
95<span class="monospaced">bas</span> <em>basdec</em> <span class="monospaced">end</span>\r
96</p>\r
97</li>\r
98<li>\r
99<p>\r
100<em>basid</em>\r
101</p>\r
102</li>\r
103<li>\r
104<p>\r
105<span class="monospaced">let</span> <em>basdec</em> <span class="monospaced">in</span> <em>basexp</em> <span class="monospaced">end</span>\r
106</p>\r
107</li>\r
108</ul></div>\r
109<div class="paragraph"><p>Nested SML-style comments (enclosed with <span class="monospaced">(*</span> and <span class="monospaced">*)</span>) are ignored\r
110(but <a href="LineDirective">LineDirective</a>s are recognized).</p></div>\r
111<div class="paragraph"><p>Paths can be relative or absolute. Relative paths are relative to the\r
112directory containing the MLB file. Paths may include path variables\r
113and are expanded according to a <a href="MLBasisPathMap">path map</a>. Unquoted\r
114paths may include alpha-numeric characters and the symbols "<span class="monospaced">-</span>" and\r
115"<span class="monospaced">_</span>", along with the arc separator "<span class="monospaced">/</span>" and extension separator\r
116"<span class="monospaced">.</span>". More complicated paths, including paths with spaces, may be\r
117included by quoting the path with <span class="monospaced">"</span>. A quoted path is lexed as an\r
118SML string constant.</p></div>\r
119<div class="paragraph"><p><a href="MLBasisAnnotations">Annotations</a> allow a library author to\r
120control options that affect the elaboration of SML source files.</p></div>\r
121</div>\r
122</div>\r
123<div class="sect1">\r
124<h2 id="_semantics">Semantics</h2>\r
125<div class="sectionbody">\r
126<div class="paragraph"><p>There is a <a href="MLBasis.attachments/mlb-formal.pdf">formal semantics</a> for\r
127ML Basis files in the style of the\r
128<a href="DefinitionOfStandardML">Definition</a>. Here, we give an informal\r
129explanation.</p></div>\r
130<div class="paragraph"><p>An SML structure is a collection of types, values, and other\r
131structures. Similarly, a basis is a collection, but of more kinds of\r
132objects: types, values, structures, fixities, signatures, functors,\r
133and other bases.</p></div>\r
134<div class="paragraph"><p>A basis declaration denotes a basis. A structure, signature, or\r
135functor declaration denotes a basis containing the corresponding\r
136module. Sequencing of basis declarations merges bases, with later\r
137definitions taking precedence over earlier ones, just like sequencing\r
138of SML declarations. Local declarations provide name hiding, just\r
139like SML local declarations. A reference to an SML source file causes\r
140the file to be elaborated in the basis extant at the point of\r
141reference. A reference to an MLB file causes the basis denoted by\r
142that MLB file to be imported&#8201;&#8212;&#8201;the basis at the point of reference\r
143does <em>not</em> affect the imported basis.</p></div>\r
144<div class="paragraph"><p>Basis expressions and basis identifiers allow binding a basis to a\r
145name.</p></div>\r
146<div class="paragraph"><p>An MLB file is elaborated starting in an empty basis. Each MLB file\r
147is elaborated and evaluated only once, with the result being cached.\r
148Subsequent references use the cached value. Thus, any observable\r
149effects due to evaluation are not duplicated if the MLB file is\r
150referred to multiple times.</p></div>\r
151</div>\r
152</div>\r
153</div>\r
154<div id="footnotes"><hr></div>\r
155<div id="footer">\r
156<div id="footer-text">\r
157</div>\r
158<div id="footer-badges">\r
159</div>\r
160</div>\r
161</body>\r
162</html>\r
mlton packaging