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Doc: fractions and dictionaries

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@ -22,7 +22,7 @@ Expressions calculator
toc::[]
#TODO: Work in progress (last update on 2024/05/07, 07:15 am)#
#TODO: Work in progress (last update on 2024/05/09, 07:17 am)#
== Expr
_Expr_ is a GO package capable of analysing, interpreting and calculating expressions.
@ -140,7 +140,44 @@ Numbers can be integers (GO int64) or float (GO float64). In mixed operations in
|===
=== String
=== Fractions
_Expr_ also suports fractions. Fraction literals are made with tow integers separated by a vertical bar `|`.
.Examples
// [source,go]
// ----
`>>>` [blue]`1 | 2` +
[green]`1|2` +
`>>>` [blue]`4|6` +
[green]`2|3` [gray]_Fractions are always reduced to theri lowest terms_ +
`>>>` [blue]`1|2 + 2|3` +
[green]`7|6` +
`>>>` [blue]`1|2 * 2|3` +
[green]`1|3` +
`>>>` [blue]`1|2 / 1|3` +
[green]`3|2` +
`>>>` [blue]`1|2 ./ 1|3` [gray]_Force decimal division_ +
[green]`1.5` +
`>>>` [blue]`-1|2` +
[green]`-1|2` +
`>>>` [blue]`1|-2` [gray]_Wrong sign specification_ +
[red]_Eval Error: [1:3] infix operator "|" requires two non-nil operands, got 1_ +
`>>>` [blue]`1|(-2)` +
[green]`-1|2`
// ----
Fractions can be used together with integers and floats in expressions.
`>>>` [blue]`1|2 + 5` +
[green]`11|2` +
`>>>` [blue]`4 - 1|2` +
[green]`7|2` +
`>>>` [blue]`1.0 + 1|2` +
[green]`1.5` +
=== Strings
Strings are character sequences enclosed between two double quote [blue]`"`. Example: [blue]`"I'm a string"`.
Some arithmetic operators can also be used with strings.
@ -232,6 +269,19 @@ _Expr_ supports list of mixed-type values, also specified by normal expressions.
| [blue]`-` | _Difference_ | Left list without elements in the right list | [blue]`[1,2,3] - [2]` _[ [1,3] ]_
|===
== Dictionaries
The _dictionary_ data-type is set of pairs _key/value_. It is also known as _map_ or _associative array_. Dictionary literals are sequences of pairs separated by comma `,`; sequences are enclosed between brace brackets.
.List examples
[source,go]
----
{1:"one", 2:"two"}
{"one":1, "two": 2}
{"sum":1+2+3, "prod":1*2*3}
----
WARNING: Support for dictionaries is still ongoing.
== Variables
A variable is an identifier with an assigned value. Variables are stored in the object that implements the _ExprContext_ interface.

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doc/Expr.html
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@ -542,31 +542,33 @@ pre.rouge .ss {
<li><a href="#_data_types">2. Data types</a>
<ul class="sectlevel2">
<li><a href="#_numbers">2.1. Numbers</a></li>
<li><a href="#_string">2.2. String</a></li>
<li><a href="#_boolean">2.3. Boolean</a></li>
<li><a href="#_list">2.4. List</a></li>
<li><a href="#_fractions">2.2. Fractions</a></li>
<li><a href="#_strings">2.3. Strings</a></li>
<li><a href="#_boolean">2.4. Boolean</a></li>
<li><a href="#_list">2.5. List</a></li>
</ul>
</li>
<li><a href="#_variables">3. Variables</a></li>
<li><a href="#_other_operations">4. Other operations</a>
<li><a href="#_dictionaries">3. Dictionaries</a></li>
<li><a href="#_variables">4. Variables</a></li>
<li><a href="#_other_operations">5. Other operations</a>
<ul class="sectlevel2">
<li><a href="#_operator">4.1. <code class="blue">;</code> operator</a></li>
<li><a href="#_but_operator">4.2. <code class="blue">but</code> operator</a></li>
<li><a href="#_assignment_operator">4.3. Assignment operator <code class="blue">=</code></a></li>
<li><a href="#_selector_operator">4.4. Selector operator <code class="blue">? : ::</code></a></li>
<li><a href="#_operator">5.1. <code class="blue">;</code> operator</a></li>
<li><a href="#_but_operator">5.2. <code class="blue">but</code> operator</a></li>
<li><a href="#_assignment_operator">5.3. Assignment operator <code class="blue">=</code></a></li>
<li><a href="#_selector_operator">5.4. Selector operator <code class="blue">? : ::</code></a></li>
</ul>
</li>
<li><a href="#_priorities_of_operators">5. Priorities of operators</a></li>
<li><a href="#_functions">6. Functions</a>
<li><a href="#_priorities_of_operators">6. Priorities of operators</a></li>
<li><a href="#_functions">7. Functions</a>
<ul class="sectlevel2">
<li><a href="#_function_calls">6.1. Function calls</a></li>
<li><a href="#_function_definitions">6.2. Function definitions</a></li>
<li><a href="#_function_calls">7.1. Function calls</a></li>
<li><a href="#_function_definitions">7.2. Function definitions</a></li>
</ul>
</li>
<li><a href="#_builtins">7. Builtins</a>
<li><a href="#_builtins">8. Builtins</a>
<ul class="sectlevel2">
<li><a href="#_builtin_functions">7.1. Builtin functions</a></li>
<li><a href="#_import">7.2. <em class="blue">import()</em></a></li>
<li><a href="#_builtin_functions">8.1. Builtin functions</a></li>
<li><a href="#_import">8.2. <em class="blue">import()</em></a></li>
</ul>
</li>
</ul>
@ -577,7 +579,7 @@ pre.rouge .ss {
<div class="sectionbody">
<!-- toc disabled -->
<div class="paragraph">
<p><mark>TODO: Work in progress (last update on 2024/05/07, 07:15 am)</mark></p>
<p><mark>TODO: Work in progress (last update on 2024/05/09, 07:17 am)</mark></p>
</div>
</div>
</div>
@ -787,7 +789,45 @@ Here are some examples of execution.</p>
</table>
</div>
<div class="sect2">
<h3 id="_string"><a class="anchor" href="#_string"></a><a class="link" href="#_string">2.2. String</a></h3>
<h3 id="_fractions"><a class="anchor" href="#_fractions"></a><a class="link" href="#_fractions">2.2. Fractions</a></h3>
<div class="paragraph">
<p><em>Expr</em> also suports fractions. Fraction literals are made with tow integers separated by a vertical bar <code>|</code>.</p>
</div>
<div class="paragraph">
<div class="title">Examples</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">1 | 2</code><br>
<code class="green">1|2</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">4|6</code><br>
<code class="green">2|3</code> <em class="gray">Fractions are always reduced to theri lowest terms</em><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|2 + 2|3</code><br>
<code class="green">7|6</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|2 * 2|3</code><br>
<code class="green">1|3</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|2 / 1|3</code><br>
<code class="green">3|2</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|2 ./ 1|3</code> <em class="gray">Force decimal division</em><br>
<code class="green">1.5</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">-1|2</code><br>
<code class="green">-1|2</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|-2</code> <em class="gray">Wrong sign specification</em><br>
<em class="red">Eval Error: [1:3] infix operator "|" requires two non-nil operands, got 1</em><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1|(-2)</code><br>
<code class="green">-1|2</code></p>
</div>
<div class="paragraph">
<p>Fractions can be used together with integers and floats in expressions.</p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">1|2 + 5</code><br>
<code class="green">11|2</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">4 - 1|2</code><br>
<code class="green">7|2</code><br>
<code>&gt;&gt;&gt;</code> <code class="blue">1.0 + 1|2</code><br>
<code class="green">1.5</code><br></p>
</div>
</div>
<div class="sect2">
<h3 id="_strings"><a class="anchor" href="#_strings"></a><a class="link" href="#_strings">2.3. Strings</a></h3>
<div class="paragraph">
<p>Strings are character sequences enclosed between two double quote <code class="blue">"</code>. Example: <code class="blue">"I&#8217;m a string"</code>.</p>
</div>
@ -828,7 +868,7 @@ Here are some examples of execution.</p>
</table>
</div>
<div class="sect2">
<h3 id="_boolean"><a class="anchor" href="#_boolean"></a><a class="link" href="#_boolean">2.3. Boolean</a></h3>
<h3 id="_boolean"><a class="anchor" href="#_boolean"></a><a class="link" href="#_boolean">2.4. Boolean</a></h3>
<div class="paragraph">
<p>Boolean data type has two values only: <em>true</em> and <em>false</em>. Relational and Boolean expressions produce Boolean values.</p>
</div>
@ -963,7 +1003,7 @@ Here are some examples of execution.</p>
</div>
</div>
<div class="sect2">
<h3 id="_list"><a class="anchor" href="#_list"></a><a class="link" href="#_list">2.4. List</a></h3>
<h3 id="_list"><a class="anchor" href="#_list"></a><a class="link" href="#_list">2.5. List</a></h3>
<div class="paragraph">
<p><em>Expr</em> supports list of mixed-type values, also specified by normal expressions.</p>
</div>
@ -1012,7 +1052,35 @@ Here are some examples of execution.</p>
</div>
</div>
<div class="sect1">
<h2 id="_variables"><a class="anchor" href="#_variables"></a><a class="link" href="#_variables">3. Variables</a></h2>
<h2 id="_dictionaries"><a class="anchor" href="#_dictionaries"></a><a class="link" href="#_dictionaries">3. Dictionaries</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>The <em>dictionary</em> data-type is set of pairs <em>key/value</em>. It is also known as <em>map</em> or <em>associative array</em>. Dictionary literals are sequences of pairs separated by comma <code>,</code>; sequences are enclosed between brace brackets.</p>
</div>
<div class="listingblock">
<div class="title">List examples</div>
<div class="content">
<pre class="rouge highlight"><code data-lang="go"><span class="p">{</span><span class="m">1</span><span class="o">:</span><span class="s">"one"</span><span class="p">,</span> <span class="m">2</span><span class="o">:</span><span class="s">"two"</span><span class="p">}</span>
<span class="p">{</span><span class="s">"one"</span><span class="o">:</span><span class="m">1</span><span class="p">,</span> <span class="s">"two"</span><span class="o">:</span> <span class="m">2</span><span class="p">}</span>
<span class="p">{</span><span class="s">"sum"</span><span class="o">:</span><span class="m">1</span><span class="o">+</span><span class="m">2</span><span class="o">+</span><span class="m">3</span><span class="p">,</span> <span class="s">"prod"</span><span class="o">:</span><span class="m">1</span><span class="o">*</span><span class="m">2</span><span class="o">*</span><span class="m">3</span><span class="p">}</span></code></pre>
</div>
</div>
<div class="admonitionblock warning">
<table>
<tr>
<td class="icon">
<i class="fa icon-warning" title="Warning"></i>
</td>
<td class="content">
Support for dictionaries is still ongoing.
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_variables"><a class="anchor" href="#_variables"></a><a class="link" href="#_variables">4. Variables</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>A variable is an identifier with an assigned value. Variables are stored in the object that implements the <em>ExprContext</em> interface.</p>
@ -1028,10 +1096,10 @@ Here are some examples of execution.</p>
</div>
</div>
<div class="sect1">
<h2 id="_other_operations"><a class="anchor" href="#_other_operations"></a><a class="link" href="#_other_operations">4. Other operations</a></h2>
<h2 id="_other_operations"><a class="anchor" href="#_other_operations"></a><a class="link" href="#_other_operations">5. Other operations</a></h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="_operator"><a class="anchor" href="#_operator"></a><a class="link" href="#_operator">4.1. <code class="blue">;</code> operator</a></h3>
<h3 id="_operator"><a class="anchor" href="#_operator"></a><a class="link" href="#_operator">5.1. <code class="blue">;</code> operator</a></h3>
<div class="paragraph">
<p>The semicolon operator <code class="blue">;</code> is an infixed pseudo-operator. It evaluates the left expression first and then the right expression. The latter is the final result.</p>
</div>
@ -1067,7 +1135,7 @@ Technically <code class="blue">;</code> is not treated as a real operator. It ac
</div>
</div>
<div class="sect2">
<h3 id="_but_operator"><a class="anchor" href="#_but_operator"></a><a class="link" href="#_but_operator">4.2. <code class="blue">but</code> operator</a></h3>
<h3 id="_but_operator"><a class="anchor" href="#_but_operator"></a><a class="link" href="#_but_operator">5.2. <code class="blue">but</code> operator</a></h3>
<div class="paragraph">
<p><code class="blue">but</code> is an infixed operator. Its operands can be expressions of any type. It evaluates the left expression first, then the right expression. The value of the right expression is the final result. Examples: <code class="blue">5 but 2</code> returns 2, <code class="blue">x=2*3 but x-1</code> returns 5.</p>
</div>
@ -1076,7 +1144,7 @@ Technically <code class="blue">;</code> is not treated as a real operator. It ac
</div>
</div>
<div class="sect2">
<h3 id="_assignment_operator"><a class="anchor" href="#_assignment_operator"></a><a class="link" href="#_assignment_operator">4.3. Assignment operator <code class="blue">=</code></a></h3>
<h3 id="_assignment_operator"><a class="anchor" href="#_assignment_operator"></a><a class="link" href="#_assignment_operator">5.3. Assignment operator <code class="blue">=</code></a></h3>
<div class="paragraph">
<p>The assignment operator <code class="blue">=</code> is used to define variables in the evaluation context or to change their value (see <em>ExprContext</em>).
The value on the left side of <code class="blue">=</code> must be an identifier. The value on the right side can be any expression and it becomes the result of the assignment operation.</p>
@ -1089,7 +1157,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
</div>
</div>
<div class="sect2">
<h3 id="_selector_operator"><a class="anchor" href="#_selector_operator"></a><a class="link" href="#_selector_operator">4.4. Selector operator <code class="blue">? : ::</code></a></h3>
<h3 id="_selector_operator"><a class="anchor" href="#_selector_operator"></a><a class="link" href="#_selector_operator">5.4. Selector operator <code class="blue">? : ::</code></a></h3>
<div class="paragraph">
<p>The <em>selector operator</em> is very similar to the <em>switch/case/default</em> statement available in many programming languages.</p>
</div>
@ -1129,7 +1197,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
</div>
</div>
<div class="sect1">
<h2 id="_priorities_of_operators"><a class="anchor" href="#_priorities_of_operators"></a><a class="link" href="#_priorities_of_operators">5. Priorities of operators</a></h2>
<h2 id="_priorities_of_operators"><a class="anchor" href="#_priorities_of_operators"></a><a class="link" href="#_priorities_of_operators">6. Priorities of operators</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>The table below shows all supported operators by decreasing priorities.</p>
@ -1350,7 +1418,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
</div>
</div>
<div class="sect1">
<h2 id="_functions"><a class="anchor" href="#_functions"></a><a class="link" href="#_functions">6. Functions</a></h2>
<h2 id="_functions"><a class="anchor" href="#_functions"></a><a class="link" href="#_functions">7. Functions</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>Functions in <em>Expr</em> are very similar to functions in many programming languages.</p>
@ -1359,13 +1427,13 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
<p>In <em>Expr</em> functions compute values in a local context (scope) that do not make effects on the calling context. This is the normal behavior. Using the reference operator <code class="blue">@</code> it is possibile to export local definition to the calling context.</p>
</div>
<div class="sect2">
<h3 id="_function_calls"><a class="anchor" href="#_function_calls"></a><a class="link" href="#_function_calls">6.1. Function calls</a></h3>
<h3 id="_function_calls"><a class="anchor" href="#_function_calls"></a><a class="link" href="#_function_calls">7.1. Function calls</a></h3>
<div class="paragraph">
<p><mark>TODO: function calls operations</mark></p>
</div>
</div>
<div class="sect2">
<h3 id="_function_definitions"><a class="anchor" href="#_function_definitions"></a><a class="link" href="#_function_definitions">6.2. Function definitions</a></h3>
<h3 id="_function_definitions"><a class="anchor" href="#_function_definitions"></a><a class="link" href="#_function_definitions">7.2. Function definitions</a></h3>
<div class="paragraph">
<p><mark>TODO: function definitions operations</mark></p>
</div>
@ -1373,17 +1441,17 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
</div>
</div>
<div class="sect1">
<h2 id="_builtins"><a class="anchor" href="#_builtins"></a><a class="link" href="#_builtins">7. Builtins</a></h2>
<h2 id="_builtins"><a class="anchor" href="#_builtins"></a><a class="link" href="#_builtins">8. Builtins</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p><mark>TODO: builtins</mark></p>
</div>
<div class="sect2">
<h3 id="_builtin_functions"><a class="anchor" href="#_builtin_functions"></a><a class="link" href="#_builtin_functions">7.1. Builtin functions</a></h3>
<h3 id="_builtin_functions"><a class="anchor" href="#_builtin_functions"></a><a class="link" href="#_builtin_functions">8.1. Builtin functions</a></h3>
</div>
<div class="sect2">
<h3 id="_import"><a class="anchor" href="#_import"></a><a class="link" href="#_import">7.2. <em class="blue">import()</em></a></h3>
<h3 id="_import"><a class="anchor" href="#_import"></a><a class="link" href="#_import">8.2. <em class="blue">import()</em></a></h3>
<div class="paragraph">
<p><em class="blue">import(<span class="grey">&lt;source-file&gt;</span>)</em> loads the multi-expression contained in the specified source and returns its value.</p>
</div>
@ -1393,7 +1461,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
</div>
<div id="footer">
<div id="footer-text">
Last updated 2024-05-08 07:50:05 +0200
Last updated 2024-05-09 07:18:01 +0200
</div>
</div>
</body>