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Celestino Amoroso
2024-09-16 06:52:29 +02:00
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@@ -567,7 +567,7 @@ pre.rouge .ss {
<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="#_variable_default_value_and">4.5. Variable default value <code class="blue">??</code> and <code class="blue">?=</code></a></li>
<li><a href="#_variable_default_value_and">4.5. Variable default value <code class="blue">??</code>, <code class="blue">?=</code>, and <code class="blue">?!</code></a></li>
</ul>
</li>
<li><a href="#_priorities_of_operators">5. Priorities of operators</a></li>
@@ -687,20 +687,20 @@ pre.rouge .ss {
<pre class="rouge highlight"><code data-lang="shell"><span class="c"># Type 'exit' or Ctrl+D to quit the program.</span>
<span class="o">[</span>user]<span class="nv">$ </span>./dev-expr
dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o">(</span>build 14<span class="o">)</span>,2024/06/17 <span class="o">(</span>celestino.amoroso@portale-stac.it<span class="o">)</span>
Based on the Expr package v0.19.0
dev-expr <span class="nt">--</span> Expressions calculator v1.12.0<span class="o">(</span>build 1<span class="o">)</span>,2024/09/14 <span class="o">(</span>celestino.amoroso@portale-stac.it<span class="o">)</span>
Based on the Expr package v0.26.0
Type <span class="nb">help </span>to get the list of available commands
See also https://git.portale-stac.it/go-pkg/expr/src/branch/main/README.adoc
<span class="o">&gt;&gt;&gt;</span> <span class="nb">help</span>
<span class="nt">---</span> REPL commands:
<span class="nb">source</span> <span class="nt">--</span> Load a file as input
<span class="nb">tty</span> <span class="nt">--</span> Enable/Disable ansi output <i class="conum" data-value="1"></i><b>(1)</b>
base <span class="nt">--</span> Set the integer output base: 2, 8, 10, or 16
<span class="nb">exit</span> <span class="nt">--</span> Exit the program
<span class="nb">help</span> <span class="nt">--</span> Show <span class="nb">command </span>list
ml <span class="nt">--</span> Enable/Disable multi-line output
mods <span class="nt">--</span> List <span class="nb">builtin </span>modules
output <span class="nt">--</span> Enable/Disable printing expression results. Options <span class="s1">'on'</span>, <span class="s1">'off'</span>, <span class="s1">'status'</span>
<span class="nb">source</span> <span class="nt">--</span> Load a file as input
<span class="nb">tty</span> <span class="nt">--</span> Enable/Disable ansi output <i class="conum" data-value="1"></i><b>(1)</b>
<span class="nt">---</span> Command line options:
<span class="nt">-b</span> &lt;<span class="nb">builtin</span><span class="o">&gt;</span> Import <span class="nb">builtin </span>modules.
@@ -805,12 +805,12 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<p><span class="blue">Floats</span></p>
</li>
<li>
<p><span class="blue">Factions</span></p>
<p><span class="blue">Fractions</span></p>
</li>
</ol>
</div>
<div class="paragraph">
<p>In mixed operations involving integers, fractions and floats, automatic type promotion to the largest type take place.</p>
<p>In mixed operations involving integers, fractions and floats, automatic type promotion to the largest type is performed.</p>
</div>
<div class="sect3">
<h4 id="_integers"><a class="anchor" href="#_integers"></a><a class="link" href="#_integers">2.1.1. Integers</a></h4>
@@ -855,33 +855,33 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">+</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>sum</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Sum</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Add two values</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-1 + 2</code> &#8594; 1</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-1 + 2</code> &#8594; <em>1</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">-</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>subtraction</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Subtraction</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Subtract the right value from the left one</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">3 - 1</code> &#8594; 2</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">3 - 1</code> &#8594; <em>2</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">*</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>product</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Product</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Multiply two values</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-1 * 2</code> &#8594; -2</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-1 * 2</code> &#8594; <em>-2</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">/</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Division</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Integer division</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Divide the left value by the right one<sup>(*)</sup></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-10 / 2</code> &#8594; 5</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-11 / 2</code> &#8594; <em>-5</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">%</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Modulo</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Remainder of the integer division</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">5 % 2</code> &#8594; 1</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">5 % 2</code> &#8594; <em>1</em></p></td>
</tr>
</tbody>
</table>
@@ -946,31 +946,31 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">+</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>sum</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Sum</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Add two values</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">4 + 0.5</code> &#8594; 4.5</p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">-</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>subtraction</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Subtraction</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Subtract the right value from the left one</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">4 - 0.5</code> &#8594; 3.5</p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">*</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>product</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Product</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Multiply two values</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">4 * 0.5</code> &#8594; 2.0</p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">/</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Division</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Float division</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Divide the left value by the right one</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">1.0 / 2</code> &#8594; 0.5</p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">./</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Float division</em></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Forced float division</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Force float division</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">-1 ./ 2</code> &#8594; -0.5</p></td>
</tr>
@@ -1074,7 +1074,7 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<code class="green">123&#160;&#160;&#160;&#160;abc</code></p>
</div>
<div class="paragraph">
<p>Some arithmetic operators can also be used with strings.</p>
<p>Some arithmetic operators also apply to strings.</p>
</div>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 3. String operators</caption>
@@ -1393,6 +1393,12 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">2 in [1,2,3]</code> &#8594; <em>true</em><br>
<code class="blue">6 in [1,2,3]</code> &#8594; <em>false</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">#</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Size</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Number of items in a list</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">#[1,2,3]</code> &#8594; <em>3</em></p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
@@ -1415,11 +1421,19 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
</div>
</div>
<div class="paragraph">
<div class="title">Items of list</div>
<div class="title">Examples: Getting items from lists</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">[1,2,3][1]</code><br>
<code class="green">2</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">index=2; ["a", "b", "c", "d"][index]</code><br>
<code class="green">c</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">["a", "b", "c", "d"][2:]</code><br>
<code class="green">["c", "d"]</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">list=[1,2,3]; list[1]</code><br>
<code class="green">2</code></p>
</div>
@@ -1432,6 +1446,10 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<code class="green">two</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">list[1]="six"; list</code><br>
<code class="green">["one", "six", "three"]</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">list[-1]</code><br>
<code class="green">three</code></p>
</div>
@@ -1440,22 +1458,42 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<code class="red">Eval Error: [1:9] index 10 out of bounds</code></p>
</div>
<div class="paragraph">
<div class="title">Example: Number of elements in a list</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">#list</code><br>
<code class="green">3</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">index=2; ["a", "b", "c", "d"][index]</code><br>
<code class="green">c</code></p>
<div class="title">Examples: Element insertion</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">"first" &gt;&gt; list</code><br>
<code class="green">["first", "one", "six", "three"]</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">["a", "b", "c", "d"][2:]</code><br>
<code class="green">["c", "d"]</code></p>
<p><code>&gt;&gt;&gt;</code> <code class="blue">list &lt;&lt; "last"</code><br>
<code class="green">["first", "one", "six", "three", "last"]</code></p>
</div>
<div class="paragraph">
<div class="title">Examples: Element in list</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">"six" in list</code><br>
<code class="green">true</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">"ten" in list</code><br>
<code class="green">false</code></p>
</div>
<div class="paragraph">
<div class="title">Examples: Concatenation and filtering</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">[1,2,3] + ["one", "two", "three"]</code><br>
<code class="green">[1, 2, 3, "one", "two", "three"]</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">[1,2,3,4] - [2,4]</code><br>
<code class="green">[1, 3]</code></p>
</div>
</div>
<div class="sect2">
<h3 id="_dictionaries"><a class="anchor" href="#_dictionaries"></a><a class="link" href="#_dictionaries">2.5. Dictionaries</a></h3>
<div class="paragraph">
<p>The <em>dictionary</em>, or <em>dict</em>, data-type is set of pairs <em>key/value</em>. It is also known as <em>map</em> or <em>associative array</em>.</p>
<p>The <em>dictionary</em>, or <em>dict</em>, data-type represents sets of pairs <em>key/value</em>. It is also known as <em>map</em> or <em>associative array</em>.</p>
</div>
<div class="paragraph">
<p>Dictionary literals are sequences of pairs separated by comma <code class="blue">,</code> enclosed between brace brackets.</p>
@@ -1514,6 +1552,12 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">"one" in {"one":1, "two":2}</code> &#8594; <em>true</em><br>
<code class="blue">"six" in {"one":1, "two":2}</code> &#8594; <em>false</em></p></td>
</tr>
<tr>
<td class="tableblock halign-center valign-top"><p class="tableblock"><code class="blue">#</code></p></td>
<td class="tableblock halign-center valign-top"><p class="tableblock"><em>Size</em></p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Number of items in a dict</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock"><code class="blue">#{1:"a",2:"b",3:"c"}</code> &#8594; <em>3</em></p></td>
</tr>
</tbody>
</table>
<div class="paragraph">
@@ -1537,6 +1581,10 @@ dev-expr <span class="nt">--</span> Expressions calculator v1.10.0<span class="o
<p><code>&gt;&gt;&gt;</code> <code class="blue">d={"one":1, "two":2}; d["six"]=6; d</code><br>
<code class="green">{"two": 2, "one": 1, "six": 6}</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">#d</code><br>
<code class="green">3</code></p>
</div>
</div>
</div>
</div>
@@ -1582,7 +1630,7 @@ The assign operator <code class="blue">=</code> returns the value assigned to th
<code class="green">3</code></p>
</div>
<div class="paragraph">
<p><code>&gt;&gt;&gt;</code> <code class="blue">x = 5.2 * (9-3)</code> <em class="gray">// The assigned value has the typical approximation error of the float data-type</em><br>
<p><code>&gt;&gt;&gt;</code> <code class="blue">x = 5.2 * (9-3)</code> <em class="gray">// The assigned value here has the typical approximation error of the float data-type</em><br>
<code class="green">31.200000000000003</code></p>
</div>
<div class="paragraph">
@@ -1751,9 +1799,9 @@ Technically <code class="blue">;</code> is not treated as a real operator. It ac
</div>
</div>
<div class="sect2">
<h3 id="_variable_default_value_and"><a class="anchor" href="#_variable_default_value_and"></a><a class="link" href="#_variable_default_value_and">4.5. Variable default value <code class="blue">??</code> and <code class="blue">?=</code></a></h3>
<h3 id="_variable_default_value_and"><a class="anchor" href="#_variable_default_value_and"></a><a class="link" href="#_variable_default_value_and">4.5. Variable default value <code class="blue">??</code>, <code class="blue">?=</code>, and <code class="blue">?!</code></a></h3>
<div class="paragraph">
<p>The left operand of these two operators must be a variable. The right operator can be any expression. They return the value of the variable if this is defined; otherwise they return the value of the right expression.</p>
<p>The left operand of first two operators, <code class="blue">??</code> and <code class="blue">?=</code>, must be a variable. The right operator can be any expression. They return the value of the variable if this is defined; otherwise they return the value of the right expression.</p>
</div>
<div class="admonitionblock important">
<table>
@@ -1774,6 +1822,21 @@ If the left variable is defined, the right expression is not evaluated at all.
<p>The <code class="blue">?=</code> assigns the calculated value of the right expression to the left variable.</p>
</div>
<div class="paragraph">
<p>The third one, <code class="blue">?!</code>, is the alternate operator. If the variable on the left size is not defined, it returns <em class="blue">nil</em>. Otherwise it returns the result of the expressione on the right side.</p>
</div>
<div class="admonitionblock important">
<table>
<tr>
<td class="icon">
<i class="fa icon-important" title="Important"></i>
</td>
<td class="content">
If the left variable is NOT defined, the right expression is not evaluated at all.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<div class="title">Examples</div>
<p><code>&gt;&gt;&gt;</code> <code class="blue">var ?? (1+2)</code><br>
<code class="green">3</code></p>
@@ -2204,7 +2267,7 @@ These operators have a high priority, in particular higher than the operator <co
</div>
<div id="footer">
<div id="footer-text">
Last updated 2024-09-12 06:56:30 +0200
Last updated 2024-09-14 11:58:38 +0200
</div>
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