Doc: some typo and better examples
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@ -203,19 +203,16 @@ The items of strings can be accessed using the dot `.` operator.
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----
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.String examples
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[source,go]
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----
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`>>>` [blue]`s="abc"` [gray]`// assign the string to variable s`
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[geen]`abc`
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`>>>` [blue]`s.1` [gray]`// char at position 1 (starting from 0)
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[blue]`b`
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`>>>` [blue]`s.(-1)` [gray]`// char at position -1, the rightmost one
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[blue]`c`
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`>>>` [blue]`#s` [gray]`// number of chars
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[blue]3`
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`>>>` [blue]`#"abc"` [gray]`// number of chars
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[blue]3`
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----
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`>>>` [blue]`s="abc"` [gray]_assign the string to variable s_ +
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[green]`abc` +
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`>>>` [blue]`s.1` [gray]_char at position 1 (starting from 0)_ +
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[green]`b` +
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`>>>` [blue]`s.(-1)` [gray]_char at position -1, the rightmost one_ +
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[green]`c` +
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`>>>` [blue]`\#s` [gray]_number of chars_ +
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[gren]`3` +
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`>>>` [blue]`#"abc"` [gray]_number of chars_ +
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[green]`3` +
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=== Boolean
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Boolean data type has two values only: _true_ and _false_. Relational and Boolean expressions produce Boolean values.
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@ -300,32 +297,27 @@ The items of array can be accessed using the dot `.` operator.
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----
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.Items of list
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[source,go]
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----
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`>>>` [blue]`[1,2,3].1`
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[green]`2`
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`>>>` [blue]`list=[1,2,3]; list.1`
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[green]`2`
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`>>>` [blue]`["one","two","three"].1`
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[green]`two`
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`>>>` [blue]`list=["one","two","three"]; list.(2-1)`
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[green]`two`
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`>>>` [blue]`list.(-1)`
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[green]`three`
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`>>>` [blue]`list.(-1)`
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[green]`three`
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`>>>` [blue]`list.(10)`
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[red]`Eval Error: [1:9] index 10 out of bounds`
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`>>>` [blue]`#list`
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`>>>` [blue]`[1,2,3].1` +
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[green]`2` +
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`>>>` [blue]`list=[1,2,3]; list.1` +
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[green]`2` +
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`>>>` [blue]`["one","two","three"].1` +
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[green]`two` +
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`>>>` [blue]`list=["one","two","three"]; list.(2-1)` +
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[green]`two` +
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`>>>` [blue]`list.(-1)` +
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[green]`three` +
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`>>>` [blue]`list.(10)` +
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[red]`Eval Error: [1:9] index 10 out of bounds` +
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`>>>` [blue]`#list` +
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[green]`3`
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----
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== Dictionaries
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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.
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.List examples
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.Dictionary examples
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[source,go]
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----
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{1:"one", 2:"two"}
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@ -336,7 +328,7 @@ The _dictionary_ data-type is set of pairs _key/value_. It is also known as _map
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WARNING: Support for dictionaries is still ongoing.
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== Variables
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A variable is an identifier with an assigned value. Variables are stored in the object that implements the _ExprContext_ interface.
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A variable is an identifier with an assigned value. Variables are stored in the object that implements the Go _ExprContext_ interface, e.g. _SimpleVarStore_ or _SimpleFuncStore_.
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.Examples
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[source,go]
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@ -390,23 +382,30 @@ The _selector operator_ is very similar to the _switch/case/default_ statement a
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<multi-expression> ::= <expression> {";" <expression>}
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----
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In other words, the selector operator evaluates the expression (`<select-expression>`) on the left-hand side of the `?` symbol; it then compares the result obtained with the values listed in the `<match-list>`'s. If the comparision find a match with a value in a match-list, the associated `<case-multi-expression>` is evaluted, and its result will be the final result of the selection operation.
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In other words, the selector operator evaluates the expression (`<select-expression>`) on the left-hand side of the `?` symbol; it then compares the result obtained with the values listed in the `<match-list>`'s. If the comparision finds a match with a value in a match-list, the associated `<case-multi-expression>` is evaluted, and its result will be the final result of the selection operation.
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The match lists are optional. In that case, the position, from left to right, of the `<selector-case>` is used as match-list. Of course, that only works if the select-expression results in an integer.
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The `:` symbol (colon) is the separator of the selector-cases. Note that if the value of the select-expression does not match any match-list, an error will be issued. Therefore, it is strongly recommended to provide a default (multi-)expression introduced by the `::` symbol (double-colon). Also note that the default expression has no match-list.
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.Examples
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[source,go]
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----
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1 ? {"a"} : {"b"} // returns "b"
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10 ? {"a"} : {"b"} :: {"c"} // returns "c"
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10 ? {"a"} :[true, 2+8] {"b"} :: {"c"} // returns "b"
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10 ? {"a"} :[true, 2+8] {"b"} ::[10] {"c"} // error: "... case list in default clause"
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10 ? {"a"} :[10] {x="b" but x} :: {"c"} // returns "b"
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10 ? {"a"} :[10] {x="b"; x} :: {"c"} // returns "b"
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10 ? {"a"} : {"b"} // error: "... no case catches the value (10) of the selection expression
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`>>>` [blue]`1 ? {"a"} : {"b"}`
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[green]`b`
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`>>>` [blue]`10 ? {"a"} : {"b"} :: {"c"}`
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[green]`c'
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[green]`>>>` [blue]`10 ? {"a"} :[true, 2+8] {"b"} :: {"c"}`
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[green]`b`
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`>>>` [blue]`10 ? {"a"} :[true, 2+8] {"b"} ::[10] {"c"}`
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[red]`Parse Error: [1:34] case list in default clause`
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[green]`>>>` [blue]`10 ? {"a"} :[10] {x="b" but x} :: {"c"}`
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[green]`b`
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`>>>` [blue]`10 ? {"a"} :[10] {x="b"; x} :: {"c"}`
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[green]`b`
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`>>>` [blue]`10 ? {"a"} : {"b"}`
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[red]`Eval Error: [1:3] no case catches the value (10) of the selection expression`
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----
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== Priorities of operators
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@ -868,6 +868,28 @@ pre.rouge .ss {
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</tr>
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</tbody>
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</table>
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<div class="paragraph">
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<p>The items of strings can be accessed using the dot <code>.</code> operator.</p>
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</div>
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<div class="listingblock">
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<div class="title">Item access syntax</div>
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<div class="content">
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<pre class="rouge highlight"><code data-lang="bnf"><item> ::= <string-expr>"."<index-expr></code></pre>
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</div>
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</div>
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<div class="paragraph">
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<div class="title">String examples</div>
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<p><code>>>></code> <code class="blue">s="abc"</code> <em class="gray">assign the string to variable s</em><br>
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<code class="green">abc</code><br>
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<code>>>></code> <code class="blue">s.1</code> <em class="gray">char at position 1 (starting from 0)</em><br>
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<code class="green">b</code><br>
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<code>>>></code> <code class="blue">s.(-1)</code> <em class="gray">char at position -1, the rightmost one</em><br>
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<code class="green">c</code><br>
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<code>>>></code> <code class="blue">#s</code> <em class="gray">number of chars</em><br>
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<code class="gren">3</code><br>
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<code>>>></code> <code class="blue">#"abc"</code> <em class="gray">number of chars</em><br>
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<code class="green">3</code><br></p>
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</div>
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</div>
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<div class="sect2">
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<h3 id="_boolean"><a class="anchor" href="#_boolean"></a><a class="link" href="#_boolean">2.4. Boolean</a></h3>
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@ -1059,23 +1081,22 @@ pre.rouge .ss {
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<pre class="rouge highlight"><code data-lang="bnf"><item> ::= <list-expr>"."<index-expr></code></pre>
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</div>
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</div>
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<div class="listingblock">
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<div class="paragraph">
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<div class="title">Items of list</div>
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<div class="content">
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<pre class="rouge highlight"><code data-lang="go"><span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`[1,2,3].1`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`2`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`list=[1,2,3]; list.1`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`2`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`["one","two","three"].1`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`two`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`list=["one","two","three"]; list.(2-1)`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`two`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`list.(-1)`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`three`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`list.(-1)`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`three`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`list.(10)`</span></code></pre>
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</div>
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<p><code>>>></code> <code class="blue">[1,2,3].1</code><br>
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<code class="green">2</code><br>
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<code>>>></code> <code class="blue">list=[1,2,3]; list.1</code><br>
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<code class="green">2</code><br>
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<code>>>></code> <code class="blue">["one","two","three"].1</code><br>
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<code class="green">two</code><br>
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<code>>>></code> <code class="blue">list=["one","two","three"]; list.(2-1)</code><br>
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<code class="green">two</code><br>
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<code>>>></code> <code class="blue">list.(-1)</code><br>
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<code class="green">three</code><br>
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<code>>>></code> <code class="blue">list.(10)</code><br>
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<code class="red">Eval Error: [1:9] index 10 out of bounds</code><br>
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<code>>>></code> <code class="blue">#list</code><br>
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<code class="green">3</code></p>
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</div>
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</div>
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</div>
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@ -1087,7 +1108,7 @@ pre.rouge .ss {
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<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>
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</div>
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<div class="listingblock">
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<div class="title">List examples</div>
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<div class="title">Dictionary examples</div>
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<div class="content">
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<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>
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<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>
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@ -1112,7 +1133,7 @@ Support for dictionaries is still ongoing.
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<h2 id="_variables"><a class="anchor" href="#_variables"></a><a class="link" href="#_variables">4. Variables</a></h2>
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<div class="sectionbody">
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<div class="paragraph">
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<p>A variable is an identifier with an assigned value. Variables are stored in the object that implements the <em>ExprContext</em> interface.</p>
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<p>A variable is an identifier with an assigned value. Variables are stored in the object that implements the Go <em>ExprContext</em> interface, e.g. <em>SimpleVarStore</em> or <em>SimpleFuncStore</em>.</p>
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</div>
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<div class="listingblock">
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<div class="title">Examples</div>
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@ -1202,7 +1223,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
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</div>
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</div>
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<div class="paragraph">
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<p>In other words, the selector operator evaluates the expression (<code><select-expression></code>) on the left-hand side of the <code>?</code> symbol; it then compares the result obtained with the values listed in the <code><match-list>’s. If the comparision find a match with a value in a match-list, the associated `<case-multi-expression></code> is evaluted, and its result will be the final result of the selection operation.</p>
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<p>In other words, the selector operator evaluates the expression (<code><select-expression></code>) on the left-hand side of the <code>?</code> symbol; it then compares the result obtained with the values listed in the <code><match-list>’s. If the comparision finds a match with a value in a match-list, the associated `<case-multi-expression></code> is evaluted, and its result will be the final result of the selection operation.</p>
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</div>
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<div class="paragraph">
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<p>The match lists are optional. In that case, the position, from left to right, of the <code><selector-case></code> is used as match-list. Of course, that only works if the select-expression results in an integer.</p>
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@ -1213,13 +1234,21 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
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<div class="listingblock">
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<div class="title">Examples</div>
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<div class="content">
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<pre class="rouge highlight"><code data-lang="go"><span class="m">1</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="c">// returns "b"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span> <span class="c">// returns "c"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="no">true</span><span class="p">,</span> <span class="m">2</span><span class="o">+</span><span class="m">8</span><span class="p">]</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span> <span class="c">// returns "b"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="no">true</span><span class="p">,</span> <span class="m">2</span><span class="o">+</span><span class="m">8</span><span class="p">]</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="o">::</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span> <span class="c">// error: "... case list in default clause"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="n">x</span><span class="o">=</span><span class="s">"b"</span> <span class="n">but</span> <span class="n">x</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span> <span class="c">// returns "b"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="n">x</span><span class="o">=</span><span class="s">"b"</span><span class="p">;</span> <span class="n">x</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span> <span class="c">// returns "b"</span>
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<span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="c">// error: "... no case catches the value (10) of the selection expression</span></code></pre>
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<pre class="rouge highlight"><code data-lang="go"><span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`1 ? {"a"} : {"b"}`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`b`</span>
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<span class="s">`>>>`</span> <span class="p">[</span><span class="n">blue</span><span class="p">]</span><span class="s">`10 ? {"a"} : {"b"} :: {"c"}`</span>
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<span class="p">[</span><span class="n">green</span><span class="p">]</span><span class="s">`c'
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[green]`</span><span class="o">>>></span><span class="s">` [blue]`</span><span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="no">true</span><span class="p">,</span> <span class="m">2</span><span class="o">+</span><span class="m">8</span><span class="p">]</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span><span class="s">`
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[green]`</span><span class="n">b</span><span class="s">`
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`</span><span class="o">>>></span><span class="s">` [blue]`</span><span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="no">true</span><span class="p">,</span> <span class="m">2</span><span class="o">+</span><span class="m">8</span><span class="p">]</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span> <span class="o">::</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span><span class="s">`
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[red]`</span><span class="n">Parse</span> <span class="n">Error</span><span class="o">:</span> <span class="p">[</span><span class="m">1</span><span class="o">:</span><span class="m">34</span><span class="p">]</span> <span class="k">case</span> <span class="n">list</span> <span class="n">in</span> <span class="k">default</span> <span class="n">clause</span><span class="s">`
|
||||
[green]`</span><span class="o">>>></span><span class="s">` [blue]`</span><span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="n">x</span><span class="o">=</span><span class="s">"b"</span> <span class="n">but</span> <span class="n">x</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span><span class="s">`
|
||||
[green]`</span><span class="n">b</span><span class="s">`
|
||||
`</span><span class="o">>>></span><span class="s">` [blue]`</span><span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span><span class="p">[</span><span class="m">10</span><span class="p">]</span> <span class="p">{</span><span class="n">x</span><span class="o">=</span><span class="s">"b"</span><span class="p">;</span> <span class="n">x</span><span class="p">}</span> <span class="o">::</span> <span class="p">{</span><span class="s">"c"</span><span class="p">}</span><span class="s">`
|
||||
[green]`</span><span class="n">b</span><span class="s">`
|
||||
`</span><span class="o">>>></span><span class="s">` [blue]`</span><span class="m">10</span> <span class="err">?</span> <span class="p">{</span><span class="s">"a"</span><span class="p">}</span> <span class="o">:</span> <span class="p">{</span><span class="s">"b"</span><span class="p">}</span><span class="s">`
|
||||
[red]`</span><span class="n">Eval</span> <span class="n">Error</span><span class="o">:</span> <span class="p">[</span><span class="m">1</span><span class="o">:</span><span class="m">3</span><span class="p">]</span> <span class="n">no</span> <span class="k">case</span> <span class="n">catches</span> <span class="n">the</span> <span class="n">value</span> <span class="p">(</span><span class="m">10</span><span class="p">)</span> <span class="n">of</span> <span class="n">the</span> <span class="n">selection</span> <span class="n">expression</span><span class="s">`
|
||||
</span></code></pre>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
@ -1490,7 +1519,7 @@ The value on the left side of <code class="blue">=</code> must be an identifier.
|
||||
</div>
|
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<div id="footer">
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<div id="footer-text">
|
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Last updated 2024-05-10 06:38:03 +0200
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||||
Last updated 2024-05-11 20:13:17 +0200
|
||||
</div>
|
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</div>
|
||||
</body>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user