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Diffstat (limited to 'docs/tutorial/list.html')
| -rw-r--r-- | docs/tutorial/list.html | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/docs/tutorial/list.html b/docs/tutorial/list.html index b3fc4b24..4d867329 100644 --- a/docs/tutorial/list.html +++ b/docs/tutorial/list.html @@ -15,7 +15,7 @@ </pre> <p>There we go. Now in BQN arrays are not just lists, which are a 1-dimensional data structure, but can have any number of dimensions. In this tutorial we're going to discuss lists only, leaving the 5-dimensional stuff for later. So we're really only seeing the power of <a href="https://aplwiki.com/wiki/K">K</a>, an APL-family language that only uses lists (and dictionaries, which BQN doesn't have). K was powerful enough for Arthur Whitney to found <a href="https://en.wikipedia.org/wiki/Kx_Systems">two</a> <a href="https://shakti.com/">companies</a> and make millions and millions of dollars, and BQN's compiler also runs almost entirely on lists, so this is probably enough power for one webpage.</p> <h2 id="list-notation">List notation</h2> -<p>There are three kinds of list notation in BQN. Every one has a subject role, even though expressions used inside it might have other roles. First, a <em>string</em> is a list of characters, and is written by placing those characters in double quotes.</p> +<p>There are three kinds of list notation in BQN. Each of them has a subject role overall, even if expressions used inside it might have other roles. First, a <em>string</em> is a list of characters, and is written by placing those characters in double quotes.</p> <pre><span class='String'>"Text!"</span> </pre> <table class='primitives'> @@ -46,7 +46,7 @@ </tr> </table> -<p>Only one character needs to be escaped to place it in a string: the double quote, which is escaped by writing it twice. Any other character, including a newline, can be placed directly in a string.</p> +<p>Just one character needs to be escaped to be used a string: the double quote has to be written twice—a lone double quote would end the string, of course. Any other character, including a newline, can be placed directly in a string. For example, <code><span class='String'>"'"""</span></code> is a string with two characters, the single and double quote.</p> <p>Second, <em>list notation</em> uses angle brackets <code><span class='Bracket'>⟨⟩</span></code>. The <em>elements</em> in the list are kept apart with one of the three <em>separator</em> characters: <code><span class='Separator'>,</span></code>, <code><span class='Separator'>⋄</span></code>, and newline. Anything can be used as an element, even a function, or a modifier like <code><span class='Modifier2'>∘</span></code>. Here's a list containing a number, a 2-modifier, a string, and a non-string list:</p> <pre><span class='Bracket'>⟨</span> <span class='Number'>π</span><span class='Separator'>,</span> <span class='Modifier2'>∘</span><span class='Separator'>,</span> <span class='String'>"element"</span> <span class='Separator'>⋄</span> <span class='Bracket'>⟨</span><span class='String'>'l'</span><span class='Separator'>,</span><span class='Number'>1</span><span class='Separator'>,</span><span class='Number'>5</span><span class='Separator'>,</span><span class='String'>'t'</span><span class='Bracket'>⟩</span> <span class='Bracket'>⟩</span> </pre> @@ -73,12 +73,12 @@ </tr> </table> -<p>Finally, <em>strand notation</em> is a shortcut for simple lists like a few numbers. It's written with the <em>ligature</em> <code><span class='Ligature'>‿</span></code>, which has a higher precedence than either functions or operators. A sequence of values joined with ligatures becomes a list, so that for example the following two expressions are equivalent:</p> +<p>Finally, <em>strand notation</em> is a shortcut for simple lists, like one that just lists a few numbers. It's written with the <em>ligature</em> <code><span class='Ligature'>‿</span></code>, which has a higher precedence than either functions or operators (and on the BQN keyboard, the ligature is written with a backslash, then a space). A sequence of values joined with ligatures becomes a list, so that for example the following two expressions are equivalent:</p> <pre><span class='Bracket'>⟨</span><span class='Number'>2</span><span class='Separator'>,</span><span class='Function'>+</span><span class='Separator'>,</span><span class='Function'>-</span><span class='Bracket'>⟩</span> <span class='Number'>2</span><span class='Ligature'>‿</span><span class='Function'>+</span><span class='Ligature'>‿</span><span class='Function'>-</span> </pre> -<p>Strand notation is shorter and looks less cluttered in this example. As with lists, anything goes in a strand, but if it's the result of a function or operator, or another strand, then it has to be put in parentheses. With one set of parentheses, a strand will be just as long as the equivalent bracketed list, and with two you're better off using the list.</p> -<p>A ligature is a kind of notation and doesn't do something specific like a function does. It's the sequence of ligatures that makes whatever they join together into a list. So if we parenthesize either ligature below, we get a different result! Ligatures aren't right-associative or left-associative.</p> +<p>Strand notation is shorter and looks less cluttered in this example. As with lists, anything goes in a strand, but if it's the result of a function or operator, or another strand, then it has to be put in parentheses first. With one set of parentheses, a strand will be just as long as the equivalent bracketed list, and with two you're better off using the list.</p> +<p>An individual ligature part of BQN syntax, not a value, and it doesn't do something specific like a function does. It's the sequence of ligatures that makes whatever they join together into a list. So if we parenthesize either ligature below, we get a different result! Ligatures aren't right-associative or left-associative.</p> <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=MOKAvzHigL8yCigw4oC/MSnigL8yCjDigL8oMeKAvzIp">↗️</a><pre> <span class='Number'>0</span><span class='Ligature'>‿</span><span class='Number'>1</span><span class='Ligature'>‿</span><span class='Number'>2</span> ⟨ 0 1 2 ⟩ <span class='Paren'>(</span><span class='Number'>0</span><span class='Ligature'>‿</span><span class='Number'>1</span><span class='Paren'>)</span><span class='Ligature'>‿</span><span class='Number'>2</span> @@ -359,7 +359,7 @@ ERROR</pre> 9 </pre> <h2 id="summary">Summary</h2> -<p>There are three types of syntax that create lists: the <code><span class='String'>"string literal"</span></code> for lists of characters and either enclosing angle brackets <code><span class='Bracket'>⟨⟩</span></code> with <code><span class='Separator'>,</span></code> or <code><span class='Separator'>⋄</span></code> or newline characters or connecting ligatures <code><span class='Ligature'>‿</span></code> for lists with arbitrary elements. The ligature has a higher precedence than functions or modifiers, so we should add to to our precedence table:</p> +<p>There are three types of syntax that create lists: the <code><span class='String'>"string literal"</span></code> for lists of characters and either enclosing angle brackets <code><span class='Bracket'>⟨⟩</span></code> with <code><span class='Separator'>,</span></code> or <code><span class='Separator'>⋄</span></code> or newline characters or connecting ligatures <code><span class='Ligature'>‿</span></code> for lists with arbitrary elements. The ligature has a higher precedence than functions or modifiers, so we should add it to our precedence table:</p> <table> <thead> <tr> @@ -435,4 +435,4 @@ ERROR</pre> </tbody> </table> <p>Additionally, we saw that the arithmetic functions work naturally on lists, automatically applying to every element of a single list argument or pairing up the elements of two list arguments.</p> -<p>Even this small amount of list functionality is enough to solve some small problems. We haven't even introduced a function notation yet!</p> +<p>Even this small amount of list functionality is enough to tackle some little problems. We haven't even introduced a function notation yet!</p> |