{"id":289,"date":"2018-11-01T12:08:26","date_gmt":"2018-11-01T12:08:26","guid":{"rendered":"https:\/\/books.compclassnotes.com\/elementarycomputing\/?page_id=289"},"modified":"2018-11-05T15:32:47","modified_gmt":"2018-11-05T15:32:47","slug":"design","status":"publish","type":"page","link":"https:\/\/books.compclassnotes.com\/elementarycomputing\/design\/","title":{"rendered":"Design"},"content":{"rendered":"
\n
\n
\n

At some point we will want to realise our beautiful designs and write code, so we need to decide what language to use. Languages such as Java and C++ are convenient, they are often too inconsistent because they contain a mix or\u00a0pre\/post\/infix (and or often know as \u201cmixfix\u201d).<\/p>\n

For example, this is a legal code snippet in Java.<\/p>\n

\r\n\r\ni++; ++i; i+i;\r\n\r\nj=i+++++i;\r\n\r\n<\/pre>\n
Yes, that is five\u00a0+<\/strong> symbols in a row! In that code, if i started with the value 3, it would finish with 5, while j would have the value 8. Hard to see why? Well, that’s partly why we’re not going to use Java! Similarly, there is always a bunch of extra syntax, things like<\/p>\n
\r\n\r\npublic static void main(String[] args)..\r\n\r\n<\/pre>\n
This appears in virtually every single Java program, but we still have to put it in. This is sometimes referred to as “syntactic sugar”: it doesn’t do anything to improve the semantics and is just there to make the program (allegedly) easier to read. However, too much sugar is neither useful nor good for you!<\/p>\n
Java isn’t the only language guilty of this, of course. Many languages suffer from it. For this book we will use\u00a0functional programming<\/em>, which is a style of programming based on expressions and functions. Functional programs are often\u00a0tiny<\/strong> and can be very efficient. For example, here’s another Java program:<\/p>\n
\r\n\r\nclass myfirstjavaprog\r\n\r\n{\r\n\r\npublic static void main(String args[])\r\n\r\n{\r\n\r\nSystem.out.println(3 + 1);\r\n\r\n}\r\n\r\n}\r\n\r\n<\/pre>\n<\/div>\n
The source code is 133 bytes. That’s not entirely awful, but when we compile it we get a whopping 14,578 bytes. Here’s the equivalent program written in a functional programming language:<\/p>\n
\r\n\r\n> (+ 3 1)\r\n\r\n<\/pre>\n
Seven bytes!<\/p>\n
We’ll look at functional programming in the next section<\/a>.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
At some point we will want to realise our beautiful designs and write code, so we need to decide what language to use. Languages such as Java and C++ are convenient, they are often too inconsistent because they contain a Continue Reading<\/a><\/span><\/p>\n","protected":false},"author":4,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-289","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/pages\/289","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/comments?post=289"}],"version-history":[{"count":6,"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/pages\/289\/revisions"}],"predecessor-version":[{"id":382,"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/pages\/289\/revisions\/382"}],"wp:attachment":[{"href":"https:\/\/books.compclassnotes.com\/elementarycomputing\/wp-json\/wp\/v2\/media?parent=289"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}