Wednesday, September 12, 2007

Morse code in @Formula language and as a function in Sametime Bot

Here comes another post about using Lotus Notes' @Formula programming language for accomplishing different tasks. This time I'll show how to convert text to Morse code. Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message.

The @Formula code is rather short. First we by specify 2 arrays: one with letters and another with corresponding morse code. Then we simply use @ReplaceSubstring function to replace the letters in the input text to corresponding elements in the morse array. As the number of elements in the 2 arrays are the same, @ReplaceSubstring function applies 1-to-1 element replacement.

letters:=" ":"A":"B":"C":"D":"E":"F":"G":"H":"I":"J":"K":"L":"M":"N":"O":"P":"Q":"R":"S":"T":"U":"V":"W":"X":"Y":"Z":"1":"2":"3":"4":"5":"6":"7":"8":"9":"0";
morse:=" ":".-":"-...":"-.-.":"-..":".":"..-.":"--.":"....":"..":".---":"-.-":".-..":"--":"-.":"---":".--.":"--.-":".-.":"...":"-":"..-":"...-":".--":"-..-":"-.--":"--..":".----":"..---":"...--":"....-":".....":"-....":"--...":"---..":"----.":"-----";
plaintext:="Morse code";
encoded:=@ReplaceSubstring(@UpperCase(plaintext);letters;morse+" ");

To reverse the process and convert from morse code to plain text following code can be used:

encoded:="-- --- .-. ... . -.-. --- -.. . ";
plain:=@ReplaceSubstring(@Implode(@Replace(@Explode(@ReplaceSubstring(encoded;" ";" _ ");" ");morse;letters);"");"_";" ");

I also implemented same morse formula as a function in Botstation Bot Framework, where user passes a text string to Sametime bot and receives the morse code as output. Here is a picture and a live example.
Bot command syntax:
demorse .. .-.. --- ...- . ... .- -- . - .. -- .

Morse Bot online example:


Monday, September 10, 2007

Remove HTML tags using one line of @Formula

When you need to remove HTML tags from HTML-formatted text, you can use following Domino @Formula:


See attached picture for example of original HTML-formatted text and of resulting text where HTML tags are stripped out.

The @Formula does following:
1) Splits the original text using "<" as separator, creating an array of strings
2) In each array element takes the text to the right of the ">" character, which gives us every HTML tag used in the original text, for example BR, B, U, LI, FONT
3) Adds "<" and ">" to the calculated tags, so the array now consists of <BR>, <B>, <U>, <LI>, <FONT> etc.
4) In the original text replaces the occurances of computed tags to empty string "", thus stripping HTML out of text.

As we often want to keep line breaks to keep the original look, then before replacing the tags with empty string, we replace <BR>, <UL>, <LI> with a hard new line. Without handling line breaks the code is much shorter: