Chapter 9. A Major Mode
Writing a simple major mode is very much like writing a minor mode, which we covered in Chapter 7. We'll just touch on the basic ideas of major modes in this chapter, preparing us for the creation of a substantial major mode—indeed, a whole new application—in the next chapter.
My Quips File
For several years I have been collecting witty quotations from various sources on the Internet, storing them in a file called Quips whose format is the same one used by the old UNIX fortune program. Each quotation is introduced by a line containing the string %%. Here's an example:
%%
I like a man who grins when he fights.
- Winston Churchill
%%
The human race has one really effective weapon, and that is laughter.
- Mark Twain
Apart from the %% lines, the file is completely free-form.
After my Quips file had been growing for a while, I found that I edited it a bit differently from the way I edit ordinary text files. For one thing, I frequently needed to confine my editing to a single quip in order to avoid accidentally straying into a neighboring quip. For another, whenever I needed to fill a paragraph at the beginning of a quip, I first had to separate it from the leading %% with a blank line. Otherwise, the %% would become filled as if it were part of the paragraph:
%%
I like a man who grins when he fights.
- Winston Churchill
%% The human race has one really ...
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