nalgene

Nalgene is a natural language generation language.

Overview

Nalgene is used to generate text from an object of values. Generation requires two things: a grammar and a phrase tree. The grammar defines how phrases join together.

Here's a very simple grammar that demonstrates the three main features of Nalgene — %phrases, ~synonyms, and $values, as well as optional? tokens:

%greeting
    ~hello $name

~hello
    hello
    hi
    hey there?

Given values {name: "Fred"} this grammar might expand to:

• "hello Fred"
• "hey Fred"
• "hey there Fred"

Repetition

With an array of values to expand, e.g. a %greeting with $names = ["Joe", "Fred", "Sam"], with expected output "hello Joe and Fred and Sam", use the $value:joiner syntax:

%greeting
    hello $names:and

If your joiner is more than two words, wrap it in parentheses like so:

%greeting
    hello $names:(and also)

If you want a different joiner for the last word, as is common in English (commas until an ending "and"), use the secondary joiner syntax. This will output "hello Joe, Fred and Sam".

%greeting
    hello $names:,:and

To keep the first joiner between the last two values, e.g. to implement an Oxford comma ("hello Joe, Fred, and Sam"), replace the second : with ;.

%greeting
    hello $names:,;and

An alternative to the above would be $names:,:(, and) but that creates an awkward situation if there are only two values: "hello Joe, and Sam".