Bare-bones text processing using keywords and regex
Extract words, special characters, or regex matches from strings of test using this simple text parser. Inspired by Todoist's Quick Add feature, which uses NLP (Natural Language Processing) to extract dates, projects, and other keywords.
Give microparsec
lists of keywords or regex you want
found and extracted, and some text to parse. It will return lists of keywords it
found or regex it matched, along with the rest of the string input.
yarn:
yarn add microparsec
npm:
npm i --save microparsec
microparsec
takes the keywords it's given and searches for their last
occurrence, using this case-insensitive regular expresssion:
/\bkeyword\b(?!.*\bkeyword\b)/i
. Keywords can have spaces in them. If a
regular expression is passed in place of a keyword, the input is matched
directly against that regex.
Initialize microparsec
with the keywords you want parsed out, which can take
the form of:
- a string
new Microparsec("keyword")
- a regex
new Microparsec(/regex/)
- an array of strings or regexes
new Microparsec(["key", "word", /regex/])
- a parser object, containing a name and list of keywords
new Microparsec({ name: "What", keywords: ["the", /heck/] })
- an array of parser objects
new Microparsec([
{ name: "What", keywords: ["the", /heck/] },
{ name: "Goodbye", keywords: ["hello", "hi"] },
])
Once initialized, you can parse any input string and expect a result like this:
const parser = new Microparsec("Hello")
const result = parser.parse("Hello World!")
console.log(result)
/*
{
matches: [
{
name: "Default",
matches: [{
match: "Hello",
replaceWith: "%0"
}]
}
],
leftovers: "World!",
interpolated: "%0 World!"
}
*/
Any parser that had a match is returned with all its matches, and the rest of
the unmatched string is returned as leftovers
, trimmed of excess whitespace.
The original parsed text is returned as interpolated
, with the matched keywords
replaced by symbols such as %0
or %1
. These symbols correspond to the
replaceWith
field in each match object.
Parsers without a match do not appear in the result. Matches against regex keywords return the text that matched, not the regex itself.
const parser = new Microparsec([
{ name: "One", keywords: [/ee+/] },
{ name: "Two", keywords: ["What", "the"] },
{ name: "Three", keywords: ["no", "matches"] },
])
const result = parser.parse("What the wheeeee is that?")
console.log(result)
/*
{
matches: [
{
name: "One",
matches: [{
match: "eeeee",
replaceWith: "%0"
}]
},
{
name: "Two",
matches: [
{
match: "What",
replaceWith: "%1"
},
{
match: "the",
replaceWith: "%2"
}]
}
],
leftovers: "wh is that?",
interpolated: "%1 %2 wh%0 is that?"
}
*/
yarn install
yarn test