tqp

README

tqp

tqp (tiny query parser) is a bare bones Go package for parsing (potentially) structured search query strings. It offers a basic ability to extract key/value attributes from the input string, and returns unparsed "noise" back to the caller so the application can further handle the input as it desires.

Schema

A key is any A-Z value (case-insensitive) string that is followed by a : character. It is followed by a non-zero length string, known as a value, which may be quoted or unquoted. Quoting the value impacts the characters it may contain. Unquoted values are limited to [a-z0-9-_]+ (ASCII letters, numbers, hyphens and underscores). Quoted values are limited to [\w()\-._ ]+ (ASCII letters, numbers, hyphens, underscores, spaces, periods, and parentheses). Any strings with disallowed characters will cause the attribute to be considered noise (aka an unparsed user string). Any strings that are not key/value attributes will automatically be appended to the noise output as well.

Technical Specifics

• Keys are converted to lowercase when stored in the attributes map
• A key can be used multiple times in a single query as each key is associated with a []string of values
• An empty value (e.g. "") will be discarded and not inserted in the attributes map
• Insertion order to value and noise slices follows the left-to-right processing of the string

Examples

Input: 'hello world name:nick'
Output:
    attributes: map[string][]string{"name": []string{"nick"}}
    noise: []string{"hello", "world"}

Input: 'today is randomattr:"long value example" monday`
Output:
    attributes: map[string][]string{"randomattr": []string{"long value example"}}
    noise: []string{"today", "is", "monday"}

Input: 'blue pants with:pockets price:"less than $20"`
Output:
    attributes: map[string][]string{"with": []string{"pockets"}, "price": []string{"less than $20"}}
    noise: []string{"blue", "pants"}

Input: 'year:2023 year:2024'
Output:
    attributes: map[string][]string{'year': []string{"2023", "2024"}}
    noise: []string{}

Usage

Install using go get github.com/Cryptkeeper/tqp

package main

import "github.com/Cryptkeeper/tqp"

func main() {
    myQuery := "hello world name:nick"
    attrs, noise := tqp.Find(myQuery)
    // attrs is map[string][]string{"name": []string{"nick"}}
    // noise is []string{"hello", "world"}
}

Documentation

Index

• func Find(s string) (attrs map[string][]string, noise []string)

Functions

func Find

func Find(s string) (attrs map[string][]string, noise []string)

Find parses a string into a map of attributes, and a slice of noise words. Attributes must be in the format of key:value or key:"value". Keys must contain only letters a-z (case-insensitive), and are converted to lowercase when stored in the map. Unquoted values may contain letters, numbers, hyphens, and underscores. Quoted values may contain letters, numbers, hyphens, underscores, spaces, periods, and parentheses. Noise words are any words that are not formatted as attributes.