sidmishraw / fmt

A simple parametric message formatter utility for Java

fmt

Author: Sidharth Mishra <[e-mail]>
Version: 1.0.0
JDK: 11

About

fmt is a simple fluent-API based string-template utility. It is used for providing parametric string formatting –– somewhat like Python's str.format().

var template = "{kong}{{kong}}!";
var result = fmt.inTemplate(template).put("kong", "King").put("king", "Kong").eval(); // KingKong!

In fmt, the template parameter is defined as {template-parameter}. Moreover, fmt makes keeps resolving all the template-parameters recursively till it can no longer resolve any more template parameters.

Approaches

The first approach would be to get a param-key-value pair out and start resolving the template recursively till all the template parameters have been resolved. For example:

template = "{king}{{one}}{{{kong}}}"

params = {
    "king": "kong",
    "one": "two",
    "kong": "king"
}

step 1: let one be picked (because I'm using a hashmap internally),
template1 = "{king}{two}{{{kong}}}"

step 2: let now king is selected
template2 = "kong{two}{{{kong}}}"

step 3: now kong is selected
template3 = "kong{two}{{king}}" << it should stop here -- for one pass >>

but the final result should be:
"kong{two}king",

to achieve the final result, fmt retries recursively trying to resolve the new template parameters. If it not able to resolve, it unwinds and returns the result.

Motivation

I needed an utility that provided parameteric substitutions in Java like in Python. The existing MessageFormatter gives indexed based substitution and it is limiting for my use-case.