quick format

Solves a problem with util.format

usage

var format = require('quick-format')
var options = {lowres: false} // <--default
format(['hello %s %j %d', 'world', {obj: true}, 4, {another: 'obj'}], options)

options

lowres

Passing an options object with lowres: true will cause quick-format any object with a circular as a string with the value '"[Circular]"'. The default behaviour is to label circular references in an object, instead of abandoning the entire object. Naturally, lowres is a faster mode, and assumes you have made the decision to ensure the objects you're passing have no circular references.

caveats

We use JSON.stringify instead of util.inspect, this means object methods (functions) will not be serialized.

util.format

In util.format for Node 5.9, performance is significantly affected when we pass in more arguments than interpolation characters, e.g

util.format('hello %s %j %d', 'world', {obj: true}, 4, {another: 'obj'})

This is mostly due to the use of util.inspect. Use JSON.stringify (safely) instead which is significantly faster.

It also takes an array instead of arguments, which helps us avoid the use of apply in some cases.

Also - for speed purposes, we ignore symbol.

Benchmarks

Whilst exact matching of objects to interpolation characters is slower, the case of additional objects is 3x faster. Further, using lowres mode brings us closer to util.inspect speeds.

util*100000: 205.978ms
quickLowres*100000: 236.337ms
quick*100000: 292.018ms
utilWithTailObj*100000: 1054.592ms
quickWithTailObjLowres*100000: 267.992ms
quickWithTailObj*100000: 343.048ms
util*100000: 212.011ms
quickLowres*100000: 226.441ms
quick*100000: 296.600ms
utilWithTailObj*100000: 1020.195ms
quickWithTailObjLowres*100000: 267.331ms
quickWithTailObj*100000: 343.867ms

Acknowledgements

Sponsored by nearForm