Scala def in an object - naming convention upper case camel case? -

given conventions here: http://docs.scala-lang.org/style/naming-conventions.html

blockquote constant names should in upper camel case. is, if member final, immutable , belongs package object or object, may considered constant (similar java’s static final members)

does mean def should fall in category too? if functionally pure. example parse method:

object parser{def parse(string: string): anyref = ??? }  

no, shouldn't.

that explanation simplification of concept of stable value. stable value can trust have same value, , how scala introduces dependent types (aka, in scala, path-dependent types).

there number of rules stable value, why simpler explanation resorted in style guide. 1 specific rule has be val -- var , def not acceptable. var not acceptable because value can change @ time, , def not acceptable because may return different values each time called (even if receives no parameters).

also related fact can override def val, not vice versa.

so val qualifies constants.

also of interest, scala optimizes final val declarations when not declare type, this:

object constants {   final val 0 = 0 } 

that cause scala replace instances of zero 0. in fact, if recompile constant changing value of zero 0 else, code making reference constants.zero has been compiled before still use 0.

if, on other hand, had declared final val zero: int = 0, not happen.