Lambda the Ultimate

We cannot compose our own code with pre-written code (terms, types, classes, mixins/traits, modules, signatures, metalinguistic abstractions, etc.) - or compose two or more already constructed code constructs - if we cannot discover that such appropriate code exists.

What language features might help or hinder "code discovery". My own thoughts are thoroughly scattered. I think about completely diverse things such as 1) the standard "omnibus" Smalltalk package/class browser; 2) Stepanov and Lee's early emphasis re: STL on the more or less precise performance characteristics of different but otherwise functionally equivalent "pluggable" algorithms; 3) the extreme encapsulation, and thus essential invisibility, permitted by languages such as Pascal and Scheme with nested functions, other terms and even nested types (Pascal?); 4) the desirability or lack thereof of ADT's (existential types) as afforded by ML signatures and the very real trade offs between such encapsulation and the pragmatics of reuse; 5) the extremely widely varying "scope" of term composition and thus the size of the unit of computation and hence composition - from the typically terse Forth "word" all the way to giant multipage C functions common in industry, or even the domain specific, typically monolithic commercial libraries or "frameworks" often comprising 100,000's of lines of code or more.

As I said, my thoughts have a few "anchors," but otherwise seem completely scattered. I seek some set of uniform, organizing principles.

Our languages (common production languages plus at least the most popular "academic" languages) seem to be all over the map regard "discover-ability" - an attribute that seems both antecedent to and essential to the "holy grail" (among others) of relatively painless code discovery and consequent code composition.

Any papers, thoughts or general enlightenment greatly appreciated, particularly related to the relationship between individual or types of language features that enhance or hinder discover-ability. Thanks much in advance.

Scott