0005537: reducing repeated indirections to access variables in nested modules

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Date Submitted

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0005537

OCaml

OCaml backend (code generation)

public

2012-03-13 20:42

2012-12-13 17:09

Reporter

sweeks

Assigned To

Priority

normal

Severity

minor

Reproducibility

always

Status

acknowledged

Resolution

open

Platform

OS Version

Product Version

Target Version

4.01.0+dev

Fixed in Version

Summary

0005537: reducing repeated indirections to access variables in nested modules

Description

OCaml's compilation strategy for variable references in nested modules leaves
around unnecessary field accesses, which are implicit, and not felt by the
programmer.

For example, if I write:

   open Core.Std
   let f () = Result.ok_unit

the reference to [Result.ok_unit] gets compiled to three field accesses, one for
each dot in [Core.Std.Result.ok_unit]. Furthermore, these accesses happen every
time [f] is called. I think it would typically be prefereable if [f] were
compiled as if it had been written as follows:

   let z = Result.ok_unit in
   let f = fun () -> z

I think it is surprising to a programmer for variable reference to be such a
non-constant-time operation.

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Attached Files

Relationships

has duplicate	0005573	acknowledged		Access to values in nested modules
related to	0005546	resolved	frisch	moving a function into an internal module slows down its use

Notes
(0008604) frisch (developer) 2012-12-13 17:09	Probably solved by 0005546.

Issue History
Date Modified	Username	Field	Change
2012-03-13 20:42	sweeks	New Issue
2012-03-20 10:44	gasche	Relationship added	related to 0005546
2012-03-26 14:41	lefessan	Status	new => acknowledged
2012-04-04 22:46	gasche	Relationship added	has duplicate 0005573
2012-07-10 11:28	doligez	Target Version	=> 4.01.0+dev
2012-07-31 13:36	doligez	Target Version	4.01.0+dev => 4.00.1+dev
2012-09-21 12:55	doligez	Target Version	4.00.1+dev => 4.01.0+dev
2012-12-13 17:09	frisch	Note Added: 0008604