TODO.md

In decisionpatterns/optigrab: Command-Line Parsing for an R World

• behaviors document

• globbing of path: should be done after

• variable name to option name mapping, e.g. --start-date -> start_date

• short options for opt_fill

• match.args ?

• opt_get_all

Rename opt_get

Is opt_get really opt_read. It seems that the verb get is for retrieving symbols internal to R; read is for getting data from outside of R.

• change 'opt_get' -> 'opt_read'

Confusion with options, getOption

First, the syntax for a global singleton for options is horribly (cf. the options package).

Number of options (n)

• Number of arguments (n) can use model formula to specify variable range of allowable values opt_get( 'foo', n = 1 ~ 3)

• Consider 'greedy' option, i.e. take all values until the next option flag. This can be set at the option levels as in:

  opt_read( ..., n=GREEDY )

GREEDY could be an exported constant such as: 1 ~ Inf

Coercision

• Auto-coerce: this is done currently to match the class of default opt_grab does not accept a default argument

With magrittr, this is less important since

"--f" %>% opt_grab %>% as.numeric

works well

Match Args (?)

• Use match.args to allow options to work like R's match.arg function (cf. match.args)

I don't like this idea as it gets too crazy, too quickly. Examples:

dothis --verbose --visible

opt_get( march('v') )  # abiguous

This is probably bad practice

opt_strict

opt_strict stops execution if unknown flag is encountered. Like opt_help, it must be used after all option processing.

Help

• Help semantics: (/) opt_help (x) optihelp() (x) AUTOHELP() (x) AUTOHELP (x) AUTOHELP : semantics

• (?) could export ActiveBinding AUTOHELP; probably not a good idea since it is not clear from the syntax what is being done.

• (?) makeActiveBinding( "option.starter" , f, baseenv(baseenv()) )

Optiion Bundling

• exact flag vs. specify flag indicators seperately. If the flag indicators are seperate, it allows

opt_unbundle

opt_unbundle should be a part of the style that gets called if it exists. It take commandArgs type array and expands the options.

% script -axe
opt_unbundle() # '-a -x -e'

Does this work on a string as well? Probably not, you probably just need it for the array version.

Syntax modifications

Create a function that will automatically produce the one-character option variant. Maybe, something like this.

"flag" %>% std_opt %>% get_opt

• Do we enforce single-letter options with a single-dash?
• If we do not know what the indicators are, how can we make it greedy?
• How do we specify multiple values: n = 1, n = 2, n=1+, .n. >= 0

DO NOT, INTIALLY SUPPORT BUNDLING

• n: 0 Can only be logical. It is possible it is the name of the option but why? 1 Most common n A specific number n = up.to(3) n = greedy

If greedy is used ... we should warn about args.

• Read from config file:
• Prompt?
• Search on local? An option can come from .rc, CLO, prompt or setting. If it is interactive

== LESSER == * Make this compatible with RApache/Rook (why)

Completed

X Drop the 'coerce' argument from 'grabOpt' since it is no different from wrapping the call in an as.* function.

opt_fill (COMPLETE)

• for recursive objects find options with the names

  opt_fill(x)

returns x (or ref to x) that is populated with options that are grabbed from the command line.

decisionpatterns/optigrab documentation built on Jan. 8, 2019, 3:28 a.m.