add crstrings library

[RaduBerinde]

This library contains some general convenience functions related to
strings and string slices.

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This change is 

[RaduBerinde]

Let me know if there are other utilities that you wish you had in the standard strings library. I plan to use some of these in Pebble soon.

[sumeerbhola]

Reviewed 2 of 2 files at r1.
Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on @itsbilal, @jbowens, and @RaduBerinde)

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crstrings/utils.go line 73 at r1 (raw file):

//
//	fmt.Sprintf("%s%s", a, crstrings.PrependIfNotEmpty(", ", b))
func PrependIfNotEmpty(prefix, s string) string {

I understand what this is trying to do, but this sample usage did not help me understand the value.
Was this meant to help with formatting loops in prepending a separator on iterations after the first iteration?

Similar question for AppendIfNotEmpty.

[RaduBerinde]

Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on @itsbilal, @jbowens, and @sumeerbhola)

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crstrings/utils.go line 73 at r1 (raw file):

Previously, sumeerbhola wrote…

I understand what this is trying to do, but this sample usage did not help me understand the value.
Was this meant to help with formatting loops in prepending a separator on iterations after the first iteration?

Similar question for AppendIfNotEmpty.

It's mostly for printf statements. E.g. Sprintf("%s%s %s%s", x, PrependIfNotEmpty(", ", y), z, PrependIfNotEmptry(", ", u) That would normally take 5+ lines of code.

[RaduBerinde]

crstrings/utils.go line 73 at r1 (raw file):

Previously, RaduBerinde wrote…

It's mostly for printf statements. E.g. Sprintf("%s%s %s%s", x, PrependIfNotEmpty(", ", y), z, PrependIfNotEmptry(", ", u) That would normally take 5+ lines of code.

Though maybe it would be cleaner to do Sprintf("%s%s%s", a, crstrings.If(b != "", ", "), b)

[sumeerbhola]

Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on @itsbilal, @jbowens, and @RaduBerinde)

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crstrings/utils.go line 73 at r1 (raw file):

Previously, RaduBerinde wrote…

Though maybe it would be cleaner to do Sprintf("%s%s%s", a, crstrings.If(b != "", ", "), b)

Thanks for the clarification. Either is fine by me.

[RaduBerinde]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @itsbilal, @jbowens, and @sumeerbhola)

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crstrings/utils.go line 73 at r1 (raw file):

Previously, sumeerbhola wrote…

Thanks for the clarification. Either is fine by me.

I replaced them with a single WithSep(a, separator, b) function.

[RaduBerinde]

TFTR!

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @itsbilal, @jbowens, and @sumeerbhola)