A friend posed this PowerShell programming puzzle (P\u00b3), which represents an actual problem he had to solve:<\/p>\n
Given a string in
$t<\/code> in snake_case<\/tt> or SHOUTY_SNAKE_CASE<\/tt>, return the corresponding PascalCase string. You may assume no consecutive underscores.<\/p><\/blockquote>\nThe initial version went like this:<\/p>\n
$uc = $true; \r\n[string]::Concat(($t.ToCharArray() | % { \r\n if ($uc) { ($_ -as [string]).ToUpper(); $uc = $false; } \r\n elseif ($_ -eq '_') { $uc = $true; } \r\n else { ($_ -as [string]).ToLower();} \r\n}))\r\n<\/pre>\nThis is a straightforward translation of the requirements: Walk through the string one character at a time. Capitalize the first letter and any letter that follows an underscore. Everything else becomes lowercase.<\/p>\n
I countered with this crazy one-liner:<\/p>\n
(Get-Culture).TextInfo.ToTitleCase(($t.ToLower() -replace \"_\", \" \")) -replace \" \", \"\"\r\n<\/pre>\nThis version cheats like crazy, but hey, we’re code-golfing. It relies on the capitalization rules of the English language, and it assumes that every word starts with a letter.<\/p>\n
The idea is to take advantage of
To\u00adTitle\u00adCase<\/code>, which capitalizes the first letter of each space-separated word. All we have to do is transform the string into something that we can feed intoTo\u00adTitle\u00adCase<\/code>.<\/p>\nSo start with the string, convert it entirely to lowercase (to avoid the feature of
To\u00adTitle\u00adCase<\/code> that preserves all-capitalized words), and change the underscores to spaces. Now we can askTo\u00adTitle\u00adCase<\/code> to capitalize the first letter of each word. Then we compress out the spaces with a final-replace<\/code>.<\/p>\nA less crazy version would be something like this:<\/p>\n
[regex]::replace($t.ToLower(), '(^|_)(.)', { $args[0].Groups[2].Value.ToUpper()})\r\n<\/pre>\nFirst, we convert the entire string to lowercase. Then we search for each character that comes after an underscore (considering the first character of the string to be after an imaginary leading underscore) and capitalize it. The underscore itself is not returned, which causes it to vanish.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Abusing linguistic helper functions for fun.<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-102844","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
Abusing linguistic helper functions for fun.<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/102844","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=102844"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/102844\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=102844"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=102844"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=102844"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}