Remove extra spaces (or other contiguous chars)

README.md

@@ -1138,6 +1138,24 @@ String#chomp'string':  2803443.5 i/s
   String#sub/regexp/:   660508.7 i/s - 4.24x slower
 ```
 
+##### Remove extra spaces (or other contiguous characters) [code](code/string/remove-extra-spaces-or-other-chars.rb)
+
+The code is tested against contiguous spaces but should work for other chars too.
+
+```
+ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-linux]
+Warming up --------------------------------------
+ String#gsub/regex+/     1.644k i/100ms
+      String#squeeze    24.681k i/100ms
+Calculating -------------------------------------
+ String#gsub/regex+/     14.668k (± 5.1%) i/s -     73.980k in   5.056887s
+      String#squeeze    372.910k (± 8.4%) i/s -      1.851M in   5.011881s
+
+Comparison:
+      String#squeeze:   372910.3 i/s
+ String#gsub/regex+/:    14668.1 i/s - 25.42x  slower
+```
+
 
 ### Range
 

code/string/remove-extra-spaces-or-other-chars.rb

@@ -0,0 +1,24 @@
+require 'benchmark/ips'
+
+PASSAGE = <<~LIPSUM
+  Lorem ipsum dolor sit amet,  consectetur adipiscing  elit, sed do eiusmod    tempor incididunt ut  labore et dolore magna aliqua. 
+  Ut enim ad  minim veniam, quis    nostrud exercitation ullamco laboris    nisi ut aliquip ex ea commodo consequat. 
+  Duis aute    irure dolor in reprehenderit    in voluptate velit    esse cillum dolore eu    fugiat nulla pariatur. 
+  Excepteur sint  occaecat cupidatat non    proident, sunt in culpa qui officia    deserunt mollit  anim id est laborum.
+LIPSUM
+
+raise unless PASSAGE.gsub(/ +/, " ") == PASSAGE.squeeze(" ")
+
+def slow
+  PASSAGE.gsub(/ +/, " ")
+end
+
+def fast
+  PASSAGE.squeeze(" ")
+end
+
+Benchmark.ips do |x|
+  x.report('String#gsub/regex+/') { slow }
+  x.report('String#squeeze')    { fast }
+  x.compare!
+end