[ruby/strscan] [DOC] Add syntax highlighting to MarkDown code blocks

(ruby/strscan#126)

Split off from ruby#12322

ruby/strscan@9bee37e0f5

Author: amomchilov

doc/strscan/helper_methods.md

@@ -10,7 +10,7 @@ Display scanner's situation:
 - Character position (`#charpos`)
 - Target string (`#rest`) and size (`#rest_size`).
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 scanner.scan(/foo/)
 put_situation(scanner)
@@ -25,7 +25,7 @@ put_situation(scanner)
 
 Display the scanner's match values:
 
-```
+```rb
 scanner = StringScanner.new('Fri Dec 12 1975 14:39')
 pattern = /(?<wday>\w+) (?<month>\w+) (?<day>\d+) /
 scanner.match?(pattern)
@@ -53,7 +53,7 @@ put_match_values(scanner)
 
 Returns whether the scanner's match values are all properly cleared:
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 match_values_cleared?(scanner) # => true
 put_match_values(scanner)
@@ -75,17 +75,15 @@ match_values_cleared?(scanner) # => false
 
 ## The Code
 
-```
+```rb
 def put_situation(scanner)
   puts '# Situation:'
   puts "#   pos:       #{scanner.pos}"
   puts "#   charpos:   #{scanner.charpos}"
   puts "#   rest:      #{scanner.rest.inspect}"
   puts "#   rest_size: #{scanner.rest_size}"
 end
-```
 
-```
 def put_match_values(scanner)
   puts '# Basic match values:'
   puts "#   matched?:       #{scanner.matched?}"
@@ -109,9 +107,7 @@ def put_match_values(scanner)
     end
   end
 end
-```
 
-```
 def match_values_cleared?(scanner)
   scanner.matched? == false &&
     scanner.matched_size.nil? &&

doc/strscan/methods/get_byte.md

@@ -10,7 +10,7 @@ Returns the next byte, if available:
     - Increments the [byte position][2].
     - Adjusts the [character position][7].
 
-    ```
+    ```rb
     scanner = StringScanner.new(HIRAGANA_TEXT)
     # => #<StringScanner 0/15 @ "\xE3\x81\x93\xE3\x82...">
     scanner.string                                   # => "こんにちは"
@@ -24,7 +24,7 @@ Returns the next byte, if available:
 
 - Otherwise, returns `nil`, and does not change the positions.
 
-    ```
+    ```rb
     scanner.terminate
     [scanner.get_byte, scanner.pos, scanner.charpos] # => [nil, 15, 5]
     ```

doc/strscan/methods/get_charpos.md

@@ -5,7 +5,7 @@ Returns the [character position][7] (initially zero),
 which may be different from the [byte position][2]
 given by method #pos:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string # => "こんにちは"
 scanner.getch  # => "こ" # 3-byte character.

doc/strscan/methods/get_pos.md

@@ -4,7 +4,7 @@ call-seq:
 Returns the integer [byte position][2],
 which may be different from the [character position][7]:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string  # => "こんにちは"
 scanner.pos     # => 0

doc/strscan/methods/getch.md

@@ -12,7 +12,7 @@ if available:
     - Increments the [byte position][2]
       by the size (in bytes) of the character.
 
-    ```
+    ```rb
     scanner = StringScanner.new(HIRAGANA_TEXT)
     scanner.string                                # => "こんにちは"
     [scanner.getch, scanner.pos, scanner.charpos] # => ["こ", 3, 1]
@@ -27,7 +27,7 @@ if available:
   (that is, not at its beginning),
   behaves like #get_byte (returns a 1-byte character):
 
-    ```
+    ```rb
     scanner.pos = 1
     [scanner.getch, scanner.pos, scanner.charpos] # => ["\x81", 2, 2]
     [scanner.getch, scanner.pos, scanner.charpos] # => ["\x93", 3, 1]
@@ -37,7 +37,7 @@ if available:
 - If the [position][2] is at the end of the [stored string][1],
   returns `nil` and does not modify the positions:
 
-    ```
+    ```rb
     scanner.terminate
     [scanner.getch, scanner.pos, scanner.charpos] # => [nil, 15, 5]
     ```

doc/strscan/methods/scan.md

@@ -11,7 +11,7 @@ If the match succeeds:
   and may increment the [character position][7].
 - Sets [match values][9].
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string     # => "こんにちは"
 scanner.pos = 6
@@ -45,7 +45,7 @@ If the match fails:
 - Does not increment byte and character positions.
 - Clears match values.
 
-```
+```rb
 scanner.scan(/nope/)           # => nil
 match_values_cleared?(scanner) # => true
 ```

doc/strscan/methods/scan_until.md

@@ -12,7 +12,7 @@ If the match attempt succeeds:
 - Returns the matched substring.
 
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string           # => "こんにちは"
 scanner.pos = 6
@@ -46,7 +46,7 @@ If the match attempt fails:
 - Returns `nil`.
 - Does not update positions.
 
-```
+```rb
 scanner.scan_until(/nope/)     # => nil
 match_values_cleared?(scanner) # => true
 ```

doc/strscan/methods/set_pos.md

@@ -9,7 +9,7 @@ Does not affect [match values][9].
 
 For non-negative `n`, sets the position to `n`:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string  # => "こんにちは"
 scanner.pos = 3 # => 3
@@ -19,7 +19,7 @@ scanner.charpos # => 1
 
 For negative `n`, counts from the end of the [stored string][1]:
 
-```
+```rb
 scanner.pos = -9 # => -9
 scanner.pos      # => 6
 scanner.rest     # => "にちは"

doc/strscan/methods/skip.md

@@ -11,7 +11,7 @@ If the match succeeds:
 - Sets [match values][9].
 - Returns the size (bytes) of the matched substring.
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string                  # => "こんにちは"
 scanner.pos = 6

doc/strscan/methods/skip_until.md

@@ -10,7 +10,7 @@ If the match attempt succeeds:
 - Sets [match values][9].
 - Returns the size of the matched substring.
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string           # => "こんにちは"
 scanner.pos = 6
@@ -43,7 +43,7 @@ If the match attempt fails:
 - Clears match values.
 - Returns `nil`.
 
-```
+```rb
 scanner.skip_until(/nope/)     # => nil
 match_values_cleared?(scanner) # => true
 ```