Add bin and edit workflow

bin/gems/coderay-1.1.3/lib/coderay/scanners/lua.rb

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+# encoding: utf-8
+
+module CodeRay
+module Scanners
+
+  # Scanner for the Lua[http://lua.org] programming lanuage.
+  #
+  # The language’s complete syntax is defined in
+  # {the Lua manual}[http://www.lua.org/manual/5.2/manual.html],
+  # which is what this scanner tries to conform to.
+  class Lua < Scanner
+    
+    register_for :lua
+    file_extension 'lua'
+    title 'Lua'
+    
+    # Keywords used in Lua.
+    KEYWORDS = %w[and break do else elseif end
+      for function goto if in
+      local not or repeat return
+      then until while
+    ]
+    
+    # Constants set by the Lua core.
+    PREDEFINED_CONSTANTS = %w[false true nil]
+    
+    # The expressions contained in this array are parts of Lua’s `basic'
+    # library. Although it’s not entirely necessary to load that library,
+    # it is highly recommended and one would have to provide own implementations
+    # of some of these expressions if one does not do so. They however aren’t
+    # keywords, neither are they constants, but nearly predefined, so they
+    # get tagged as `predefined' rather than anything else.
+    #
+    # This list excludes values of form `_UPPERCASE' because the Lua manual
+    # requires such identifiers to be reserved by Lua anyway and they are
+    # highlighted directly accordingly, without the need for specific
+    # identifiers to be listed here.
+    PREDEFINED_EXPRESSIONS = %w[
+      assert collectgarbage dofile error getmetatable
+      ipairs load loadfile next pairs pcall print
+      rawequal rawget rawlen rawset select setmetatable
+      tonumber tostring type xpcall
+    ]
+    
+    # Automatic token kind selection for normal words.
+    IDENT_KIND = CodeRay::WordList.new(:ident).
+      add(KEYWORDS, :keyword).
+      add(PREDEFINED_CONSTANTS, :predefined_constant).
+      add(PREDEFINED_EXPRESSIONS, :predefined)
+    
+    protected
+    
+    # Scanner initialization.
+    def setup
+      @state = :initial
+      @brace_depth = 0
+    end
+    
+    # CodeRay entry hook. Starts parsing.
+    def scan_tokens(encoder, options)
+      state = options[:state] || @state
+      brace_depth = @brace_depth
+      num_equals = nil
+      
+      until eos?
+        case state
+        
+        when :initial
+          if match = scan(/\-\-\[\=*\[/)   #--[[ long (possibly multiline) comment ]]
+            num_equals = match.count("=") # Number must match for comment end
+            encoder.begin_group(:comment)
+            encoder.text_token(match, :delimiter)
+            state = :long_comment
+          
+          elsif match = scan(/--.*$/) # --Lua comment
+            encoder.text_token(match, :comment)
+          
+          elsif match = scan(/\[=*\[/)     # [[ long (possibly multiline) string ]]
+            num_equals = match.count("=") # Number must match for string end
+            encoder.begin_group(:string)
+            encoder.text_token(match, :delimiter)
+            state = :long_string
+          
+          elsif match = scan(/::\s*[a-zA-Z_][a-zA-Z0-9_]+\s*::/) # ::goto_label::
+            encoder.text_token(match, :label)
+          
+          elsif match = scan(/_[A-Z]+/) # _UPPERCASE are names reserved for Lua
+            encoder.text_token(match, :predefined)
+          
+          elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) # Normal letters (or letters followed by digits)
+            kind = IDENT_KIND[match]
+            
+            # Extra highlighting for entities following certain keywords
+            if kind == :keyword and match == "function"
+              state = :function_expected
+            elsif kind == :keyword and match == "goto"
+              state = :goto_label_expected
+            elsif kind == :keyword and match == "local"
+              state = :local_var_expected
+            end
+            
+            encoder.text_token(match, kind)
+          
+          elsif match = scan(/\{/) # Opening table brace {
+            encoder.begin_group(:map)
+            encoder.text_token(match, brace_depth >= 1 ? :inline_delimiter : :delimiter)
+            brace_depth += 1
+            state        = :map
+          
+          elsif match = scan(/\}/) # Closing table brace }
+            if brace_depth == 1
+              brace_depth = 0
+              encoder.text_token(match, :delimiter)
+              encoder.end_group(:map)
+            elsif brace_depth == 0 # Mismatched brace
+              encoder.text_token(match, :error)
+            else
+              brace_depth -= 1
+              encoder.text_token(match, :inline_delimiter)
+              encoder.end_group(:map)
+              state = :map
+            end
+          
+          elsif match = scan(/["']/) # String delimiters " and '
+            encoder.begin_group(:string)
+            encoder.text_token(match, :delimiter)
+            start_delim = match
+            state       = :string
+          
+                            # ↓Prefix                hex number ←|→ decimal number
+          elsif match = scan(/-? (?:0x\h* \. \h+ (?:p[+\-]?\d+)? | \d*\.\d+ (?:e[+\-]?\d+)?)/ix) # hexadecimal constants have no E power, decimal ones no P power
+            encoder.text_token(match, :float)
+          
+                            # ↓Prefix         hex number ←|→ decimal number
+          elsif match = scan(/-? (?:0x\h+ (?:p[+\-]?\d+)? | \d+ (?:e[+\-]?\d+)?)/ix) # hexadecimal constants have no E power, decimal ones no P power
+            encoder.text_token(match, :integer)
+          
+          elsif match = scan(/[\+\-\*\/%^\#=~<>\(\)\[\]:;,] | \.(?!\d)/x) # Operators
+            encoder.text_token(match, :operator)
+          
+          elsif match = scan(/\s+/) # Space
+            encoder.text_token(match, :space)
+          
+          else # Invalid stuff. Note that Lua doesn’t accept multibyte chars outside of strings, hence these are also errors.
+            encoder.text_token(getch, :error)
+          end
+          
+          # It may be that we’re scanning a full-blown subexpression of a table
+          # (tables can contain full expressions in parts).
+          # If this is the case, return to :map scanning state.
+          state = :map if state == :initial && brace_depth >= 1
+        
+        when :function_expected
+          if match = scan(/\(.*?\)/m) # x = function() # "Anonymous" function without explicit name
+            encoder.text_token(match, :operator)
+            state = :initial
+          elsif match = scan(/[a-zA-Z_] (?:[a-zA-Z0-9_\.] (?!\.\d))* [\.\:]/x) # function tbl.subtbl.foo() | function tbl:foo() # Colon only allowed as last separator
+            encoder.text_token(match, :ident)
+          elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) # function foo()
+            encoder.text_token(match, :function)
+            state = :initial
+          elsif match = scan(/\s+/) # Between the `function' keyword and the ident may be any amount of whitespace
+            encoder.text_token(match, :space)
+          else
+            encoder.text_token(getch, :error)
+            state = :initial
+          end
+        
+        when :goto_label_expected
+          if match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/)
+            encoder.text_token(match, :label)
+            state = :initial
+          elsif match = scan(/\s+/) # Between the `goto' keyword and the label may be any amount of whitespace
+            encoder.text_token(match, :space)
+          else
+            encoder.text_token(getch, :error)
+          end
+        
+        when :local_var_expected
+          if match = scan(/function/) # local function ...
+            encoder.text_token(match, :keyword)
+            state = :function_expected
+          elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/)
+            encoder.text_token(match, :local_variable)
+          elsif match = scan(/,/)
+            encoder.text_token(match, :operator)
+          elsif match = scan(/\=/)
+            encoder.text_token(match, :operator)
+            # After encountering the equal sign, arbitrary expressions are
+            # allowed again, so just return to the main state for further
+            # parsing.
+            state = :initial
+          elsif match = scan(/\n/)
+            encoder.text_token(match, :space)
+            state = :initial
+          elsif match = scan(/\s+/)
+            encoder.text_token(match, :space)
+          else
+            encoder.text_token(getch, :error)
+          end
+        
+        when :long_comment
+          if match = scan(/.*?(?=\]={#{num_equals}}\])/m)
+            encoder.text_token(match, :content)
+            
+            delim = scan(/\]={#{num_equals}}\]/)
+            encoder.text_token(delim, :delimiter)
+          else # No terminator found till EOF
+            encoder.text_token(rest, :error)
+            terminate
+          end
+          encoder.end_group(:comment)
+          state = :initial
+        
+        when :long_string
+          if match = scan(/.*?(?=\]={#{num_equals}}\])/m) # Long strings do not interpret any escape sequences
+            encoder.text_token(match, :content)
+            
+            delim = scan(/\]={#{num_equals}}\]/)
+            encoder.text_token(delim, :delimiter)
+          else # No terminator found till EOF
+            encoder.text_token(rest, :error)
+            terminate
+          end
+          encoder.end_group(:string)
+          state = :initial
+        
+        when :string
+          if match = scan(/[^\\#{start_delim}\n]+/) # Everything except \ and the start delimiter character is string content (newlines are only allowed if preceeded by \ or \z)
+            encoder.text_token(match, :content)
+          elsif match = scan(/\\(?:['"abfnrtv\\]|z\s*|x\h\h|\d{1,3}|\n)/m)
+            encoder.text_token(match, :char)
+          elsif match = scan(Regexp.compile(start_delim))
+            encoder.text_token(match, :delimiter)
+            encoder.end_group(:string)
+            state = :initial
+          elsif match = scan(/\n/) # Lua forbids unescaped newlines in normal non-long strings
+            encoder.text_token("\\n\n", :error) # Visually appealing error indicator--otherwise users may wonder whether the highlighter cannot highlight multine strings
+            encoder.end_group(:string)
+            state = :initial
+          else
+            encoder.text_token(getch, :error)
+          end
+        
+        when :map
+          if match = scan(/[,;]/)
+            encoder.text_token(match, :operator)
+          elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]* (?=\s*=)/x)
+            encoder.text_token(match, :key)
+            encoder.text_token(scan(/\s+/), :space) if check(/\s+/)
+            encoder.text_token(scan(/\=/), :operator)
+            state = :initial
+          elsif match = scan(/\s+/m)
+            encoder.text_token(match, :space)
+          else
+            # Note this clause doesn’t advance the scan pointer, it’s a kind of
+            # "retry with other options" (the :initial state then of course
+            # advances the pointer).
+            state = :initial
+          end
+        else
+          raise
+        end
+        
+      end
+      
+      if options[:keep_state]
+        @state = state
+      end
+      
+      encoder.end_group :string if [:string].include? state
+      brace_depth.times { encoder.end_group :map }
+      
+      encoder
+    end
+    
+  end
+  
+end
+end