1 files changed, 142 insertions, 0 deletions
diff --git a/lib/coderay/scanners/lua3.rb b/lib/coderay/scanners/lua3.rb
new file mode 100644
index 0000000..f0693bb
--- /dev/null
+++ b/lib/coderay/scanners/lua3.rb
@@ -0,0 +1,142 @@
+# encoding: utf-8
+# Pseudocode: states optionally define groups, comments removed, counter definition?
+
+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 Lua3 < RuleBasedScanner
+    
+    register_for :lua3
+    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
+      super
+      @brace_depth = 0
+      @num_equals = nil
+    end
+    
+    counter :brace_depth
+    
+    state :initial, :map => :map do
+      on %r/\-\-\[\=*\[/, push(:long_comment), :delimiter, set(:num_equals, -> (match) { match.count('=') })
+      on %r/--.*$/, :comment
+      on %r/\[=*\[/, push(:long_string), :delimiter, set(:num_equals, -> (match) { match.count('=') })
+      on %r/::\s*[a-zA-Z_][a-zA-Z0-9_]+\s*::/, :label
+      on %r/_[A-Z]+/, :predefined
+      on check_if(:brace_depth, :>, 0), %r/([a-zA-Z_][a-zA-Z0-9_]*) (\s+)?(=)/x, groups(:key, :space, :operator)
+      on %r/[a-zA-Z_][a-zA-Z0-9_]*/, kind { |match| IDENT_KIND[match] }, push_state { |match, kind|
+        if kind == :keyword && match == 'function'
+          :function_expected
+        elsif kind == :keyword && match == 'goto'
+          :goto_label_expected
+        elsif kind == :keyword && match == 'local'
+          :local_var_expected
+        end
+      }
+      
+      on %r/\{/, push(:map), kind { |brace_depth| brace_depth > 0 ? :inline_delimiter : :delimiter }, increment(:brace_depth)
+      on check_if(:brace_depth, :==, 1), %r/\}/, :delimiter, pop, decrement(:brace_depth)
+      on check_if(:brace_depth, :==, 0), %r/\}/, :error
+      on %r/\}/, :inline_delimiter, pop, decrement(:brace_depth)
+      
+      on %r/"/, push(:double_quoted_string), :delimiter
+      on %r/'/, push(:single_quoted_string), :delimiter
+          
+      on %r/-? (?:0x\h* \. \h+ (?:p[+\-]?\d+)? | \d*\.\d+ (?:e[+\-]?\d+)?)/ix, :float
+          
+      on %r/-? (?:0x\h+ (?:p[+\-]?\d+)? | \d+ (?:e[+\-]?\d+)?)/ix, :integer
+      on %r/[\+\-\*\/%^\#=~<>\(\)\[\]:;,] | \.(?!\d)/x, :operator
+      on %r/\s+/, :space
+    end
+    
+    state :function_expected do
+      on %r/\(.*?\)/m, :operator, pop
+      on %r/[a-zA-Z_] (?:[a-zA-Z0-9_\.] (?!\.\d))* [\.\:]/x, :ident
+      on %r/[a-zA-Z_][a-zA-Z0-9_]*/, :function, pop
+      on %r/\s+/, :space
+    end
+    
+    state :goto_label_expected do
+      on %r/[a-zA-Z_][a-zA-Z0-9_]*/, :label, pop
+      on %r/\s+/, :space
+    end
+    
+    state :local_var_expected do
+      on %r/function/, :keyword, pop, push(:function_expected)
+      on %r/[a-zA-Z_][a-zA-Z0-9_]*/, :local_variable
+      on %r/,/, :operator
+      on %r/\=/, :operator, pop
+      on %r/\n/, :space, pop
+      on %r/\s+/, :space
+    end
+    
+    state :long_comment => :comment do
+      on pattern { |num_equals| %r/(.*?)(\]={#{num_equals}}\])/m }, groups(:content, :delimiter), pop(:comment)
+      on %r/.*/m, :error, pop(:comment)
+    end
+    
+    state :long_string => :string do
+      on pattern { |num_equals| %r/(.*?)(\]={#{num_equals}}\])/m }, groups(:content, :delimiter), pop(:string)
+      on %r/.*/m, :error, pop(:string)
+    end
+    
+    state :single_quoted_string => :string do
+      on %r/[^\\'\n]+/, :content
+      on %r/\\(?:["'abfnrtv\\]|z\s*|x\h\h|\d{1,3}|\n)/m, :char
+      on %r/'/, :delimiter, pop(:string)
+      on %r/\n/, :error, pop(:string)
+    end
+    
+    state :double_quoted_string => :string do
+      on %r/[^\\"\n]+/, :content
+      on %r/\\(?:["'abfnrtv\\]|z\s*|x\h\h|\d{1,3}|\n)/m, :char
+      on %r/"/, :delimiter, pop(:string)
+      on %r/\n/, :error, pop(:string)
+    end
+  end
+  
+end
+end