raabro.rb in raabro-1.0.0

- old
+ new

@@ -24,29 +24,29 @@
 #++
 
 
 module Raabro
 
-  VERSION = '0.9.0'
+  VERSION = '1.0.0'
 
   class Input
 
     attr_accessor :string, :offset
     attr_reader :options
 
-    def initialize(string, options={})
+    def initialize(string, offset=0, options={})
 
       @string = string
-      @offset = 0
-      @options = options
+      @offset = offset.is_a?(Hash) ? 0 : offset
+      @options = offset.is_a?(Hash) ? offset : options
     end
 
     def match(str_or_regex)
 
       if str_or_regex.is_a?(Regexp)
         m = @string[@offset..-1].match(str_or_regex)
-        m ? m[0].length : false
+        m && (m.offset(0).first == 0) ? m[0].length : false
       else # String or whatever responds to #to_s
         s = str_or_regex.to_s
         l = s.length
         @string[@offset, l] == s ? l : false
       end
@@ -69,126 +69,344 @@
       @offset = input.offset
       @length = 0
       @children = []
     end
 
+    def successful_children
+
+      @children.select { |c| c.result == 1 }
+    end
+
+    def prune!
+
+      @children = successful_children
+    end
+
+    def shrink!
+
+      @children =
+        @children.inject([]) do |a, c|
+          a << c.shrink! if c.result == 1 && c.name
+          a
+        end
+
+      self
+    end
+
+    def string
+
+      @input.string[@offset, @length]
+    end
+
+    def lookup(name)
+
+      name = name.to_s
+
+      return self if @name.to_s == name
+      @children.each { |c| if n = c.lookup(name); return n; end }
+      nil
+    end
+
+    def gather(name, acc=[])
+
+      name = name.to_s
+
+      if @name.to_s == name
+        acc << self
+      else
+        @children.each { |c| c.gather(name, acc) }
+      end
+
+      acc
+    end
+
     def to_a(opts={})
 
+      opts = Array(opts).inject({}) { |h, e| h[e] = true; h } \
+        unless opts.is_a?(Hash)
+
       cn =
         opts[:leaves] && (@result == 1) && @children.empty? ?
-        @input.string[@offset, @length] :
+        string :
         @children.collect { |e| e.to_a(opts) }
 
       [ @name, @result, @offset, @length, @note, @parter, cn ]
     end
-  end
 
-  def self.match(name, input, parter, regex_or_string)
+    def to_s(depth=0, io=StringIO.new)
 
-    r = Tree.new(name, parter, input)
+      io.print "\n" if depth > 0
+      io.print '  ' * depth
+      io.print "#{@result} #{@name.inspect} #{@offset},#{@length}"
+      io.print result == 1 && children.size == 0 ? ' ' + string.inspect : ''
 
-    if l = input.match(regex_or_string)
-      r.result = 1
-      r.length = l
-      input.offset += l
-    end
+      @children.each { |c| c.to_s(depth + 1, io) }
 
-    r
+      depth == 0 ? io.string : nil
+    end
   end
 
-  def self.str(name, input, string)
+  module ModuleMethods
 
-    match(name, input, :str, string)
-  end
+    def _match(name, input, parter, regex_or_string)
 
-  def self.rex(name, input, regex_or_string)
+      r = Raabro::Tree.new(name, parter, input)
 
-    match(name, input, :rex, Regexp.new(regex_or_string))
-  end
+      if l = input.match(regex_or_string)
+        r.result = 1
+        r.length = l
+        input.offset += l
+      end
 
-  def self.narrow(parser)
+      r
+    end
 
-    return parser if parser.is_a?(Method)
-    return method(parser) if parser.is_a?(Symbol)
+    def str(name, input, string)
 
-    k, m = parser.to_s.split('.')
-    k, m = [ Object, k ] unless m
+      _match(name, input, :str, string)
+    end
 
-    Kernel.const_get(k).method(m)
-  end
+    def rex(name, input, regex_or_string)
 
-  def self.parse(parser, input)
+      _match(name, input, :rex, Regexp.new(regex_or_string))
+    end
 
-    narrow(parser).call(input)
-  end
+    def _quantify(parser)
 
-  def self.seq(name, input, *parsers)
+      return nil if parser.is_a?(Symbol) && respond_to?(parser)
+        # so that :plus and co can be overriden
 
-    r = Tree.new(name, :seq, input)
+      case parser
+        when '?', :q, :qmark then [ 0, 1 ]
+        when '*', :s, :star then [ 0, 0 ]
+        when '+', :p, :plus then [ 1, 0 ]
+        else nil
+      end
+    end
 
-    start = input.offset
-    c = nil
+    def _narrow(parser)
 
-    parsers.each do |pa|
-      c = parse(pa, input)
-      r.children << c
-      break if c.result != 1
+      raise ArgumentError.new("lone quantifier #{parser}") if _quantify(parser)
+
+      return parser if parser.is_a?(Method)
+      return method(parser) if parser.is_a?(Symbol)
+
+      k, m = parser.to_s.split('.')
+      k, m = [ Object, k ] unless m
+
+      Kernel.const_get(k).method(m)
     end
 
-    if c && c.result == 1
-      r.result = 1
-      r.length = input.offset - start
-    else
-      input.offset = start
+    def _parse(parser, input)
+
+      _narrow(parser).call(input)
     end
 
-    r
-  end
+    def seq(name, input, *parsers)
 
-  def self.alt(name, input, *parsers)
+      r = ::Raabro::Tree.new(name, :seq, input)
 
-    r = Tree.new(name, :alt, input)
+      start = input.offset
+      c = nil
 
-    c = nil
+      loop do
 
-    parsers.each do |pa|
-      c = parse(pa, input)
-      r.children << c
-      break if c.result == 1
+        pa = parsers.shift
+        break unless pa
+
+        if q = _quantify(parsers.first)
+          parsers.shift
+          c = rep(nil, input, pa, *q)
+          r.children.concat(c.children)
+        else
+          c = _parse(pa, input)
+          r.children << c
+        end
+
+        break if c.result != 1
+      end
+
+      if c && c.result == 1
+        r.result = 1
+        r.length = input.offset - start
+      else
+        input.offset = start
+      end
+
+      r
     end
 
-    if c && c.result == 1
-      r.result = 1
-      r.length = c.length
+    def alt(name, input, *parsers)
+
+      greedy =
+        if parsers.last == true || parsers.last == false
+          parsers.pop
+        else
+          false
+        end
+
+      r = ::Raabro::Tree.new(name, greedy ? :altg : :alt, input)
+
+      start = input.offset
+      c = nil
+
+      parsers.each do |pa|
+
+        cc = _parse(pa, input)
+        r.children << cc
+
+        input.offset = start
+
+        if greedy
+          if cc.result == 1 && cc.length > (c ? c.length : -1)
+            c.result = 0 if c
+            c = cc
+          end
+        else
+          c = cc
+          break if c.result == 1
+        end
+      end
+
+      if c && c.result == 1
+        r.result = 1
+        r.length = c.length
+        input.offset = start + r.length
+      end
+
+      r.prune! if input.options[:prune]
+
+      r
     end
 
-    r
-  end
+    def altg(name, input, *parsers)
 
-  def self.rep(name, input, parser, min, max=0)
+      alt(name, input, *parsers, true)
+    end
 
-    min = 0 if min == nil || min < 0
-    max = nil if max.nil? || max < 1
+    def rep(name, input, parser, min, max=0)
 
-    r = Tree.new(name, :rep, input)
-    start = input.offset
-    count = 0
+      min = 0 if min == nil || min < 0
+      max = nil if max.nil? || max < 1
 
-    loop do
-      c = parse(parser, input)
+      r = ::Raabro::Tree.new(name, :rep, input)
+      start = input.offset
+      count = 0
+
+      loop do
+        c = _parse(parser, input)
+        r.children << c
+        break if c.result != 1
+        count += 1
+        break if max && count == max
+      end
+
+      if count >= min && (max == nil || count <= max)
+        r.result = 1
+        r.length = input.offset - start
+      else
+        input.offset = start
+      end
+
+      r.prune! if input.options[:prune]
+
+      r
+    end
+
+    def ren(name, input, parser)
+
+      r = _parse(parser, input)
+      r.name = name
+
+      r
+    end
+    alias rename ren
+
+    def all(name, input, parser)
+
+      start = input.offset
+      length = input.string.length - input.offset
+
+      r = ::Raabro::Tree.new(name, :all, input)
+      c = _parse(parser, input)
       r.children << c
-      break if c.result != 1
-      count += 1
-      break if max && count == max
+
+      if c.length < length
+        input.offset = start
+      else
+        r.result = 1
+        r.length = c.length
+      end
+
+      r
     end
 
-    if count >= min && (max == nil || count <= max)
+    def eseq(name, input, startpa, eltpa, seppa=nil, endpa=nil)
+
+      jseq = false
+
+      if seppa.nil? && endpa.nil?
+        jseq = true
+        seppa = eltpa; eltpa = startpa; startpa = nil
+      end
+
+      start = input.offset
+      r = ::Raabro::Tree.new(name, jseq ? :jseq : :eseq, input)
       r.result = 1
-      r.length = input.offset - start
-    else
-      input.offset = start
+      c = nil
+
+      if startpa
+        c = _parse(startpa, input)
+        r.children << c
+        r.result = 0 if c.result != 1
+      end
+
+      if r.result == 1
+
+        i = 1
+        count = 0
+
+        loop do
+
+          i = (i + 1) % 2
+          pa = i == 0 ? eltpa : seppa
+
+          c = _parse(pa, input)
+          r.children << c
+
+          break if c.result != 1
+
+          count += 1
+        end
+
+        r.result = 0 if jseq && count < 1
+      end
+
+      if r.result == 1 && endpa
+        c = _parse(endpa, input)
+        r.children << c
+        r.result = 0 if c.result != 1
+      end
+
+      if r.result == 1
+        r.length = input.offset - start
+      else
+        input.offset = start
+      end
+
+      r.prune! if input.options[:prune]
+
+      r
     end
+    alias jseq eseq
+  end
+  extend ModuleMethods
 
-    r
+  def self.included(target)
+
+    target.instance_eval do
+      extend ::Raabro::ModuleMethods
+      extend self
+    end
   end
 end
 