module ActionController
module CodeGeneration #:nodoc
class GenerationError < StandardError
end
class Source
attr_reader :lines, :indentation_level
IndentationString = ' '
def initialize
@lines, @indentation_level = [], 0
end
def line(line)
@lines << (IndentationString * @indentation_level + line)
end
alias :<< :line
def indent
@indentation_level += 1
yield
ensure
@indentation_level -= 1
end
def to_s() lines.join("\n") end
end
class CodeGenerator
attr_accessor :source, :locals
def initialize(source = nil)
@locals = []
@source = source || Source.new
end
BeginKeywords = %w(if unless begin until while def).collect {|kw| kw.to_sym}
ResumeKeywords = %w(elsif else rescue).collect {|kw| kw.to_sym}
Keywords = BeginKeywords + ResumeKeywords
def method_missing(keyword, *text)
if Keywords.include? keyword
if ResumeKeywords.include? keyword
raise GenerationError, "Can only resume with #{keyword} immediately after an end" unless source.lines.last =~ /^\s*end\s*$/
source.lines.pop # Remove the 'end'
end
line "#{keyword} #{text.join ' '}"
begin source.indent { yield(self.dup) }
ensure line 'end'
end
else
super(keyword, *text)
end
end
def line(*args) self.source.line(*args) end
alias :<< :line
def indent(*args, &block) source(*args, &block) end
def to_s() source.to_s end
def share_locals_with(other)
other.locals = self.locals = (other.locals | locals)
end
FieldsToDuplicate = [:locals]
def dup
copy = self.class.new(source)
self.class::FieldsToDuplicate.each do |sym|
value = self.send(sym)
value = value.dup unless value.nil? || value.is_a?(Numeric)
copy.send("#{sym}=", value)
end
return copy
end
end
class RecognitionGenerator < CodeGenerator
Attributes = [:after, :before, :current, :results, :constants, :depth, :move_ahead, :finish_statement]
attr_accessor(*Attributes)
FieldsToDuplicate = CodeGenerator::FieldsToDuplicate + Attributes
def initialize(*args)
super(*args)
@after, @before = [], []
@current = nil
@results, @constants = {}, {}
@depth = 0
@move_ahead = nil
@finish_statement = Proc.new {|hash_expr| hash_expr}
end
def if_next_matches(string, &block)
test = Routing.test_condition(next_segment(true), string)
self.if(test, &block)
end
def move_forward(places = 1)
dup = self.dup
dup.depth += 1
dup.move_ahead = places
yield dup
end
def next_segment(assign_inline = false, default = nil)
if locals.include?(segment_name)
code = segment_name
else
code = "#{segment_name} = #{path_name}[#{index_name}]"
if assign_inline
code = "(#{code})"
else
line(code)
code = segment_name
end
locals << segment_name
end
code = "(#{code} || #{default.inspect})" if default
return code.to_s
end
def segment_name() "segment#{depth}".to_sym end
def path_name() :path end
def index_name
move_ahead, @move_ahead = @move_ahead, nil
move_ahead ? "index += #{move_ahead}" : 'index'
end
def continue
dup = self.dup
dup.before << dup.current
dup.current = dup.after.shift
dup.go
end
def go
if current then current.write_recognition(self)
else self.finish
end
end
def result(key, expression, delay = false)
unless delay
line "#{key}_value = #{expression}"
expression = "#{key}_value"
end
results[key] = expression
end
def constant_result(key, object)
constants[key] = object
end
def finish(ensure_traversal_finished = true)
pairs = []
(results.keys + constants.keys).uniq.each do |key|
pairs << "#{key.to_s.inspect} => #{results[key] ? results[key] : constants[key].inspect}"
end
hash_expr = "{#{pairs.join(', ')}}"
statement = finish_statement.call(hash_expr)
if ensure_traversal_finished then self.if("! #{next_segment(true)}") {|gp| gp << statement}
else self << statement
end
end
end
class GenerationGenerator < CodeGenerator
Attributes = [:after, :before, :current, :segments]
attr_accessor(*Attributes)
FieldsToDuplicate = CodeGenerator::FieldsToDuplicate + Attributes
def initialize(*args)
super(*args)
@after, @before = [], []
@current = nil
@segments = []
end
def hash_name() 'hash' end
def local_name(key) "#{key}_value" end
def hash_value(key, assign = true, default = nil)
if locals.include?(local_name(key)) then code = local_name(key)
else
code = "hash[#{key.to_sym.inspect}]"
if assign
code = "(#{local_name(key)} = #{code})"
locals << local_name(key)
end
end
code = "(#{code} || (#{default.inspect}))" if default
return code
end
def expire_for_keys(*keys)
return if keys.empty?
conds = keys.collect {|key| "expire_on[#{key.to_sym.inspect}]"}
line "not_expired, #{hash_name} = false, options if not_expired && #{conds.join(' && ')}"
end
def add_segment(*segments)
d = dup
d.segments.concat segments
yield d
end
def go
if current then current.write_generation(self)
else self.finish
end
end
def continue
d = dup
d.before << d.current
d.current = d.after.shift
d.go
end
def finish
line %("/#{segments.join('/')}")
end
def check_conditions(conditions)
tests = []
generator = nil
conditions.each do |key, condition|
tests << (generator || self).hash_value(key, true) if condition.is_a? Regexp
tests << Routing.test_condition((generator || self).hash_value(key, false), condition)
generator = self.dup unless generator
end
return tests.join(' && ')
end
end
end
end
