#
# irb/ruby-lex.rb - ruby lexcal analyzer
# $Release Version: 0.9.6$
# $Revision: 38632 $
# by Keiju ISHITSUKA(keiju@ruby-lang.org)
#
# --
#
#
#
require "e2mmap"
require "irb/slex"
require "irb/ruby-token"
# :stopdoc:
class RubyLex
@RCS_ID='-$Id: ruby-lex.rb 38632 2012-12-27 14:48:42Z keiju $-'
extend Exception2MessageMapper
def_exception(:AlreadyDefinedToken, "Already defined token(%s)")
def_exception(:TkReading2TokenNoKey, "key nothing(key='%s')")
def_exception(:TkSymbol2TokenNoKey, "key nothing(key='%s')")
def_exception(:TkReading2TokenDuplicateError,
"key duplicate(token_n='%s', key='%s')")
def_exception(:SyntaxError, "%s")
def_exception(:TerminateLineInput, "Terminate Line Input")
include RubyToken
class << self
attr_accessor :debug_level
def debug?
@debug_level > 0
end
end
@debug_level = 0
def initialize
lex_init
set_input(STDIN)
@seek = 0
@exp_line_no = @line_no = 1
@base_char_no = 0
@char_no = 0
@rests = []
@readed = []
@here_readed = []
@indent = 0
@indent_stack = []
@lex_state = EXPR_BEG
@space_seen = false
@here_header = false
@post_symbeg = false
@continue = false
@line = ""
@skip_space = false
@readed_auto_clean_up = false
@exception_on_syntax_error = true
@prompt = nil
end
attr_accessor :skip_space
attr_accessor :readed_auto_clean_up
attr_accessor :exception_on_syntax_error
attr_reader :seek
attr_reader :char_no
attr_reader :line_no
attr_reader :indent
# io functions
def set_input(io, p = nil, &block)
@io = io
if p.respond_to?(:call)
@input = p
elsif block_given?
@input = block
else
@input = Proc.new{@io.gets}
end
end
def get_readed
if idx = @readed.rindex("\n")
@base_char_no = @readed.size - (idx + 1)
else
@base_char_no += @readed.size
end
readed = @readed.join("")
@readed = []
readed
end
def getc
while @rests.empty?
# return nil unless buf_input
@rests.push nil unless buf_input
end
c = @rests.shift
if @here_header
@here_readed.push c
else
@readed.push c
end
@seek += 1
if c == "\n"
@line_no += 1
@char_no = 0
else
@char_no += 1
end
c
end
def gets
l = ""
while c = getc
l.concat(c)
break if c == "\n"
end
return nil if l == "" and c.nil?
l
end
def eof?
@io.eof?
end
def getc_of_rests
if @rests.empty?
nil
else
getc
end
end
def ungetc(c = nil)
if @here_readed.empty?
c2 = @readed.pop
else
c2 = @here_readed.pop
end
c = c2 unless c
@rests.unshift c #c =
@seek -= 1
if c == "\n"
@line_no -= 1
if idx = @readed.rindex("\n")
@char_no = idx + 1
else
@char_no = @base_char_no + @readed.size
end
else
@char_no -= 1
end
end
def peek_equal?(str)
chrs = str.split(//)
until @rests.size >= chrs.size
return false unless buf_input
end
@rests[0, chrs.size] == chrs
end
def peek_match?(regexp)
while @rests.empty?
return false unless buf_input
end
regexp =~ @rests.join("")
end
def peek(i = 0)
while @rests.size <= i
return nil unless buf_input
end
@rests[i]
end
def buf_input
prompt
line = @input.call
return nil unless line
@rests.concat line.chars.to_a
true
end
private :buf_input
def set_prompt(p = nil, &block)
p = block if block_given?
if p.respond_to?(:call)
@prompt = p
else
@prompt = Proc.new{print p}
end
end
def prompt
if @prompt
@prompt.call(@ltype, @indent, @continue, @line_no)
end
end
def initialize_input
@ltype = nil
@quoted = nil
@indent = 0
@indent_stack = []
@lex_state = EXPR_BEG
@space_seen = false
@here_header = false
@continue = false
@post_symbeg = false
prompt
@line = ""
@exp_line_no = @line_no
end
def each_top_level_statement
initialize_input
catch(:TERM_INPUT) do
loop do
begin
@continue = false
prompt
unless l = lex
throw :TERM_INPUT if @line == ''
else
@line.concat l
if @ltype or @continue or @indent > 0
next
end
end
if @line != "\n"
@line.force_encoding(@io.encoding)
yield @line, @exp_line_no
end
break unless l
@line = ''
@exp_line_no = @line_no
@indent = 0
@indent_stack = []
prompt
rescue TerminateLineInput
initialize_input
prompt
get_readed
end
end
end
end
def lex
until (((tk = token).kind_of?(TkNL) || tk.kind_of?(TkEND_OF_SCRIPT)) &&
!@continue or
tk.nil?)
#p tk
#p @lex_state
#p self
end
line = get_readed
# print self.inspect
if line == "" and tk.kind_of?(TkEND_OF_SCRIPT) || tk.nil?
nil
else
line
end
end
def token
# require "tracer"
# Tracer.on
@prev_seek = @seek
@prev_line_no = @line_no
@prev_char_no = @char_no
begin
begin
tk = @OP.match(self)
@space_seen = tk.kind_of?(TkSPACE)
@lex_state = EXPR_END if @post_symbeg && tk.kind_of?(TkOp)
@post_symbeg = tk.kind_of?(TkSYMBEG)
rescue SyntaxError
raise if @exception_on_syntax_error
tk = TkError.new(@seek, @line_no, @char_no)
end
end while @skip_space and tk.kind_of?(TkSPACE)
if @readed_auto_clean_up
get_readed
end
# Tracer.off
tk
end
ENINDENT_CLAUSE = [
"case", "class", "def", "do", "for", "if",
"module", "unless", "until", "while", "begin" #, "when"
]
DEINDENT_CLAUSE = ["end" #, "when"
]
PERCENT_LTYPE = {
"q" => "\'",
"Q" => "\"",
"x" => "\`",
"r" => "/",
"w" => "]",
"W" => "]",
"i" => "]",
"I" => "]",
"s" => ":"
}
PERCENT_PAREN = {
"{" => "}",
"[" => "]",
"<" => ">",
"(" => ")"
}
Ltype2Token = {
"\'" => TkSTRING,
"\"" => TkSTRING,
"\`" => TkXSTRING,
"/" => TkREGEXP,
"]" => TkDSTRING,
":" => TkSYMBOL
}
DLtype2Token = {
"\"" => TkDSTRING,
"\`" => TkDXSTRING,
"/" => TkDREGEXP,
}
def lex_init()
@OP = IRB::SLex.new
@OP.def_rules("\0", "\004", "\032") do |op, io|
Token(TkEND_OF_SCRIPT)
end
@OP.def_rules(" ", "\t", "\f", "\r", "\13") do |op, io|
@space_seen = true
while getc =~ /[ \t\f\r\13]/; end
ungetc
Token(TkSPACE)
end
@OP.def_rule("#") do |op, io|
identify_comment
end
@OP.def_rule("=begin",
proc{|op, io| @prev_char_no == 0 && peek(0) =~ /\s/}) do
|op, io|
@ltype = "="
until getc == "\n"; end
until peek_equal?("=end") && peek(4) =~ /\s/
until getc == "\n"; end
end
gets
@ltype = nil
Token(TkRD_COMMENT)
end
@OP.def_rule("\n") do |op, io|
print "\\n\n" if RubyLex.debug?
case @lex_state
when EXPR_BEG, EXPR_FNAME, EXPR_DOT
@continue = true
else
@continue = false
@lex_state = EXPR_BEG
until (@indent_stack.empty? ||
[TkLPAREN, TkLBRACK, TkLBRACE,
TkfLPAREN, TkfLBRACK, TkfLBRACE].include?(@indent_stack.last))
@indent_stack.pop
end
end
@here_header = false
@here_readed = []
Token(TkNL)
end
@OP.def_rules("*", "**",
"=", "==", "===",
"=~", "<=>",
"<", "<=",
">", ">=", ">>",
"!", "!=", "!~") do
|op, io|
case @lex_state
when EXPR_FNAME, EXPR_DOT
@lex_state = EXPR_ARG
else
@lex_state = EXPR_BEG
end
Token(op)
end
@OP.def_rules("<<") do
|op, io|
tk = nil
if @lex_state != EXPR_END && @lex_state != EXPR_CLASS &&
(@lex_state != EXPR_ARG || @space_seen)
c = peek(0)
if /\S/ =~ c && (/["'`]/ =~ c || /\w/ =~ c || c == "-")
tk = identify_here_document
end
end
unless tk
tk = Token(op)
case @lex_state
when EXPR_FNAME, EXPR_DOT
@lex_state = EXPR_ARG
else
@lex_state = EXPR_BEG
end
end
tk
end
@OP.def_rules("'", '"') do
|op, io|
identify_string(op)
end
@OP.def_rules("`") do
|op, io|
if @lex_state == EXPR_FNAME
@lex_state = EXPR_END
Token(op)
else
identify_string(op)
end
end
@OP.def_rules('?') do
|op, io|
if @lex_state == EXPR_END
@lex_state = EXPR_BEG
Token(TkQUESTION)
else
ch = getc
if @lex_state == EXPR_ARG && ch =~ /\s/
ungetc
@lex_state = EXPR_BEG;
Token(TkQUESTION)
else
if (ch == '\\')
read_escape
end
@lex_state = EXPR_END
Token(TkINTEGER)
end
end
end
@OP.def_rules("&", "&&", "|", "||") do
|op, io|
@lex_state = EXPR_BEG
Token(op)
end
@OP.def_rules("+=", "-=", "*=", "**=",
"&=", "|=", "^=", "<<=", ">>=", "||=", "&&=") do
|op, io|
@lex_state = EXPR_BEG
op =~ /^(.*)=$/
Token(TkOPASGN, $1)
end
@OP.def_rule("+@", proc{|op, io| @lex_state == EXPR_FNAME}) do
|op, io|
@lex_state = EXPR_ARG
Token(op)
end
@OP.def_rule("-@", proc{|op, io| @lex_state == EXPR_FNAME}) do
|op, io|
@lex_state = EXPR_ARG
Token(op)
end
@OP.def_rules("+", "-") do
|op, io|
catch(:RET) do
if @lex_state == EXPR_ARG
if @space_seen and peek(0) =~ /[0-9]/
throw :RET, identify_number
else
@lex_state = EXPR_BEG
end
elsif @lex_state != EXPR_END and peek(0) =~ /[0-9]/
throw :RET, identify_number
else
@lex_state = EXPR_BEG
end
Token(op)
end
end
@OP.def_rule(".") do
|op, io|
@lex_state = EXPR_BEG
if peek(0) =~ /[0-9]/
ungetc
identify_number
else
# for "obj.if" etc.
@lex_state = EXPR_DOT
Token(TkDOT)
end
end
@OP.def_rules("..", "...") do
|op, io|
@lex_state = EXPR_BEG
Token(op)
end
lex_int2
end
def lex_int2
@OP.def_rules("]", "}", ")") do
|op, io|
@lex_state = EXPR_END
@indent -= 1
@indent_stack.pop
Token(op)
end
@OP.def_rule(":") do
|op, io|
if @lex_state == EXPR_END || peek(0) =~ /\s/
@lex_state = EXPR_BEG
Token(TkCOLON)
else
@lex_state = EXPR_FNAME
Token(TkSYMBEG)
end
end
@OP.def_rule("::") do
|op, io|
# p @lex_state.id2name, @space_seen
if @lex_state == EXPR_BEG or @lex_state == EXPR_ARG && @space_seen
@lex_state = EXPR_BEG
Token(TkCOLON3)
else
@lex_state = EXPR_DOT
Token(TkCOLON2)
end
end
@OP.def_rule("/") do
|op, io|
if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
identify_string(op)
elsif peek(0) == '='
getc
@lex_state = EXPR_BEG
Token(TkOPASGN, "/") #/)
elsif @lex_state == EXPR_ARG and @space_seen and peek(0) !~ /\s/
identify_string(op)
else
@lex_state = EXPR_BEG
Token("/") #/)
end
end
@OP.def_rules("^") do
|op, io|
@lex_state = EXPR_BEG
Token("^")
end
# @OP.def_rules("^=") do
# @lex_state = EXPR_BEG
# Token(OP_ASGN, :^)
# end
@OP.def_rules(",") do
|op, io|
@lex_state = EXPR_BEG
Token(op)
end
@OP.def_rules(";") do
|op, io|
@lex_state = EXPR_BEG
until (@indent_stack.empty? ||
[TkLPAREN, TkLBRACK, TkLBRACE,
TkfLPAREN, TkfLBRACK, TkfLBRACE].include?(@indent_stack.last))
@indent_stack.pop
end
Token(op)
end
@OP.def_rule("~") do
|op, io|
@lex_state = EXPR_BEG
Token("~")
end
@OP.def_rule("~@", proc{|op, io| @lex_state == EXPR_FNAME}) do
|op, io|
@lex_state = EXPR_BEG
Token("~")
end
@OP.def_rule("(") do
|op, io|
@indent += 1
if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
@lex_state = EXPR_BEG
tk_c = TkfLPAREN
else
@lex_state = EXPR_BEG
tk_c = TkLPAREN
end
@indent_stack.push tk_c
Token(tk_c)
end
@OP.def_rule("[]", proc{|op, io| @lex_state == EXPR_FNAME}) do
|op, io|
@lex_state = EXPR_ARG
Token("[]")
end
@OP.def_rule("[]=", proc{|op, io| @lex_state == EXPR_FNAME}) do
|op, io|
@lex_state = EXPR_ARG
Token("[]=")
end
@OP.def_rule("[") do
|op, io|
@indent += 1
if @lex_state == EXPR_FNAME
tk_c = TkfLBRACK
else
if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
tk_c = TkLBRACK
elsif @lex_state == EXPR_ARG && @space_seen
tk_c = TkLBRACK
else
tk_c = TkfLBRACK
end
@lex_state = EXPR_BEG
end
@indent_stack.push tk_c
Token(tk_c)
end
@OP.def_rule("{") do
|op, io|
@indent += 1
if @lex_state != EXPR_END && @lex_state != EXPR_ARG
tk_c = TkLBRACE
else
tk_c = TkfLBRACE
end
@lex_state = EXPR_BEG
@indent_stack.push tk_c
Token(tk_c)
end
@OP.def_rule('\\') do
|op, io|
if getc == "\n"
@space_seen = true
@continue = true
Token(TkSPACE)
else
read_escape
Token("\\")
end
end
@OP.def_rule('%') do
|op, io|
if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
identify_quotation
elsif peek(0) == '='
getc
Token(TkOPASGN, :%)
elsif @lex_state == EXPR_ARG and @space_seen and peek(0) !~ /\s/
identify_quotation
else
@lex_state = EXPR_BEG
Token("%") #))
end
end
@OP.def_rule('$') do
|op, io|
identify_gvar
end
@OP.def_rule('@') do
|op, io|
if peek(0) =~ /[\w@]/
ungetc
identify_identifier
else
Token("@")
end
end
# @OP.def_rule("def", proc{|op, io| /\s/ =~ io.peek(0)}) do
# |op, io|
# @indent += 1
# @lex_state = EXPR_FNAME
# # @lex_state = EXPR_END
# # until @rests[0] == "\n" or @rests[0] == ";"
# # rests.shift
# # end
# end
@OP.def_rule("") do
|op, io|
printf "MATCH: start %s: %s\n", op, io.inspect if RubyLex.debug?
if peek(0) =~ /[0-9]/
t = identify_number
elsif peek(0) =~ /[^\x00-\/:-@\[-^`{-\x7F]/
t = identify_identifier
end
printf "MATCH: end %s: %s\n", op, io.inspect if RubyLex.debug?
t
end
p @OP if RubyLex.debug?
end
def identify_gvar
@lex_state = EXPR_END
case ch = getc
when /[~_*$?!@\/\\;,=:<>".]/ #"
Token(TkGVAR, "$" + ch)
when "-"
Token(TkGVAR, "$-" + getc)
when "&", "`", "'", "+"
Token(TkBACK_REF, "$"+ch)
when /[1-9]/
while getc =~ /[0-9]/; end
ungetc
Token(TkNTH_REF)
when /\w/
ungetc
ungetc
identify_identifier
else
ungetc
Token("$")
end
end
def identify_identifier
token = ""
if peek(0) =~ /[$@]/
token.concat(c = getc)
if c == "@" and peek(0) == "@"
token.concat getc
end
end
while (ch = getc) =~ /[^\x00-\/:-@\[-^`{-\x7F]/
print ":", ch, ":" if RubyLex.debug?
token.concat ch
end
ungetc
if (ch == "!" || ch == "?") && token[0,1] =~ /\w/ && peek(0) != "="
token.concat getc
end
# almost fix token
case token
when /^\$/
return Token(TkGVAR, token)
when /^\@\@/
@lex_state = EXPR_END
# p Token(TkCVAR, token)
return Token(TkCVAR, token)
when /^\@/
@lex_state = EXPR_END
return Token(TkIVAR, token)
end
if @lex_state != EXPR_DOT
print token, "\n" if RubyLex.debug?
token_c, *trans = TkReading2Token[token]
if token_c
# reserved word?
if (@lex_state != EXPR_BEG &&
@lex_state != EXPR_FNAME &&
trans[1])
# modifiers
token_c = TkSymbol2Token[trans[1]]
@lex_state = trans[0]
else
if @lex_state != EXPR_FNAME
if ENINDENT_CLAUSE.include?(token)
# check for ``class = val'' etc.
valid = true
case token
when "class"
valid = false unless peek_match?(/^\s*(<<|\w|::)/)
when "def"
valid = false if peek_match?(/^\s*(([+\-\/*&\|^]|<<|>>|\|\||\&\&)=|\&\&|\|\|)/)
when "do"
valid = false if peek_match?(/^\s*([+\-\/*]?=|\*|<|>|\&)/)
when *ENINDENT_CLAUSE
valid = false if peek_match?(/^\s*([+\-\/*]?=|\*|<|>|\&|\|)/)
else
# no nothing
end
if valid
if token == "do"
if ![TkFOR, TkWHILE, TkUNTIL].include?(@indent_stack.last)
@indent += 1
@indent_stack.push token_c
end
else
@indent += 1
@indent_stack.push token_c
end
# p @indent_stack
end
elsif DEINDENT_CLAUSE.include?(token)
@indent -= 1
@indent_stack.pop
end
@lex_state = trans[0]
else
@lex_state = EXPR_END
end
end
return Token(token_c, token)
end
end
if @lex_state == EXPR_FNAME
@lex_state = EXPR_END
if peek(0) == '='
token.concat getc
end
elsif @lex_state == EXPR_BEG || @lex_state == EXPR_DOT
@lex_state = EXPR_ARG
else
@lex_state = EXPR_END
end
if token[0, 1] =~ /[A-Z]/
return Token(TkCONSTANT, token)
elsif token[token.size - 1, 1] =~ /[!?]/
return Token(TkFID, token)
else
return Token(TkIDENTIFIER, token)
end
end
def identify_here_document
ch = getc
# if lt = PERCENT_LTYPE[ch]
if ch == "-"
ch = getc
indent = true
end
if /['"`]/ =~ ch
lt = ch
quoted = ""
while (c = getc) && c != lt
quoted.concat c
end
else
lt = '"'
quoted = ch.dup
while (c = getc) && c =~ /\w/
quoted.concat c
end
ungetc
end
ltback, @ltype = @ltype, lt
reserve = []
while ch = getc
reserve.push ch
if ch == "\\"
reserve.push ch = getc
elsif ch == "\n"
break
end
end
@here_header = false
# while l = gets
# l = l.sub(/(:?\r)?\n\z/, '')
# if (indent ? l.strip : l) == quoted
# break
# end
# end
line = ""
while ch = getc
if ch == "\n"
if line == quoted
break
end
line = ""
else
line.concat ch unless indent && line == "" && /\s/ =~ ch
if @ltype != "'" && ch == "#" && peek(0) == "{"
identify_string_dvar
end
end
end
@here_header = true
@here_readed.concat reserve
while ch = reserve.pop
ungetc ch
end
@ltype = ltback
@lex_state = EXPR_END
Token(Ltype2Token[lt])
end
def identify_quotation
ch = getc
if lt = PERCENT_LTYPE[ch]
ch = getc
elsif ch =~ /\W/
lt = "\""
else
RubyLex.fail SyntaxError, "unknown type of %string"
end
# if ch !~ /\W/
# ungetc
# next
# end
#@ltype = lt
@quoted = ch unless @quoted = PERCENT_PAREN[ch]
identify_string(lt, @quoted)
end
def identify_number
@lex_state = EXPR_END
if peek(0) == "0" && peek(1) !~ /[.eE]/
getc
case peek(0)
when /[xX]/
ch = getc
match = /[0-9a-fA-F_]/
when /[bB]/
ch = getc
match = /[01_]/
when /[oO]/
ch = getc
match = /[0-7_]/
when /[dD]/
ch = getc
match = /[0-9_]/
when /[0-7]/
match = /[0-7_]/
when /[89]/
RubyLex.fail SyntaxError, "Invalid octal digit"
else
return Token(TkINTEGER)
end
len0 = true
non_digit = false
while ch = getc
if match =~ ch
if ch == "_"
if non_digit
RubyLex.fail SyntaxError, "trailing `#{ch}' in number"
else
non_digit = ch
end
else
non_digit = false
len0 = false
end
else
ungetc
if len0
RubyLex.fail SyntaxError, "numeric literal without digits"
end
if non_digit
RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
end
break
end
end
return Token(TkINTEGER)
end
type = TkINTEGER
allow_point = true
allow_e = true
non_digit = false
while ch = getc
case ch
when /[0-9]/
non_digit = false
when "_"
non_digit = ch
when allow_point && "."
if non_digit
RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
end
type = TkFLOAT
if peek(0) !~ /[0-9]/
type = TkINTEGER
ungetc
break
end
allow_point = false
when allow_e && "e", allow_e && "E"
if non_digit
RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
end
type = TkFLOAT
if peek(0) =~ /[+-]/
getc
end
allow_e = false
allow_point = false
non_digit = ch
else
if non_digit
RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
end
ungetc
break
end
end
Token(type)
end
def identify_string(ltype, quoted = ltype)
@ltype = ltype
@quoted = quoted
subtype = nil
begin
nest = 0
while ch = getc
if @quoted == ch and nest == 0
break
elsif @ltype != "'" && ch == "#" && peek(0) == "{"
identify_string_dvar
elsif @ltype != "'" && @ltype != "]" && @ltype != ":" and ch == "#"
subtype = true
elsif ch == '\\' and @ltype == "'" #'
case ch = getc
when "\\", "\n", "'"
else
ungetc
end
elsif ch == '\\' #'
read_escape
end
if PERCENT_PAREN.values.include?(@quoted)
if PERCENT_PAREN[ch] == @quoted
nest += 1
elsif ch == @quoted
nest -= 1
end
end
end
if @ltype == "/"
while /[imxoesun]/ =~ peek(0)
getc
end
end
if subtype
Token(DLtype2Token[ltype])
else
Token(Ltype2Token[ltype])
end
ensure
@ltype = nil
@quoted = nil
@lex_state = EXPR_END
end
end
def identify_string_dvar
begin
getc
reserve_continue = @continue
reserve_ltype = @ltype
reserve_indent = @indent
reserve_indent_stack = @indent_stack
reserve_state = @lex_state
reserve_quoted = @quoted
@ltype = nil
@quoted = nil
@indent = 0
@indent_stack = []
@lex_state = EXPR_BEG
loop do
@continue = false
prompt
tk = token
if @ltype or @continue or @indent > 0
next
end
break if tk.kind_of?(TkRBRACE)
end
ensure
@continue = reserve_continue
@ltype = reserve_ltype
@indent = reserve_indent
@indent_stack = reserve_indent_stack
@lex_state = reserve_state
@quoted = reserve_quoted
end
end
def identify_comment
@ltype = "#"
while ch = getc
# if ch == "\\" #"
# read_escape
# end
if ch == "\n"
@ltype = nil
ungetc
break
end
end
return Token(TkCOMMENT)
end
def read_escape
case ch = getc
when "\n", "\r", "\f"
when "\\", "n", "t", "r", "f", "v", "a", "e", "b", "s" #"
when /[0-7]/
ungetc ch
3.times do
case ch = getc
when /[0-7]/
when nil
break
else
ungetc
break
end
end
when "x"
2.times do
case ch = getc
when /[0-9a-fA-F]/
when nil
break
else
ungetc
break
end
end
when "M"
if (ch = getc) != '-'
ungetc
else
if (ch = getc) == "\\" #"
read_escape
end
end
when "C", "c" #, "^"
if ch == "C" and (ch = getc) != "-"
ungetc
elsif (ch = getc) == "\\" #"
read_escape
end
else
# other characters
end
end
end
# :startdoc: