    indexing
    	description: "Mechanisms for building lexical analyzers from regular expressions."
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	date: "$Date: 2006-01-22 18:25:44 -0800 (Sun, 22 Jan 2006) $"
    	revision: "$Revision: 56675 $"

    class interface
    	METALEX

    create
    	make
    			-- Set up the analyzer.
    			-- (from LEX_BUILDER)
    		ensure -- from LEX_BUILDER
    			last_character_set: last_character_code = last_ascii

    	make_extended (char_code: INTEGER_32)
    			-- Set up the analyzer with `char_code' as 'last_character_code'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			valid_char_code: char_code > 0
    		ensure -- from LEX_BUILDER
    			last_character_set: last_character_code = char_code

    feature -- Initialization

    	initialize
    			-- Set up attributes of analyzer.
    			-- (from LEX_BUILDER)
    		ensure -- from LEX_BUILDER
    			initialized

    	make
    			-- Set up the analyzer.
    			-- (from LEX_BUILDER)
    		ensure -- from LEX_BUILDER
    			last_character_set: last_character_code = last_ascii

    	pdfa_make (n, i: INTEGER_32)
    			-- Make a PDFA with `n' states, and `i' + 1 inputs.
    			-- (from PDFA)

    	array_make (min_index, max_index: INTEGER_32)
    			-- Allocate array; set index interval to
    			-- `min_index' .. `max_index'; set all values to default.
    			-- (Make array empty if `min_index' = `max_index' + 1).
    			-- (from ARRAY)
    		require -- from ARRAY
    			valid_bounds: min_index <= max_index + 1
    		ensure -- from ARRAY
    			lower_set: lower = min_index
    			upper_set: upper = max_index
    			items_set: all_default

    	make_analyzer
    			-- Create analyzer (if Void) and initialize it.
    		require
    			not_initialized: not initialized
    		ensure
    			initialized
    			analyzer_created: analyzer /= Void
    			lexical_frozen

    	make_extended (char_code: INTEGER_32)
    			-- Set up the analyzer with `char_code' as 'last_character_code'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			valid_char_code: char_code > 0
    		ensure -- from LEX_BUILDER
    			last_character_set: last_character_code = char_code

    	make_from_array (a: ARRAY [LINKED_LIST [INTEGER_32]])
    			-- Initialize from the items of `a'.
    			-- (Useful in proper descendants of class `ARRAY',
    			-- to initialize an array-like object from a manifest array.)
    			-- (from ARRAY)
    		require -- from ARRAY
    			array_exists: a /= Void

    	make_from_cil (na: NATIVE_ARRAY [like pdfa_item])
    			-- Initialize array from `na'.
    			-- (from ARRAY)
    		require -- from ARRAY
    			is_dotnet: {PLATFORM}.is_dotnet
    			na_not_void: na /= Void

    feature -- Access

    	ack: INTEGER_32 is 6
    			-- (from ASCII)

    	ampersand: INTEGER_32 is 38
    			-- (from ASCII)

    	analyzer: LEXICAL
    			-- The lexical analyzer built so far
    			-- (from LEX_BUILDER)

    	area: SPECIAL [LINKED_LIST [INTEGER_32]]
    			-- Special data zone
    			-- (from TO_SPECIAL)

    	back_space: INTEGER_32 is 8
    			-- (from ASCII)

    	backslash: INTEGER_32 is 92
    			-- (from ASCII)

    	bar: INTEGER_32 is 124
    			-- (from ASCII)

    	bel: INTEGER_32 is 7
    			-- (from ASCII)

    	blank: INTEGER_32 is 32
    			-- (from ASCII)

    	break: INTEGER_32 is -7
    			-- (from ASCII)

    	bs: INTEGER_32 is 8
    			-- (from ASCII)

    	buf_overflow: INTEGER_32 is -9
    			-- (from ASCII)

    	can: INTEGER_32 is 24
    			-- (from ASCII)

    	carriage_return: INTEGER_32 is 13
    			-- (from ASCII)

    	case_diff: INTEGER_32 is 32
    			-- Lower_a - Upper_a
    			-- (from ASCII)

    	case_sensitive: BOOLEAN
    			-- Will future tools be case-sensitive?
    			-- (from LEX_BUILDER)

    	categories_table: ARRAY [INTEGER_32]
    			-- Table of category numbers for each input
    			-- (from LEX_BUILDER)

    	character_set_size: INTEGER_32 is 128
    			-- (from ASCII)

    	circumflex: INTEGER_32 is 94
    			-- (from ASCII)

    	closing_brace: INTEGER_32 is 125
    			-- (from ASCII)

    	colon: INTEGER_32 is 58
    			-- (from ASCII)

    	comma: INTEGER_32 is 44
    			-- (from ASCII)

    	commercial_at: INTEGER_32 is 64
    			-- (from ASCII)

    	cr: INTEGER_32 is 13
    			-- (from ASCII)

    	ctrl_a: INTEGER_32 is 1
    			-- (from ASCII)

    	ctrl_b: INTEGER_32 is 2
    			-- (from ASCII)

    	ctrl_backslash: INTEGER_32 is 28
    			-- (from ASCII)

    	ctrl_c: INTEGER_32 is 3
    			-- (from ASCII)

    	ctrl_circumflex: INTEGER_32 is 30
    			-- (from ASCII)

    	ctrl_d: INTEGER_32 is 4
    			-- (from ASCII)

    	ctrl_e: INTEGER_32 is 5
    			-- (from ASCII)

    	ctrl_f: INTEGER_32 is 6
    			-- (from ASCII)

    	ctrl_g: INTEGER_32 is 7
    			-- (from ASCII)

    	ctrl_h: INTEGER_32 is 8
    			-- (from ASCII)

    	ctrl_i: INTEGER_32 is 9
    			-- (from ASCII)

    	ctrl_j: INTEGER_32 is 10
    			-- (from ASCII)

    	ctrl_k: INTEGER_32 is 11
    			-- (from ASCII)

    	ctrl_l: INTEGER_32 is 12
    			-- (from ASCII)

    	ctrl_lbracket: INTEGER_32 is 27
    			-- (from ASCII)

    	ctrl_m: INTEGER_32 is 13
    			-- (from ASCII)

    	ctrl_n: INTEGER_32 is 14
    			-- (from ASCII)

    	ctrl_o: INTEGER_32 is 15
    			-- (from ASCII)

    	ctrl_p: INTEGER_32 is 16
    			-- (from ASCII)

    	ctrl_q: INTEGER_32 is 17
    			-- (from ASCII)

    	ctrl_questmark: INTEGER_32 is 127
    			-- (from ASCII)

    	ctrl_r: INTEGER_32 is 18
    			-- (from ASCII)

    	ctrl_rbracket: INTEGER_32 is 29
    			-- (from ASCII)

    	ctrl_s: INTEGER_32 is 19
    			-- (from ASCII)

    	ctrl_t: INTEGER_32 is 20
    			-- (from ASCII)

    	ctrl_u: INTEGER_32 is 21
    			-- (from ASCII)

    	ctrl_underlined: INTEGER_32 is 31
    			-- (from ASCII)

    	ctrl_v: INTEGER_32 is 22
    			-- (from ASCII)

    	ctrl_w: INTEGER_32 is 23
    			-- (from ASCII)

    	ctrl_x: INTEGER_32 is 24
    			-- (from ASCII)

    	ctrl_y: INTEGER_32 is 25
    			-- (from ASCII)

    	ctrl_z: INTEGER_32 is 26
    			-- (from ASCII)

    	dc1: INTEGER_32 is 17
    			-- (from ASCII)

    	dc2: INTEGER_32 is 18
    			-- (from ASCII)

    	dc3: INTEGER_32 is 19
    			-- (from ASCII)

    	dc4: INTEGER_32 is 20
    			-- (from ASCII)

    	del: INTEGER_32 is 127
    			-- (from ASCII)

    	dfa: FIXED_DFA
    			-- DFA built by routine construct_dfa,
    			-- which recognizes the same language.
    			-- (from NDFA)

    	dle: INTEGER_32 is 16
    			-- (from ASCII)

    	dollar: INTEGER_32 is 36
    			-- (from ASCII)

    	dot: INTEGER_32 is 46
    			-- (from ASCII)

    	doublequote: INTEGER_32 is 34
    			-- (from ASCII)

    	down_arrow: INTEGER_32 is -3
    			-- (from ASCII)

    	eight: INTEGER_32 is 56
    			-- (from ASCII)

    	em: INTEGER_32 is 25
    			-- (from ASCII)

    	enq: INTEGER_32 is 5
    			-- (from ASCII)

    	entry (i: INTEGER_32): LINKED_LIST [INTEGER_32]
    			-- Entry at index `i', if in index interval
    			-- (from ARRAY)
    		require -- from ARRAY
    			valid_key: valid_index (i)

    	eot: INTEGER_32 is 4
    			-- (from ASCII)

    	equal_sign: INTEGER_32 is 61
    			-- (from ASCII)

    	error_list: ERROR_LIST
    			-- List of error messages
    			-- (from LEX_BUILDER)

    	esc: INTEGER_32 is 27
    			-- (from ASCII)

    	etb: INTEGER_32 is 23
    			-- (from ASCII)

    	etx: INTEGER_32 is 3
    			-- (from ASCII)

    	exclamation: INTEGER_32 is 33
    			-- (from ASCII)

    	final_array: ARRAY [INTEGER_32]
    			-- The `final' value for each state
    			-- (regular expression, if any, for which it is final).
    			-- (from PDFA)

    	first_printable: INTEGER_32 is 32
    			-- (from ASCII)

    	five: INTEGER_32 is 53
    			-- (from ASCII)

    	four: INTEGER_32 is 52
    			-- (from ASCII)

    	fs: INTEGER_32 is 28
    			-- (from ASCII)

    	generating_type: STRING_8
    			-- Name of current object's generating type
    			-- (type of which it is a direct instance)
    			-- (from ANY)

    	generator: STRING_8
    			-- Name of current object's generating class
    			-- (base class of the type of which it is a direct instance)
    			-- (from ANY)

    	grave_accent: INTEGER_32 is 96
    			-- (from ASCII)

    	greaterthan: INTEGER_32 is 62
    			-- (from ASCII)

    	greatest_input: INTEGER_32
    			-- Greatest input used for the transitions from state
    			-- to state (the smallest one is zero)
    			-- (from AUTOMATON)

    	gs: INTEGER_32 is 29
    			-- (from ASCII)

    	has (v: LINKED_LIST [INTEGER_32]): BOOLEAN
    			-- Does `v' appear in array?
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from ARRAY)
    		ensure -- from CONTAINER
    			not_found_in_empty: Result implies not is_empty

    	has_letters: BOOLEAN
    			-- Are there any letters among the active transitions?
    			-- (from PDFA)

    	home_arrow: INTEGER_32 is -6
    			-- (from ASCII)

    	ht: INTEGER_32 is 9
    			-- (from ASCII)

    	input_array: ARRAY [FIXED_INTEGER_SET]
    			-- For each input, set of the states which have
    			-- a transition on this input to the following state
    			-- (from PDFA)

    	item alias "[]" (i: INTEGER_32): LINKED_LIST [INTEGER_32] assign put
    			-- Entry at index `i', if in index interval
    			-- Was declared in ARRAY as synonym of infix "@".
    			-- (from ARRAY)
    		require -- from TABLE
    			valid_key: valid_index (i)
    		require -- from TO_SPECIAL
    			valid_index: valid_index (i)

    	keyword_h_table: HASH_TABLE [INTEGER_32, STRING_8]
    			-- Keyword table
    			-- (from LEX_BUILDER)

    	keywords_case_sensitive: BOOLEAN
    			-- Will future tools be case-sensitive for keywords?
    			-- (from LEX_BUILDER)

    	keywords_list: LINKED_LIST [STRING_8]
    			-- Keywords associated with current automaton.
    			-- (from PDFA)

    	last_ascii: INTEGER_32 is 127
    			-- (from ASCII)

    	last_character_code: INTEGER_32
    			-- Last character code recognized by the language
    			-- (from LEX_BUILDER)

    	last_created_tool: INTEGER_32
    			-- Identification number of the last
    			-- regular expression put in tool_list
    			-- (from LEX_BUILDER)

    	last_printable: INTEGER_32 is 126
    			-- (from ASCII)

    	lbracket: INTEGER_32 is 91
    			-- (from ASCII)

    	lcurly: INTEGER_32 is 40
    			-- (from ASCII)

    	left_arrow: INTEGER_32 is -4
    			-- (from ASCII)

    	lessthan: INTEGER_32 is 60
    			-- (from ASCII)

    	letter_layout: INTEGER_32 is 70
    			-- (from ASCII)

    	lexical_frozen: BOOLEAN
    			-- Has the lexical grammar been finalized?
    			-- | (in other words: has the DFA been built?)
    			-- (from LEX_BUILDER)

    	line_feed: INTEGER_32 is 10
    			-- (from ASCII)

    	lower_a: INTEGER_32 is 97
    			-- (from ASCII)

    	lower_b: INTEGER_32 is 98
    			-- (from ASCII)

    	lower_c: INTEGER_32 is 99
    			-- (from ASCII)

    	lower_d: INTEGER_32 is 100
    			-- (from ASCII)

    	lower_e: INTEGER_32 is 101
    			-- (from ASCII)

    	lower_f: INTEGER_32 is 102
    			-- (from ASCII)

    	lower_g: INTEGER_32 is 103
    			-- (from ASCII)

    	lower_h: INTEGER_32 is 104
    			-- (from ASCII)

    	lower_i: INTEGER_32 is 105
    			-- (from ASCII)

    	lower_j: INTEGER_32 is 106
    			-- (from ASCII)

    	lower_k: INTEGER_32 is 107
    			-- (from ASCII)

    	lower_l: INTEGER_32 is 108
    			-- (from ASCII)

    	lower_m: INTEGER_32 is 109
    			-- (from ASCII)

    	lower_n: INTEGER_32 is 110
    			-- (from ASCII)

    	lower_o: INTEGER_32 is 111
    			-- (from ASCII)

    	lower_p: INTEGER_32 is 112
    			-- (from ASCII)

    	lower_q: INTEGER_32 is 113
    			-- (from ASCII)

    	lower_r: INTEGER_32 is 114
    			-- (from ASCII)

    	lower_s: INTEGER_32 is 115
    			-- (from ASCII)

    	lower_t: INTEGER_32 is 116
    			-- (from ASCII)

    	lower_u: INTEGER_32 is 117
    			-- (from ASCII)

    	lower_v: INTEGER_32 is 118
    			-- (from ASCII)

    	lower_w: INTEGER_32 is 119
    			-- (from ASCII)

    	lower_x: INTEGER_32 is 120
    			-- (from ASCII)

    	lower_y: INTEGER_32 is 121
    			-- (from ASCII)

    	lower_z: INTEGER_32 is 122
    			-- (from ASCII)

    	minus: INTEGER_32 is 45
    			-- (from ASCII)

    	nak: INTEGER_32 is 21
    			-- (from ASCII)

    	nine: INTEGER_32 is 57
    			-- (from ASCII)

    	nl: INTEGER_32 is 10
    			-- (from ASCII)

    	np: INTEGER_32 is 12
    			-- (from ASCII)

    	nul: INTEGER_32 is 0
    			-- (from ASCII)

    	number_sign: INTEGER_32 is 35
    			-- (from ASCII)

    	one: INTEGER_32 is 49
    			-- (from ASCII)

    	opening_brace: INTEGER_32 is 123
    			-- (from ASCII)

    	overflow: INTEGER_32 is -8
    			-- (from ASCII)

    	percent: INTEGER_32 is 37
    			-- (from ASCII)

    	plus: INTEGER_32 is 43
    			-- (from ASCII)

    	questmark: INTEGER_32 is 63
    			-- (from ASCII)

    	rbracket: INTEGER_32 is 93
    			-- (from ASCII)

    	rcurly: INTEGER_32 is 41
    			-- (from ASCII)

    	right_arrow: INTEGER_32 is -5
    			-- (from ASCII)

    	rs: INTEGER_32 is 30
    			-- (from ASCII)

    	selected_tools: LINKED_LIST [INTEGER_32]
    			-- Regular expressions included in the main one
    			-- (from LEX_BUILDER)

    	semicolon: INTEGER_32 is 59
    			-- (from ASCII)

    	seven: INTEGER_32 is 55
    			-- (from ASCII)

    	si: INTEGER_32 is 15
    			-- (from ASCII)

    	singlequote: INTEGER_32 is 39
    			-- (from ASCII)

    	six: INTEGER_32 is 54
    			-- (from ASCII)

    	slash: INTEGER_32 is 47
    			-- (from ASCII)

    	so: INTEGER_32 is 14
    			-- (from ASCII)

    	soh: INTEGER_32 is 1
    			-- (from ASCII)

    	sp: INTEGER_32 is 32
    			-- (from ASCII)

    	star: INTEGER_32 is 42
    			-- (from ASCII)

    	start_number: INTEGER_32
    			-- Unique start state used for the beginning of
    			-- the automaton's operation
    			-- (from AUTOMATON)

    	stx: INTEGER_32 is 2
    			-- (from ASCII)

    	sub: INTEGER_32 is 26
    			-- (from ASCII)

    	syn: INTEGER_32 is 22
    			-- (from ASCII)

    	tabulation: INTEGER_32 is 9
    			-- (from ASCII)

    	three: INTEGER_32 is 51
    			-- (from ASCII)

    	tilde: INTEGER_32 is 126
    			-- (from ASCII)

    	token_type_list: LINKED_LIST [INTEGER_32]
    			-- Token types of the selected tools.
    			-- Indexed by tool numbers.
    			-- (from LEX_BUILDER)

    	tool_list: LINKED_LIST [PDFA]
    			-- Regular expressions used as auxiliary tools
    			-- (from LEX_BUILDER)

    	tool_names: LINKED_LIST [STRING_8]
    			-- Names of regular expressions in tool list
    			-- (from LEX_BUILDER)

    	two: INTEGER_32 is 50
    			-- (from ASCII)

    	underlined: INTEGER_32 is 95
    			-- (from ASCII)

    	up_arrow: INTEGER_32 is -2
    			-- (from ASCII)

    	upper_a: INTEGER_32 is 65
    			-- (from ASCII)

    	upper_b: INTEGER_32 is 66
    			-- (from ASCII)

    	upper_c: INTEGER_32 is 67
    			-- (from ASCII)

    	upper_d: INTEGER_32 is 68
    			-- (from ASCII)

    	upper_e: INTEGER_32 is 69
    			-- (from ASCII)

    	upper_f: INTEGER_32 is 70
    			-- (from ASCII)

    	upper_g: INTEGER_32 is 71
    			-- (from ASCII)

    	upper_h: INTEGER_32 is 72
    			-- (from ASCII)

    	upper_i: INTEGER_32 is 73
    			-- (from ASCII)

    	upper_j: INTEGER_32 is 74
    			-- (from ASCII)

    	upper_k: INTEGER_32 is 75
    			-- (from ASCII)

    	upper_l: INTEGER_32 is 76
    			-- (from ASCII)

    	upper_m: INTEGER_32 is 77
    			-- (from ASCII)

    	upper_n: INTEGER_32 is 78
    			-- (from ASCII)

    	upper_o: INTEGER_32 is 79
    			-- (from ASCII)

    	upper_p: INTEGER_32 is 80
    			-- (from ASCII)

    	upper_q: INTEGER_32 is 81
    			-- (from ASCII)

    	upper_r: INTEGER_32 is 82
    			-- (from ASCII)

    	upper_s: INTEGER_32 is 83
    			-- (from ASCII)

    	upper_t: INTEGER_32 is 84
    			-- (from ASCII)

    	upper_u: INTEGER_32 is 85
    			-- (from ASCII)

    	upper_v: INTEGER_32 is 86
    			-- (from ASCII)

    	upper_w: INTEGER_32 is 87
    			-- (from ASCII)

    	upper_x: INTEGER_32 is 88
    			-- (from ASCII)

    	upper_y: INTEGER_32 is 89
    			-- (from ASCII)

    	upper_z: INTEGER_32 is 90
    			-- (from ASCII)

    	us: INTEGER_32 is 31
    			-- (from ASCII)

    	vt: INTEGER_32 is 11
    			-- (from ASCII)

    	zero: INTEGER_32 is 48
    			-- (from ASCII)

    	infix "@" (i: INTEGER_32): LINKED_LIST [INTEGER_32] assign put
    			-- Entry at index `i', if in index interval
    			-- Was declared in ARRAY as synonym of `item'.
    			-- (from ARRAY)
    		require -- from TABLE
    			valid_key: valid_index (i)
    		require -- from TO_SPECIAL
    			valid_index: valid_index (i)

    feature -- Measurement

    	additional_space: INTEGER_32
    			-- Proposed number of additional items
    			-- (from RESIZABLE)
    		ensure -- from RESIZABLE
    			at_least_one: Result >= 1

    	capacity: INTEGER_32
    			-- Number of available indices
    			-- Was declared in ARRAY as synonym of count.
    			-- (from ARRAY)
    		require -- from  BOUNDED
    			True
    		ensure then -- from ARRAY
    			consistent_with_bounds: Result = upper - lower + 1

    	count: INTEGER_32
    			-- Number of available indices
    			-- Was declared in ARRAY as synonym of capacity.
    			-- (from ARRAY)
    		require -- from  FINITE
    			True
    		ensure then -- from ARRAY
    			consistent_with_bounds: Result = upper - lower + 1

    	growth_percentage: INTEGER_32 is 50
    			-- Percentage by which structure will grow automatically
    			-- (from RESIZABLE)

    	index_set: INTEGER_INTERVAL
    			-- Range of acceptable indexes
    			-- (from ARRAY)
    		require -- from  INDEXABLE
    			True
    		ensure -- from INDEXABLE
    			not_void: Result /= Void
    		ensure then -- from ARRAY
    			same_count: Result.count = count
    			same_bounds: ((Result.lower = lower) and (Result.upper = upper))

    	lower: INTEGER_32
    			-- Minimum index
    			-- (from ARRAY)

    	minimal_increase: INTEGER_32 is 5
    			-- Minimal number of additional items
    			-- (from RESIZABLE)

    	nb_states: INTEGER_32
    			-- Number of states in the automaton
    			-- (from AUTOMATON)

    	occurrences (v: LINKED_LIST [INTEGER_32]): INTEGER_32
    			-- Number of times `v' appears in structure
    			-- (from ARRAY)
    		ensure -- from BAG
    			non_negative_occurrences: Result >= 0

    	upper: INTEGER_32
    			-- Maximum index
    			-- (from ARRAY)

    feature -- Comparison

    	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void
    			-- or attached to isomorphic object structures?
    			-- (from ANY)
    		ensure -- from ANY
    			shallow_implies_deep: standard_equal (some, other) implies Result
    			both_or_none_void: (some = Void) implies (Result = (other = Void))
    			same_type: (Result and (some /= Void)) implies some.same_type (other)
    			symmetric: Result implies deep_equal (other, some)

    	frozen equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached
    			-- to objects considered equal?
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.is_equal (other))

    	is_equal (other: like Current): BOOLEAN
    			-- Is array made of the same items as `other'?
    			-- (from ARRAY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			symmetric: Result implies other.is_equal (Current)
    			consistent: standard_is_equal (other) implies Result

    	frozen standard_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached to
    			-- field-by-field identical objects of the same type?
    			-- Always uses default object comparison criterion.
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.standard_is_equal (other))

    	frozen standard_is_equal (other: like Current): BOOLEAN
    			-- Is `other' attached to an object of the same type
    			-- as current object, and field-by-field identical to it?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			same_type: Result implies same_type (other)
    			symmetric: Result implies other.standard_is_equal (Current)

    feature -- Status report

    	all_default: BOOLEAN
    			-- Are all items set to default values?
    			-- (from ARRAY)
    		ensure -- from ARRAY
    			definition: Result = (count = 0 or else ((pdfa_item (upper) = Void or else pdfa_item (upper) = pdfa_item (upper).default) and subarray (lower, upper - 1).all_default))

    	changeable_comparison_criterion: BOOLEAN
    			-- May object_comparison be changed?
    			-- (Answer: yes by default.)
    			-- (from CONTAINER)

    	conforms_to (other: ANY): BOOLEAN
    			-- Does type of current object conform to type
    			-- of `other' (as per Eiffel: The Language, chapter 13)?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void

    	extendible: BOOLEAN
    			-- May items be added?
    			-- (Answer: no, although array may be resized.)
    			-- (from ARRAY)

    	full: BOOLEAN
    			-- Is structure filled to capacity? (Answer: yes)
    			-- (from ARRAY)
    		require -- from  BOX
    			True

    	is_empty: BOOLEAN
    			-- Is structure empty?
    			-- (from FINITE)
    		require -- from  CONTAINER
    			True

    	is_inserted (v: LINKED_LIST [INTEGER_32]): BOOLEAN
    			-- Has `v' been inserted by the most recent insertion?
    			-- (By default, the value returned is equivalent to calling
    			-- `has (v)'. However, descendants might be able to provide more
    			-- efficient implementations.)
    			-- (from COLLECTION)

    	object_comparison: BOOLEAN
    			-- Must search operations use equal rather than `='
    			-- for comparing references? (Default: no, use `='.)
    			-- (from CONTAINER)

    	prunable: BOOLEAN
    			-- May items be removed? (Answer: no.)
    			-- (from ARRAY)

    	resizable: BOOLEAN
    			-- May capacity be changed? (Answer: yes.)
    			-- (from RESIZABLE)

    	same_items (other: like Current): BOOLEAN
    			-- Do `other' and Current have same items?
    			-- (from ARRAY)
    		require -- from ARRAY
    			other_not_void: other /= Void
    		ensure -- from ARRAY
    			definition: Result = ((count = other.count) and then (count = 0 or else (pdfa_item (upper) = other.pdfa_item (other.upper) and subarray (lower, upper - 1).same_items (other.subarray (other.lower, other.upper - 1)))))

    	same_type (other: ANY): BOOLEAN
    			-- Is type of current object identical to type of `other'?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			definition: Result = (conforms_to (other) and other.conforms_to (Current))

    	valid_index (i: INTEGER_32): BOOLEAN
    			-- Is `i' within the bounds of the array?
    			-- (from ARRAY)
    		require -- from  TABLE
    			True
    		require -- from  TO_SPECIAL
    			True
    		ensure then -- from INDEXABLE
    			only_if_in_index_set: Result implies ((i >= index_set.lower) and (i <= index_set.upper))

    	valid_index_set: BOOLEAN
    			-- (from ARRAY)

    feature -- Status setting

    	compare_objects
    			-- Ensure that future search operations will use equal
    			-- rather than `=' for comparing references.
    			-- (from CONTAINER)
    		require -- from CONTAINER
    			changeable_comparison_criterion: changeable_comparison_criterion
    		ensure -- from CONTAINER
    			object_comparison

    	compare_references
    			-- Ensure that future search operations will use `='
    			-- rather than equal for comparing references.
    			-- (from CONTAINER)
    		require -- from CONTAINER
    			changeable_comparison_criterion: changeable_comparison_criterion
    		ensure -- from CONTAINER
    			reference_comparison: not object_comparison

    	set_e_transition (source, target: INTEGER_32)
    			-- Set epsilon transition from `source' to `target'.
    			-- (from PDFA)
    		require -- from NDFA
    			source_in_automaton: source >= 1 and source <= nb_states
    			target_in_automaton: target >= 1 and target <= nb_states

    	set_final (s, r: INTEGER_32)
    			-- Make `s' the final state of regular expression `r'.
    			-- (from PDFA)

    	set_letters
    			-- Direct the active transitions to include letters.
    			-- (from PDFA)

    	set_start (n: INTEGER_32)
    			-- Select state `n' as the starting state.
    			-- (from AUTOMATON)
    		require -- from AUTOMATON
    			no_other_start: start_number = 0 or start_number = n
    			is_in_automaton: n <= nb_states and n >= 1

    	set_transition (source, input_doc, target: INTEGER_32)
    			-- Set transition from `source' to `target' on `input_doc'.
    			-- (from PDFA)
    		require -- from  AUTOMATON
    			True
    		require else -- from NDFA
    			source_in_automaton: source >= 1 and source <= nb_states
    			target_in_automaton: target >= 1 and target <= nb_states
    			possible_input_doc: input_doc >= 0 and input_doc <= greatest_input
    		require else -- from PDFA
    			source_in_automaton: source >= 1 and source <= nb_states
    			target_in_automaton: target >= 1 and target <= nb_states
    			possible_input_doc: input_doc >= 0 and input_doc <= greatest_input
    			good_successor: target = source + 1

    feature -- Element change

    	add_keyword (word: STRING_8)
    			-- Insert `word' in the keyword list.
    			-- (from PDFA)

    	add_word (s: STRING_8; n: INTEGER_32)
    			-- Record the word `s' and
    			-- associate it with token type `n'.
    		require
    			s_not_void: s /= Void
    			s_not_empty: s.capacity >= 1

    	any_character
    			-- Create regular expression $. matching all characters.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen

    	any_printable
    			-- Create regular expression $P matching all
    			-- printable characters.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen

    	append (p, s: INTEGER_32)
    			-- Create regular expression `p'`s':
    			-- `s' appended to `p'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			p_in_tool: p >= 1 and p <= last_created_tool
    			s_in_tool: s >= 1 and s <= last_created_tool

    	append_optional (p, s: INTEGER_32)
    			-- Create regular expression `p'[`s']:
    			-- `s' optionally appended to `p'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			p_in_tool: p >= 1 and p <= last_created_tool
    			s_in_tool: s >= 1 and s <= last_created_tool

    	associate (t, n: INTEGER_32)
    			-- Associate the `t'-th tool with token type `n'.
    			-- If this routine is not used, the default value is `t'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			t_selected: selected_tools.has (t)
    			n_not_zero: n /= 0
    			n_not_minus_one: n /= -1

    	build_dollar_any
    			-- Build $., matching any character.
    			-- (from HIGH_BUILDER)
    		require -- from HIGH_BUILDER
    			good_first_character: description.item (cursor) = '.'

    	build_dollar_b
    			-- Build $B, matching any number of break characters:
    			-- blank, new-line, tabulation, carriage-return.
    			-- (from HIGH_BUILDER)

    	build_dollar_n
    			-- Build $N, matching natural integer constants.
    			-- +('0'..'9')
    			-- (from HIGH_BUILDER)

    	build_dollar_p
    			-- Build $P, matching any printable character.
    			-- (from HIGH_BUILDER)
    		require -- from HIGH_BUILDER
    			good_first_character: description.item (cursor) = 'P'

    	build_dollar_r
    			-- Build $R, matching floating point constants.
    			-- ['+' | '-'] +('0'..'9') '.' *('0'..'9') ['e' | 'E' ['+' | '-']
    			-- +('0'..'9')]
    			-- (from HIGH_BUILDER)

    	build_dollar_z
    			-- Build $Z, matching possibly signed integer constants.
    			-- ['+' | '-'] +('0'..'9')
    			-- (from HIGH_BUILDER)

    	case_insensitive (c: INTEGER_32)
    			-- Create regular expression ~(`c'):
    			-- like `c', but case-insensitive.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			z_possible: last_character_code >= lower_z
    			c_in_tool: c >= 1 and c <= last_created_tool

    	difference (r: INTEGER_32; c: CHARACTER_8)
    			-- Create regular expression representing
    			-- the difference `r' - `c'.
    			-- `r' must be a simple category, such as `a'..`z',
    			-- or a union of simple categories,
    			-- such as `a'..`z' | `0'..`9'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			r_exists: r >= 1 and r <= last_created_tool
    			r_simple_category: tool_list.i_th (r).nb_states = 2

    	enter (v: like pdfa_item; i: INTEGER_32)
    			-- Replace `i'-th entry, if in index interval, by `v'.
    			-- (from ARRAY)
    		require -- from ARRAY
    			valid_key: valid_index (i)

    	fill (other: CONTAINER [LINKED_LIST [INTEGER_32]])
    			-- Fill with as many items of `other' as possible.
    			-- The representations of `other' and current structure
    			-- need not be the same.
    			-- (from COLLECTION)
    		require -- from COLLECTION
    			other_not_void: other /= Void
    			extendible: extendible

    	force (v: like pdfa_item; i: INTEGER_32)
    			-- Assign item `v' to `i'-th entry.
    			-- Always applicable: resize the array if `i' falls out of
    			-- currently defined bounds; preserve existing items.
    			-- (from ARRAY)
    		ensure -- from ARRAY
    			inserted: pdfa_item (i) = v
    			higher_count: count >= old count

    	include (fa: PDFA; shift: INTEGER_32)
    			-- Copy `fa' with state numbers shifted
    			-- by `shift' positions in the transitions.
    			-- Do not preserve the `final' values.
    			-- (from PDFA)
    		require -- from PDFA
    			same_inputs: greatest_input = fa.greatest_input
    			nb_states_large_enough: nb_states >= fa.nb_states + shift

    	interval (b, e: CHARACTER_8)
    			-- Create regular expression `b'..`e', or `b' if `b' = `e'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_built: not lexical_frozen
    			e_code_small_enough: e.code <= last_character_code
    			b_code_large_enough: b.code >= 0
    			b_before_e: b.code <= e.code

    	iteration (c: INTEGER_32)
    			-- Create regular expression *(`c'): zero or more
    			-- consecutive occurrences of `c'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			c_in_tool: c >= 1 and c <= last_created_tool

    	iteration1 (c: INTEGER_32)
    			-- Create regular expression +(`c'): one or more
    			-- consecutive occurrences of `c'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			c_in_tool: c >= 1 and c <= last_created_tool

    	iteration_n (n, c: INTEGER_32)
    			-- Create regular expression `n'(`c'):
    			-- exactly `n' consecutive occurrences of `c'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			n_large_enough: n > 0
    			c_in_tool: c >= 1 and c <= last_created_tool

    	optional (c: INTEGER_32)
    			-- Create regular expression [`c']:
    			-- optional `c'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			c_in_tool: c >= 1 and c <= last_created_tool

    	prepend_optional (p, s: INTEGER_32)
    			-- Create regular expression [`p']`s':
    			-- `s' appended to optional `p'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			p_in_tool: p >= 1 and p <= last_created_tool
    			s_in_tool: s >= 1 and s <= last_created_tool

    	pdfa_put (v: like pdfa_item; i: INTEGER_32)
    			-- Replace `i'-th entry, if in index interval, by `v'.
    			-- (from ARRAY)
    		require -- from TABLE
    			valid_key: valid_index (i)
    		require -- from TO_SPECIAL
    			valid_index: valid_index (i)
    		ensure then -- from INDEXABLE
    			insertion_done: pdfa_item (i) = v
    		ensure -- from TO_SPECIAL
    			inserted: pdfa_item (i) = v

    	put_expression (s: STRING_8; n: INTEGER_32; c: STRING_8)
    			-- Record the regular expression described by `s'
    			-- and associate it with token type `n' and name `c'.
    		require
    			source_long_enough: s.capacity > 0

    	put_keyword (s: STRING_8; exp: INTEGER_32)
    			-- Declare `s' as a keyword described by
    			-- the regular expression of code `exp'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			exp_selected: token_type_list /= Void and then token_type_list.has (exp)

    	put_nameless_expression (s: STRING_8; n: INTEGER_32)
    			-- Record the regular expression described
    			-- by `s', and associate it with token type `n'.
    			-- (from HIGH_BUILDER)
    		require -- from HIGH_BUILDER
    			source_long_enough: s.count > 0

    	recognize (s: STRING_8): INTEGER_32
    			-- Token_type of `s'; 0 if not recognized
    			-- (from LEX_BUILDER)

    	remove_case_sensitiveness
    			-- Remove case sensitiveness.
    			-- (from PDFA)
    		require -- from PDFA
    			z_possible: greatest_input >= lower_z

    	select_tool (i: INTEGER_32)
    			-- Select the `i'_th tool for inclusion in the main
    			-- regular expression.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			i_exist: i > 0 and i <= last_created_tool
    		ensure -- from LEX_BUILDER
    			i_selected: selected_tools.has (i)

    	set_word (word: STRING_8)
    			-- Create regular expression for `word':
    			-- synonym for concatenation (`w' `o' `r' `d').
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			word_not_empty: word.count >= 1

    	subcopy (other: ARRAY [like pdfa_item]; start_pos, end_pos, index_pos: INTEGER_32)
    			-- Copy items of `other' within bounds `start_pos' and `end_pos'
    			-- to current array starting at index `index_pos'.
    			-- (from ARRAY)
    		require -- from ARRAY
    			other_not_void: other /= Void
    			valid_start_pos: other.valid_index (start_pos)
    			valid_end_pos: other.valid_index (end_pos)
    			valid_bounds: (start_pos <= end_pos) or (start_pos = end_pos + 1)
    			valid_index_pos: valid_index (index_pos)
    			enough_space: (upper - index_pos) >= (end_pos - start_pos)

    	union (a, b: INTEGER_32)
    			-- Create regular expression for the multiple union
    			-- `a' | `a'+1 | .. | `b': matches any occurrence of
    			-- `a', or `a'+1, .., or `b'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			a_not_too_small: a >= 1
    			b_not_too_large: b <= last_created_tool
    			a_smaller_than_b: a <= b

    	union2 (a, b: INTEGER_32)
    			-- Create regular expression `a' | `b': union of
    			-- `a' and `b' (matches an occurrence of `a' or `b')).
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			a_in_tool: a >= 1 and a <= last_created_tool
    			b_in_tool: b >= 1 and b <= last_created_tool

    	up_to (word: STRING_8)
    			-- Create regular expression ->"`word'", which is a
    			-- set of any number of any characters ended by "`word'".
    			-- Example: "/* C comment */" matches (->"*/").
    			-- The difference between (+$. '*' '/') and
    			-- (->"*/") is that "*/..*/..*/" matches
    			-- the first but not the second.
    			-- The difference between
    			-- ((($.-'*') | ('*'($.-'/'))) +('*' '/') )
    			-- and "(->"*/")" is that "..**/" matches
    			-- the second but not the first.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			word_not_empty: word.count > 0
    			not_frozen: not lexical_frozen

    feature -- Removal

    	clear_all
    			-- Reset all items to default values.
    			-- (from ARRAY)
    		ensure -- from ARRAY
    			stable_lower: lower = old lower
    			stable_upper: upper = old upper
    			default_items: all_default

    	delete_transition (source, input_doc, target: INTEGER_32)
    			-- Delete transition from `source' to `target' on `input_doc'.
    			-- (from PDFA)
    		require -- from NDFA
    			source_in_automaton: source >= 1 and source <= nb_states
    			target_in_automaton: target >= 1 and target <= nb_states
    			possible_input_doc: input_doc >= 0 and input_doc <= greatest_input
    		require else -- from PDFA
    			source_in_automaton: source >= 1 and source <= nb_states
    			target_in_automaton: target >= 1 and target <= nb_states
    			possible_input_doc: input_doc >= 0 and input_doc <= greatest_input
    			good_successor: target = source + 1

    	discard_items
    			-- Reset all items to default values with reallocation.
    			-- (from ARRAY)
    		ensure -- from ARRAY
    			default_items: all_default

    	prune_all (v: LINKED_LIST [INTEGER_32])
    			-- Remove all occurrences of `v'.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from COLLECTION)
    		require -- from COLLECTION
    			prunable: prunable
    		ensure -- from COLLECTION
    			no_more_occurrences: not has (v)

    	remove
    			-- Remove the last regular expression
    			-- from the tool list.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			not_frozen: not lexical_frozen
    			at_least_one_regular: last_created_tool >= 1

    feature -- Resizing

    	automatic_grow
    			-- Change the capacity to accommodate at least
    			-- Growth_percentage more items.
    			-- (from RESIZABLE)
    		ensure -- from RESIZABLE
    			increased_capacity: capacity >= old capacity + old capacity * growth_percentage // 100

    	conservative_resize (min_index, max_index: INTEGER_32)
    			-- Rearrange array so that it can accommodate
    			-- indices down to `min_index' and up to `max_index'.
    			-- Do not lose any previously entered item.
    			-- (from ARRAY)
    		require -- from ARRAY
    			good_indices: min_index <= max_index
    		ensure -- from ARRAY
    			no_low_lost: lower = min_index or else lower = old lower
    			no_high_lost: upper = max_index or else upper = old upper

    	grow (i: INTEGER_32)
    			-- Change the capacity to at least `i'.
    			-- (from ARRAY)
    		ensure -- from RESIZABLE
    			new_capacity: capacity >= i

    feature -- Transformation

    	construct_dfa
    			-- Create an equivalent deterministic finite automaton.
    			-- (from NDFA)
    		require -- from NDFA
    			start_number_designated: start_number > 0

    feature -- Conversion

    	linear_representation: LINEAR [LINKED_LIST [INTEGER_32]]
    			-- Representation as a linear structure
    			-- (from ARRAY)

    	to_cil: NATIVE_ARRAY [LINKED_LIST [INTEGER_32]]
    			-- Address of actual sequence of values,
    			-- for passing to external (non-Eiffel) routines.
    			-- (from ARRAY)
    		require -- from ARRAY
    			is_dotnet: {PLATFORM}.is_dotnet
    		ensure -- from ARRAY
    			to_cil_not_void: Result /= Void

    	to_special: SPECIAL [LINKED_LIST [INTEGER_32]]
    			-- 'area'.
    			-- (from ARRAY)
    		ensure -- from ARRAY
    			to_special_not_void: Result /= Void

    feature -- Duplication

    	copy (other: like Current)
    			-- Reinitialize by copying all the items of `other'.
    			-- (This is also used by clone.)
    			-- (from ARRAY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_equal: is_equal (other)
    		ensure then -- from ARRAY
    			equal_areas: area.is_equal (other.area)

    	frozen deep_copy (other: like Current)
    			-- Effect equivalent to that of:
    			--		copy (`other' . deep_twin)
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, other)

    	frozen deep_twin: like Current
    			-- New object structure recursively duplicated from Current.
    			-- (from ANY)
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, Result)

    	frozen standard_copy (other: like Current)
    			-- Copy every field of `other' onto corresponding field
    			-- of current object.
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_standard_equal: standard_is_equal (other)

    	frozen standard_twin: like Current
    			-- New object field-by-field identical to `other'.
    			-- Always uses default copying semantics.
    			-- (from ANY)
    		ensure -- from ANY
    			standard_twin_not_void: Result /= Void
    			equal: standard_equal (Result, Current)

    	subarray (start_pos, end_pos: INTEGER_32): ARRAY [LINKED_LIST [INTEGER_32]]
    			-- Array made of items of current array within
    			-- bounds `start_pos' and `end_pos'.
    			-- (from ARRAY)
    		require -- from ARRAY
    			valid_start_pos: valid_index (start_pos)
    			valid_end_pos: end_pos <= upper
    			valid_bounds: (start_pos <= end_pos) or (start_pos = end_pos + 1)
    		ensure -- from ARRAY
    			lower: Result.lower = start_pos
    			upper: Result.upper = end_pos

    	frozen twin: like Current
    			-- New object equal to `Current'
    			-- twin calls copy; to change copying/twining semantics, redefine copy.
    			-- (from ANY)
    		ensure -- from ANY
    			twin_not_void: Result /= Void
    			is_equal: Result.is_equal (Current)

    feature -- Basic operations

    	frozen default: like Current
    			-- Default value of object's type
    			-- (from ANY)

    	frozen default_pointer: POINTER
    			-- Default value of type `POINTER'
    			-- (Avoid the need to write `p'.default for
    			-- some `p' of type `POINTER'.)
    			-- (from ANY)

    	default_rescue
    			-- Process exception for routines with no Rescue clause.
    			-- (Default: do nothing.)
    			-- (from ANY)

    	frozen do_nothing
    			-- Execute a null action.
    			-- (from ANY)

    feature -- Implementation

    	cursor: INTEGER_32
    			-- Position in description.
    			-- (from HIGH_BUILDER)

    	description: STRING_8
    			-- Description of the regular expression
    			-- (from HIGH_BUILDER)

    	initialized: BOOLEAN
    			-- Is analyzer initialized?
    			-- (from LEX_BUILDER)

    feature -- Input

    	no_token: INTEGER_32 is 0

    	read_grammar (token_file_name: STRING_8)
    			-- Create lexical analyzer for grammar in file of name
    			-- `token_file_name'. File structure:
    			-- One or more lines of the form
    			-- `name'  `regular_expression'
    			-- then a line beginning with two dashes --
    			-- then zero or more lines containing one keyword each.
    		ensure
    			analyzer_exists: analyzer /= Void

    feature {ANY} -- Input

    	retrieve_analyzer (file_name: STRING_8)
    			-- Retrieve analyzer from file named `file_name'.
    			-- (from LEX_BUILDER)

    feature -- Iteration

    	do_all (action: PROCEDURE [ANY, TUPLE [LINKED_LIST [INTEGER_32]]])
    			-- Apply `action' to every item.
    			-- Semantics not guaranteed if `action' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from ARRAY)
    		require -- from ARRAY
    			action_not_void: action /= Void

    	do_if (action: PROCEDURE [ANY, TUPLE [LINKED_LIST [INTEGER_32]]]; test: FUNCTION [ANY, TUPLE [LINKED_LIST [INTEGER_32]], BOOLEAN])
    			-- Apply `action' to every item that satisfies `test'.
    			-- Semantics not guaranteed if `action' or `test' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from ARRAY)
    		require -- from ARRAY
    			action_not_void: action /= Void
    			test_not_void: test /= Void

    	for_all (test: FUNCTION [ANY, TUPLE [LINKED_LIST [INTEGER_32]], BOOLEAN]): BOOLEAN
    			-- Is `test' true for all items?
    			-- (from ARRAY)
    		require -- from ARRAY
    			test_not_void: test /= Void

    	there_exists (test: FUNCTION [ANY, TUPLE [LINKED_LIST [INTEGER_32]], BOOLEAN]): BOOLEAN
    			-- Is `test' true for at least one item?
    			-- (from ARRAY)
    		require -- from ARRAY
    			test_not_void: test /= Void

    feature {ANY} -- Output

    	store_analyzer (file_name: STRING_8)
    			-- Store analyzer in file named `file_name'.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			initialized: initialized

    feature -- Output

    	io: STD_FILES
    			-- Handle to standard file setup
    			-- (from ANY)

    	out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of tagged_out.
    			-- (from ANY)

    	print (some: ANY)
    			-- Write terse external representation of `some'
    			-- on standard output.
    			-- (from ANY)

    	frozen tagged_out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of out.
    			-- (from ANY)

    	trace
    			-- Output an internal representation
    			-- of the current automaton.
    			-- (from PDFA)

    feature -- Platform

    	operating_environment: OPERATING_ENVIRONMENT
    			-- Objects available from the operating system
    			-- (from ANY)

    feature -- Status setting

    	distinguish_case
    			-- Make letter case significant in future tools.
    			-- Default is ignore case.
    			-- (from LEX_BUILDER)
    		ensure -- from LEX_BUILDER
    			case_sensitive

    	ignore_case
    			-- Make letter case not significant in future tools.
    			-- This is the default.
    			-- (from LEX_BUILDER)
    		ensure -- from LEX_BUILDER
    			not case_sensitive

    	keywords_distinguish_case
    			-- Make letter case not significant for keywords
    			-- in future tools.
    			-- Default is ignore case.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			no_tool_built: tool_list.is_empty
    		ensure -- from LEX_BUILDER
    			keywords_case_sensitive

    	keywords_ignore_case
    			-- Make letter case not significant for keywords
    			-- in future tools.
    			-- This is the default.
    			-- (from LEX_BUILDER)
    		require -- from LEX_BUILDER
    			no_tools_built: tool_list = Void or else tool_list.is_empty
    		ensure -- from LEX_BUILDER
    			not keywords_case_sensitive

    invariant
    		-- from HIGH_BUILDER
    	cursor_not_too_far: cursor <= description_length

    		-- from LEX_BUILDER
    	last_created: tool_list = Void or else last_created_tool = tool_list.count

    		-- from ARRAY
    	area_exists: area /= Void
    	consistent_size: capacity = upper - lower + 1
    	non_negative_count: count >= 0
    	index_set_has_same_count: valid_index_set

    		-- from RESIZABLE
    	increase_by_at_least_one: minimal_increase >= 1

    		-- from BOUNDED
    	valid_count: count <= capacity
    	full_definition: full = (count = capacity)

    		-- from FINITE
    	empty_definition: is_empty = (count = 0)
    	non_negative_count: count >= 0

    		-- from ANY
    	reflexive_equality: standard_is_equal (Current)
    	reflexive_conformance: conforms_to (Current)

    		-- from INDEXABLE
    	index_set_not_void: index_set /= Void

    indexing
    	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
    	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
    	source: "[
    		Eiffel Software
    		356 Storke Road, Goleta, CA 93117 USA
    		Telephone 805-685-1006, Fax 805-685-6869
    		Website http://www.eiffel.com
    		Customer support http://support.eiffel.com
    	]"

    end -- class METALEX