Eiffel : The Language

Preface:Meeting the challenge of software quality (in progress)
Preface to the third edition
About the status of Eiffel
About the language description
Contents
	1.1 OVERVIEW
	1.2 GENERAL PROPERTIES
	1.3 THE SOFTWARE PROCESS IN EIFFEL
		Clusters and the cluster model
		Seamlessness and reversibility
		Generalization and reuse
		Constant availability
		Compilation technology
		Quality and functionality
	1.4 HELLO WORLD
	1.5 THE STATIC PICTURE: SYSTEM ORGANIZATION
		Systems
		Classes
		Class relations
		The global inheritance structure
		Clusters
		External software
	1.6 THE DYNAMIC STRUCTURE: EXECUTION MODEL
		Objects, fields, values and references
		Features
		A simple class
		Creating and initializing objects
		Entities
		Calls
		Infix and prefix notation
		Type declaration
		Type categories
		Basic operations
		Deep operations and persistence
		Memory management
		Information hiding and the call rule
		Execution scenario
		Abstraction
	1.7 GENERICITY
	1.8 DESIGN BY CONTRACT, ASSERTIONS, EXCEPTIONS
		Design by Contract basics
		Expressing assertions
		Using assertions for built-in reliability
		Run-time assertion monitoring
		The short form of a class
		Exception handling
		Other applications of Design by Contract
	1.9 THE INHERITANCE MECHANISM
		Basic inheritance structure
		Redefinition
		Polymorphism
		Dynamic binding
		Deferred features and classes
		Applications of deferred classes
		Structural property classes
		Multiple inheritance and feature renaming
		Inheritance and contracts
		Join and uneffecting
		Changing the export status
		Flat and flat-short forms
		Repeated inheritance and selection
		Constrained genericity
		Assignment attempt
		Covariance and anchored declarations
	1.10 OTHER IMPORTANT MECHANISMS
		Once routines, shared objects, smart initialization and on-demand execution
		Constant attributes
		Instructions
		Lexical conventions
	1.11 CONCURRENCY AND FURTHER DEVELOPMENTS
		SCOOP
		Other developments
2 2 Syntax, validity and semantics
	2.1 OVERVIEW
	2.2 SYNTAX: COMPONENTS, SPECIMENS, CONSTRUCTS
		Syntax, BNF-E
		Component, construct, specimen
		Construct Specimen convention
		Construct Name convention
	2.3 TERMINALS, NON-TERMINALS AND TOKENS
		Terminal, non-terminal, token
	2.4 THE LEXICAL LEVEL
	2.5 PRODUCTIONS
		Production
		Kinds of production
		Aggregate productions
		Aggregate production
		Choice productions
		Choice production
		Repetition productions
		Repetition production, separator
		Using recursive productions
		One production per non-terminal
		Basic syntax description rule
		Non-production syntax rules
		Non-production syntax rule
	2.6 REPRESENTING TERMINALS
		Textual conventions
	2.7 VALIDITY
		Validity constraint
		Valid
	2.8 INTERPRETING THE CONSTRAINTS
	2.9 SEMANTICS
		Semantics
	2.10 CORRECTNESS
	2.11 TWO-TIER DEFINITION AND UNFOLDED FORMS
	2.12 THE CONTEXT OF EXECUTING SYSTEMS
		Execution terminology
	2.13 TEXTUAL CONVENTIONS
		Upper name, lower name
		Syntax (non-production): Semicolon Optionality rule
3 3 The architecture of Eiffel software
	3.1 OVERVIEW
	3.2 CLASSES
	3.3 CLASS TEXTS AND CLASS NAMES
	3.4 CLUSTERS
		Cluster, subcluster, contains directly, contains
		Terminal cluster, internal cluster
	3.5 SYSTEMS
		Universe
		System, root type name, root procedure name
		Type dependency
		Root type, root procedure, root class
4 4 Classes
	4.1 OVERVIEW
	4.2 OBJECTS
	4.3 FEATURES
	4.4 USE OF CLASSES
	4.5 THE CURRENT CLASS
		Current class
	4.6 CLASS TEXT STRUCTURE
	4.7 PARTS OF A CLASS TEXT
	4.8 ANNOTATING A CLASS
	4.9 CLASS HEADER
		Deferred classes
		Expanded classes
		Validity of a class header
		Expanded, frozen, deferred, effective class
	4.10 FORMAL GENERIC PARAMETERS
	4.11 OBSOLETE MARK
5 5 Features
	5.1 OVERVIEW
	5.2 THE ROLE OF FEATURES
	5.3 FEATURE CATEGORIES
	5.4 IMMEDIATE AND INHERITED FEATURES
		Inherited, immediate; origin; redeclaration; introduce
	5.5 FEATURES PART: EXAMPLE
	5.6 GRAPHICAL REPRESENTATION
	5.7 FEATURES PART: SYNTAX
	5.8 FORMS OF FEATURE
		Feature categories: overview
	5.9 FEATURE DECLARATIONS: EXAMPLES
	5.10 FEATURE DECLARATIONS: SYNTAX
	5.11 FEATURE BODIES
	5.12 HOW TO RECOGNIZE FEATURES
		Variable attribute
		Constant attribute
		Routine, function, procedure
		Command, query
	5.13 THE SIGNATURE OF A FEATURE
		Signature, argument signature of a feature
	5.14 FEATURE NAME
		Feature principle
		Syntax (non-production): Alias Syntax rule
		Operator feature, bracket feature, identifier-only
		Identifier of a feature name
		Same feature name, same operator, same alias
	5.15 OPERATOR FEATURES
	5.16 ASSIGNER PROCEDURES
	5.17 BRACKET FEATURE
	5.18 SYNONYMS AND MULTIPLE DECLARATION
		Synonym
		Unfolded form of a possibly multiple declaration
	5.19 VALIDITY OF FEATURE DECLARATIONS
	5.20 SCOPE OF NAMES
	5.21 OBSOLETE FEATURES
	5.22 NO IN-CLASS OVERLOADING
6 6 The inheritance relation
	6.1 OVERVIEW
	6.2 AN INHERITANCE PART
	6.3 FORM OF THE INHERITANCE PART
		Syntax (non-production): Feature adaptation
		Parent part for a type, for a class
	6.4 GRAPHICAL CONVENTION
	6.5 ANY
		Unfolded Inheritance Part of a class
	6.6 NONE
	6.7 RELATIONS INDUCED BY INHERITANCE
		Multiple, single inheritance
		Inherit, heir, parent
		Conforming, non-conforming parent
		Ancestor types of a type, of a class
		Ancestor, descendant
		Proper ancestor, proper descendant
	6.6 PROHIBITING CYCLES
	6.7 ADAPTING INHERITED FEATURES
	6.8 NON-CONFORMING INHERITANCE
	6.9 RENAMING
	6.10 FEATURES AND THEIR NAMES
		Final name, extended final name, final name set
		Inherited name
		Declaration for a feature
	6.11 INDEPENDENCE OF INHERITANCE AND EXPANSION
7 7 Clients and exports
	7.1 OVERVIEW
	7.2 ENTITIES
	7.3 CONVENTIONS
		Client relation between classes and types
		Client relation between classes
		Supplier
	7.4 SIMPLE CLIENTS
		Simple client
	7.5 EXPANDED CLIENTS
		Expanded client
	7.6 GENERIC CLIENTS
		Generic client, generic supplier
	7.7 INDIRECT CLIENTS
		Indirect client
	7.8 EXPORT CONTROLS AND INFORMATION HIDING
		Restricting exports
		Exporting to oneself
		Exporting to descendants
		Making a feature secret
		Adapting the export status of inherited features
		Expanding or restricting the export status
		The export status of features
		Client set of a Clients part
		Rules on setting the export status
		Client set of a feature
		Available for call, available
		Exported, selectively available, secret
	7.9 -DOCUMENTING THE CLIENT INTERFACE OF A CLASS
		Selecting features
		Contract views
		Secret, public
		Incremental contract view, short form
		Contract view, flat-short form
8 8 Routines
	8.1 OVERVIEW
	8.2 ROUTINE DECLARATION
	8.3 FORMAL ARGUMENTS
		Formal argument, actual argument
	8.4 USING A VARIABLE NUMBER OF ARGUMENTS
	8.5 ROUTINE BODY
		Once routine, once procedure, once function
	8.6 LOCAL VARIABLES AND RESULT
		Local variable
	8.7 EXTERNALS
	8.8 TYPES OF INSTRUCTIONS
9 9 Correctness and contracts
	9.1 OVERVIEW
	9.2 WHY ASSERTIONS?
	9.3 GRAPHICAL CONVENTION
	9.4 USES OF ASSERTIONS
	9.5 FORM OF ASSERTIONS
		Syntax (non-production): Assertion Syntax rule
		Precondition, postcondition, invariant
	9.6 UNFOLDING ASSERTIONS UNDER INHERITANCE
	9.7 ASSERTIONS ON INDIVIDUAL FEATURES
		Preconditions and postconditions
		The contract of a routine
		Contract, subcontract
		Constraints on routine assertions
		Availability of an assertion clause
		“Old” expression
		“Only” clause
		Unfolded feature list of an Only clause
		Unfolded Only clause
	9.8 CLASS INVARIANTS
	9.9 THE CONSISTENCY OF A CLASS
		Hoare triple notation (total correctness)
	9.10 CHECK INSTRUCTIONS
		Check-correct
	9.11 LOOP INVARIANTS AND VARIANTS
		Loop invariant and variant
		Loop-correct
	9.12 THE CORRECTNESS OF A CLASS
		Correctness (class)
	9.13 RULES OF RUN-TIME ASSERTION MONITORING
		Associated boolean expression
		Local unfolded form of an assertion
		Assertion monitoring
		Levels of assertion monitoring
		Invariant and qualified calls
10 10 Feature adaptation
	10.1 OVERVIEW
	10.2 TERMINOLOGY: REDECLARATION, REDEFINITION, EFFECTING
	10.3 REDECLARING INHERITED FEATURES: WHY AND HOW
		Redeclare, redeclaration
	10.4 FEATURE ADAPTATION CLAUSES
	10.5 WHY REDEFINE?
	10.6 REDEFINITION EXAMPLES
	10.7 THE REDEFINITION CLAUSE
	10.8 REDEFINITION IN THE SOFTWARE PROCESS
	10.9 CHANGING THE SIGNATURE
	10.10 THE NEED FOR ANCHORED DECLARATIONS
	10.11 DEFERRED FEATURES
	10.12 DEFERRED CLASSES FOR DESCRIBING ABSTRACTIONS
	10.13 DEFERRED CLASSES FOR SYSTEM DESIGN AND ANALYSIS
	10.14 EFFECTING A DEFERRED FEATURE
	10.15 PARTIALLY DEFERRED CLASSES AND PROGRAMMED ITERATION
	10.16 REDECLARATION AND TYPING
	10.17 REDECLARATION AND ASSERTIONS
	10.18 RULES ON INHERITED ASSERTIONS
		Unfolded form of an assertion
		Assertion extensions
		Covariance-aware form of an assertion extension
		Combined precondition, postcondition
	10.19 UNDEFINING A FEATURE
		Inherited as effective, inherited as deferred
	10.20 REDEFINITION AND EFFECTING
		Effect, effecting
		Redefine, redefinition
	10.21 THE JOIN MECHANISM
	10.22 MERGING EFFECTIVE FEATURES
	10.23 NAME CLASHES
		Name clash
	10.24 ADDING TO INHERITED BEHAVIOR: PRECURSOR
		The need for a precursor mechanism
		Precursor basics and examples
		Choosing between multiple precursors
		Precursor specification
		Relative unfolded form of a Precursor
		Unfolded form of a Precursor
	10.25 REDEFINITION AND UNDEFINITION RULES
	10.26 DEFERRED AND EFFECTIVE FEATURES AND CLASSES
		Effective, deferred feature
		Effecting
		Deferred class property
		Effective class property
	10.27 ORIGIN AND SEED
		Origin, seed
	10.28 REDECLARATION RULES
	10.29 RULES ON JOINING FEATURES
		Precursor (joined features)
		Transposition to a class or type
		Transposition
		Unfolded redeclaration
11 11 Types
	11.1 OVERVIEW
	11.2 THE ROLE OF TYPES
	11.3 WHERE TO USE TYPES
	11.4 HOW TO DECLARE A TYPE
	11.5 INSTANCES AND VALUES
	11.6 INSTANCES OF A CLASS
		Instance, direct instance of a class
	11.7 BASE CLASS, BASE TYPE AND TYPE SEMANTICS
		Base principle
		Base rule
		Base class and base type of an expression
	11.8 CLASS TYPES WITHOUT GENERICITY
	11.9 EXPANDED TYPES
		Role of expanded types
		Defining expanded types
		Expanded type, reference type
		Basic types
		Basic type
	11.10 ANCHORED TYPES
		Anchor, anchored type, anchored entity
		Anchored examples
		Anchoring to Current
		Anchoring to an expanded or generic
		Avoiding anchor cycles
		Anchor set; cyclic anchor
		Types and classes involved in a type
		Validity and semantics of anchored types
		Deanchored form of a type
	11.11 GUARANTEEING ATTACHMENT
		Attached, detachable
	11.12 STAND-ALONE TYPES
		Stand-alone type
12 12 Genericity
	12.1 OVERVIEW
	12.2 GENERIC CLASSES
	12.3 GENERIC CLASSES AND GENERIC DERIVATIONS
		Generic class; constrained, unconstrained
		Generic derivation, non-generic type
	12.4 SELF-INITIALIZING FORMAL PARAMETERS
		Self-initializing formal parameter
	12.5 CONSTRAINED AND UNCONSTRAINED GENERICITY
		Constraint, constraining types of a Formal_generic
	12.6 CONSTRAINED GENERICITY
	12.7 RULES ON CONSTRAINED GENERICITY
		Constraining creation features
	12.8 CONSTRAINTS AND CREATION
		Generic-creation-ready type
	12.9 RECURSIVE GENERIC CONSTRAINTS
	12.10 SEMANTICS OF GENERIC TYPES
		Base type of a single-constrained formal generic
		Base type of an unconstrained formal generic
		Reference or expanded status of a formal generic
	12.11 CURRENT TYPE, FEATURES OF A TYPE
		Current type
		Features of a type
	12.12 APPLYING GENERICITY TO TYPES
		Generic substitution
		Generic Type Adaptation rule
	12.13 THE CASE OF MULTIPLE CONSTRAINTS
		Generically constrained feature name
		Base type of a multi-constraint formal generic type
13 13 Tuples
	13.1 OVERVIEW
	13.2 TUPLES IN A NUTSHELL
	13.3 USING TUPLE TYPES AND TUPLES
		Type sequence of a tuple type
		Value sequences associated with a tuple type
	13.4 ANONYMOUS CLASSES
	13.5 CONFORMANCE ==== TO BE REWRITTEN
	13.6 MULTIPLE RESULTS AND VARIABLE NUMBERS OF ARGUMENTS
		Emulating multiple results
		Emulating a variable number of arguments
	13.7 TUPLES AS ARRAYS ==== TO BE REWRITTEN
14 14 Conformance
	14.1 OVERVIEW
	14.2 CONVERTIBILITY AND COMPATIBILITY
		Compatibility between types
		Compatibility between expressions
		Expression conformance
	14.3 APPLICATIONS OF CONFORMANCE
	14.4 EXPRESSION AND SIGNATURE CONFORMANCE
		Covariant argument
	14.5 DIRECT AND INDIRECT CONFORMANCE
		Conformance path
	14.6 CONFORMANCE TO A NON-GENERIC REFERENCE TYPE
	14.7 GENERICALLY DERIVED REFERENCE TYPES
	14.8 FORMAL GENERIC PARAMETER CONFORMANCE
	14.9 EXPANDED TYPE CONFORMANCE
	14.10 TUPLE TYPE CONFORMANCE
	14.11 ANCHORED TYPE CONFORMANCE
15 15 Convertibility
	Conversion procedure, conversion type
	Conversion query, conversion feature
	Converting to a class
	Converting to and from a type
	Converting “through”
	Explicit conversion
	Statically satisfied precondition
16 Repeated inheritance
	16.1 OVERVIEW
	16.2 CASES OF REPEATED INHERITANCE
		Repeated inheritance, ancestor, descendant
	16.3 THE TWO QUESTIONS OF REPEATED INHERITANCE
	16.4 SHARING AND REPLICATION
		Sharing, replication
	16.5 THE CASE OF REDECLARED FEATURES
	16.6 THE CASE OF ATTRIBUTES
	16.7 THE CASE OF CONFLICTING GENERIC DERIVATIONS
	16.8 KEEPING THE ORIGINAL VERSION OF A REDEFINED FEATURE
	16.9 USING REPLICATION: COUNTERS AND ITERATION
	16.10 THE SEMANTICS OF REPLICATION
	16.11 RETAINING VICTORS FROM ALTERNATIVE BRANCHES
	16.12 THE NEED FOR SELECT
	16.13 THE REPEATED INHERITANCE CONSISTENCY CONSTRAINT
		Version
		Multiple versions
		Dynamic binding version
	16.14 THE INHERITED FEATURES OF A CLASS
		Inherited features
		Precursor
17 17 Control structures
	17.1 OVERVIEW
	17.2 COMPOUND
	17.3 CONDITIONAL
		Secondary part
		Prevailing immediately
	17.4 MULTI-BRANCH CHOICE
		Inspect expression
		Interval
		Unfolded form of a multi-branch
		Unfolded form of an interval
		Inspect values of a multi-branch
	17.5 OBJECT TEST
	17.6 USING SELECTION INSTRUCTIONS PROPERLY
	17.7 LOOP
		Loop structure and properties
		Loop semantics
		Ensuring non-void references in a loop
	17.8 THE DEBUG INSTRUCTION
18 18 Attributes
	18.1 OVERVIEW
	18.2 GRAPHICAL REPRESENTATION
	18.3 VARIABLE ATTRIBUTES
	18.4 ATTRIBUTES IN FULL FORM
	18.5 CONSTANT ATTRIBUTES
	18.6 CONSTANT ATTRIBUTES WITH MANIFEST VALUES
19 19 Objects, values and entities
	19.1 OVERVIEW
	19.2 OBJECTS AND THEIR TYPES
	19.3 VALUES AND INSTANCES
		Reference, void, attached, attached to
	19.4 BASIC TYPES
	19.5 REFERENCE AND COPY SEMANTICS
		Object semantics
	19.6 COMPOSITE OBJECTS AND THEIR FIELDS
		Non-basic class, non-basic type, field
		Subobject, composite object
	19.7 REFERENCE ATOMICITY
	19.8 EXPRESSIONS AND ENTITIES
		Entity, variable, read-only
	19.9 SEMANTICS: EVALUATING AND INITIALIZING ENTITIES
		Self-initializing type
		Self-initializing variable
		Evaluation position, precedes
		Setter instruction
		Properly set variable
		Variable setting and its value
		Execution context
20 20 Creating objects
	20.1 OVERVIEW
	20.2 FORMS OF CREATION: AN OVERVIEW
		Creation operation
	20.3 BASIC FORM OF CREATION INSTRUCTIONS
	20.4 OMITTING THE CREATION PROCEDURE
	20.5 CREATORS AND INHERITANCE
	20.6 USING AN EXPLICIT TYPE
	20.7 RESTRICTING CREATION AVAILABILITY
	20.8 THE CASE OF EXPANDED TYPES
	20.9 CREATING INSTANCES OF FORMAL GENERICS
	20.10 PRECONDITIONS OF CREATION PROCEDURES
	20.11 CREATION SYNTAX AND VALIDITY
		Unfolded Creators part of a class
		Creation procedures of a class
		Creation procedure property
		Creation procedures of a type
		Available for creation; general creation procedure
		Creation target, creation type
		Unfolded form of a creation instruction
	20.12 CREATION SEMANTICS
	20.13 REMOTE CREATION
	20.14 CREATION EXPRESSIONS AND ANONYMOUS OBJECTS
		Properties of a creation expression
	20.15 GARBAGE COLLECTION
		Garbage Collection, not enough memory available
21 21 Comparing and duplicating objects
	21.1 OVERVIEW
	21.2 COPYING AN OBJECT
	21.3 EQUALITY EXPRESSIONS
		Object comparison features from ANY
		Copying and cloning features from ANY
		Deep equality, copying and cloning
		Effect of a copy operation
		Specification of default copy
		Tuning copy semantics
	21.4 CLONING AN OBJECT
		Using cloning
		Twin
		Specification of default cloning
		Cloning, types and factories
	21.5 DEEP COPYING AND CLONING
	21.6 OBJECT EQUALITY
	21.7 DEEP EQUALITY
22 22 Attaching values to entities
	22.1 OVERVIEW
	22.2 ROLE OF REATTACHMENT OPERATIONS
		Reattachment, source, target
	22.3 FORMS OF UNCONDITIONAL REATTACHMENT
	22.4 SYNTAX AND VALIDITY OF ASSIGNMENT
	22.5 THE STATUS OF FORMAL ROUTINE ARGUMENTS
	22.6 CONVERSIONS
	22.7 SEMANTICS OF REATTACHMENT
	22.8 AN EXAMPLE
	22.9 ABOUT REATTACHMENT
	22.10 EFFECT ON GENERIC PROGRAMMING
	22.11 POLYMORPHISM
		Dynamic type
		Polymorphic expression; dynamic type and class sets
	22.12 ASSIGNER CALL
	22.13 SEMI-STRICT OPERATORS
		The notion of strictness
		The need for semi-strict operators
		More on strictness
	22.14 CONDITIONAL REATTACHMENT
		Limitations of unconditional reattachment
	22.15 MEMORY MANAGEMENT
	22.16 SEMANTICS OF EQUALITY
23 23 Feature call
	23.1 OVERVIEW
	23.2 PARTS OF A CALL
	23.3 USES OF CALLS
	23.4 UNIFORM ACCESS
	23.5 OPERATOR AND BRACKET FORMS
	23.6 COMPLEX TARGETS
	23.7 CALL SYNTAX
		Unqualified, qualified call
	23.8 COMPONENTS OF A CALL
		Target of a call
		Target type of a call
		Feature of a call
	23.9 NON-OBJECT CALLS
		Imported form of a Non_object_call
	23.10 CLASS VALIDITY
		Export validity
		Argument validity
		Target validity and Void-Safe Eiffel
		Combining the rules
		Void-Unsafe
	23.11 INTRODUCTION TO CALL SEMANTICS
		Target Object
	23.12 DYNAMIC BINDING
		Dynamic feature of a call
	23.13 THE IMPORTANCE OF BEING DYNAMIC
	23.14 ONCE ROUTINES
		Once basics
		Once uses
		Predefined once keys
		Further once tuning
		Once routine semantics
		Freshness of a once routine call
		Latest applicable target and result of a non-fresh call
	23.15 ATTRIBUTES AND EXTERNALS
	23.16 THE MACHINERY OF EXECUTING CALLS
		Scheme for a routine call
		Current object and routine
		Naming the current object
	23.17 PRECISE CALL SEMANTICS
		Rule for non-once routines
		General call semantics
	23.18 CALLS AS EXPRESSIONS
		Type of a Call used as expression
24 24 Eradicating void calls
	24.1 OVERVIEW
	24.2 OVERALL SCHEME
	24.3 THE OBJECT TEST
		Object-Test Local
		Conjunctive, disjunctive, implicative; Term, semistrict term
		Scope of an Object-Test Local
	24.4 VOID TESTS
		Read-only void test
		Scope of a read-only void test
	24.5 CERTIFIED ATTACHMENT PATTERNS
		Certified Attachment Pattern
	24.6 ATTACHED EXPRESSIONS
		Attached expression
25 25 Typing-related properties
	25.1 OVERVIEW
		Catcall
	25.2 SYNTAX VARIANTS
	25.3 BASIC CONCEPTS
	25.4
	25.5 SYSTEM-LEVEL VALIDITY
	25.6 VIOLATING SYSTEM VALIDITY
	25.7 NOTES ON THE TYPE POLICY
	25.8 WHY DISTINGUISH?
	25.9 A LOOK AT THE DYNAMIC CLASS SET
	25.10 THE CALL VALIDITY RULE
	25.11 CREATION VALIDITY (SYSTEM-LEVEL)
26 26 Exception handling
	26.1 OVERVIEW
	26.2 WHAT IS AN EXCEPTION?
		Failure, exception, trigger
	26.3 EXCEPTION HANDLING POLICY
	26.4 RESCUE CLAUSES AND ORGANIZED PANIC
	26.5 THE DEFAULT RESCUE
	26.6 RETRY INSTRUCTIONS AND RESUMPTION
	26.7 SYSTEM FAILURE AND THE EXCEPTION HISTORY TABLE
	26.8 SYNTAX AND VALIDITY OF THE EXCEPTION CONSTRUCTS
	26.9 EXCEPTION CORRECTNESS
		Exception-correct
	26.10 SEMANTICS OF EXCEPTION HANDLING
		Rescue block
		Type of an exception
	26.11 EXCEPTION CORRECTNESS
	26.12 FINE-TUNING THE MECHANISM
		Ignoring, continuing an exception
	26.13 OVERVIEW
	26.14 PLATFORM-DEPENDENT SIGNAL CODES
	26.15 CLASS EXCEPTIONS
27 27 Agents, iteration and introspection
	27.1 OVERVIEW
	27.2 A QUICK PREVIEW
	27.3 FROM CALLS TO AGENTS
		Feature calls and their operands
		Operands of a call
		Operand position
		Delaying calls
		Agents and their operands
		Construction time, call time
	27.4 AGENT TYPES
	27.5 CALL AGENTS
		All-closed agents
		Keeping operands open
		The brace convention
		Omitting the argument list
		A summary of the possibilities
		Syntactical forms for a call agent
	27.6 USING AGENTS
		GUI programming: establishing a direct connection to the Business Model
		Integrating a function
		Iteration examples
	27.7 TWO ADVANCED EXAMPLES
		Error processing without the mess
		Once per object
	27.8 USING INLINE AGENTS
	27.9 ACCESSING FEATURE PROPERTIES
	27.10 THE BASE CLASS AND TYPE
	27.11 AGENT SYNTAX
		Syntax of call agents
		Syntax of inline agents
	27.12 AGENT VALIDITY
		Validity of call agents
		Target type of an call agent
		Validity of inline agents
		Associated feature of an inline agent
	27.13 AGENT SEMANTICS
		Call-agent equivalent of an inline agent
		Call-agent equivalent of an inline agent
		Open and closed operands
		Open and closed operands
		Open and closed operand positions
		Type and value of an agent expression
		Type of an agent expression
28 28 Expressions
	28.1 OVERVIEW
	28.2 GENERAL FORM OF EXPRESSIONS
	28.3 SUBEXPRESSIONS
		Subexpression, operand
	28.4 PARENTHESIZED EXPRESSIONS
	28.5 OPERATOR EXPRESSIONS
		Operator expression basics
		Operator expression syntax
		Precedence and Parenthesized Form
		Operator precedence levels
		Parenthesized Form of an expression
		Accounting for target conversion
		Target-converted form of a binary expression
		Operator expression validity and semantics
	28.6 SEMISTRICT BOOLEAN OPERATORS
		Semistrict operators
	28.7 BRACKET EXPRESSIONS
	28.8 THE EQUIVALENT DOT FORM
		Equivalent Dot Form of an expression
	28.9 BOOLEAN EXPRESSIONS
	28.10 ENTITIES
	28.11 THE TYPE OF AN EXPRESSION
		Type of an expression
	28.12 EXPRESSIONS AND THE SEMICOLON
29 29 Constants
	29.1 OVERVIEW
	29.2 GENERAL FORM OF CONSTANTS
		Syntax (non-production): Sign Syntax rule
		Syntax (non-production): Character Syntax rule
	29.3 FORCING A TYPE ON A CONSTANT
	29.4 THE TYPE OF A CONSTANT
		Type of a manifest constant
		Manifest value of a constant
	29.5 INTEGER CONSTANTS
	29.6 REAL CONSTANTS
	29.7 CHARACTER CONSTANTS
	29.8 MANIFEST STRINGS
		Syntax (non-production): Line sequence
		Syntax (non-production): Manifest String rule
		Basic manifest strings
		Line_wrapping_part
		Verbatim strings
		Prefix, longest break prefix, left-aligned form
		Choosing between basic and verbatim manifest strings
		“Once” string expressions
		Run-time model for manifest strings
	29.9 MANIFEST TUPLES
	29.10 SEMANTICS OF CONSTANT ATTRIBUTES
30 30 Basic types
	30.1 OVERVIEW
	30.2 EXPANSION STATUS
	30.3 BASIC CLASSES AND THEIR INHERITANCE STRUCTURE
		Basic types and their sized variants
		Sized variants of STRING
	30.4 BOOLEANS
	30.5 CHARACTERS
	30.6 INTEGERS
	30.7 REALS
	30.8 ADDRESSES
31 31 Interfacing with C, C++ and other environments
	31.1 OVERVIEW: THE COMPONENT COMBINATOR
	31.2 WHAT EIFFEL CAN DO WITH THE REST OF THE WORLD
	31.3 WHEN TO USE EXTERNAL SOFTWARE
	31.4 REGISTERED LANGUAGES AND THE ROLE OF C
	31.5 BASICS OF EXTERNAL ROUTINES
	31.6 EXECUTING AN EXTERNAL CALL
	31.7 ARGUMENT AND RESULT TRANSMISSION
	31.8 PASSING THE ADDRESS OF AN EIFFEL FEATURE
	31.9 SPECIAL INTERFACE SUBLANGUAGES
	31.10 GENERAL SUBLANGUAGE MECHANISMS
		Specifying an external routine signature
		Specifying external files
	31.11 THE C INTERFACE SUBLANGUAGE
		Syntax specification
		Specifying C code inline
		Controlling the Eiffel-C type correspondence
	31.12 THE C++ INTERFACE SUBLANGUAGE
		The syntax specification
		Conditions on C++ features
		Processing C++ features
		Extra argument
	31.13 WRAPPING C++ CLASSES: LEGACY++
		The role of Legacy++
		Calling Legacy++
		Result of applying Legacy++
		Legacy++ limitations
		Legacy++ example
	31.14 USING DYNAMIC LINKE LIBRARIES (DLLS)
		The static DLL sublanguage
	31.15 DESC: CALLING A DLL ROUTINE DETERMINED AT RUN TIME
		DESC overview
		Creating a library object
		Creating a routine object
		Type codes
		Calling a routine
		Accessing the result of a function
		Consistency requirements and protection against errors
		Sharing and freeing
	31.16 THE CECIL LIBRARY
		Cecil overview
		Cecil role and status
		Compiling for Cecil
		Avoiding abusive optimization
		Basic Cecil conventions
		Initializing the Eiffel 4 run-time
		Manipulating values of basic Eiffel types
		Manipulating Eiffel class types
		Accessing an Eiffel object
		Creating an Eiffel object
		Calling routines
		Requesting a non-existing routine
		Accessing field objects
		ISE Eiffel specifics
32 32 Lexical components
	32.1 OVERVIEW
	32.2 CHARACTER SETS
		Syntax (non-production): Character, character set
	32.3 CHARACTER CATEGORIES
		Letter, alpha_betic, numeric, alpha_numeric, printable
	32.4 GENERAL FORMAT
	32.5 BREAKS
		Break character, break
	32.6 COMMENTS
		Expected, free comment
		Syntax (non-production): “Blanks or tabs”, new line
		Syntax (non-production): Free Comment rule
		Header comment rule
	32.7 TEXT LAYOUT
		Symbol, word
		Syntax (non-production): Break rule
	32.8 LETTER CASE
	32.9 TOKEN CATEGORIES
	32.10 RESERVED WORDS
		Reserved word, keyword
		Syntax (non-production): Double Reserved Word rule
	32.11 SPECIAL SYMBOLS
		Special symbol
	32.12 IDENTIFIERS
		Syntax (non-production): Identifier
	32.13 OPERATORS
		Predefined operator
		Standard operator
		Operator symbol
		Free operator
	32.14 CHARACTERS
		Syntax (non-production): Manifest character
		Special characters and their codes
		Syntax (non-production): Percent variants
	32.15 STRINGS
		Syntax (non-production): String, simple string
	32.16 INTEGERS
	32.17 REAL NUMBERS
		Syntax (non-production): Real number
	33.1 OVERVIEW
	34.1 OVERVIEW
	34.2 LETTER CASE
	34.3 CHOICE OF NAMES
	34.4 GRAMMATICAL CATEGORIES FOR FEATURE NAMES
	34.5 GROUPING FEATURES
	34.6 HEADER COMMENTS
	34.7 OTHER COMMENTS
	34.8 EIFFEL NAMES IN COMMENTS
	34.9 LAYOUT
	34.10 OPTIONAL SEMICOLONS
	34.11 LEXICAL CONVENTIONS
	34.12 FONTS
	34.13 GUIDELINES FOR ANNOTATING CLASSES
	35.1 OVERVIEW
	35.2 INPUT AND OUTPUT FEATURES
	35.3 DUPLICATION AND COMPARISON ROUTINES
	35.4 OBJECT PROPERTIES
	35.5 PLATFORM-DEPENDENT FEATURES
	35.6 OTHER UNIVERSAL FEATURES
	36.1 OVERVIEW
	36.2 REPRESENTATION
	36.3 RESIZING
	36.4 BASIC ARRAY HANDLING
	36.5 COPYING AND COMPARING ARRAYS
	36.6 MANIFEST ARRAYS
	36.7 STRINGS
	37.1 OVERVIEW
	37.2 CLASSES FOR PERSISTENCE
	37.3 OBJECTS AND THEIR DEPENDENTS
	37.4 RETRIEVAL, TYPING, AND THE ASSIGNMENT ATTEMPT
	37.5 STORING AND RETRIEVING AN ENTIRE STRUCTURE
	37.6 CLASS STORABLE
	37.7 ENVIRONMENTS
	37.8 OPENING AND CLOSING ENVIRONMENTS
	37.9 RECORDING AND ACCESSING OBJECTS IN AN ENVIRONMENT
	37.10 THE OBJECTS OF AN ENVIRONMENT
	37.11 REQUESTING INFORMATION ABOUT ENVIRONMENTS
	37.12 STORING ENVIRONMENTS
	37.13 RETRIEVING AN ENVIRONMENT
	37.14 AN ENVIRONMENT EXAMPLE
	37.15 CLASS ENVIRONMENT
	38.1 OVERVIEW
	38.2 PURPOSE OF THE CLASS
	38.3 INPUT TECHNIQUES
	38.4 CLASS STANDARD_FILES
A A ELKS: The Eiffel Library Kernel Standard
	A.1 OVERVIEW
	A.2 CONTENTS OF THIS STANDARD
	A.3 COMPATIBILITY CONDITIONS
	A.4 REQUIRED CLASSES
	A.5 REQUIRED ANCESTRY LINKS
	A.6 SHORT FORMS OF REQUIRED CLASSES
	A.6.1 CLASS ANY
	A.6.2 CLASS TYPE
	A.6.3 CLASS PART_COMPARABLE
	A.6.4 CLASS COMPARABLE
	A.6.5 CLASS HASHABLE
	A.6.6 CLASS NUMERIC
	A.6.7 CLASS INTERVAL
	A.6.8 CLASS BOOLEAN
	A.6.9 CLASS CHARACTER
	A.6.10 CLASS INTEGER_GENERAL
	A.6.11 CLASS INTEGER
	A.6.12 CLASS INTEGER_8
	A.6.13 CLASS INTEGER_16
	A.6.14 CLASS INTEGER_64
	A.6.15 CLASS REAL_GENERAL
	A.6.16 CLASS REAL
	A.6.17 CLASS TYPED_POINTER
	A.6.18 CLASS POINTER
	A.6.19 CLASS ARRAY
	A.6.20 CLASS ANONYMOUS
	A.6.21 CLASS STRING
	A.6.22 CLASS STD_FILES
	A.6.23 CLASS FILE
	A.6.24 CLASS STORABLE
	A.6.25 CLASS MEMORY
	A.6.26 CLASS EXCEPTIONS
	A.6.27 CLASS ARGUMENTS
	A.6.28 CLASS PLATFORM
	A.6.29 CLASS ONCE_MANAGER
	A.6.30 CLASS ROUTINE
	A.6.31 CLASS PROCEDURE
	A.6.32 CLASS FUNCTION
	A.6.33 CLASS PREDICATE
B B Specifying systems in Lace (in progress)
C C On language design and evolution
E E A brief history of Eiffel
F F Language changes from the previous edition
	38.5 SEMANTIC EXTENSIONS AND CHANGES
G G Changes from early versions
H H An Eiffel tutorial
I I Eiffel bibliography (not done)
K K Syntax in alphabetical order
L L Reserved words, special symbols, operator precedence
M Syntax diagrams (not done)
	Eiffel Analysis, Design and Programming Language
	ECMA-367-3 (Draft)
	Standard
	ECMA-367
		Eiffel Analysis, Design and Programming Language
		1.1 Overview
		1.2 “The Standard”
		1.3 Aspects covered
		1.4 Aspects not covered
		2.1 Definition
		2.2 Compatibility and non-default options
		2.3 Departure from the Standard
		3.1 Earlier Eiffel language specifications
		3.2 Eiffel Kernel Library
		3.3 Floating point number representation
		3.4 Character set: Unicode
		3.5 Character set: ASCII
		3.6 Phonetic alphabet
		5.1 Standard elements
		5.2 Normative elements
		5.3 Rules on definitions
		5.4 Use of defined terms
		5.5 Unfolded forms
		5.6 Language description
		5.7 Validity: “if and only if” rules
		6.1 Name of the language
		6.2 Pronunciation
		7.1 Design principles
		7.2 Object-oriented design
		7.3 Classes
		7.4 Types
		7.5 Assertions
		7.6 Exceptions
		7.7 Genericity
		7.8 Inheritance
		7.9 Polymorphism and dynamic binding
		7.10 Combining genericity and inheritance
		7.11 Deferred classes
		7.12 Tuples and agents
		7.13 Type- and void-safety
		7.14 Putting a system together
			8.3.4 Syntax : Class names
			8.4.2 Syntax : Class declarations
			8.4.3 Syntax : Notes
			8.4.5 Syntax : Class headers
			8.4.8 Syntax : Obsolete marks
			8.5.2 Syntax : Feature parts
			8.5.4 Syntax : Feature declarations
			8.5.5 Syntax : New feature lists
			8.5.6 Syntax : Feature bodies
			8.5.14 Syntax : Feature names
			8.5.20 Syntax : Operators
			8.5.21 Syntax : Assigner marks
			8.6.1 Syntax : Inheritance parts
			8.6.14 Syntax : Rename clauses
			8.7.9 Syntax : Clients
			8.7.10 Syntax : Export adaptation
			8.8.2 Syntax : Formal argument and entity declarations
			8.8.5 Syntax : Routine bodies
			8.8.7 Syntax : Local variable declarations
			8.8.10 Syntax : Instructions
			8.9.1 Syntax : Assertions
			8.9.7 Syntax : “Old” postcondition expressions
			8.9.11 Syntax : “Only” postcondition clauses
			8.9.17 Syntax : Check instructions
			8.9.19 Syntax : Variants
			8.10.10 Syntax : Precursor
			8.10.15 Syntax : Redefinition
			8.10.18 Syntax : Undefine clauses
			8.11.1 Syntax : Types
			8.12.1 Syntax : Actual generic parameters
			8.12.2 Syntax : Formal generic parameters
			8.12.8 Syntax : Generic constraints
			8.13.1 Syntax : Tuple types
			8.13.2 Syntax : Manifest tuples
			8.15.6 Syntax : Converter clauses
			8.16.6 Syntax : Select clauses
			8.17.2 Syntax : Conditionals
			8.17.7 Syntax : Multi-branch instructions
			8.17.16 Syntax : Loops
			8.17.18 Syntax : Debug instructions
			8.18.1 Syntax : Attribute bodies
			8.19.8 Syntax : Entities and variables
			8.20.4 Syntax : Creators parts
			8.20.11 Syntax : Creation instructions
			8.20.18 Syntax : Creation expressions
			8.21.2 Syntax : Equality expressions
			8.22.2 Syntax : Assignments
			8.22.10 Syntax : Assigner calls
			8.23.2 Syntax : Feature calls
			8.23.3 Syntax : Actual arguments
			8.24.1 Syntax : Object test
			8.26.2 Syntax : Rescue clauses
			8.27.5 Syntax : Agents
			8.27.6 Syntax : Call agent bodies
			8.28.1 Syntax : Expressions
			8.28.4 Syntax : Operator expressions
			8.28.12 Syntax : Bracket expressions
			8.29.1 Syntax : Constants
			8.29.3 Syntax : Manifest constants
			8.29.10 Syntax : Manifest strings
			8.31.1 Syntax : External routines
			8.31.3 Syntax : Registered languages
			8.31.4 Syntax : External signatures
			8.31.7 Syntax : External file use
			8.31.10 Syntax : C externals
			8.31.13 Syntax : C++ externals
			8.31.16 Syntax : DLL externals
			8.32.7 Syntax : Comments
			8.32.28 Syntax : Integers
Index
	Symbols
	A
	B
	C
	D
	E
	F
	G
	H
	I
	J
	K
	L
	M
	N
	O
	P
	Q
	R
	S
	T
	U
	V
	W
	Y
	Z