The Perfect Developer Language Reference Manual
Version 5.0, September 2011
Disclaimer
The information in this publication is given in good faith but may contain errors and omissions. The contents of this document and the specifications of Perfect Developer and the Perfect language are subject to change without notice.
Contents
1.1 Purpose of this manual
1.2 Status of this edition
1.3 Organization
1.4 Syntax used to describe the grammar of Perfect
2. Goals and principles of the language
3.1 Overview
3.2 Character set
3.3 Comments
3.4 White space
3.5 Multi-character tokens
3.6 Reserved words
3.7 Identifiers
3.8 Character literals
3.9 String literals
3.10 Integer literals
3.11 Real literals
4.1 Overview
4.2 Concepts of type4.3 Predefined classes
4.4 Predefined types
4.5 Literals for predefined classes
4.6 Class declarations4.6.1 Enumeration generator
4.6.2 Tag generator
4.6.3 Abstract class declarations4.7 Type expressions
4.8 Instantiating class templates
4.9 Constrained types
4.10 United types
4.11 Union of all derived classes
4.12 Reference types
4.13 Type naming
4.14 Predefined class templates4.14.3 Sequences
4.14.4 Pairs
4.14.5 Triples
4.14.6 Mappings4.15.1 Overview
4.15.2 Fundamental type relations
4.15.3 Examples
5.1 Overview
5.2 Functions, Selectors and Constructors
5.3 Operators5.2.1 Using functions and selectors
5.2.2 Using constructors5.4 Other expression constructs5.3.1 Unary operators
5.3.2 Binary operators
5.3.3 Equality operator
5.3.4 Rank operator
5.3.5 Type comparison operator
5.3.6 Operator precedence
5.3.7 Suggested operator pronunciation5.5 Writable, Limited writable and Non-writable expressions5.4.1 Operators on types
5.4.2 Brackets, temporary names, assertions and conditionals
5.4.3 Choosing
5.4.4 Transforms
5.4.5 Quantified expressions
5.4.6 Cast expression
5.4.7 Type widening expression
5.4.8 Type enquiry expression
5.4.9 Subclass expression
5.4.10 Subjunctive expression
5.4.11 Over expression
5.4.12 Heap expression
5.4.13 Value expression
5.4.14 Converting between types
5.4.15 Scope resolution
5.4.16 "?" expression
5.6 Primed expressions
6.1 Declarations
6.2 Constant declaration
6.3 Heap declarations
6.4 Variable declarations
6.5 Function declarations6.5.1 Syntax of function declarations
6.5.2 Polymorphic function declarations
6.5.3 Function usage6.6.1 Syntax of operator declarations
6.6.2 Comparison operator declarations
6.6.3 Declaring operator properties6.8 Schema declarations6.9 Property declarations6.9.1 Syntax of property declarations6.10 Axiom declaration
6.11 Type compatibility of parameters and results6.11.1 Type compatibility of undecorated parameters
6.11.2 Type compatibility of parameters decorated with "!"
6.11.3 Type compatibility of repeated parameter groups
6.11.4 Type compatibility of result values6.12 Function, Operator, Selector and Schema Overloading
6.13 Modules
7.1 Abstract class declaration
7.1.1 Syntax
7.1.2 Class specification
7.1.3 Inherits part
7.1.4 Abstract members
7.1.5 Internal members
7.1.6 Confined and Interface members
7.1.7 Rank and equality declarations
7.1.8 Nonmember declarations
7.1.9 Recursive class declarations
7.1.10 Class invariants
7.1.11 History invariants
7.1.12 Storable classes7.2 Constructors
7.3 Derived abstract classes7.3.1 Inheriting another abstract class
7.3.2 Overriding inherited declarations
7.3.3 Accessing overridden members
7.3.4 Deferred abstract classes
8. Implementations and Proof Lists
8.1 Overview
8.2 Syntax of implementations8.2.1 Declarations
8.2.2 Let-statement
8.2.3 Postcondition statement
8.2.4 Labels
8.2.5 Jumps
8.2.6 Loops
8.2.7 Assertions
8.2.8 Conditional statement
8.2.9 Block statements
8.2.10 Value completors
8.2.11 State completors
8.2.12 Throw statements
8.2.13 Try statements
9. Scopes, Overloading and Binding
9.1 Overview
9.2 Name spaces
9.3 Definition of the various declaration contexts
9.4 Overloading class and type names
9.5 Overloading variable and function names
9.6 Overloading operator and selector symbols
9.7 How binding is defined in Perfect
9.8 Uniting and Core
9.9 Definition of the general dictionary for various regions9.9.1 Global declaration list
9.9.2 General dictionary for declarations of functions, operators and selectors
9.9.3 General dictionary for declarations of schemas
9.9.4 General dictionary for declarations of constructors defined using a result expression
9.9.5 General dictionary for declarations of constructors defined without using a result expression
9.9.6 General dictionary for implementations
9.9.7 General dictionary for the inherits-part of a class declaration
9.9.8 General dictionary for member declaration regions of a class declaration
9.9.9 Bracketed expressions
9.9.10 Expressions involving bound variables9.10 Class member dictionaries
9.11 Access restrictions
9.12 Forward referencing and references to declarations in imported files
10. Interface to other languages
11.1 Order and sorting
11.2 Input/Output
11.3 Debugging functions11.2.1 Console input / output
11.2.2 File operations
11.2.3 Disk operations
11.2.4 Opening sockets
11.2.5 Other environment methods
11.2.6 Runtime checks and profiling
11.4 Streams
11.5 Serialization
11.6 Character encoding and decoding
12. Application Startup and Initialization
12.1 Program entry point written in Perfect
12.2 Program entry point not written in Perfect
debugPrint
debugHalt
flatten
interleave
loadObject
max
min
storeObject
swapanything
bag of X
bool
byte
ByteData
ByteInputStream
ByteOutputStream
char
CharDecoder
CharEncoder
CharEncoderDecoder
Comparator of X
DebugType
Environment
FileAttribute
FileError
FileHandle
FileInputStream
FileMode
FileModeType
FilePath
FileStats
FileOutputStream
GuardedObject of X
InputStream
int
map of (X -> Y)
nat
OsInfo
OsType
OutputStream
pair of (X, Y)
rank
real
ReverseComparator of X
seq of X
SerialError
SerialErrorType
set of X
SimpleComparator of X
SocketError
SocketMode
StandardInputStream
StandardOutputStream
Storable
string
Time
triple of (X, Y, Z)
void
Perfect Language Reference Manual, Version 5.0, September 2011.
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