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ALGOL Programming Reference Manual, Volume 1: Basic Implementation
CHECKPOINT Statement
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Example of a CHECKPOINT Statement
BOOL := CHECKPOINT(DISK,PURGE)
Contents
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Program Structure
Documentation Updates
What's New?
Overview of the Language
Program Unit
Elements of an ALGOL Program
Scope of an Identifier
Language Components
Basic Symbol
Identifier
Number
Number Ranges
Compiler Number Conversion
Exponents
Remark
String Literal
Character Size
String Code
String Length
ASCII Strings
Quotation Mark
Dollar Sign
Declarations
ALPHA Declaration
ARRAY Declaration
PRIVATE and PUBLIC Specifiers
LONG Arrays
OWN Arrays
Identifiers
Array Class
Bound Pair List
Examples of ARRAY Declarations
ARRAY REFERENCE Declaration
Identifiers
Lower Bounds
Examples of ARRAY REFERENCE Declarations
BOOLEAN Declaration
Equation Part
Boolean Simple Variable Values
Examples of BOOLEAN Declarations
COMPLEX Declaration
Complex Variables
Examples of COMPLEX Declarations
CONNECTION BLOCK REFERENCE VARIABLE Declaration
CONNECTION BLOCK TYPE Declaration
Examples of CONNECTION BLOCK TYPE Declaration
CONNECTION LIBRARY Declaration
Explanation
DEFINE Declaration
Formal Symbol Part
Define Invocation
Examples of DEFINE Declarations
DINTEGER Declaration
Declaration of Simple Variables
Examples of DINTEGER Declarations
DIRECT ARRAY Declaration
Declaring Direct Arrays
Examples of DIRECT ARRAY Declarations
DOUBLE Declaration
Declaration of Simple Variables
Examples of DOUBLE Declarations
DUMP Declaration
Control Part
Form of Output
Examples of DUMP Declarations
EPILOG PROCEDURE Declaration
Restrictions on Epilog Procedures
Example of an Epilog Procedure
EVENT and EVENT ARRAY Declarations
Event Designator
Examples of EVENT and EVENT ARRAY Declarations
EXCEPTION PROCEDURE Declaration
Restrictions on Exception Procedures
Example of an EXCEPTION PROCEDURE Declaration
EXPORT Declaration
Library Entry Point Types and Parameters
Conditions in Which Errors Can Occur
Examples of EXPORT Declarations
EXPORTLIBRARY Declaration
FILE Declaration
Identifiers
Attribute Specifications
Examples of FILE Declarations
FORMAT Declaration
In-Out Part
Format Part
Editing Phrases
Editing Modifiers
Examples of FORMAT Declarations
FORWARD REFERENCE Declaration
Order of Referencing
Examples of FORWARD REFERENCE Declarations
IMPORTED Declaration
Examples of IMPORTED Declaration
INTEGER Declaration
Equation Part
Examples of INTEGER Declarations
INTERLOCK and INTERLOCK ARRAY Declarations
Interlock Designator
INTERRUPT Declaration
Interrupting a Program
Examples of INTERRUPT Declarations
LABEL Declaration
Using Label Identifiers
Examples of LABEL Declarations
LIBRARY Declaration
Library Attribute Specifications
Examples of LIBRARY Declarations
LIST Declaration
List Elements
Examples of LIST Declarations
MONITOR Declaration
Monitor Elements
Examples of MONITOR Declarations
OUTPUTMESSAGE ARRAY Declaration
Output Message
Translators' Help Text
Examples of OUTPUTMESSAGE ARRAY Declarations
PENDING PROCEDURE Declaration
PENDING PROCEDURE ACTUAL Declaration
PICTURE Declaration
String Literals
Introduction
Introduction Codes
Characters Used by Picture Symbols
Flip-Flops Used by Picture Symbols
Character Fields
Picture Skip Characters
Control Character
Single Picture Characters
Picture Characters
Examples of PICTURE Declarations
POINTER Declaration
OWN Pointers
Lex Level Restriction Part
Examples of POINTER Declarations
PROCEDURE Declaration
Identifiers
Formal Parameter Part
Specification
Allowed Formal and Actual Parameters
Parameter Matching
Examples of PROCEDURE Declarations
PROCEDURE REFERENCE Declaration
Identifiers
Example of a PROCEDURE REFERENCE Declaration
PROCEDURE REFERENCE ARRAY Declaration
Placement of Procedure Reference Arrays
Example of a PROCEDURE REFERENCE ARRAY Declaration
PROLOG PROCEDURE Declaration
REAL Declaration
Declaration of Simple Variables
Examples of REAL Declarations
SIMPLE VARIABLE Declaration
STRING Declaration
STRING Type
Examples of STRING Declarations
STRING ARRAY Declaration
String Array Type
Examples of STRING ARRAY Declarations
STRUCTURE BLOCK ARRAY Declaration
STRUCTURE BLOCK REFERENCE VARIABLE Declaration
STRUCTURE BLOCK TYPE Declaration
STRUCTURE BLOCK VARIABLE Declaration
SWITCH FILE Declaration
Switch File List
Example of a SWITCH FILE Declaration
SWITCH FORMAT Declaration
Switch Format List
Examples of SWITCH FORMAT Declarations
SWITCH LABEL Declaration
Switch Label List
Examples of SWITCH LABEL Declarations
SWITCH LIST Declaration
List Designator
Example of a SWITCH LIST Declaration
TASK and TASK ARRAY Declarations
Task and Task Array Designator
Examples of TASK and TASK ARRAY Declarations
TRANSLATETABLE Declaration
Translation Specifier
Translate Table Indexing
Examples of TRANSLATETABLE Declarations
TRUTHSET Declaration
Membership Expression
Truth Set Test
Examples of TRUTHSET Declarations
VALUE ARRAY Declaration
Constants
Example of a VALUE ARRAY Declaration
Statements
ACCEPT Statement
ACCEPT Parameters
Examples of ACCEPT Statements
ASSIGNMENT Statement
Arithmetic Assignment
Array Reference Assignment
Boolean Assignment
Complex Assignment
Connection Block Reference Assignment
Mnemonic Attribute Assignment
Pointer Assignment
Procedure Reference Assignment
String Assignment
Structure Block Reference Assignment
Task Assignment
ATTACH Statement
Attachment of Interrupts
Examples of ATTACH Statements
AWAITOPEN Statement
PARTICIPATE Option
CONNECTTIMELIMIT Option
Examples of AWAITOPEN Statements
CALL Statement
Coroutines
Examples of a CALL Statement
CANCEL Statement
Delinking a Library from a Program
Example of a CANCEL Statement
CASE Statement
Unnumbered Statement List
Numbered Statement List
Examples of CASE Statements
CAUSE Statement
Causes of Events
Examples of CAUSE Statements
CAUSE1 Statement
CAUSEANDRESET Statement
Relationship to CAUSE Statement
Examples of CAUSEANDRESET Statements
CHANGEFILE Statement
Directory Element
Example of a CHANGEFILE Statement
CHECKPOINT Statement
Disposition Option
Restarting a Job
Locking
Rerunning Programs
Example of a CHECKPOINT Statement
CLOSE Statement
CLOSE Options
PORT CLOSE Option
Examples of CLOSE Statements
CONTINUE Statement
Coroutines
Examples of CONTINUE Statements
DEALLOCATE Statement
Deallocation with Arrays
Examples of DEALLOCATE Statements
DETACH Statement
Detaching Interrupts
Example of a DETACH Statement
DISABLE Statement
Disabling Interrupts
Examples of DISABLE Statements
DISPLAY Statement
Pointer and String Expressions
Examples of DISPLAY Statements
DO Statement
Evaluation of Boolean Expression
Examples of DO Statements
ENABLE Statement
Enabling Interrupts
Examples of ENABLE Statements
ERASE Statement
EVENT Statement
EXCHANGE Statement
Conditions for Execution of the EXCHANGE Statement
Examples of EXCHANGE Statements
FILL Statement
Initialization
Examples of FILL Statements
FIX Statement
FIX Statement as a Boolean Function
Examples of FIX Statements
FOR Statement
Forms of the FOR Statement
Examples of FOR Statements
FREE Statement
FREE Statement as a Boolean Function
Examples of FREE Statements
FREEZE Statement
FREEZE Statements in Library Procedures
Examples of FREEZE Statement
GO TO Statement
Bad GO TO
Examples of GO TO Statements
I/O Statement
Normal I/O
Direct I/O
IF Statement
Forms of the IF Statement
Examples of IF Statements
INTERRUPT Statement
INVOCATION Statement
LIBERATE Statement
Execution of Implicit CAUSE Statement
Examples of LIBERATE Statements
LOCK File Statement
Lock Options
Examples of LOCK File Statements
LOCK Interlock Statement
Timeout Option
Examples of LOCK Interlock Statements
MERGE Statement
Merge Options
Example of a MERGE Statement
MESSAGESEARCHER Statement
Finding a Requested Message
MESSAGESEARCHER Statement as an Arithmetic Function
Example of a MESSAGESEARCHER Statement
MLSACCEPT Statement
MLSACCEPT Used for Data Input
MLSACCEPT Used as a Boolean Function
Additional MLSACCEPT Options
Example of an MLSACCEPT Statement
MLSDISPLAY Statement
MLSTRANSLATE Statement
MLSTRANSLATE Options
MLSTRANSLATE as an Arithmetic Function
Example of an MLSTRANSLATE Statement
MULTIPLE ATTRIBUTE ASSIGNMENT Statement
Assignment of Values
Examples of MULTIPLE ATTRIBUTE ASSIGNMENT Statements
ON Statement
Enabling ON Statements
Fault List
Fault Information Part
Fault Stack History
Fault Action
Disabling ON Statement
Fault Action with No ON Statement
Examples of ON Statements
OPEN Statement
OPEN Options
Examples of OPEN Statements
POINTER Statement
POINTER Statement Options
Temporary Storage
PROCEDURE INVOCATION Statement
Calling Procedures with Parameters
Examples of PROCEDURE INVOCATION Statements
PROCEDURE REFERENCE Statement
Using Procedure References
Example of a PROCEDURE REFERENCE Statement
PROCESS Statement
Initiation of an Asynchronous Process
Critical Block
Examples of PROCESS Statements
PROCURE Statement
Testing the Available State
Sharing Resources Among Programs
Examples of PROCURE Statements
PROGRAMDUMP Statement
PROGRAMDUMP Options
Programdump Destination Options
Relation to OPTION Task Attribute
Retrieval of Binding Information
Examples of PROGRAMDUMP Statements
READ Statement
File Part
I/O Option or Carriage Control
Subfile Specification
Core-to-Core Part
Core-to-Core Blocking Part
Format and List Part
Action Labels or Finished Event
Data Format for Free-Field Input
Examples of READ Statements
REMOVEFILE Statement
Directory Element
REMOVEFILE Statement as a Boolean Function
Family Substitution
Example of a REMOVEFILE Statement
REPLACE Statement
Source Part List
Source Part Combinations
String Literal Source Parts
Arithmetic Expression Source Parts
Pointer Expression (<source>) Source Parts
Source Parts with Boolean Conditions
Other Source Parts
Examples of REPLACE Statements
REPLACE FAMILY-CHANGE Statement
Specification of Valid Stations
Examples of REPLACE FAMILY-CHANGE Statements
REPLACE POINTER-VALUED ATTRIBUTE Statement
Specification of the Simple Source
Examples of REPLACE POINTER-VALUED ATTRIBUTE Statements
RESET Statement
WAIT and WAITANDRESET Statements
Examples of RESET Statements
RESIZE Statement
Array Row Resize Parameters
Special Array Resize Parameters
Run-Time Error Messages
Examples of RESIZE Statements
RESPOND Statement
RESPOND Statement Options
Examples of RESPOND Statements
REWIND Statement
Effects on Designated Files
Example of a REWIND Statement
RUN Statement
Initiating Procedures
Examples of a RUN Statement
SCAN Statement
Scan Part Combinations
Scan Parts without Count Parts
Scan Parts with Count Parts
Examples of SCAN Statements
SEEK Statement
SEEK Statement as a Boolean Function
Example of a SEEK Statement
SET Statement
SET Statement Options
Examples of SET Statements
SETABSTRACTVALUE Statement
Setting the File Attribute
Examples of SETABSTRACTVALUE Statements
SORT Statement
Output Option
Input Option
Number of Tapes
Compare Procedure
Record Length
Size Specifications
Restart Specifications
Arrays in Sort Procedures
Examples of SORT Statements
SPACE Statement
SPACE Statement as a Boolean Function
Examples of SPACE Statements
SWAP Statement
Variable Type Matching
Example of a SWAP Statement
THRU Statement
Value of the Arithmetic Expression
Examples of THRU Statements
TRY Statement
TRY Normal Form
TRY Limited Form
Considerations for Use
UNLOCK Statement
Examples of UNLOCK Statements
WAIT Statement
Wait Option List
WAIT Parameter List
Start Index
Direct Array Row
Examples of WAIT Statements
WAITANDRESET Statement
WAITANDRESET Statement as an Arithmetic Function
Examples of WAITANDRESET Statements
WHEN Statement
Characteristics of the Time Option
Examples of WHEN Statements
WHILE Statement
Execution of the WHILE Statement
Examples of WHILE Statements
WRITE Statement
I/O Option or Carriage Control
Write Subfile Specification
Format and List Part
Action Labels or Finished Event
Examples of WRITE Statements
ZIP Statement
Expressions
Arithmetic Expressions
Arithmetic Operators
Arithmetic Primaries
Bit Manipulation Expressions
Concatenation Expression
Partial Word Expression
Boolean Expressions
Logical Operators
IS and ISNT Operators
Relational Operators
Boolean Primaries
Boolean Value
Arithmetic Relation
Complex Relation
String Relation
Pointer Relation
String Expression Relation
Table Membership
Case Expression
Complex Expressions
Conditional Expressions
Designational Expressions
Function Expressions
Arithmetic Function Designator
Boolean Function Designator
Complex Function Designator
Pointer Function Designator
String Function Designator
NULL Value
Pointer Expression
String Expression
TRY Expression
Intrinsic Functions
Intrinsic Names by Type Returned
Arithmetic Intrinsic Names
Boolean Intrinsic Names
Complex Intrinsic Names
Pointer Intrinsic Names
String Intrinsic Names
Intrinsic Function Descriptions
ABS Function
ACCEPT Statement
ARCCOS Function
ARCSIN Function
ARCTAN Function
ARCTAN2 Function
ARRAYSEARCH Function
ATANH Function
AVAILABLE Function
BOOLEAN Function
CABS Function
CCOS Function
CEXP Function
CHANGEFILE Statement
CHECKPOINT Statement
CHECKSUM Function
CLN Function
CLOSE Statement
COMPILETIME Function
COMPLEX Function
CONJUGATE Function
COS Function
COSH Function
COTAN Function
CSIN Function
CSQRT Function
DABS Function
DALPHA Function
DAND Function
DARCCOS Function
DARCSIN Function
DARCTAN Function
DARCTAN2 Function
DCOS Function
DCOSH Function
DECIMAL Function
DELINKLIBRARY Function
DELTA Function
DEQV Function
DERF Function
DERFC Function
DEXP Function
DGAMMA Function
DIMP Function
DINTEGER Function
DINTEGERT Function
DLGAMMA Function
DLN Function
DLOG Function
DMAX Function
DMIN Function
DNABS Function
DNORMALIZE Function
DNOT Function
DOR Function
DOUBLE Function
DREAL Function
DROP Function
DSCALELEFT Function
DSCALERIGHT Function
DSCALERIGHTT Function
DSIN Function
DSINH Function
DSQRT Function
DTAN Function
DTANH Function
ENTIER Function
ERF Function
ERFC Function
EXP Function
FIRST Function
FIRSTONE Function
FIRSTWORD Function
FIX Statement
FREE Statement
GAMMA Function
HAPPENED Function
HEAD Function
IMAG Function
INTEGER Function
INTEGERT Function
ISVALID Function
LENGTH Function
LINENUMBER Function
LINKLIBRARY Function
LISTLOOKUP Function
LN Function
LNGAMMA Function
LOCK Interlock Function
LOCKSTATUS Function
LOG Function
MASKSEARCH Function
MAX Function
MESSAGESEARCHER Statement
MIN Function
MLSACCEPT Statement
MLSDISPLAY Statement
MLSTRANSLATE Statement
NABS Function
NORMALIZE Function
OFFSET Function
ONES Function
OPEN Statement
POINTER Function
POT Function
PROCESSID Function
RANDOM Function
READ Statement
READLOCK Function
READYCL Function
REAL Function
REMAININGCHARS Function
REMOVEFILE Statement
REPEAT Function
SCALELEFT Function
SCALERIGHT Function
SCALERIGHTF Function
SCALERIGHTT Function
SECONDWORD Function
SEEK Statement
SETACTUALNAME Function
SIGN Function
SIN Function
SINGLE Function
SINH Function
SIZE Function
SPACE Statement
SQRT Function
STRING Function
TAIL Function
TAKE Function
TAN Function
TANH Function
THIS Function
THISCL Function
TIME Function
TRANSLATE Function
UNLOCK Statement
UNREADYCL Function
USERDATA Function
USERDATALOCATOR Function
USERDATAREBUILD Function
VALUE Function
WAIT Statement
WAITANDRESET Statement
WRITE Statement
Compiling Programs
Files Used by the Compiler
Input Files
Output Files
Source Record Format
Compiler Control Options
Compiler Control Records
Option Descriptions
Compile-Time Facility
Compile-Time Variable
Compile-Time Statements
BEGIN Statement
DEFINE Statement
FOR Statement
IF Statement
INVOKE Statement
LET Statement
THRU Statement
WHILE Statement
Extension to the Define Declaration
Compile-Time Compiler Control Options
CTLIST Option
CTMON Option
CTTRACE Option
LISTSKIP Option
Library Facility
Operating the Components of the Library Facility
Library Programs
Calling Programs
Library Directories and Templates
Library Initiation
Linkage Provisions
Discontinuing Linkage
Error Handling
Creating Libraries
Referencing Libraries
Library Attributes
Entry Point Type Matching
Parameter Passing
Library Examples
Library: OBJECT/FILEMANAGER/LIB
Calling Program #1
Library: OBJECT/SAMPLE/LIBRARY
Library: OBJECT/SAMPLE/DYNAMICLIB
Calling Program #2
Library: MCPSUPPORT
CONVERTDATEANDTIME Procedure
TIMEZONENAME Procedure
TIMEZONEOFFSET Procedure
Using the EVENT_STATUS Entry Point
Internationalization
Accessing the Internationalization Features
Using the Ccsversion, Language, and Convention Default Settings
Understanding the Hierarchy for Default Settings
Understanding the Components of the MLS Environment
Coded Character Sets and Ccsversions
Providing Support for Natural Languages
Providing Support for Business and Cultural Conventions
Summary of CENTRALSUPPORT Library Procedures
Library Calls
Parameter Categories
Procedure Descriptions
CCSINFO
CCSTOCCS_TRANS_TABLE
CCSTOCCS_TRANS_TABLE_ALT
CCSTOCCS_TRANS_TEXT
CCSTOCCS_TRANS_TEXT_COMPLEX
CCSVSN_NAMES_NUMS
CENTRALSTATUS
CNV_ADD
CNV_CONVERTCURRENCY_STAR
CNV_CONVERTDATE_STAR
CNV_CONVERTNUMERIC_STAR
CNV_CONVERTTIME_STAR
CNV_CURRENCYEDIT_DOUBLE
CNV_CURRENCYEDITTMP_DOUBLE
CNV_DELETE
CNV_DISPLAYMODEL
CNV_FORMATDATE
CNV_FORMATDATETMP
CNV_FORMATTIME
CNV_FORMATTIMETMP
CNV_FORMSIZE
CNV_INFO
CNV_MODIFY
CNV_NAMES
CNV_SYMBOLS
CNV_SYSTEMDATETIME
CNV_SYSTEMDATETIMETMP
CNV_TEMPLATE
CNV_VALIDATENAME
COMPARE_TEXT_USING_ORDER_INFO
CURRENT_MACHINE_ID
GET_CS_MSG
INSERT_MACHINE_NAME
INSERT_PRODUCTLINE_NAME
INSERT_VENDOR_NAME
MCP_BOUND_LANGUAGES
VALIDATE_NAME_RETURN_NUM
VALIDATE_NUM_RETURN_NAME
VSNCOMPARE_TEXT
VSNESCAPEMENT
VSNGETORDERINGFOR_ONE_TEXT
VSNINFO
VSNINSPECT_TEXT
VSNORDERING_INFO
VSNTRANSTABLE
VSNTRANS_TEXT
VSNTRUTHSET
Explanation of Error Values
COBOL85 Compatible Time and Date Procedures
CURRENT_DATE
DATE_OF_INTEGER
INTEGER_OF_DATE
INTEGER_OF_TIME
TIME_OF_INTEGER
Run-Time Format-Error Messages
Free-Field Input
Formatted Output
Formatted Input
Reserved Words
Data Representation
Character Representation
Character Values and Graphics
Default Character Type
Signs of Numeric Fields
One-Word Operands
Real Operand
Integer Operand
Boolean Operand
Two-Word Operands
Dinteger Operand
Double-Precision Operand
Complex Operand
Type Coercion of One-Word and Two-Word Operands
Data Descriptors and Pointer
Understanding Railroad Diagrams
Railroad Diagram Concepts
Paths
Constants and Variables
Constraints
Following the Paths of a Railroad Diagram
Railroad Diagram Examples with Sample Input
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