Chapter One: How To Use This Manual

Chapter One: How To Use This Manual __________________________________________________

Table of Contents Introduction .............................................................................................................. 1 1.1 Chapter Summaries .......................................................................................... 2 1.2 How To Read Syntax Diagrams ........................................................................ 5

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Introduction Introduction This reference manual is a comprehensive guide to using the XGEN system. New users should read the manual from the beginning to build a foundation of concepts and terminology. All aspects of XGEN are explained and defined, with examples and crossreferences. Review the chapter summaries that follow. Once you are familiar with XGEN essentials, you can locate individual items by referring to the index or scanning page headers.

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1.1 Chapter Summaries 1.1 Chapter Summaries Volume I Chapter 2: XGEN Overview The XGEN system consists of the XGEN 4GL COBOL generator, the XGEN Data Dictionary, the XGEN Online Designer, the XGEN Online Administrator, and XGEN documentation and training. The data dictionary interfaces all XGEN components with application data structures. The XGEN Online Designer provides an easy to use facility for painting screens and reports and other functions. The Online Administrator is used to maintain the configuration file, which contains default file titles, default naming patterns, and default options. Chapter 3: XGEN Online Administrator The XGEN Online Administrator provides an easy to use facility for maintaining configuration files, security, and the messages used by XGEN components. This chapter describes how to create and maintain configuration files, establish and maintain security, and perform message functions. Chapter 4: XGEN Data Dictionary The XGEN Data Dictionary links all system components with application data structures, including files and databases. This chapter describes how to create dictionaries, how to add new data structures and update old ones, how to declare dictionaries, and how each XGEN component uses the data dictionary. Chapter 5: XGEN Program Types and Flow XGEN is capable of generating three major program types, online programs, batch process programs, and batch transaction programs. Every program consists of declarations and one or more process definitions. Each process contains a complete high level application function. Processes may call procedures, which may call other procedures, in order to perform tasks required by the process. XGEN provides the ability to automatically invoke procedures upon the occurrence of specified events during application program execution.

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1.1 Chapter Summaries Chapter 6: XGEN Program Concepts This chapter discusses how XGEN handles data processing functions. Topics include: Breaks Parameter Passing Control Structures Patterns Databases Reads Datacom Formats Reports Date/time Arithmetic Sorts And Merges Edits Tables Files Update Structures Chapter 7: XGEN Online Designer The XGEN Online Designer greatly simplifies the process of formatting CRT screens and printed reports and other functions. The Designer provides tools for painting screens and reports and generating the associated COBOL record formats and screen images needed to incorporate them into applications. Volume II Chapter 8: XGEN Language Components The definitions for the XGEN statements contain a number of common semantic items. These common items are defined in this chapter. Definitions include the purpose, usage notes, syntax diagrams, semantic description, and examples of each item. The definitions are listed in alphabetical order. Chapter 9: XGEN 4GL Statements This chapter contains a section for each XGEN statement including syntax, semantics, and examples. Syntax diagrams are provided for each statement. The sections are arranged in alphabetical order. Where applicable, related statements or COBOL forms are referenced. Chapter 10: XGEN Application Generation This chapter details how to actually code an XGEN program and run the generator. Topics include coding, copying text from other files, and including COBOL source code and comments in the XGEN program. Chapter 11: XGEN Model Programs This chapter provides examples of XGEN 4GL programs and program segments. Model XGEN 4GL samples are provided for more than 100 common programming tasks. HOW TO USE THIS MANUAL

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1.1 Chapter Summaries

Chapter 12: XGEN Trace Utility This chapter explains setting up for and running the XGEN Trace Utility. The XGEN Trace Utility is used to run a trace, which is used to obtain statistical and run-time flow information for an XGEN-generated program.

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1.2 How To Read Syntax Diagrams 1.2 How To Read Syntax Diagrams Syntax diagrams are found throughout this manual. They are similar to railroad tracks, because you follow the line from beginning to end without leaving the "track" or reversing direction. Required syntax items are on the "main line", and optional items are on the "branches" above or below the main line. Any item encountered on the main line or on a desired branch line is coded. XGEN statement

required item optional item

Multiple Choice Items Multiple choice items are indicated by combining a required item (on the main line) and one or more optional items (below the main line). This indicates that any one item must be selected. XGEN statement

multiple choice items

Multiple Choice Options Multiple choice options are indicated by multiple optional items without a required item. This indicates that no items need be selected, but one optional item may be selected. XGEN statement multiple choice options Direction of Flow Always move along branches in a counter-clockwise direction. Branches above the main line move to the left and below the main line move to the right. Any punctuation encountered along a line is required. Counter-clockwise movement along a line above the mainline indicates a loop; the section may be repeated as needed. line with loop

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1.2 How To Read Syntax Diagrams Continued Lines Within a Syntax Diagram Continued lines are terminated by an arrow symbol. The continuation begins with a diamond symbol. line contents additional contents

.

Descriptors and Expansions For clarity, some diagrams represent complex structures within the primary diagram by a single descriptor. A complete expansion of the complex structure follows. descriptor XGEN statement . descriptor additional syntax items in expansion Upper and Lowercase Items Uppercase words must be coded exactly as shown. Lowercase words represent semantic variables; the value of the variable is coded. Examples: Each example below was derived from the appropriate syntax diagram found in Chapter 9. Boldface is used to emphasize required items. ADD syntax: ADD

, item9

TO GIVING

dataname9

. ROUNDED

ADD WS-1 TO WS-TOTAL ROUNDED. ADD TAXAMT, SALEPRICE GIVING ITEMCOST, PURCHASE. READ syntax: READ

filefd

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select-part

FIRST NEXT

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1.2 How To Read Syntax Diagrams select-part: SELECT AFTER name

WHEN cond LIMIT item9

READ ACTION-CODES. READ PERSONNEL SELECT WHEN SALARY < 25000. READ NEXT SALES SELECT WHEN ITEMCT >= 2 LIMIT LIST-SIZE.

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