Understanding. AutoLISP. Programming for Productivity, Second Edition. William and Denise Kramer. ö Delmar. Publishers Inc.

Transcription

1 Understanding AutoLISP Programming for Productivity, Second Edition William and Denise Kramer ö Delmar Publishers Inc.

2 Contents Introduction xxi 1. Introduction to AutoLISP 1 Historical Perspective 1 How AutoLISP Differs from LISP 2 The Nature of LISP 3 AutoLISP Inside AutoCAD 4 2. AutoLISP Building Blocks 7 LISP Data Elements 7 Evaluating Expressions in LISP 11 LISP Syntax 12 Inverted Tree Diagrams 13 LISP Expressions 14 Assigning Values to Variables 16 What's in a Variable? 17 Mathematical Results from LISP 18 Binary Operations 20 Example Functions 21 Rtd.Lsp, Dlr.Lsp, Tan.Lsp, Acos.Lsp, Asin.Lsp, LoglO.Lsp Exercises 22 v

3 3. Manipulating Lists 25 Why Manipulate Lists? 25 Manipulating Lists 26 AutoLISP List Functions 27 List Creation 27 List Searching 29 Element Extraction 30 Miscellaneous List Manipulation 30 Point-Related Lists and Mathematics Functions 31 Point Mathematics Example 32 PC.Lsp Association List Handling Examples 33 Columns.Lsp Association Lists as Database Systems 36 Bom.Lsp Number List Example Functions 37 Äverage.Lsp, Median.Lsp, XAverage.Lsp, YAverage.Lsp, ZÄverage.Lsp, PtÄverage.Lsp Exercises Defining New Functions 39 The Defun Expression 39 DegRad.Lsp Debugging with Trace 40 Bound, Free and Local Variables 41 Keep Your Variables Straight! 42 VaraTest.Lsp Call By Value 43 ParaTest.Lsp The Heap and the Stack 44 Mindl.Lsp, Mind2.Lsp, Mind3.Lsp Storing AutoLISP Functions 46 Adding New Commands with C: 47 Example Functions 48 Dms2R.Lsp, Ppl.Lsp, AddList Executing AutoCAD Commands within AutoLISP 49 More Example Functions 50 Rect.Lsp, Pyramid.Lsp Exercises 52 vi

4 5. Input and Output Functions 53 The User Interface 53 Asking the User for Input 54 Preparing the Input Handling System 54 AutoLISP Getx Input Statements 55 R2d.Lsp Special Format Control Characters 60 AutoLISP Output Statements 60 Input/Output Function Examples 62 Info.Lsp, AscüS.Lsp, IsoTri.Lsp Display Controls 64 Using Ansi.sys Calls from AutoLISP 64 Example Ansi.Sys Functions 65 Cls.Lsp, TxLoc.Lsp, Textlo.Lsp Exercises Conditional Expressions 67 Conditional Branching 67 Conditionals in Programming 68 True and False Test Expressions 69 AutoLISP Relationship Predicates 69 Predicate Combination Tests 70 Usage Tests 70 String Testing 72 Using Conditionals in AutoLISP 74 Differences Between Cond and If 74 R_from_D.Lsp, Make_Signl.Lsp, Make_Sign2.Lsp The Progn in AutoLISP 76 Conditional Examples 77 FindCh.Lsp Exercises Looping with AutoLISP 81 Loops in Programming 81 Iterative Looping Expressions 82 The Repeat Expression 83 SeqLinesl.Lsp The While Expression 83 SeqLinesl.Lsp, LText.Lsp List-Based Iterations 85 vn

5 Recursion ' F.Lsp Recursion Examples 88 My-Member.Lsp, My-Length.Lsp, My-Assoc.Lsp, Headers.Lsp, Farthest.Lsp Looping Examples 89 Our-Line.Lsp, Atom-Count.Lsp, Correct.Lsp, DraivPts.Lsp, XMinSort.Lsp Exercises External File Processing 95 Data File Concepts 95 File Accessing Techniques 96 Opening Files 97 Closing Files 98 Finding Files 98 FindOpen.Lsp File Input Expressions 99 FDisp.Lsp File Output with AutoLISP 100 Write-Long-Line.Lsp, List-Output.Lsp File Input Examples 103 My-Scripts.Lsp, Txtlnp.Lsp, FAssoc.Lsp Exercises Changing Data Types 107 Data Type Handling 107 String Manipulation 108 SParse.Lsp Changing Strings to Other Variables Types 110 CLRead.Lsp Changing Other Variable Types to Strings 112 AnglText.Lsp, My-GetReal.Lsp, My-GetInt.Lsp, Read-Long-Line.Lsp Changing Numeric Types 116 Round.Lsp Data Conversion Examples 117 StrRepl.Lsp, StrRev.Lsp, Get.Lsp, Import.Lsp, Read-Rec.Lsp, Xyz_Sdf.Lsp, XyzJZdf.Lsp, FindJZh.Lsp Exercises 122 vin

6 10. Accessing the AutoCAD Drawing Database... Access to the Drawing Database Selection Sets and Expressions Creating Selection Sets Window_Select. Lsp Selection Set Manipulation CWindozv.Lsp Entity Names and Accessing Expressions Operator Selection of an Entity Sequential Drawing Access DittoLast.Lsp Entity Delete Flash.Lsp Entity Lists and Accessing Entity Data LayerSwüch.Lsp, Bom_2x4.Lsp Entity Modification Expressions 2x4Check.Lsp Entity Handling Examples FixLayer.Lsp, PlDistl.Lsp, Select_Set.Lsp, Animate.Lsp Extended Data in Entities Get_App.Lsp, Sub_App.Lsp, App_Size_Check.Lsp Exercises 11. The AutoLISP Environment Accessing and Changing System Variables SaveSysVar.Lsp, RestoreSysVar.Lsp AutoCAD System Variables Table Access in AutoCAD NewJLayer.Lsp, LIByC.Lsp, MCols.Lsp, BlkExtrm.Lsp Controlling Display and Input Devices Program Recovery from Errors *Error*.Lsp DOS AutoLISP Considerations Klean.Lsp Virtual Memory Lhs.Lsp Exercises IX

7 12. AutoLISP for Release 12 Testing for Release 11 vs 12 l_ver.lsp Loading AutoLISP and MNL Files Selection Set Improvements Text Box Utility String to Real Conversion Fixed Dialog Box Functions Programmable Dialog Box Functions Dialog Box Processing SetJTile.Lsp List Box Preparations Image Box Preparations Start the Dialog Box Interaction Finishing a Dialog Box System Control Command Divide.Lsp Example Functions Layer Control Example Ly.Lsp, Ly_Setup.Lsp, Ly_Get_L_C.Lsp, Ly_Prep_Tües. Lsp, Ly_Set_L_C. Lsp Dialog Box Test Sequence DT est.lsp Title Block Manipulation Title.Lsp, Title_Setup.Lsp, Update_Atts.Lsp, Set_Date.Lsp Dynamic Dialog Boxes Do_Dcl_List.Lsp, Make_List_Dcl.Lsp, Add_2_List.Lsp, Del_F_List.Lsp Appendix A: Answers to Exercises SubJTüle.Lsp, x