Aros/Developer/Docs/E
AmigaE
editRead more here.
Amiga E, or very often simply E, is a programming language created by Wouter van Oortmerssen on the Amiga.
Amiga E is a combination of many features from a number of languages, but follows the original C Programming and C++, most closely in terms of basic concepts like in the sense that it is fast and weakly typed, and had a rich set of features from procedural, object oriented and functional programming languages.
Amiga E's main benefits are fast compilation (allowing it to be used in place of a scripting language), very readable source code, flexible type system, powerful module system, exception handling (not C++ variant) and object oriented programming.
Contact the AmigaE IRC channel irc.freenode.net at #amigaE
PortablE
editFor further information and questions, Portable E has its own forum here. PortablE is an AmigaE compiler, written from scratch in E, and able to compile itself. There is a mailing list for E where you might get some answers.
Read more here.
This is how PortablE works. You write your Amiga E code, use PortablE to translate it into a .cpp file and then use any C++ compiler to compile the file into an executable. I have been using g++ inside AROS. If you want to go to Amiga Classic, you can use PortablE to translate to Amiga E and then move it to Classic where you can use an Amiga E compiler like CreativE.
If PortablE is not already set up for use, you need to set a Stack of at least 100000 to run PortablE. You can set this up by typing in the AROS shell.
stack 100000
You need to do an assign for PEmodules.
Assign PEmodules: VolumeName:PEmodules
You can put Assign commands like this in your user-startup file in AROS so you don’t have to do it everytime. User-startup is in System:S (S drawer).
You also need some Assigns placed in there for g++. The exact Assigns you need can be found in the INSTALL file located in System:Development
So here are the commands I entered on the command line once I had things setup to test a simple program.
PortablE test.e (This gave me a file named test.cpp)
g++ test.cpp -o test (This gave me a file named test to run as an executable)
So then I just typed in the name of my executable at the shell and it ran and printed “Hello, World!”.
Syntax
editRead more here.
Procedures
editA "hello world" program in Amiga E calling another procedure inside
PROC main() DEF z WriteF('Hello, World!\n') z:=1 Another() ENDPROC PROC another DEF y y:=2 ENDPROC
Loops
editIF x>0 x:=x+1 WriteF('Increment: x is now \d\n', x) ELSEIF x<0 x:=x-1 WriteF('Decrement: x is now \d\n', x) ELSE WriteF('Zero: x is 0\n') ENDIF
SELECT x CASE 0 WriteF('x is zero\n') CASE 10 WriteF('x is ten\n') CASE -2 WriteF('x is -2\n') DEFAULT WriteF('x is not zero, ten or -2\n') ENDSELECT
PROC main() DEF x x:=1 WHILE x<=100 WriteF('\d ', x) x:=x+1 ENDWHILE WriteF('\n') ENDPROC
PROC main() DEF x x:=1 REPEAT WriteF('\d ', x) x:=x+1 UNTIL x>100 WriteF('\n') ENDPROC
Summary
editPROC main() DEF x,y x:=1 y:=2 WHILE (x<10) AND (y<10) WriteF('x is \d and y is \d\n', x, y) x:=x+2 y:=y+2 ENDWHILE ENDPROC
- The procedure definition.
- The declaration of the procedure main, with no parameters.
- The declaration of local variables x and y
- Initialization of x and y using assignment statements.
- The WHILE loop
- The loop check for the WHILE loop using the logical operator AND, the comparison operator <, and parentheses to group the expression.
- The call to the (built-in) procedure WriteF using parameters. Notice the string, the place holders for numbers, \d, and the linefeed, \n.
- Assignments to x and y, adding two to their values.
- The marker for the end of the WHILE loop.
- The marker for the end of the procedure.
To return a value, replace ENDPROC with ENDPROC value
Data Structures
editRead more about here.
Constants
Numeric
String
Named
Enumeration
Sets
Types
editLONG
PTR
ARRAY
OBJECT
LIST
STRING
Linked Lists
Built-In
edit- Constants - TRUE, FALSE, NIL, ALL, GADGETSIZE, OLDFILE, NEWFILE, STRLEN
- Variables - arg, wbmessage, stdout, conout, stdrast, dosbase, execbase, gfxbase, intuitionbase,
- Functions - \c (Number Character) - \d (Number Decimal) - \h (Number Hexadecimal), \s (String String)
- Functions - \l Left justify in field, \r Right justify in field, \z Set fill character to "0"
- Functions - WriteF, StringF, Out, Inp, ReadStr, FileLength, SetStdOut,
- Functions (Intuition) - OpenW, CloseW, OpenS, CloseS, Gadget, Mouse, MouseX, MouseY, WaitIMessage,
- Functions (Graphics) - Plot, Line, Box, Colour, TextF, SetStdRast, SetTopaz,
- Functions (Maths) - Abs, Even, Odd, Mod, Rnd, RndQ, Shl, Shr, Long, Int, Char, PutLong, PutInt, PutChar,
- Functions (System) - New, Dispose, DisposeLink, CleanUp, CtrlC, FreeStack,
Modules
editExceptions
editConversion
editThe hardest part when moving from BASIC to C, C++ and E is pointers & strings. E & C deal with strings in almost exactly the same way, so there is no great benefit to E there.
AmigaE's treatment of pointers is far simpler than C's, due to C's design. You have to think very carefully about what kind of pointer is required in case a "&" or "*" needs to be added. While with E there is almost never any such worry.
Plus "PTR TO xxx" seems easier to grasp than "xxx*".
Note that there are some good C guides that explain the principles of strings & pointers, using 'box & arrow' diagrams, which you may still find helpful when learning E.
You can just open workbench.library (version 44 or newer required) and call OpenWorkbenchObjectA() as it is documented in autodocs.
Examples
edit/* DirList3.e */ MODULE 'std/cGUI', 'std/cPath' STATIC app_name = 'DirList' PROC main() DEF dirPath:STRING, dir:PTR TO cDir, dirList:PTR TO cDirEntryList DEF win:PTR TO cGuiWindow, guiLastFile:PTR TO cGuiTextBox, guiOK DEF quit:BOOL, item:PTR TO cGuiItem, entry:PTR TO cGuiFixedListEntry ->describe our app CreateApp(app_name).initDescription('This is a simple PortablE demo.').build() ->scan directory dirPath := ImportDirPath('EnvArc:') NEW dir.new() IF dir.open(dirPath, /*readOnly*/ TRUE) = FALSE THEN Throw("ERR", 'Failed to open directory') dirList := dir.makeEntryList() dir.close() ->build the GUI win := CreateGuiWindow(app_name) win.beginGroupVertical() win.addTextBox('').setState('Below is a list of all the files inside EnvArc:') win.beginFixedList().initSelectableEntries(/*multiSelect*/ TRUE) ->step through each file IF dirList.gotoFirst(/*any0file1dir2*/ 1) REPEAT ->add line for file win.addFixedListEntry(dirList.infoName()) UNTIL dirList.gotoNext(1) = FALSE ENDIF win.endFixedList() guiLastFile := win.addTextBox('The last ticked file:') guiOK := win.addButton('OK') win.endGroup() win.build() ->handle user interaction with GUI quit := FALSE REPEAT item := WaitForChangedGuiItem() IF item = NIL IF win.getCloseRequest() THEN quit := TRUE ELSE IF item = guiOK quit := TRUE ELSE IF item.IsOfClassType(TYPEOF cGuiFixedListEntry) entry := item::cGuiFixedListEntry IF entry.getState() ->(a file was ticked) so tell user which file they just ticked guiLastFile.setState(entry.infoLabel()) ENDIF ENDIF UNTIL quit win.close() FINALLY PrintException() END dirPath, dir ENDPROC
-> Shared MUI Custom Class Skeleton. Needs minimum ECX 2.x OPT PREPROCESS #define CLASS_NAME 'mytest.mcc' #define CLASS_VERSION 1 #define CLASS_REVISION 0 #define CLASS_IDSTRING 'mytest.mcc by me' ->#define ONLYGLOBAL ->#define INFOCLASS #ifdef __MORPHOS__ OPT EXENAME = CLASS_NAME + '.elf' #else OPT EXENAME = CLASS_NAME #endif #define SUPERCLASS MUIC_Area ->#define SUPERCLASSP -> Let ECX create a convenient multi base library for us LIBRARY CLASS_NAME, CLASS_VERSION, CLASS_REVISION, CLASS_IDSTRING IS mcc_query(D0) #define DoMethodA(obj,attrs) doMethodA(obj,attrs) #define DoSuperMethodA(class,obj,attrs) doSuperMethodA(class,obj,attrs) #define CoerceMethodA(class,obj,attrs) coerceMethodA(class,obj,attrs) -> handy.. #ifdef DEBUG #define DEBUGF(str,...) DebugF(str,...) #else #define DEBUGF(str,...) #endif MODULE 'amigalib/boopsi' MODULE 'muimaster', 'libraries/mui', 'libraries/muip', 'mui/muicustomclass' MODULE 'intuition/intuition', 'intuition/classes', 'intuition/classusr' MODULE 'exec/libraries', 'exec/nodes', 'exec/memory' MODULE 'utility', 'utility/tagitem', 'utility/hooks' OBJECT classdata ENDOBJECT OBJECT classdatap ENDOBJECT STATIC g_usedclasses=[NIL] STATIC g_usedclassesp=[NIL] STATIC g_shorthelp = '' DEF g_prefsimageobject=NIL DEF g_thisclass=NIL:PTR TO mui_customclass DEF g_thisclassp=NIL:PTR TO mui_customclass PROC main() HANDLE IFN muimasterbase := OpenLibrary(MUIMASTER_NAME,MUIMASTER_VMIN) THEN Throw("LIB", MUIMASTER_NAME) IFN utilitybase := OpenLibrary('utility.library',39) THEN Throw("LIB", 'utility.library') #ifdef SUPERCLASS IFN g_thisclass := eMui_CreateCustomClass(librarybase,SUPERCLASS,NIL, SIZEOF classdata,{classDispatcher}) Raise("CMCC") ENDIF #endif #ifdef SUPERCLASSP IFN g_thisclassp := eMui_CreateCustomClass(librarybase,SUPERCLASSP,NIL, SIZEOF classdatap,{classDispatcherP}) Raise("CMCC") ENDIF #endif EXCEPT DebugF('mcc open() failed: ') SELECT exception CASE "LIB" ; DebugF('Could not open library "\s"\n', exceptioninfo) CASE "CMCC" ; DebugF('Could not create mui custom class\n') DEFAULT ; DebugF('Unknown exception $\h\n', exception) ENDSELECT close() RETURN NIL -> make OpenLibrary() fail. ENDPROC TRUE PROC close() IF g_thisclassp THEN Mui_DeleteCustomClass(g_thisclassp) IF g_thisclass THEN Mui_DeleteCustomClass(g_thisclass) CloseLibrary(utilitybase) CloseLibrary(muimasterbase) ENDPROC -> the special fuction needed for any MCC PROC mcc_query(which) SELECT which CASE 0 RETURN g_thisclass CASE 1 RETURN g_thisclassp CASE 2 RETURN g_prefsimageobject CASE 3 #ifdef ONLYGLOBAL RETURN TRUE #else RETURN FALSE #endif CASE 4 #ifdef INFOCLASS RETURN TRUE #else RETURN FALSE #endif CASE 5 RETURN g_usedclasses CASE 6 RETURN g_usedclassesp CASE 7 RETURN g_shorthelp ENDSELECT ENDPROC NIL #ifdef SUPERCLASS PROC classDispatcher(cl:PTR TO iclass, obj:PTR TO object, msg:PTR TO opset) SELECT msg.methodid -> CASE OM_NEW ; RETURN classNew (cl,obj,msg) -> CASE OM_DISPOSE ; RETURN classDispose (cl,obj,msg) -> CASE MUIM_AskMinMax ; RETURN classAskMinMax(cl,obj,msg) -> CASE MUIM_Show ; RETURN classShow(cl, obj, msg) -> CASE MUIM_Hide ; RETURN classHide(cl, obj, msg) -> CASE OM_SET ; RETURN classSet(cl,obj,msg) -> CASE OM_GET ; RETURN classGet(cl,obj,msg) ENDSELECT ENDPROC DoSuperMethodA(cl,obj,msg) #endif #ifdef SUPERCLASSP PROC classDispatcherP(cl:PTR TO iclass, obj:PTR TO object, msg:PTR TO opset) ENDPROC #endif PROC classNew(cl:PTR TO iclass,obj:PTR TO object,msg:PTR TO opset) DEF data:PTR TO classdata IFN obj := DoSuperMethodA(cl,obj,msg) THEN RETURN 0 data := INST_DATA(cl,obj) ENDPROC obj PROC classDispose(cl:PTR TO iclass,obj:PTR TO object,msg:PTR TO msg) DEF data:PTR TO classdata data := INST_DATA(cl,obj) ENDPROC DoSuperMethodA(cl,obj,msg) PROC classSet(cl:PTR TO iclass,obj:PTR TO object,msg:PTR TO opset) DEF data:REG PTR TO classdata, tags:PTR TO tagitem, tag:REG PTR TO tagitem data := INST_DATA(cl,obj) tags := msg.attrlist WHILE tag := NextTagItem({tags}) SELECT tag.tag ->CASE MUIA_Xxx_Yyy ->data.xxxyyy := tag.data DEFAULT ENDSELECT ENDWHILE ENDPROC DoSuperMethodA(cl,obj,msg) PROC classGet(cl:PTR TO iclass,obj:PTR TO object,msg:PTR TO opget) DEF data:PTR TO classdata data := INST_DATA(cl,obj) SELECT msg.attrid ->CASE MUIA_Xxx_Yzz -> PutLong(msg.storage,data.xxxyyy) -> RETURN MUI_TRUE ENDSELECT ENDPROC DoSuperMethodA(cl,obj,msg) PROC classAskMinMax(cl:PTR TO iclass,obj:PTR TO object,msg:PTR TO muip_askminmax) DEF data:PTR TO classdata, mi:PTR TO mui_minmax DoSuperMethodA(cl,obj,msg) data := INST_DATA(cl,obj) mi := msg.minmaxinfo mi.minwidth += 16 mi.minheight += 16 mi.defwidth += 128 mi.defheight += 128 mi.maxwidth += MUI_MAXMAX mi.maxheight += MUI_MAXMAX ENDPROC 0 PROC classShow(cl:PTR TO iclass, obj:PTR TO object, msg:PTR TO opset) DEF data:PTR TO classdata IFN DoSuperMethodA(cl,obj,msg) THEN RETURN FALSE data := INST_DATA(cl, obj) ENDPROC MUI_TRUE PROC classHide(cl:PTR TO iclass, obj:PTR TO object, msg:PTR TO opset) DEF data:PTR TO classdata data := INST_DATA(cl, obj) ENDPROC DoSuperMethodA(cl, obj, msg)
References
editAmigaE works well and integrates with Assembly well also. Just don't go writing shared libraries with it since there are design flaws with the library mode. Also, if you plan on using multiple return codes, keep them in the same source as your application code because the module generation doesn't work right with multiple return codes. Lastly, don't nest the function form of the IF keyword (the AmigaE equivalent of the ? : operators in C). Those are all of the bugs I can think of in the compiler.