"

 COPYRIGHT (c) 2006 by eXept Software AG

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

"{ Package: 'stx:libbasic' }"

"{ NameSpace: Smalltalk }"

Object subclass:#ReadEvalPrintLoop

	instanceVariableNames:'inputStream outputStream errorStream compiler prompt

		doChunkFormat traceFlag timingFlag printFlag exitAction

		currentDirectory'

	classVariableNames:''

	poolDictionaries:''

	category:'System-Support'

!

!ReadEvalPrintLoop class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 2006 by eXept Software AG

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    A simple read-eval-print loop for non-GUI or stscript operation.

    Invoked, for example if stx is started with a --repl argument.

.

    A line starting with '?' shows the usage message.

    Lines starting with '#' are directives:

	#exit   - exit the rep-loop

    The input can be in one of two formats:

	1) traditional chunk format (bang-separated chunks, bangs duplicated)

	  this is the traditional fileIn format, as generated by fileOut from the browser

	2) interactive line mode. Chunks are any number of lines up to either an empty line or

	  a line ending in a period. This is more useful for an interactive REPL, where statements/expressions

	  are entered linewise by a user.

    The input can is switched to non-chunk format whenever a line with a '#' in the first column appears.

"

! !

!ReadEvalPrintLoop methodsFor:'accessing'!

compiler:something

    "assign a compiler to use;could be used to change the language"

    compiler := something.

!

doChunkFormat

    "true if currently reading chunk format"

    ^ doChunkFormat ? true

    "Created: / 07-12-2006 / 18:24:04 / cg"

!

doChunkFormat:aBoolean

    "enable/disable chunk format"

    doChunkFormat := aBoolean.

    "Created: / 07-12-2006 / 18:24:04 / cg"

!

error:aStream

    "assign an error stream"

    errorStream := aStream.

    "Created: / 07-12-2006 / 17:33:39 / cg"

!

errorStream

    "return the current error stream"

    errorStream notNil ifTrue:[^ errorStream].

    ^ Processor activeProcess stderr

    "Created: / 07-12-2006 / 19:12:27 / cg"

!

input:aStream

    "assign an input stream"

    inputStream := aStream asLineNumberReadStream.

    "Modified: / 07-12-2006 / 17:33:31 / cg"

!

inputStream

    "get the current input stream"

    inputStream notNil ifTrue:[^ inputStream].

    ^ Processor activeProcess stdin

    "Created: / 07-12-2006 / 19:12:13 / cg"

!

output:aStream

    "assign an output stream"

    outputStream := aStream.

    "Created: / 07-12-2006 / 17:27:48 / cg"

!

outputStream

    "return the current output stream"

    outputStream notNil ifTrue:[^ outputStream].

    ^ Processor activeProcess stdout

    "Created: / 07-12-2006 / 19:12:27 / cg"

!

prompt:aString

    "set the prompt"

    prompt := aString.

! !

!ReadEvalPrintLoop methodsFor:'compiler interface-error handling'!

correctableError:message position:pos1 to:pos2 from:aCompiler

    "compiler notifies us of an error - ignore it"

    ^ false "/ no correction

!

correctableSelectorWarning:aString position:relPos to:relEndPos from:aCompiler

    "compiler notifies us of a warning - ignore it"

    ^ false

!

correctableWarning:message position:pos1 to:pos2 from:aCompiler

    "compiler notifies us of an error - ignore it"

    ^ false

    "Created: / 02-11-2010 / 13:29:22 / cg"

!

error:aString position:relPos to:relEndPos from:aCompiler

    "compiler notifies us of a warning - ignore it"

    ^ false

!

unusedVariableWarning:aString position:relPos to:relEndPos from:aCompiler

    "compiler notifies us of a warning - ignore it"

    ^ false

!

warning:aString position:relPos to:relEndPos from:aCompiler

    "compiler notifies us of a warning - ignore it"

    ^ self

! !

!ReadEvalPrintLoop methodsFor:'directives'!

cmd_clear:lineStream

    self cmd_setOrClear:lineStream to:false

    "Created: / 07-12-2006 / 19:04:50 / cg"

!

cmd_exit:lineStream

    exitAction value

    "Created: / 07-12-2006 / 18:55:46 / cg"

!

cmd_help:lineStream

    self errorStream

	nextPutAll:

'Everything entered up to an empty line or a line ending in "." is called a "chunk" and evaluated.

Lines starting with "#" are commands to the read-eval-print interpreter.

Valid commands are:

    #help ............... this text

    #exit ............... exit interpreter loop

    #use <package>....... use (load) a package

	stx:libwidg .............. GUI package

	stx:libtool .............. IDE tool package

	stx:goodies/regex ........ regex package

	stx:goodies/petitparser .. peg parser package

    #read <filename>..... read another script or source file

    #show <what> ........ show info

	variables .......... interpreter variables

	processes .......... processes

	memory ............. memory usage

	flags .............. flags

	modules ............ loaded modules

    #set/clear <flag> ... set or clear a flag

	trace .............. tracing execution

	timing ............. timing execution

	chunkFormat ........ traditional bang chunk format input mode

The MiniDebugger (if entered) shows its own help with "?".

'

    "Created: / 07-12-2006 / 18:54:20 / cg"

!

cmd_read:lineStream

    |filename newInput savedPrompt savedPrint savedInput savedCurrentDirectory|

    lineStream skipSeparators.

    filename := lineStream upToEnd withoutSeparators.

    filename isNil ifTrue:[

	'? which file?' errorPrintCR.

	^ self.

    ].

    filename := filename withoutSeparators.

    filename isEmpty ifTrue:[

	'? which file?' errorPrintCR.

	^ self.

    ].

    filename := filename asFilename.

    filename isAbsolute ifFalse:[

	filename := currentDirectory construct:filename.

    ].

    newInput := filename readStream.

    newInput isNil ifTrue:[

	('Could not find file: "',filename,'"') errorPrintCR.

	^ self.

    ].

    [

	savedCurrentDirectory := currentDirectory.

	savedInput := inputStream.

	savedPrint := printFlag.

	savedPrompt := prompt.

	currentDirectory := filename directory.

	inputStream := newInput.

	self

	    basicReadEvalPrintLoopWithInput:newInput

	    output:outputStream

	    error:errorStream

	    compiler:compiler

	    prompt:false

	    print:false.

    ] ensure:[

	currentDirectory := savedCurrentDirectory.

	inputStream := savedInput.

	printFlag := savedPrint.

	prompt := savedPrompt

    ].

!

cmd_set:lineStream

    self cmd_setOrClear:lineStream to:true

    "Modified: / 07-12-2006 / 19:04:46 / cg"

!

cmd_setOrClear:lineStream to:aBoolean

    |what|

    lineStream skipSeparators.

    what := lineStream nextAlphaNumericWord.

    what notNil ifTrue:[

	(what startsWith:'tra') ifTrue:[

	    traceFlag := aBoolean.

	    ^ self.

	].

	(what startsWith:'tim') ifTrue:[

	    timingFlag := aBoolean.

	    ^ self.

	].

	(what startsWith:'chunk') ifTrue:[

	    doChunkFormat := aBoolean.

	    ^ self.

	].

    ].

    self errorStream nextPutLine:'? which flag ?'.

    "Modified: / 07-12-2006 / 19:13:34 / cg"

!

cmd_show:lineStream

    |errStream what all printModule|

"

 self basicNew cmd_show:'packages' readStream

"

    errStream := self errorStream.

    lineStream skipSeparators.

    what := lineStream nextAlphaNumericWord.

    what notNil ifTrue:[

        (what startsWith:'var') ifTrue:[

            Workspace notNil ifTrue:[

                ].

            ].

            ^ self.

        ].

        (what startsWith:'proc') ifTrue:[

            MiniDebugger basicNew showProcesses.

            ^ self.

        ].

        (what startsWith:'mod') ifTrue:[

            printModule :=

                [:mod |

                    errStream

                        nextPutAll:'  ';

                        nextPutAll:(mod package "libraryName");

                        nextPutLine:' (',(mod type),')'.

                ].

            errStream nextPutLine:'builtIn:'.

            ((ObjectMemory binaryModuleInfo

                reject:[:m | m dynamic])

                    asSortedCollection:[:a :b | a name < b name]) do:printModule.

            errStream nextPutLine:'dynamic:'.

            ((ObjectMemory binaryModuleInfo

                select:[:m | m dynamic])

                    asSortedCollection:[:a :b | a name < b name]) do:printModule.

            ^ self.

        ].

        (what startsWith:'mem') ifTrue:[

            all := ObjectMemory oldSpaceUsed + ObjectMemory symSpaceUsed

                                             + ObjectMemory newSpaceUsed.

            errStream

                nextPutLine:('overall: ',(all // 1024) printString,' Kb');

                nextPutLine:('in use : ',(ObjectMemory bytesUsed // 1024) printString,' Kb');

                nextPutLine:('free   : ',(ObjectMemory freeSpace // 1024) printString,' Kb');

                nextPutLine:('minorGC: ',(ObjectMemory scavengeCount) printString);

                nextPutLine:('majorGC: ',(ObjectMemory garbageCollectCount) printString).

            ^ self.

        ].

        (what startsWith:'flag') ifTrue:[

            errStream

                nextPutLine:('trace :      ',traceFlag printString);

                nextPutLine:('timing:      ',timingFlag printString);

                nextPutLine:('chunkFormat: ',doChunkFormat printString).

            ^ self.

        ].

    ].

    errStream nextPutLine:'? show what ?'.

    "Modified: / 07-12-2011 / 22:15:07 / cg"

!

cmd_use:lineStream

    |pkg|

    lineStream skipSeparators.

    pkg := lineStream upToEnd.

    pkg isNil ifTrue:[

	'? which package?' errorPrintCR.

	^ self.

    ].

    pkg := pkg withoutSeparators.

    pkg isEmpty ifTrue:[

	'? which package?' errorPrintCR.

	^ self.

    ].

    [

	Smalltalk loadPackage:pkg.

    ] on:PackageLoadError do:[:ex|

	"/ allow for some shortcuts...

	(pkg includes:$:) ifTrue:[

	    self errorStream nextPutLine:('Failed to load package: "',pkg,'"').

	] ifFalse:[

	    "/ try stx standard package

	    pkg := 'stx:', pkg.

	    ex restart.

	].

    ].

    "Created: / 07-12-2006 / 19:07:56 / cg"

!

directive:line

    |s cmd|

    s := line readStream.

    s next. "/ skip the hash

    s skipSeparators.

    cmd := s nextAlphaNumericWord.

    cmd notNil ifTrue:[

	self

	    perform:('cmd_',cmd) asMutator with:s

	    ifNotUnderstood:[

		self errorStream

		    nextPutAll:'?? invalid command: ';

		    nextPutAll:cmd;

		    nextPutAll:'. Type "#help" for help.';

		    cr.

	    ].

    ].

    "Created: / 07-12-2006 / 18:49:17 / cg"

! !

!ReadEvalPrintLoop methodsFor:'evaluation'!

basicReadEvalPrintLoopWithInput:input output:output error:error

    compiler:compilerClass prompt:prompt print:doPrint

    "{ Pragma: +optSpace }"

    "the core of the interpreter loop; extracted and parametrized, so it can be called recursive

     for included scripts.

     If chunkFormat is true, chunks are read.

     Otherwise, lines up to an empty line (or EOF) or a line ending in '.' are read.

     A '#' character appearing in the first column of the first line turns off chunkmode."

    [

        |lines chunk|

        prompt notNil ifTrue:[

            error nextPutAll:prompt.

        ].

        input atEnd ifTrue:[

            error cr.

            ^ self.

        ].

        input peek == $# ifTrue:[

            self doChunkFormat:false.

        ].

        self doChunkFormat ifTrue:[

            input skipSeparators.

            chunk := input nextChunk.

        ] ifFalse:[

            lines := OrderedCollection new.

            [

                |line|

                line := input nextLine.

                line notEmptyOrNil ifTrue:[

                    line = '?' ifTrue:[

                        self cmd_help:nil.

                        prompt notNil ifTrue:[

                            error nextPutAll:prompt.

                        ].

                    ] ifFalse:[

                        (line startsWith:'#') ifTrue:[

                            self directive:line.

                            prompt notNil ifTrue:[

                                error nextPutAll:prompt.

                            ].

                        ] ifFalse:[

                            lines add:line.

                        ]

                    ]