"{ Encoding: utf8 }"

"

 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 profilingFlag printFlag

		exitAction currentDirectory lastEditedClass lastEditedSelector

		editorCommand'

	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

        #show ...       - show various infos

        #use package    - show various infos

        type '?' to see more.

    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.

    Try it (but only if you have a console):

        Smalltalk readEvalPrintLoop

    [Author:]

        Claus Gittinger

"

! !

!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"

!

editorCommand

    "the editor command to use with the #edit directive.

     Uses the STX_EDITOR or EDITOR shell variables' value, if defined;

     if not, the value in the classvar EDITORCOMMAND if non-nil; 

     otheriwse vi (notepad on windows)"

    |editor|

    (editor := editorCommand) isNil ifTrue:[

        editor := OperatingSystem getEnvironment:'STX_EDITOR'.

        editor isNil ifTrue:[

            editor := OperatingSystem getEnvironment:'EDITOR'.

            editor isNil ifTrue:[

                OperatingSystem isMSWINDOWSlike ifTrue:[

                    editor := 'notepad'.

                ] ifFalse:[

                    editor := 'vi'.

                ].    

            ].    

        ].    

    ].

    ^ editor

    "Created: / 08-11-2016 / 22:45:22 / cg"

    "Modified: / 24-06-2017 / 09:54:10 / 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_debug:lineStream

    MiniDebugger enter.

!

cmd_edit:lineStream

    "edit a class or selector in an external editor"

    |errStream classOrMethodName cls methodName selector 

     code isNewClass editFullClass tmpFile modifiedTime|

    errStream := self errorStream.

    isNewClass := editFullClass := false.

    lineStream skipSeparators.

    lineStream atEnd ifTrue:[

        cls := lastEditedClass.

        methodName := lastEditedSelector.

    ] ifFalse:[    

        classOrMethodName := lineStream 

                                upToElementForWhich:[:ch | 

                                    ch isLetterOrDigit not and:[ch ~~ $_]

                                ].

        "/ 

        (classOrMethodName isUppercaseFirst) ifTrue:[ 

            (cls := Smalltalk classNamed:classOrMethodName) isNil ifTrue:[

                errStream show:'edit: no such class: ',classOrMethodName,' ; create (y/n)? '.

                (self inputStream nextLine withoutSeparators startsWith:'y') ifFalse:[^ self].

                isNewClass := true.

                code := 

'"/ change the code as required, then save and exit the editor.

"/ To cancel this edit, leave the editor WITHOUT saving.

"/

Object

  subclass:#%1

  instanceVariableNames:''''

  classVariableNames:''''

  poolDictionaries:''''

  category:''user classes''

'                   bindWith:classOrMethodName.

            ] ifFalse:[ 

                lineStream skipSeparators.

                lineStream atEnd ifFalse:[

                    methodName := lineStream upToSeparator.

                ].

            ].

        ] ifFalse:[

            methodName := classOrMethodName   

        ].

    ].

    isNewClass ifFalse:[

        cls := cls ? lastEditedClass.

        cls isNil ifTrue:[

            errStream showCR:'edit usage:'.

            errStream showCR:'   #edit className selector'.

            errStream showCR:'   #edit className '.

            errStream showCR:'   #edit selector (class as in previous edit)'.

            errStream showCR:'   #edit          (class/method as in previous edit)'.

            ^ self.

        ].

        lastEditedClass := cls.

        lastEditedSelector := methodName.

        methodName isNil ifTrue:[

            editFullClass := true.

            code := cls source asString

        ] ifFalse:[    

            ((selector := methodName asSymbolIfInterned) isNil 

            or:[ (cls implements:selector) not]) ifTrue:[

                errStream show:('"',methodName,'" is a new method; create (y/n)? ').

                (self inputStream nextLine withoutSeparators startsWith:'y') ifFalse:[^ self].

                code := 

'"/ change the code as required, then save and exit the editor.

"/ To cancel this edit, leave the editor WITHOUT saving.

%1

    "this is a new method"

    self halt

'                   bindWith:methodName.

            ] ifFalse:[

                code := (cls compiledMethodAt:selector) source.

            ].    

        ].    

    ].

    [

        |ok cmd|

        tmpFile := Filename newTemporary.

        tmpFile contents:code.

        modifiedTime := tmpFile modificationTime.

        cmd := '%1 "%2"'.

        OperatingSystem isUNIXlike ifTrue:[

            cmd := '%1 "%2" </dev/tty'.

        ].

        ok := OperatingSystem 

                executeCommand:(cmd bindWith:(self editorCommand) with:tmpFile pathName)

                inputFrom:Stdin 

                outputTo:Stdout 

                errorTo:Stderr

                auxFrom:nil

                environment:nil

                inDirectory:nil

                lineWise:false

                newPgrp:false

                showWindow:true

                onError:[:status | false].

        (ok and:[tmpFile modificationTime ~= modifiedTime]) ifTrue:[

            isNewClass ifTrue:[

                Compiler evaluate:tmpFile contentsOfEntireFile.    

                errStream showCR:'Class (re)defined.'

            ] ifFalse:[

                editFullClass ifTrue:[

                    tmpFile fileIn.

                    errStream showCR:'Class (re)compiled.'

                ] ifFalse:[    

                    cls compile:tmpFile contentsOfEntireFile classified:'*as yet uncategorized'.    

                    errStream showCR:'Method (re)compiled.'

                ].    

            ].    

        ] ifFalse:[

            errStream showCR:'No change.'

        ].    

    ] ensure:[

        tmpFile notNil ifTrue:[

            tmpFile remove

        ]

    ].

    "

     Smalltalk readEvalPrintLoop

     self new 

        input:Stdin;

        cmd_edit:'MyClass foo' readStream

    "

    "Modified: / 08-11-2016 / 22:46:12 / cg"

!

cmd_exit:lineStream

    "exit directive - leaves the repl"

    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

        packages ........... available packages to load

        all ................ all of the above

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

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

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

        profiling .......... show execution profile

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

        editor ............. command used with #edit directive

    #debug ................. enter a MiniDebugger

    #edit <what> ........ open an external editor 

        class .............. on a class

        class selector ..... on a method

        <empty> ............ on previously edited method/last class

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

'

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

    "Modified: / 08-11-2016 / 22:53:53 / cg"

!

cmd_read:lineStream

    |filename newInput savedPrompt savedPrint savedInput savedCurrentDirectory savedDoChunkFormat|

    lineStream skipSeparators.

    filename := lineStream upToEnd withoutSeparators.

        ^ self.

    ].

    currentDirectory := currentDirectory ? (Filename currentDirectory).

    filename := filename asFilename.

    filename isAbsolute ifFalse:[

        filename := currentDirectory construct:filename.

    ].

    StreamError ignoreIn:[

        newInput := filename readStream.

    ].

    newInput isNil ifTrue:[

        self errorStream showCR:('Could not find file: "',filename pathName,'"').

        ^ self.

    ].

    [

        savedCurrentDirectory := currentDirectory.

        savedDoChunkFormat := doChunkFormat.

        savedInput := inputStream.

        savedPrint := printFlag.

        savedPrompt := prompt.

        currentDirectory := filename directory.

        inputStream := newInput.

        self

            basicReadEvalPrintLoopWithInput:newInput

            output:outputStream

            error:errorStream

            compiler:(compiler ? Compiler ? Parser)

            prompt:false

            print:false.

    ] ensure:[

        newInput close.

        doChunkFormat := savedDoChunkFormat.

        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"