"{ Package: 'stx:libbasic2' }"

Object subclass:#PrintfScanf

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'System-Support'

!

!PrintfScanf class methodsFor:'documentation'!

documentation

"   

    Contributed by Jan Steinman donated to the

    community in 1989.

    Provided AS-IS - no warranty, use at your own risk.

    Original comment:

        NAME            printf-scanf

        AUTHOR          Jan Steinman <jans@tekgvs.labs.tek.com>

        FUNCTION        printf and scanf for Smalltalk

        ST-VERSIONS     Tek 2.2.2a 4.0

        PREREQUISITES   CharacterComparing

        CONFLICTS       

        DISTRIBUTION    world

        VERSION         1.1

        DATE            Apr 1989?

        SUMMARY 

    The following methods implement printf and scanf functionality.  They

    are intended to be used to ease porting between Smalltalk and C, and

    for facilitating machine-machine communication.  They are not at all

    intended as replacements for Smalltalk's printOn: functionality.

    Jan Steinman - N7JDB

    Tektronix Electronic Systems Laboratory

    Box 500, MS 50-370, Beaverton, OR 97077

    (w)503/627-5881 (h)503/657-7703

"

!

examples

"

    self new printf:'%#x %#X %03o%*.*s' arguments: #(16rABCD 16rEF 5 9 5 ''ghijklmn'') 

    self new printf:'%- 10.4s%.2e' arguments: (Array with: 'abcdefghijkl' with: Float pi)  

    self new printf:'%8.3f' arguments: (Array with: 200 sqrt negated)

    self new printf:'%c' arguments: #(16r41) 

    self new printf:'%c' arguments: #( $A )  

    self new printf:'%s' arguments: #( $A )  

    self new printf:'%s' arguments: #( 'hello' )   

    self new printf:'%4s' arguments: #( 'hello' )   

    self new printf:'%7s' arguments: #( 'hello' )   

    self new sscanf:'%f%2s%s%s%s' string: '237.0 this is a test' 

    self new sscanf:'%d%f%s' fromString: '25 54.32e-01 monday'

    self new sscanf:'%f%*f %8[A-F0-9]%c%d 0x%x%f' fromString: '12.45 1048.73 AE40Z527 0x75BCD15 34' 

    '%#x %#X %03o%*.*s' printf: #(16rABCD 16rEF 5 9 5 ''ghijklmn'') 

    '%- 10.4s%.2e' printf: (Array with: 'abcdefghijkl' with: Float pi)  

    '%8.3f' printf: (Array with: 200 sqrt negated)

    '%c' printf: #(16r41)

    '%f%2s%s%s%s' sscanf: '237.0 this is a test' 

    '%d%f%s' sscanf: '25 54.32e-01 monday'

    '%f%*f %8[A-F0-9]%c%d 0x%x%f' sscanf: '12.45 1048.73 AE40Z527 0x75BCD15 34'

"

! !

!PrintfScanf methodsFor:'printing'!

printArgFrom:inStream to:outStream arguments:argStream

    "Interpret the required number of arguments from <argStream>

     according to the formatting information in <inStream>.  Place

     the interpretation on <outStream>.  The interpretation is C

     printf(3) style, as described in the UTek manual page for

     printf(3).  <inStream> is assumed to be positioned just past

     $%, and a complete control string is assumed available.     

     Return when the conversion control string is consumed.  

     Leave <inStream> pointing past the last character in the conversion control string.

     This code assumes that <inStream> is formatted according to

     specification, and error checking is minimal.  Unexpected

     results will be obtained by illegal control strings, or when

     argument types do not match conversion codes, but it probably

     won't dump core, like C does in such cases!!!!"    

    | ljust plus pound width precision pad char arg argString sci |

    ljust := plus := pound := false.

    width := 0.

    precision := SmallInteger maxVal.

    pad := $ .

    char := inStream peek.

    char == $% ifTrue:[ 

        ^ outStream nextPut: inStream next

    ].

    char == $- ifTrue:[

        ljust := true.  

        inStream next.  

        char := inStream peek

    ].

    char == $  ifTrue:[

        outStream space.  

        inStream next.  

        char := inStream peek

    ].

    char == $+ ifTrue:[

        plus := true.  

        inStream next. 

        char := inStream peek

    ].

    char == $# ifTrue:[

        pound := true.  

        inStream next.  

        char := inStream peek

    ].

    char == $* ifTrue:[

        width := argStream next.  

        inStream next.  

        char := inStream peek

    ].

    char isDigit ifTrue:[

        char == $0 ifTrue: [pad _ $0].

        width := Integer readFrom: inStream.  

        char := inStream peek

    ].

    char == $. ifTrue:[

        inStream next.  char _ inStream peek.

        char == $*

                    ifTrue: [precision _ argStream next.  inStream next.  char _ inStream peek]

                    ifFalse: [precision _ Integer readFrom: inStream.  char _ inStream peek]

    ].

    char == $l ifTrue:[

        "Ignore long specifier."

        inStream next.  char _ inStream peek

    ].

    ('feg' includes: char) ifTrue:[

            arg _ argStream next asFloat.

            precision _ precision min: 6.

            argString _ WriteStream on: String new.

            char == $g ifTrue:

                    [self absPrintFloat:arg on: argString digits: precision + 1].

            char == $f ifTrue:

                    [self absDecimalPrintFloat:arg on: argString digits: precision + arg abs log + 1].

            char == $e ifTrue:

                    [self absScientificPrintFloat:arg on: argString digits: precision + 1].

            argString _ argString contents.

            arg < 0

                    ifTrue: [argString _ '-', argString]

                    ifFalse: [plus ifTrue: [argString _ '+', argString]].

            (precision = 0 and: [pound not]) ifTrue:

                    [(argString includes: $e)

                            ifTrue: ["self halt"]

                            ifFalse:

                                    [argString _ arg truncated printString]].

            pound ifTrue:

                    [(argString includes: $e)

                            ifTrue: ["self halt"]

                            ifFalse:

                                    [precision - (argString size - (argString indexOf: $.)) timesRepeat:

                                            [argString _ argString, '0']]].

            ljust ifTrue: [outStream nextPutAll: argString].

            width - argString size timesRepeat: [outStream space].

            ljust ifFalse: [outStream nextPutAll: argString].

            ^inStream next

    ].

    char == $c ifTrue:[

        arg _ String with: argStream next asCharacter

    ].

    char == $s ifTrue:[

        "Assume the arg is a String or Symbol."

        arg _ argStream next asString

    ].

    char == $d ifTrue:[

        arg _ argStream next asInteger printString.

        plus ifTrue: [arg _ '+', arg]

    ].

    char == $u ifTrue:[

        arg _ argStream next asInteger abs printString

    ].

    char == $o ifTrue:[

        arg _ argStream next asInteger abs printStringRadix: 8.

            pound ifTrue: [arg _ '0', arg]

    ].

    ('xX' includes: char) ifTrue:[

        arg _ argStream next asInteger abs printStringRadix: 16.

        pound ifTrue: [arg _ '0x', arg]

    ].

    char == $x ifTrue:[

        1 to: arg size do: [:i |

                    ('ABCDEF' includes: (arg at: i)) ifTrue:

                            [arg at: i put: ((arg at: i) asciiValue + 16r20) asCharacter]]

    ].

    precision _ precision min: arg size.

    ljust ifTrue: [outStream nextPutAll: (arg copyFrom: 1 to: precision)].

    width - precision timesRepeat: [outStream nextPut: pad].

    ljust ifFalse: [outStream nextPutAll: (arg copyFrom: 1 to: precision)].

    ^ inStream next

!

printf:aString arguments:args 

    "Format and print the receiver with <args> formatted in C style, 

     as described in the UTek manual page for printf(3)."

    |aStream|

    aStream := WriteStream on:String new.

    self 

        printf:aString

        on:aStream

        arguments:args.

    ^ aStream contents

    "

     self new printf:'%d %x' arguments:#(1234 45054) 

    "

!

printf:aFormatString on:outStream arguments: args

    "Format and print aFormatString on <outStream> with <args>

     formatted in C style, as described in the UTek manual page for

     printf(3).  This method is designed for producing output

     suitable for a machine."     

    | argStream inStream char |

    argStream := ReadStream on: args.

    inStream := ReadStream on: aFormatString.

    [inStream atEnd] whileFalse:[

        (char := inStream next) == $% ifFalse: [

            outStream nextPut: char

        ] ifTrue: [

            self printArgFrom:inStream to:outStream arguments:argStream

        ]

    ]

! !

!PrintfScanf methodsFor:'queries'!

absDecimalPrintFloat:aFloat on:aStream digits:digits 

    "Place a string representation of the receiver on <aStream> using <digits> significant digits, using decimal notation."

    |exp x fuzz i|

    "x is myself normalized to (1.0, 10.0), exp is my exponent"

    exp := aFloat abs < 1.0 ifTrue:[

                (10.0 / aFloat abs) log floor negated

            ] ifFalse:[

                aFloat abs log floor

            ].

    x := aFloat abs / (10.0 raisedTo:exp).

    fuzz := 10.0 raisedTo:1 - digits.

    x := 0.5 * fuzz + x.

    x >= 10.0 ifTrue:[ 

        "check if rounding has unnormalized x" 

        x := x / 10.0.

        exp := exp + 1

    ].

    exp < 0 ifTrue:[

        1 to:1 - exp do:[:j | 

            aStream nextPut:('0.000000000000' at:j)

        ]

    ].

    [ x >= fuzz ] whileTrue:[ 

        "use fuzz to track significance" 

        i := x truncated.

        aStream nextPut:(48 + i) asCharacter.

        x := (x - i) * 10.0.

        fuzz := fuzz * 10.0.

        exp := exp - 1.

        exp = -1 ifTrue:[

            aStream nextPut:$.

        ]

    ].

    [ exp >= -1 ] whileTrue:[

        aStream nextPut:$0.

        exp := exp - 1.

        exp = -1 ifTrue:[

            aStream nextPut:$.

        ]

    ]

!

absPrintFloat:aFloat on:aStream digits:digits 

    "Place a string representation of the receiver on <aStream> using <digits> significant digits."

    (aFloat < 1.0e6 and:[ aFloat > 1.0e-4 ]) ifTrue:[

        self 

            absDecimalPrintFloat:aFloat

            on:aStream

            digits:digits

    ] ifFalse:[

        aFloat 

            absScientificPrintFloat:aFloat

            on:aStream

            digits:digits

    ]

!

absScientificPrintFloat:aFloat on:aStream digits:digits 

    "Place a string representation of the receiver on <aStream> using <digits> significant digits, using scientific notation."

    |exp fuzz x q i|

    "x is myself normalized to [1.0, 10.0), exp is my exponent"

    exp := aFloat abs < 1.0 ifTrue:[

                (10.0 / aFloat abs) log floor negated

            ] ifFalse:[

                aFloat abs log floor

            ].

    x := aFloat abs / (10.0 raisedTo:exp).

    fuzz := 10.0 raisedTo:1 - digits.

    x := 0.5 * fuzz + x.

    x >= 10.0 ifTrue:[ "check if rounding has unnormalized x" 

        x := x / 10.0.

        exp := exp + 1

    ].

    q := exp.

    exp := 0.

    [ x >= fuzz ] whileTrue:[

        "use fuzz to track significance" 

        i := x truncated.

        aStream nextPut:(48 + i) asCharacter.

        x := (x - i) * 10.0.

        fuzz := fuzz * 10.0.

        exp := exp - 1.

        exp = -1 ifTrue:[

            aStream nextPut:$.

        ]

    ].

    [ exp >= -1 ] whileTrue:[

        aStream nextPut:$0.

        exp := exp - 1.

        exp = -1 ifTrue:[

            aStream nextPut:$.

        ]

    ].

    aStream nextPut:$e.

    q printOn:aStream

!

formatArgCountFor:aFormatString

    "Return the number of arguments required/produced,

     if the argument is interpreted as a printf/scanf format control string."

    |nonConsecutive count|

    nonConsecutive := true.

    count := 0.

    aFormatString do:[:c |

        c == $% ifTrue:[

            nonConsecutive ifTrue:[

                count := count + 1. 

                nonConsecutive := false

            ] ifFalse:[

                count := count - 1. 

                nonConsecutive := true

            ]

        ] ifFalse:[

            nonConsecutive := true

        ]

    ].

    ^ count

! !

!PrintfScanf methodsFor:'scanning'!

scanArgFrom:dataStream to:collection format:format 

    "Add to <collection> an object who's representation is found

     in <dataStream> interpreted according to the conversion

     control string in the Stream <format>.  <format> is assumed to

     be positioned just past a $%, and a complete control string is

     assumed available.    

     Return when the conversion control string is consumed.  Leave

     <format> pointing past the last character in the conversion

     control string, leave <dataStream> pointing past any width

     specified in <format>, or at the first character that doesn't

     make sense for the <format>."

    |final width char pos data scanset exclusive return last|

    final := [:retval | 

            collection add:retval.

            data == dataStream ifFalse:[

                dataStream position:dataStream position + data position

            ].

            ^ self

        ].

    char := format peek.

    char == $% ifTrue:[

        ^ dataStream peekFor:char

    ].

    char == $* ifTrue:[

        format next.

        char := format peek.

        final := [:retval | 

                data == dataStream ifFalse:[

                    dataStream position:dataStream position + data position

                ].

                ^ self

            ]

    ].

    width := 0.

    char isDigit ifTrue:[

        width := Integer readFrom:format.

        char := format peek

    ].

    ('slhduoxfeg' includes:char) ifTrue:[

        dataStream skipSeparators

    ].

    width = 0 ifTrue:[

        data := dataStream

    ] ifFalse:[

        pos := dataStream position.

        data := ReadStream on:(dataStream next:width).

        dataStream position:pos

    ].

    char == $s ifTrue:[

        final value:(data upToSeparator)

    ].

    char == $c ifTrue:[

        width = 0 ifTrue:[

            final value:(String with:data next)

        ] ifFalse:[

            final value:data contents

        ]

    ].

    char == $[ ifTrue:[

        "What a mess!!!!" 

        return := WriteStream on:(String new:8).

        scanset := IdentitySet new.

        format next.

        width = 0 ifTrue:[

            width := SmallInteger maxVal

        ].

        exclusive := format peekFor:$^.

        [

            last := char.

            char := format next.

            char == $]

        ] whileFalse:[

            char == $- ifFalse:[

                scanset add:char

            ] ifTrue:[

                (last to:format next) do:[:c | 

                    scanset add:c

                ]

            ]

        ].

        [

            data atEnd not and:[ (scanset includes:data peek) xor:exclusive ]

        ] whileTrue:[ return nextPut:data next ].

        final value:return contents

    ].

    ('lh' includes:char) ifTrue:[

        format next.

        char := format peek

    ].

    ('DUdu' includes:char) ifTrue:[

        final value:(Integer readFrom:data)

    ].

    ('FEGfeg' includes:char) ifTrue:[

        final value:(Float readFrom:data)

    ].

    ('Oo' includes:char) ifTrue:[

        final value:(Integer readFrom:data radix:8)

    ].

    ('Xx' includes:char) ifTrue:[

        final value:(Integer readFrom:data radix:16)

    ]

!

scanf:formatString fromStream:dataStream 

    "Return a Collection of objects found in the Character Stream

     <dataStream> as interpreted according to the receiver.  The

     receiver is assumed to be a conversion control string as

     specified in the UTek manual page for scanf(3)."

    |results format char|

    results := OrderedCollection new.

    format := ReadStream on:formatString.

    [ format atEnd ] whileFalse:[

        char := format next.

        (char == Character space or:[ char == Character tab ]) ifTrue:[

            dataStream skipSeparators.

            format skipSeparators