On Tue, Feb 5, 2013 at 10:14 PM, Eliot Miranda eliot.miranda@gmail.comwrote:

Hi All,

I had fun implementing a quasi-quote for Squeak today.  This is a

convenient way of embedding substrings in format strings (a little like printf), and, because it uses a different quote character, a convenient way of embedding code form other languages in a string literal.

An example of the former usage is `hello [#cruel] world` which evaluates to 'hello cruel world' And `Float pi is [Float pi]` evaluates to 'Float pi is 3.141592653589793'

An example of the latter use is that one can write `printf("%s: %c\n", "a string", 'C');` instead of 'printf("%s: %c\n", "a string", ''C'');'

This last example shows a limitation; The use of \ to escape characters ($\ $[ and $`) in quasi-quote might not be such a good choice.

Anyway I thought I'd put this in the in-box for people to play with and savage. Please let me know what you think, both about the semantics and the implementation. This is a quick hack and I'm sure that there's plenty of scope for clean-up.

And while I have it compiling, reporting errors, running and decompiling, I don't have it syntax highlighting yet.

cheers Eliot

On Tue, Feb 5, 2013 at 9:54 PM, commits@source.squeak.org wrote:

...

A new version of Compiler was added to project The Inbox: http://source.squeak.org/inbox/Compiler.quasiquote-eem.248.mcz

==================== Summary ====================

Name: Compiler.quasiquote-eem.248 Author: eem Time: 5 February 2013, 9:54:20.317 pm UUID: ef044906-3339-48cc-856b-9b5172e3e81b Ancestors: Compiler-cwp.247

Add a quasi-quote form that allows convenient embedding of substrings within a format string, and provides a convenient way of embedding literal strings within an alternative literal string whose string delimiter is different.

e.g. `hello [#cruel] world!` evaluates to 'hello cruel world'.

    `S1[B1]...SN[BN]SN+1`

is equivalent to { 'S1'. [B1] value. ... 'SN'. [BN] value. 'SN+1' } concatenateQuasiQuote where concatenateQuasiQuote sends asString to each element and answers the concatenation of those elements.

however, single-statement blocks are inlined, so e.g. the above `hello [#cruel] world!` is compiled as { 'hello '. #cruel. ' world!' } concatenateQuasiQuote

See Tests.quasiquote-eem.188 for tests and examples.

=============== Diff against Compiler-cwp.247 ===============

Item was added:

• ----- Method: Array>>concatenateQuasiQuote (in category

'*Compiler-support') -----

• concatenateQuasiQuote

•   "This method is used in compilation of quasi-quote constructs.
  

•   It MUST NOT be deleted or altered."
  

•   | s sz |
  

•   sz := self size.
  

•   s := WriteStream on: (String new: sz * 16).
  

•   1 to: sz do:
  

•           [:i| s nextPutAll: (self at: i) asString].
  

•   ^s contents!
  
  

Item was removed:

• ----- Method: Decompiler>>checkForBlock:selector:arguments: (in

category 'control') -----

• checkForBlock: receiver selector: selector arguments: arguments

•   selector == #blockCopy: ifTrue:
  

•           [^self checkForBlockCopy: receiver].
  

•   self assert: selector == #closureCopy:copiedValues:.
  

•   ^self checkForClosureCopy: receiver arguments: arguments!
  
  

Item was added:

• ----- Method: Decompiler>>checkForMacroMessage:selector:arguments: (in

category 'control') -----

• checkForMacroMessage: rcvr selector: selector arguments: args

•   ^       (selector == #concatenateQuasiQuote
  

•              and: [self checkForQuasiQuote: rcvr selector: selector
  

arguments: args])

•     or: [(#closureCopy:copiedValues: == selector
  

•              and: [self checkForClosureCopy: rcvr arguments: args])
  

•     or: [#blockCopy: == selector
  

•             and: [self checkForBlockCopy: rcvr]]]!
  
  

Item was added:

• ----- Method: Decompiler>>checkForQuasiQuote:selector:arguments: (in

category 'control') -----

• checkForQuasiQuote: rcvr "<BraceNode>" selector: selector "<Symbol>"

arguments: args "<Array>"

•   stack addLast:
  

•           ((MessageNode new
  

•                           receiver: rcvr
  

•                           selector: (SelectorNode new key:
  

#concatenateQuasiQuote code: nil)

•                           arguments: args
  

•                           precedence: 1)
  

•                   notePrintingSelector: #printQuasiQuoteOn:indent:;
  

•                   yourself).
  

•   ^true!
  
  

Item was changed: ----- Method: Decompiler>>send:super:numArgs: (in category 'instruction decoding') ----- send: selector super: superFlag numArgs: numArgs

    | args rcvr selNode msgNode messages |
    args := Array new: numArgs.
    (numArgs to: 1 by: -1) do:
            [:i | args at: i put: stack removeLast].
    rcvr := stack removeLast.
    superFlag ifTrue: [rcvr := constructor codeSuper].

•   (self checkForMacroMessage: rcvr selector: selector arguments:
  

args) ifFalse:

•   ((#(blockCopy: closureCopy:copiedValues:) includes: selector)
  

•     and: [self checkForBlock: rcvr selector: selector arguments:
  

args]) ifFalse: [selNode := constructor codeAnySelector: selector. rcvr == CascadeFlag ifTrue: ["May actually be a cascade or an ifNil: for value." self willJumpIfFalse ifTrue: "= generated by a case macro" [selector == #= ifTrue: [" = signals a case statement..." statements addLast: args first. stack addLast: rcvr. "restore CascadeFlag" ^ self]. selector == #== ifTrue: [" == signals an ifNil: for value..." stack removeLast; removeLast. rcvr := stack removeLast. stack addLast: IfNilFlag; addLast: (constructor

codeMessage: rcvr

selector: selNode

arguments: args). ^ self]] ifFalse: [(self willJumpIfTrue and: [selector == #==]) ifTrue: [" == signals an ifNotNil: for value..." stack removeLast; removeLast. rcvr := stack removeLast. stack addLast: IfNilFlag; addLast: (constructor

codeMessage: rcvr

selector: selNode

arguments: args). ^ self]]. msgNode := constructor

codeCascadedMessage: selNode

arguments: args. stack last == CascadeFlag ifFalse: ["Last message of a cascade" statements addLast: msgNode. messages := self popTo: stack removeLast. "Depth saved by first dup" msgNode := constructor

codeCascade: stack removeLast

messages: messages]] ifFalse: [msgNode := constructor codeMessage: rcvr selector: selNode arguments: args]. stack addLast: msgNode]!

Item was changed: ----- Method: MessageNode class>>initialize (in category 'class initialization') ----- initialize "MessageNode initialize" MacroSelectors := #( ifTrue: ifFalse: ifTrue:ifFalse: ifFalse:ifTrue: and: or: whileFalse: whileTrue: whileFalse whileTrue to:do: to:by:do: caseOf: caseOf:otherwise: ifNil: ifNotNil: ifNil:ifNotNil: ifNotNil:ifNil:

•                   repeat
  

•                   nil "space for concatenateQuasiQuote" ).
  

•                   repeat ).
    MacroTransformers :=
            #(      transformIfTrue: transformIfFalse:
  

transformIfTrueIfFalse: transformIfFalseIfTrue: transformAnd: transformOr: transformWhile: transformWhile: transformWhile: transformWhile: transformToDo: transformToDo: transformCase: transformCase: transformIfNil: transformIfNil: transformIfNilIfNotNil: transformIfNotNilIfNil:

•                   transformRepeat:
  

•                   nil "space for concatenateQuasiQuote" ).
  

•                   transformRepeat: ).
    MacroEmitters :=
            #(      emitCodeForIf:encoder:value:
  

emitCodeForIf:encoder:value: emitCodeForIf:encoder:value: emitCodeForIf:encoder:value: emitCodeForIf:encoder:value: emitCodeForIf:encoder:value: emitCodeForWhile:encoder:value: emitCodeForWhile:encoder:value: emitCodeForWhile:encoder:value: emitCodeForWhile:encoder:value: emitCodeForToDo:encoder:value: emitCodeForToDo:encoder:value: emitCodeForCase:encoder:value: emitCodeForCase:encoder:value: emitCodeForIfNil:encoder:value: emitCodeForIfNil:encoder:value: emitCodeForIf:encoder:value: emitCodeForIf:encoder:value:

•                   emitCodeForRepeat:encoder:value:
  

•                   nil "space for concatenateQuasiQuote").
  

•                   emitCodeForRepeat:encoder:value:).
    MacroSizers :=
            #(      sizeCodeForIf:value: sizeCodeForIf:value:
  

sizeCodeForIf:value: sizeCodeForIf:value: sizeCodeForIf:value: sizeCodeForIf:value: sizeCodeForWhile:value: sizeCodeForWhile:value: sizeCodeForWhile:value: sizeCodeForWhile:value: sizeCodeForToDo:value: sizeCodeForToDo:value: sizeCodeForCase:value: sizeCodeForCase:value: sizeCodeForIfNil:value: sizeCodeForIfNil:value: sizeCodeForIf:value: sizeCodeForIf:value:

•                   sizeCodeForRepeat:value:
  

•                   nil "space for concatenateQuasiQuote").
  

•                   sizeCodeForRepeat:value:).
    MacroPrinters :=
            #(      printIfOn:indent: printIfOn:indent:
  

printIfOn:indent: printIfOn:indent: printIfOn:indent: printIfOn:indent: printWhileOn:indent: printWhileOn:indent: printWhileOn:indent: printWhileOn:indent: printToDoOn:indent: printToDoOn:indent: printCaseOn:indent: printCaseOn:indent: printIfNil:indent: printIfNil:indent: printIfNilNotNil:indent: printIfNilNotNil:indent:

•                   printRepeatOn:indent:
  

•                   printQuasiQuoteOn:indent:)!
  

•                   printRepeatOn:indent:)!
  
  

Item was added:

• ----- Method: MessageNode>>notePrintingSelector: (in category 'macro

transformations') -----

• notePrintingSelector: printingSelectorSymbol

•   "decompile"
  

•   special := MacroPrinters indexOf: printingSelectorSymbol!
  
  

Item was added:

• ----- Method: MessageNode>>printQuasiQuoteOn:indent: (in category

'printing') -----

• printQuasiQuoteOn: aStream indent: level

•   aStream nextPut: $`.
  

•   receiver elements do:
  

•           [:parseNode|
  

•           (parseNode isLiteralNode
  

•            and: [parseNode key class == 'literal' class])
  

•                   ifTrue:
  

•                           [parseNode key do:
  

•                                   [:char|
  

•                                   ('`[\' includes: char) ifTrue:
  

•                                           [aStream nextPut: $\].
  

•                                   aStream nextPut: char]]
  

•                   ifFalse:
  

•                           [(parseNode isMessageNode
  

•                             and: [parseNode selector key == #value
  

•                             and: [parseNode receiver isBlockNode]])
  

•                                   ifTrue:
  

•                                           [parseNode receiver
  

printOn: aStream indent: 0]

•                                   ifFalse:
  

•                                           [aStream nextPut: $[.
  

•                                            parseNode printOn:
  

aStream indent: 0.

•                                            aStream nextPut: $]]]].
  

•   aStream nextPut: $`!
  
  

Item was changed: ----- Method: Parser>>advance (in category 'scanning') ----- advance | this | prevMark := hereMark. prevEnd := hereEnd. this := here. here := token. hereType := tokenType. hereMark := mark. hereEnd := source position - (aheadChar == DoItCharacter ifTrue: [hereChar == DoItCharacter ifTrue: [0] ifFalse: [1]] ifFalse: [2]).

•   hereType ~~ #backQuote ifTrue:
  

•           [self scanToken].
  

•   self scanToken.
    "Transcript show: 'here: ', here printString, ' mark: ', hereMark
  

printString, ' end: ', hereEnd printString; cr." ^this!

Item was changed: ----- Method: Parser>>expression (in category 'expression types') ----- expression

•   (hereType == #word and: [tokenType == #leftArrow]) ifTrue:
  

•           [^self assignment: self variable].
  

•   hereType == #backQuote
  

•           ifTrue: [self quasiQuoteExpression]
  

•           ifFalse:
  

•                   [hereType == #leftBrace
  

•                           ifTrue: [self braceExpression]
  

•                           ifFalse:
  

•                                   [self primaryExpression ifFalse:
  

•                                           [^false]]].
  

•   (self messagePart: 3 repeat: true) ifTrue:
  

•           [hereType == #semicolon ifTrue:
  

•                   [self cascade]].
  

•   ^true!
  

•   (hereType == #word and: [tokenType == #leftArrow])
  

•           ifTrue: [^ self assignment: self variable].
  

•   hereType == #leftBrace
  

•           ifTrue: [self braceExpression]
  

•           ifFalse: [self primaryExpression ifFalse: [^ false]].
  

•   (self messagePart: 3 repeat: true)
  

•           ifTrue: [hereType == #semicolon ifTrue: [self cascade]].
  

•   ^ true!
  
  

Item was added:

• ----- Method: Parser>>nonQuasiQuoteExpression (in category 'expression

types') -----

• nonQuasiQuoteExpression

•   (hereType == #word and: [tokenType == #leftArrow])
  

•           ifTrue: [^ self assignment: self variable].
  

•   hereType == #leftBrace
  

•           ifTrue: [self braceExpression]
  

•           ifFalse: [self primaryExpression ifFalse: [^ false]].
  

•   (self messagePart: 3 repeat: true)
  

•           ifTrue: [hereType == #semicolon ifTrue: [self cascade]].
  

•   ^ true!
  
  

Item was added:

• ----- Method: Parser>>quasiQuoteExpression (in category 'expression

types') -----

• quasiQuoteExpression

•   "`quasi-quote`
  

•           => { elements } concatenateQuasiQuote
  

•                   => MessageNode receiver: BraceNode selector:
  

#concatenateQuasiQuote.

•    The syntax of quasi-quote is
  

•           quasi-quote := $` (characters | blockExpression) * $`
  

•           characters := (unescapedCharacter | $\ escapedCharacter) *
  

•   The semantics of quasi-quote are that each blockExpression is
  

evaluated

•    left-to-right in the scope of the enclosing method or block.
  

The sequence

•    of interspersed character sequences and expressions are
  

concatenated

•    left-to-right, sending asString to each element immediately
  

prior to concatenation.

•    The concatenation is then the result of the expression.  It is
  

always a new string.

•    The implementation inlines single-statement blocks into the
  

brace expression that

•    comprises the receiver of concatenateQuasiQuote"
  

•   | elements locations stringStream loc |
  

•   elements := OrderedCollection new.
  

•   locations := OrderedCollection new.
  

•   stringStream := WriteStream on: (String new: 16).
  

•   [loc := hereMark + requestorOffset.
  

•    hereType == #doit ifTrue:
  

•           [^self expected: 'back quote'].
  

•    hereType == #leftBracket
  

•           ifTrue:
  

•                   [self scanToken; advance.
  

•                    parseNode := nil.
  

•                    self blockExpression.
  

•                    parseNode statements size = 1
  

•                           ifTrue:
  

•                                   [elements addLast: parseNode
  

statements first]

•                           ifFalse:
  

•                                   [elements addLast: (MessageNode
  

new

•         receiver: parseNode
  

•         selector: #value
  

•         arguments: #()
  

•         precedence: 1
  

•         from: encoder)].
  

•                    source position: hereMark - 1.
  

•                    [source peek ~~ $]] whileTrue:
  

•                           [source position: source position - 1].
  

•                    source next.
  

•                    self step; step.
  

•                    self setHereTypeForQuasiQuote.
  

•                    locations addLast: loc]
  

•           ifFalse:
  

•                   [(self scanQuasiQuoteCharactersUsing:
  

stringStream) ifNotNil:

•                           [:lit|
  

•                            elements addLast: lit.
  

•                            locations addLast: loc]].
  

•    hereType ~~ #backQuote] whileTrue.
  

•   parseNode := MessageNode new
  

•                                   receiver: (BraceNode new
  

elements: elements sourceLocations: locations)

•                                   selector: #concatenateQuasiQuote
  

•                                   arguments: #()
  

•                                   precedence: 1
  

•                                   from: encoder.
  

•   self scanToken; advance.
  

•   ^true!
  
  

Item was changed:

• ----- Method: Parser>>queriedUnusedTemporaries (in category 'temps')

---

• ----- Method: Parser>>queriedUnusedTemporaries (in category

'accessing') ----- queriedUnusedTemporaries

    queriedUnusedTemporaries ifNil:
            [queriedUnusedTemporaries := Dictionary new].
    ^queriedUnusedTemporaries!

Item was added:

• ----- Method: Parser>>scanQuasiQuoteCharactersUsing: (in category

'scanning') -----

• scanQuasiQuoteCharactersUsing: stringStream

•   "Answer the next non-empty sequence of characters in a
  

quasi-quote string, or nil, if none."

•   stringStream reset.
  

•   [hereChar ~~ $` and: [hereChar ~~ $[ and: [hereChar ~~
  

DoItCharacter]]] whileTrue:

•           [hereChar == $\
  

•                   ifTrue:
  

•                           [stringStream nextPut: aheadChar. self
  

step]

•                   ifFalse:
  

•                           [stringStream nextPut: hereChar].
  

•            self step].
  

•   self setHereTypeForQuasiQuote.
  

•   ^stringStream position > 0 ifTrue:
  

•           [encoder encodeLiteral: stringStream contents]!
  
  

Item was added:

• ----- Method: Parser>>setHereTypeForQuasiQuote (in category 'scanning')

---

• setHereTypeForQuasiQuote

•   "Set hereType appropriately based on hereChar.  Used only for
  

quasi-quote parsing."

•   hereChar == $`
  

•           ifTrue:
  

•                   [hereType := #backQuote.
  

•                    self step]
  

•           ifFalse:
  

•                   [hereChar == $[
  

•                           ifTrue:
  

•                                   [hereType := #leftBracket.
  

•                                    self step]
  

•                           ifFalse:
  

•                                   [hereChar == DoItCharacter ifTrue:
  

•                                           [hereType := #doit]]]!
  
  

Item was changed:

• ----- Method: Parser>>tempsMark (in category 'temps') -----

• ----- Method: Parser>>tempsMark (in category 'accessing') ----- tempsMark ^ tempsMark!

Item was changed:

• ----- Method: Parser>>tempsMark: (in category 'temps') -----

• ----- Method: Parser>>tempsMark: (in category 'accessing') ----- tempsMark: aNumber tempsMark := aNumber!

Item was changed: ----- Method: Scanner class>>initializeTypeTable (in category 'initialization') ----- initializeTypeTable "self initializeTypeTable"

    | newTable |
    newTable := Array new: 256 withAll: #xBinary. "default"
    newTable atAll: #(9 10 12 13 32 ) put: #xDelimiter. "tab lf ff cr

space" newTable atAll: ($0 asciiValue to: $9 asciiValue) put: #xDigit.

    1 to: 255
            do: [:index |
                    (Character value: index) isLetter
                            ifTrue: [newTable at: index put:

#xLetter]].

    newTable at: $" asciiValue put: #xDoubleQuote.
    newTable at: $# asciiValue put: #xLitQuote.
    newTable at: $$ asciiValue put: #xDollar.
    newTable at: $' asciiValue put: #xSingleQuote.

•   newTable at: $` asciiValue put: #backQuote.
    newTable at: $: asciiValue put: #xColon.
    newTable at: $( asciiValue put: #leftParenthesis.
    newTable at: $) asciiValue put: #rightParenthesis.
    newTable at: $. asciiValue put: #period.
    newTable at: $; asciiValue put: #semicolon.
    newTable at: $[ asciiValue put: #leftBracket.
    newTable at: $] asciiValue put: #rightBracket.
    newTable at: ${ asciiValue put: #leftBrace.
    newTable at: $} asciiValue put: #rightBrace.
    newTable at: $^ asciiValue put: #upArrow.
    newTable at: $_ asciiValue put: #xUnderscore.
    newTable at: $| asciiValue put: #verticalBar.
    TypeTable := newTable "bon voyage!!"!
  
  
  
  

-- best, Eliot

I'm reminded at this point of SmalltalkAgents which used curly quotes (single and double) so that literals and comments could nest. FWIW

On 2/6/13 1:14 AM, Eliot Miranda wrote:

Hi All,

I had fun implementing a quasi-quote for Squeak today.  This is a 

convenient way of embedding substrings in format strings (a little like printf), and, because it uses a different quote character, a convenient way of embedding code form other languages in a string literal.

An example of the former usage is `hello [#cruel] world` which evaluates to 'hello cruel world' And `Float pi is [Float pi]` evaluates to 'Float pi is 3.141592653589793'

An example of the latter use is that one can write `printf("%s: %c\n", "a string", 'C');` instead of 'printf("%s: %c\n", "a string", ''C'');'

This last example shows a limitation; The use of \ to escape characters ($\ $[ and $`) in quasi-quote might not be such a good choice.

Anyway I thought I'd put this in the in-box for people to play with and savage. Please let me know what you think, both about the semantics and the implementation. This is a quick hack and I'm sure that there's plenty of scope for clean-up.

cheers Eliot

On Tue, Feb 5, 2013 at 9:54 PM, <commits@source.squeak.org mailto:commits@source.squeak.org> wrote:

A new version of Compiler was added to project The Inbox:
http://source.squeak.org/inbox/Compiler.quasiquote-eem.248.mcz

==================== Summary ====================

Name: Compiler.quasiquote-eem.248
Author: eem
Time: 5 February 2013, 9:54:20.317 pm
UUID: ef044906-3339-48cc-856b-9b5172e3e81b
Ancestors: Compiler-cwp.247

Add a quasi-quote form that allows convenient embedding
of substrings within a format string, and provides a
convenient way of embedding literal strings within an
alternative literal string whose string delimiter is different.

e.g.
        `hello [#cruel] world!`
evaluates to
        'hello cruel world'.

        `S1[B1]...SN[BN]SN+1`

is equivalent to
        { 'S1'. [B1] value. ... 'SN'. [BN] value. 'SN+1' }
concatenateQuasiQuote
where concatenateQuasiQuote sends asString to each
element and answers the concatenation of those elements.

however, single-statement blocks are inlined, so e.g. the
above `hello [#cruel] world!` is compiled as
        { 'hello '. #cruel. ' world!' } concatenateQuasiQuote

See Tests.quasiquote-eem.188 for tests and examples.

=============== Diff against Compiler-cwp.247 ===============

Item was added:
+ ----- Method: Array>>concatenateQuasiQuote (in category
'*Compiler-support') -----
+ concatenateQuasiQuote
+       "This method is used in compilation of quasi-quote constructs.
+       It MUST NOT be deleted or altered."
+
+       | s sz |
+       sz := self size.
+       s := WriteStream on: (String new: sz * 16).
+       1 to: sz do:
+               [:i| s nextPutAll: (self at: i) asString].
+       ^s contents!

Item was removed:
- ----- Method: Decompiler>>checkForBlock:selector:arguments: (in
category 'control') -----
- checkForBlock: receiver selector: selector arguments: arguments
-       selector == #blockCopy: ifTrue:
-               [^self checkForBlockCopy: receiver].
-       self assert: selector == #closureCopy:copiedValues:.
-       ^self checkForClosureCopy: receiver arguments: arguments!

Item was added:
+ ----- Method:
Decompiler>>checkForMacroMessage:selector:arguments: (in category
'control') -----
+ checkForMacroMessage: rcvr selector: selector arguments: args
+       ^       (selector == #concatenateQuasiQuote
+                  and: [self checkForQuasiQuote: rcvr selector:
selector arguments: args])
+         or: [(#closureCopy:copiedValues: == selector
+                  and: [self checkForClosureCopy: rcvr arguments:
args])
+         or: [#blockCopy: == selector
+                 and: [self checkForBlockCopy: rcvr]]]!

Item was added:
+ ----- Method: Decompiler>>checkForQuasiQuote:selector:arguments:
(in category 'control') -----
+ checkForQuasiQuote: rcvr "<BraceNode>" selector: selector
"<Symbol>" arguments: args "<Array>"
+       stack addLast:
+               ((MessageNode new
+                               receiver: rcvr
+                               selector: (SelectorNode new key:
#concatenateQuasiQuote code: nil)
+                               arguments: args
+                               precedence: 1)
+                       notePrintingSelector:
#printQuasiQuoteOn:indent:;
+                       yourself).
+       ^true!

Item was changed:
  ----- Method: Decompiler>>send:super:numArgs: (in category
'instruction decoding') -----
  send: selector super: superFlag numArgs: numArgs

        | args rcvr selNode msgNode messages |
        args := Array new: numArgs.
        (numArgs to: 1 by: -1) do:
                [:i | args at: i put: stack removeLast].
        rcvr := stack removeLast.
        superFlag ifTrue: [rcvr := constructor codeSuper].
+       (self checkForMacroMessage: rcvr selector: selector
arguments: args) ifFalse:
-       ((#(blockCopy: closureCopy:copiedValues:) includes: selector)
-         and: [self checkForBlock: rcvr selector: selector
arguments: args]) ifFalse:
                [selNode := constructor codeAnySelector: selector.
                rcvr == CascadeFlag
                        ifTrue:
                                ["May actually be a cascade or an
ifNil: for value."
                                self willJumpIfFalse
                                        ifTrue: "= generated by a
case macro"
                                                [selector == #=
ifTrue:
                                                        [" =
signals a case statement..."
statements addLast: args first.
stack addLast: rcvr. "restore CascadeFlag"
                                                        ^ self].
                                                selector == #==
ifTrue:
                                                        [" ==
signals an ifNil: for value..."
stack removeLast; removeLast.
                                                        rcvr :=
stack removeLast.
stack addLast: IfNilFlag;
    addLast: (constructor
            codeMessage: rcvr
            selector: selNode
            arguments: args).
                                                        ^ self]]
                                        ifFalse:
                                                [(self
willJumpIfTrue and: [selector == #==]) ifTrue:
                                                        [" ==
signals an ifNotNil: for value..."
stack removeLast; removeLast.
                                                        rcvr :=
stack removeLast.
stack addLast: IfNilFlag;
    addLast: (constructor
            codeMessage: rcvr
            selector: selNode
            arguments: args).
                                                        ^ self]].
                                msgNode := constructor
    codeCascadedMessage: selNode
    arguments: args.
                                stack last == CascadeFlag ifFalse:
                                        ["Last message of a cascade"
                                        statements addLast: msgNode.
                                        messages := self popTo:
stack removeLast.  "Depth saved by first dup"
                                        msgNode := constructor
            codeCascade: stack removeLast
            messages: messages]]
                        ifFalse:
                                [msgNode := constructor
codeMessage: rcvr
selector: selNode
arguments: args].
                stack addLast: msgNode]!

Item was changed:
  ----- Method: MessageNode class>>initialize (in category 'class
initialization') -----
  initialize
        "MessageNode initialize"
        MacroSelectors :=
                #(      ifTrue: ifFalse: ifTrue:ifFalse:
ifFalse:ifTrue:
                        and: or:
                        whileFalse: whileTrue: whileFalse whileTrue
                        to:do: to:by:do:
                        caseOf: caseOf:otherwise:
                        ifNil: ifNotNil:  ifNil:ifNotNil:
ifNotNil:ifNil:
+                       repeat
+                       nil "space for concatenateQuasiQuote" ).
-                       repeat ).
        MacroTransformers :=
                #(      transformIfTrue: transformIfFalse:
transformIfTrueIfFalse: transformIfFalseIfTrue:
                        transformAnd: transformOr:
                        transformWhile: transformWhile:
transformWhile: transformWhile:
                        transformToDo: transformToDo:
                        transformCase: transformCase:
                        transformIfNil: transformIfNil:
 transformIfNilIfNotNil: transformIfNotNilIfNil:
+                       transformRepeat:
+                       nil "space for concatenateQuasiQuote" ).
-                       transformRepeat: ).
        MacroEmitters :=
                #(      emitCodeForIf:encoder:value:
emitCodeForIf:encoder:value:
                        emitCodeForIf:encoder:value:
emitCodeForIf:encoder:value:
                        emitCodeForIf:encoder:value:
emitCodeForIf:encoder:value:
                        emitCodeForWhile:encoder:value:
emitCodeForWhile:encoder:value:
                        emitCodeForWhile:encoder:value:
emitCodeForWhile:encoder:value:
                        emitCodeForToDo:encoder:value:
emitCodeForToDo:encoder:value:
                        emitCodeForCase:encoder:value:
emitCodeForCase:encoder:value:
                        emitCodeForIfNil:encoder:value:
emitCodeForIfNil:encoder:value:
                        emitCodeForIf:encoder:value:
emitCodeForIf:encoder:value:
+                       emitCodeForRepeat:encoder:value:
+                       nil "space for concatenateQuasiQuote").
-                       emitCodeForRepeat:encoder:value:).
        MacroSizers :=
                #(      sizeCodeForIf:value: sizeCodeForIf:value:
sizeCodeForIf:value: sizeCodeForIf:value:
                        sizeCodeForIf:value: sizeCodeForIf:value:
                        sizeCodeForWhile:value:
sizeCodeForWhile:value: sizeCodeForWhile:value:
sizeCodeForWhile:value:
                        sizeCodeForToDo:value: sizeCodeForToDo:value:
                        sizeCodeForCase:value: sizeCodeForCase:value:
                        sizeCodeForIfNil:value:
sizeCodeForIfNil:value: sizeCodeForIf:value: sizeCodeForIf:value:
+                       sizeCodeForRepeat:value:
+                       nil "space for concatenateQuasiQuote").
-                       sizeCodeForRepeat:value:).
        MacroPrinters :=
                #(      printIfOn:indent: printIfOn:indent:
printIfOn:indent: printIfOn:indent:
                        printIfOn:indent: printIfOn:indent:
                        printWhileOn:indent: printWhileOn:indent:
printWhileOn:indent: printWhileOn:indent:
                        printToDoOn:indent: printToDoOn:indent:
                        printCaseOn:indent: printCaseOn:indent:
                        printIfNil:indent: printIfNil:indent:
printIfNilNotNil:indent: printIfNilNotNil:indent:
+                       printRepeatOn:indent:
+                       printQuasiQuoteOn:indent:)!
-                       printRepeatOn:indent:)!

Item was added:
+ ----- Method: MessageNode>>notePrintingSelector: (in category
'macro transformations') -----
+ notePrintingSelector: printingSelectorSymbol
+       "decompile"
+
+       special := MacroPrinters indexOf: printingSelectorSymbol!

Item was added:
+ ----- Method: MessageNode>>printQuasiQuoteOn:indent: (in
category 'printing') -----
+ printQuasiQuoteOn: aStream indent: level
+       aStream nextPut: $`.
+       receiver elements do:
+               [:parseNode|
+               (parseNode isLiteralNode
+                and: [parseNode key class == 'literal' class])
+                       ifTrue:
+                               [parseNode key do:
+                                       [:char|
+                                       ('`[\' includes: char) ifTrue:
+                                               [aStream nextPut: $\].
+                                       aStream nextPut: char]]
+                       ifFalse:
+                               [(parseNode isMessageNode
+                                 and: [parseNode selector key ==
#value
+                                 and: [parseNode receiver
isBlockNode]])
+                                       ifTrue:
+                                               [parseNode
receiver printOn: aStream indent: 0]
+                                       ifFalse:
+                                               [aStream nextPut: $[.
+                                                parseNode
printOn: aStream indent: 0.
+                                                aStream nextPut:
$]]]].
+       aStream nextPut: $`!

Item was changed:
  ----- Method: Parser>>advance (in category 'scanning') -----
  advance
        | this |
        prevMark := hereMark.
        prevEnd := hereEnd.
        this := here.
        here := token.
        hereType := tokenType.
        hereMark := mark.
        hereEnd := source position - (aheadChar == DoItCharacter
                ifTrue: [hereChar == DoItCharacter
                        ifTrue: [0]
                        ifFalse: [1]]
                ifFalse: [2]).
+       hereType ~~ #backQuote ifTrue:
+               [self scanToken].
-       self scanToken.
        "Transcript show: 'here: ', here printString, ' mark: ',
hereMark printString, ' end: ', hereEnd printString; cr."
        ^this!

Item was changed:
  ----- Method: Parser>>expression (in category 'expression
types') -----
  expression

+       (hereType == #word and: [tokenType == #leftArrow]) ifTrue:
+               [^self assignment: self variable].
+       hereType == #backQuote
+               ifTrue: [self quasiQuoteExpression]
+               ifFalse:
+                       [hereType == #leftBrace
+                               ifTrue: [self braceExpression]
+                               ifFalse:
+                                       [self primaryExpression
ifFalse:
+                                               [^false]]].
+       (self messagePart: 3 repeat: true) ifTrue:
+               [hereType == #semicolon ifTrue:
+                       [self cascade]].
+       ^true!
-       (hereType == #word and: [tokenType == #leftArrow])
-               ifTrue: [^ self assignment: self variable].
-       hereType == #leftBrace
-               ifTrue: [self braceExpression]
-               ifFalse: [self primaryExpression ifFalse: [^ false]].
-       (self messagePart: 3 repeat: true)
-               ifTrue: [hereType == #semicolon ifTrue: [self
cascade]].
-       ^ true!

Item was added:
+ ----- Method: Parser>>nonQuasiQuoteExpression (in category
'expression types') -----
+ nonQuasiQuoteExpression
+
+       (hereType == #word and: [tokenType == #leftArrow])
+               ifTrue: [^ self assignment: self variable].
+       hereType == #leftBrace
+               ifTrue: [self braceExpression]
+               ifFalse: [self primaryExpression ifFalse: [^ false]].
+       (self messagePart: 3 repeat: true)
+               ifTrue: [hereType == #semicolon ifTrue: [self
cascade]].
+       ^ true!

Item was added:
+ ----- Method: Parser>>quasiQuoteExpression (in category
'expression types') -----
+ quasiQuoteExpression
+       "`quasi-quote`
+               => { elements } concatenateQuasiQuote
+                       => MessageNode receiver: BraceNode
selector: #concatenateQuasiQuote.
+
+        The syntax of quasi-quote is
+               quasi-quote := $` (characters | blockExpression) * $`
+               characters := (unescapedCharacter | $\
escapedCharacter) *
+
+       The semantics of quasi-quote are that each blockExpression
is evaluated
+        left-to-right in the scope of the enclosing method or
block.  The sequence
+        of interspersed character sequences and expressions are
concatenated
+        left-to-right, sending asString to each element
immediately prior to concatenation.
+        The concatenation is then the result of the expression.
 It is always a new string.
+
+        The implementation inlines single-statement blocks into
the brace expression that
+        comprises the receiver of concatenateQuasiQuote"
+
+       | elements locations stringStream loc |
+       elements := OrderedCollection new.
+       locations := OrderedCollection new.
+       stringStream := WriteStream on: (String new: 16).
+       [loc := hereMark + requestorOffset.
+        hereType == #doit ifTrue:
+               [^self expected: 'back quote'].
+        hereType == #leftBracket
+               ifTrue:
+                       [self scanToken; advance.
+                        parseNode := nil.
+                        self blockExpression.
+                        parseNode statements size = 1
+                               ifTrue:
+                                       [elements addLast:
parseNode statements first]
+                               ifFalse:
+                                       [elements addLast:
(MessageNode new
+                             receiver: parseNode
+                             selector: #value
+                             arguments: #()
+                             precedence: 1
+                             from: encoder)].
+                        source position: hereMark - 1.
+                        [source peek ~~ $]] whileTrue:
+                               [source position: source position
- 1].
+                        source next.
+                        self step; step.
+                        self setHereTypeForQuasiQuote.
+                        locations addLast: loc]
+               ifFalse:
+                       [(self scanQuasiQuoteCharactersUsing:
stringStream) ifNotNil:
+                               [:lit|
+                                elements addLast: lit.
+                                locations addLast: loc]].
+        hereType ~~ #backQuote] whileTrue.
+       parseNode := MessageNode new
+                                       receiver: (BraceNode new
elements: elements sourceLocations: locations)
+                                       selector:
#concatenateQuasiQuote
+                                       arguments: #()
+                                       precedence: 1
+                                       from: encoder.
+       self scanToken; advance.
+       ^true!

Item was changed:
+ ----- Method: Parser>>queriedUnusedTemporaries (in category
'temps') -----
- ----- Method: Parser>>queriedUnusedTemporaries (in category
'accessing') -----
  queriedUnusedTemporaries

        queriedUnusedTemporaries ifNil:
                [queriedUnusedTemporaries := Dictionary new].
        ^queriedUnusedTemporaries!

Item was added:
+ ----- Method: Parser>>scanQuasiQuoteCharactersUsing: (in
category 'scanning') -----
+ scanQuasiQuoteCharactersUsing: stringStream
+       "Answer the next non-empty sequence of characters in a
quasi-quote string, or nil, if none."
+       stringStream reset.
+       [hereChar ~~ $` and: [hereChar ~~ $[ and: [hereChar ~~
DoItCharacter]]] whileTrue:
+               [hereChar == $\
+                       ifTrue:
+                               [stringStream nextPut: aheadChar.
self step]
+                       ifFalse:
+                               [stringStream nextPut: hereChar].
+                self step].
+       self setHereTypeForQuasiQuote.
+       ^stringStream position > 0 ifTrue:
+               [encoder encodeLiteral: stringStream contents]!

Item was added:
+ ----- Method: Parser>>setHereTypeForQuasiQuote (in category
'scanning') -----
+ setHereTypeForQuasiQuote
+       "Set hereType appropriately based on hereChar.  Used only
for quasi-quote parsing."
+       hereChar == $`
+               ifTrue:
+                       [hereType := #backQuote.
+                        self step]
+               ifFalse:
+                       [hereChar == $[
+                               ifTrue:
+                                       [hereType := #leftBracket.
+                                        self step]
+                               ifFalse:
+                                       [hereChar == DoItCharacter
ifTrue:
+                                               [hereType := #doit]]]!

Item was changed:
+ ----- Method: Parser>>tempsMark (in category 'temps') -----
- ----- Method: Parser>>tempsMark (in category 'accessing') -----
  tempsMark
        ^ tempsMark!

Item was changed:
+ ----- Method: Parser>>tempsMark: (in category 'temps') -----
- ----- Method: Parser>>tempsMark: (in category 'accessing') -----
  tempsMark: aNumber
  tempsMark := aNumber!

Item was changed:
  ----- Method: Scanner class>>initializeTypeTable (in category
'initialization') -----
  initializeTypeTable
        "self initializeTypeTable"

        | newTable |
        newTable := Array new: 256 withAll: #xBinary. "default"
        newTable atAll: #(9 10 12 13 32 ) put: #xDelimiter. "tab
lf ff cr space"
        newTable atAll: ($0 asciiValue to: $9 asciiValue) put:
#xDigit.

        1 to: 255
                do: [:index |
                        (Character value: index) isLetter
                                ifTrue: [newTable at: index put:
#xLetter]].

        newTable at: $" asciiValue put: #xDoubleQuote.
        newTable at: $# asciiValue put: #xLitQuote.
        newTable at: $$ asciiValue put: #xDollar.
        newTable at: $' asciiValue put: #xSingleQuote.
+       newTable at: $` asciiValue put: #backQuote.
        newTable at: $: asciiValue put: #xColon.
        newTable at: $( asciiValue put: #leftParenthesis.
        newTable at: $) asciiValue put: #rightParenthesis.
        newTable at: $. asciiValue put: #period.
        newTable at: $; asciiValue put: #semicolon.
        newTable at: $[ asciiValue put: #leftBracket.
        newTable at: $] asciiValue put: #rightBracket.
        newTable at: ${ asciiValue put: #leftBrace.
        newTable at: $} asciiValue put: #rightBrace.
        newTable at: $^ asciiValue put: #upArrow.
        newTable at: $_ asciiValue put: #xUnderscore.
        newTable at: $| asciiValue put: #verticalBar.
        TypeTable := newTable "bon voyage!!"!

-- best, Eliot