I stand corrected. Nuclear style feature then.
'Let me get out of here {Smalltalk snapshot:false andQuit: true}. BOOM' interpolate Feels like STR='sudo reboot'; $(STR) in bash when one is sudoer. Phil On Thu, Sep 28, 2017 at 4:43 PM, Sven Van Caekenberghe <s...@stfx.eu> wrote: > > > > On 28 Sep 2017, at 16:27, p...@highoctane.be wrote: > > > > We also have http://norbert.hartl.name/blog/2013/10/03/mustache- > templates-for-smalltalk/ > > > > Phil > > Yes, Mustache is a cool templating engine, but it is similar to #format: > not to #interpolate. With true string interpolation, you do not provide a > context, you just write the expressions inline. Compare the following two: > > 'Today is {1} format: { Date today }. > > 'Today is { Date today }' interpolate. > > > On Thu, Sep 28, 2017 at 4:20 PM, Sven Van Caekenberghe <s...@stfx.eu> > wrote: > > Hi, > > > > I got into a little office discussion about string interpolation as it > is done in different programming languages. > > > > In Pharo we have String>>#format: which is pretty nice. It works as > follows: > > > > | x y | > > x := 123. > > y := #foo. > > 'x={1} and y={2}' format: { x. y }. > > > > It is also possible to use a dictionary with keys, like this: > > > > | x y | > > x := 123. > > y := #foo. > > 'x={x} and y={y}' format: { #x->x. #y->y } asDictionary. > > > > But this is not true string interpolation as described in [ > https://en.wikipedia.org/wiki/String_interpolation ]. The idea is to > write the value generating expressions directly inside the strings. > > > > Since in Pharo we add features not by extending the syntax but by adding > messages I wondered if it could be done for string interpolation. The goal > is to make the following work: > > > > | x y | > > x := 123. > > y := #foo. > > 'It seems x equals {x} and y equals {y} while Pi is still {Float pi}' > interpolate. > > > > => 'It seems x equals 123 and y equals foo while Pi is still > 3.141592653589793' > > > > Here is the implementation I came up with: > > > > String>>#interpolate > > "Format the receiver by interpolating the evaluation of expressions > > in between curly brackets in the context of the sender as in the > following 3 oneline examples. > > 'Today is {Date today}' interpolate. > > | x | x := 123. 'x equals {x} and pi equals {Float pi}' interpolate. > > 'In {#strings} you can escape \{ by prefixing it with \\' interpolate." > > > > | senderContext | > > senderContext := thisContext sender. > > ^ self class new: self size streamContents: [ :out | | stream | > > stream := self readStream. > > [ stream atEnd ] whileFalse: [ | currentChar | > > (currentChar := stream next) == ${ > > ifTrue: [ | expression result | > > expression := stream upTo: $}. > > result := Compiler new > > evaluate: expression in: senderContext to: nil notifying: > nil ifFail: [ ^ nil ] logged: false. > > out nextPutAll: result asString ] > > ifFalse: [ > > currentChar == $\ > > ifTrue: [ stream atEnd ifFalse: [ out nextPut: stream next > ] ] > > ifFalse: [ out nextPut: currentChar ] ] ] ] > > > > It is a hack that could certainly be improved. And there is of course an > obvious security problem. > > > > Thoughts ? > > > > Sven > > > > > > > > >