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A note to anyone who creates a new programming language: Please put up a quick bite of sample code that shows how your language looks and what it does on the si

A note to anyone who creates a new programming language: Please put up a quick bite of sample code that shows how your language looks and what it does on the site, and don't require me to download a PDF and search through it.

benhoyt 18y ago
Good call. Quote from the PDF in the meantime: "To give a sense of what programming in Boomerang is like, we will define the lens implementing the transformations between XML and CSV composers shown above. First we define a lens c that handles a single <composer> element. It uses a number of functions defined in our XML library, as well as primtives for copying (copy) and deleting (del) strings, and for concatenating lenses (.). let c : lens = Xml.elt NL2 "composer" begin Xml.simple_elt NL4 "name" (copy [A-Za-z ]+ . ins ", ") . Xml.attr2_elt_no_kids NL4 "years" "birth" (copy NUMBER . ins "-") "death" (copy NUMBER) . Xml.simple_elt NL4 "nationality" (del [A-Za-z]+) end Using c, we then define a lens that handles a top-level <composers> element, enclosing a list of <composers>. This lens is defined using the features already described, a primitive for inserting a string (ins), as well as union (|) and Kleene star. let cs : lens = Xml.elt NL0 "composers" begin copy EPSILON | c . (ins newline . c)* end ..."
- benhoyt 18y ago
  Ask HN/PG: Asterisks around something make it italics (except in indented code, apparently). In the above comment I had to remove a literal asterisk in the text because I couldn't figure out how to escape it. Backslash doesn't work, and two stars in a row doesn't work. Any ideas? Update: Okay, so putting spaces around it ( * ) works. But the asterisk in question was inside parens without spaces.

benhoyt 18y ago

Good call. Quote from the PDF in the meantime: "To give a sense of what programming in Boomerang is like, we will define the lens implementing the transformations between XML and CSV composers shown above. First we define a lens c that handles a single <composer> element. It uses a number of functions defined in our XML library, as well as primtives for copying (copy) and deleting (del) strings, and for concatenating lenses (.). let c : lens = Xml.elt NL2 "composer" begin Xml.simple_elt NL4 "name" (copy [A-Za-z ]+ . ins ", ") . Xml.attr2_elt_no_kids NL4 "years" "birth" (copy NUMBER . ins "-") "death" (copy NUMBER) . Xml.simple_elt NL4 "nationality" (del [A-Za-z]+) end Using c, we then define a lens that handles a top-level <composers> element, enclosing a list of <composers>. This lens is defined using the features already described, a primitive for inserting a string (ins), as well as union (|) and Kleene star. let cs : lens = Xml.elt NL0 "composers" begin copy EPSILON | c . (ins newline . c)* end ..."

benhoyt 18y ago
Ask HN/PG: Asterisks around something make it italics (except in indented code, apparently). In the above comment I had to remove a literal asterisk in the text because I couldn't figure out how to escape it. Backslash doesn't work, and two stars in a row doesn't work. Any ideas? Update: Okay, so putting spaces around it ( * ) works. But the asterisk in question was inside parens without spaces.