Hello, Doug! As you know, I'm a newbie in Factor, so if I ask some dumb questions, please have patience or postpone your answer until you can contain your rage : )) Basically, I did not understand most of what you wrote in that epochal e-mail about the locals-and-roots branch, and some of the things I imagine I did understand I'd like you to comment on, just to make sure I have too vivid an imagination. 04.07.2016, 05:18, "Doug Coleman" :There's a branch called locals-and-roots that has locals/fry/macros/memoize/stack-checker in core Does that mean that the minimal size of the executable is growing again? A) Goals of the new parser: 1) Simplify/regularize the Factor syntax2) Remove parsing words' ability to take over the parser3) Keep the parsed text for refactoring4) Allow out of order definitions and maybe circular vocabulary dependencies Ouch! Are you sure about this? Is there a need that outweighs the headache? Or is there no headache? 5) Easier syntax for DSLs6) Support the same syntax everywhere7) Allow custom lexer/file extension associations8) Load all code on every platform (but not run) How will 3) and 8) affect the minimum memory footprint?What about the image file size? 9) Add strings with arbitrary payloads What's an arbitrary payload? An example or a use case would be nice. 10) Make most valid-looking syntax lex, but not necessarily compile B) Syntax cheat sheet: TAG: objs ;TAG< FOO: ... ; BAR: ... ; TAG>tag[ objs ] tag{ objs } tag( objs )tag"text" tag[[text]] tag{{text}} tag((text))tag`text tag``text`` tag```text``` In the line above - does the first piece mean that tag`text does not have to end with a closing `?That seems weird and inconsistent. Is there a justification? Do I have to use double ticks to include a space? tag\ text In the line above can text be "a quoted text with spaces" or is it limited to a spaceless token?If it can be quoted, can it be tagged as well? tag1\ tag2\ tag3[text tag3]? tag:: objobj1: obj2 ! { obj1 obj2 }-- ! splits a sequence, e.g. ( a -- b ) -> ( { a } { b } )tag! text til end of line C) More syntax explanation: Top level definitions are: FOO: ... ; or FOO: ... FOO; Delimiters close like:V{ 1 2 3 } or V{ 1 2 3 V}asdf[ 1 2 3 ] or asdf[ 1 2 3 asdf] What about tag"some string tag"? Is the second instance of "tag" a part of the tagged string, or is it a repeated closing tag? Nesting definitions inside others:PRIVATE< FOO: ... ; BAR: ... ;PRIVATE> Does this mean that the old syntax of is no longer valid, or is it no longer idiomatic, or both?I kind of like the syntax, and find it easily understandable. Will it be possible to define words like cm>inch, or will that open a scope that has to end with cm<, or will it trigger the syntax error of "missing the starting cm< tag"? Syntax itself is concatenative -- you can do things like this:V{ 1 2 3 }[ 0 ] ! should desugar to C-style array access Even without the explicit nth word? I don't understand this. Isn't [ 0 ] a quotation that pushes 0 onto stack? D) Implementation: All syntax starts with tags (text without delimiters) and tokens end with whitespace or a delimiter. Could you define "delimiter", please? A lexing rule is some self-contained rule that parses text according to the delimiter encountered. These rules are used to group tokens together, so at the end of parsing a .factor file, there is a sequence of standalone definitions grouped with their decorators, like inline/foldable/flushable/etc. In theory, you could at this point ``randomize`` the top-level definitions, rewrite them to disk, then reparse and have the same code, even repeating any number of times. 1) single-line-lexer - like a ! comment right now The tags for these rules should just be for metadata. I want to change the comment character to # eventually instead of ! (thoughts?) Examples:author! erg! No tag, plain comment While I have no objection to # for a comment starter, I don't necessarily like the idea of a tagged comment.But even if there is a good use for such things, to me, a comment starts with a designated character and continues to EOL. It can't eat a word to the left of it.Same as with 2) backtick-lexer - single backtick parses til whitespace, multiple parses til matching number of backticks. Examples:char`a char``a`` char```a```fixnum`3 fixnum``345`` Why not always parse to matching backtick count?How will this case be handled?fixnum``hello```world`Will the parsing error tell me that ` is not closed, or that `` is not closed, or that EOF is not expected, wherever it is. 4) dquote-lexer - multiline string parsing until the matching ", with \" escapes SBUF" needs a space after right now, but with the new branch, you can just do sbuf"hello". Examples:url"factorcode.org""dquote in string \"wow\"" I like this. 5) single-matched-lexer - lex things until a matching delimiter ( ) things are datastack/function call things{ } things are data structures[ ] things are code blocks/lamda/quotation things shuffle( a b -- b a )V
