--- /dev/null
+! Copyright (C) 2008 Slava Pestov.
+! See http://factorcode.org/license.txt for BSD license.
+USING: slides help.markup math arrays hashtables namespaces
+sequences kernel parser memoize io.encodings.binary
+locals kernel.private help.vocabs assocs quotations
+urls peg.ebnf tools.annotations tools.crossref
+help.topics math.functions compiler.tree.optimizer
+compiler.cfg.optimizer fry ;
+IN: talks.galois-talk
+
+CONSTANT: galois-slides
+{
+ { $slide "Factor!"
+ { $url "http://factorcode.org" }
+ "Development started in 2003"
+ "Open source (BSD license)"
+ "Influenced by Forth, Lisp, and Smalltalk"
+ "Blurs the line between language and library"
+ "Interactive development"
+ }
+ { $slide "Words and the stack"
+ "Stack based, dynamically typed"
+ { $code "{ 1 1 3 4 4 8 9 9 } dup duplicates diff ." }
+ "Words: named code snippets"
+ { $code ": remove-duplicates ( seq -- seq' )" " dup duplicates diff ;" }
+ { $code "{ 1 1 3 4 4 8 9 9 } remove-duplicates ." }
+ }
+ { $slide "Vocabularies"
+ "Vocabularies: named sets of words"
+ { $link "vocab-index" }
+ { { $link POSTPONE: USING: } " loads dependencies" }
+ "Source, docs, tests in one place"
+ }
+ { $slide "Interactive development"
+ "Programming is hard, let's play tetris"
+ { $vocab-link "tetris" }
+ "Tetris is hard too... let's cheat"
+ "Factor workflow: change code, F2, test, repeat"
+ }
+ { $slide "Quotations"
+ "Quotation: unnamed block of code"
+ "Combinators: words taking quotations"
+ { $code "10 dup 0 < [ 1 - ] [ 1 + ] if ." }
+ { $code "{ -1 1 -2 0 3 } [ 0 max ] map ." }
+ "Partial application:"
+ { $code ": clamp ( seq n -- seq' ) '[ _ max ] map ;" "{ -1 1 -2 0 3 } 0 clamp" }
+ }
+ { $slide "Object system"
+ "CLOS with single dispatch"
+ "A tuple is a user-defined class which holds named values."
+ { $code
+ "TUPLE: rectangle width height ;"
+ "TUPLE: circle radius ;"
+ }
+ }
+ { $slide "Object system"
+ "Constructing instances:"
+ { $code "rectangle new" }
+ { $code "rectangle boa" }
+ "Let's encapsulate:"
+ { $code
+ ": <rectangle> ( w h -- r ) rectangle boa ;"
+ ": <circle> ( r -- c ) circle boa ;"
+ }
+ }
+ { $slide "Object system"
+ "Generic words and methods"
+ { $code "GENERIC: area ( shape -- n )" }
+ "Two methods:"
+ { $code
+ "USE: math.constants"
+ ""
+ "M: rectangle area"
+ " [ width>> ] [ height>> ] bi * ;"
+ ""
+ "M: circle area radius>> sq pi * ;"
+ }
+ }
+ { $slide "Object system"
+ "We can compute areas now."
+ { $code "100 20 <rectangle> area ." }
+ { $code "3 <circle> area ." }
+ }
+ { $slide "Object system"
+ "Object system handles dynamic redefinition very well"
+ { $code "TUPLE: person name age occupation ;" }
+ "Make an instance..."
+ }
+ { $slide "Object system"
+ "Let's add a new slot:"
+ { $code "TUPLE: person name age address occupation ;" }
+ "Fill it in with inspector..."
+ "Change the order:"
+ { $code "TUPLE: person name occupation address ;" }
+ }
+ { $slide "Object system"
+ "How does it work?"
+ "Objects are not hashtables; slot access is very fast"
+ "Redefinition walks the heap; expensive but rare"
+ }
+ { $slide "Object system"
+ "Supports \"duck typing\""
+ "Two tuples can have a slot with the same name"
+ "Code that uses accessors will work on both"
+ "Accessors are auto-generated generic words"
+ }
+ { $slide "Object system"
+ "Predicate classes"
+ { $code
+ "PREDICATE: positive < integer 0 > ;"
+ "PREDICATE: negative < integer 0 < ;"
+ ""
+ "GENERIC: abs ( n -- )"
+ ""
+ "M: positive abs ;"
+ "M: negative abs -1 * ;"
+ "M: integer abs ;"
+ }
+ }
+ { $slide "Object system"
+ "More: inheritance, type declarations, read-only slots, union, intersection, singleton classes, reflection"
+ "Object system is entirely implemented in Factor"
+ }
+ { $slide "The parser"
+ "All data types have a literal syntax"
+ "Literal hashtables and arrays are very useful in data-driven code"
+ "\"Code is data\" because quotations are objects (enables Lisp-style macros)"
+ { $code "H{ { \"cookies\" 12 } { \"milk\" 10 } }" }
+ "Libraries can define new parsing words"
+ }
+ { $slide "Example: regexp"
+ { $vocab-link "regexp" }
+ "Pre-compiles regexp at parse time"
+ "Implemented with library code"
+ { $code "USE: regexp" }
+ { $code "\"ababbc\" \"[ab]+c\" <regexp> matches? ." }
+ { $code "\"ababbc\" R/ [ab]+c/ matches? ." }
+ }
+ { $slide "Example: memoization"
+ { "Memoization with " { $link POSTPONE: MEMO: } }
+ { $code
+ ": fib ( m -- n )"
+ " dup 1 > ["
+ " [ 1 - fib ] [ 2 - fib ] bi +"
+ " ] when ;"
+ }
+ "Very slow! Let's profile it..."
+ }
+ { $slide "Example: memoization"
+ { "Let's use " { $link POSTPONE: MEMO: } " instead of " { $link POSTPONE: : } }
+ { $code
+ "MEMO: fib ( m -- n )"
+ " dup 1 > ["
+ " [ 1 - fib ] [ 2 - fib ] bi +"
+ " ] when ;"
+ }
+ "Much faster"
+ }
+ { $slide "Meta-circularity"
+ { { $link POSTPONE: MEMO: } " is just a library word" }
+ { "But so is " { $link POSTPONE: : } }
+ "Factor's parser is written in Factor"
+ { "All syntax is just parsing words: " { $link POSTPONE: [ } ", " { $link POSTPONE: " } }
+ }
+ { $slide "Extensible syntax, DSLs"
+ "Most parsing words fall in one of two categories"
+ "First category: literal syntax for new data types"
+ "Second category: defining new types of words"
+ "Some parsing words are more complicated"
+ }
+ { $slide "Example: printf"
+ { { $link POSTPONE: EBNF: } ": a complex parsing word" }
+ "Implements a custom syntax for expressing parsers: like OMeta!"
+ { "Example: " { $vocab-link "printf-example" } }
+ { $code "\"cheese\" \"vegan\" \"%s is not %s\\n\" printf" }
+ { $code "\"Factor\" 5 \"%s is %d years old\\n\" printf" }
+ }
+ { $slide "Example: simple web browser"
+ { $vocab-link "webkit-demo" }
+ "Demonstrates Cocoa binding"
+ "Let's deploy a stand-alone binary with the deploy tool"
+ "Deploy tool generates binaries with no external dependencies"
+ }
+ { $slide "Locals and lexical scope"
+ "Sometimes, there's no good stack solution to a problem"
+ "Or, you're porting existing code in a quick-and-dirty way"
+ "Our solution: implement named locals as a DSL in Factor"
+ "Influenced by Scheme and Lisp"
+ }
+ { $slide "Locals and lexical scope"
+ { "Define lambda words with " { $link POSTPONE: :: } }
+ { "Establish bindings with " { $link POSTPONE: [let } " and " { $snippet "[let*" } }
+ "Mutable bindings with correct semantics"
+ { "Named inputs for quotations with " { $link POSTPONE: [| } }
+ "Full closures"
+ }
+ { $slide "Locals and lexical scope"
+ "Combinator with 5 parameters!"
+ { $code
+ ":: branch ( a b neg zero pos -- )"
+ " a b = zero [ a b < neg pos if ] if ; inline"
+ }
+ "Unwieldy with the stack"
+ }
+ { $slide "Locals and lexical scope"
+ { $code
+ ": check-drinking-age ( age -- )"
+ " 21"
+ " [ \"You're underage!\" print ]"
+ " [ \"Grats, you're now legal\" print ]"
+ " [ \"Go get hammered\" print ]"
+ " branch ;"
+ }
+ }
+ { $slide "Locals and lexical scope"
+ "Locals are entirely implemented in Factor"
+ "Example of compile-time meta-programming"
+ "No performance penalty -vs- using the stack"
+ "In the base image, only 59 words out of 13,000 use locals"
+ }
+ { $slide "More about partial application"
+ { { $link POSTPONE: '[ } " is \"fry syntax\"" }
+ { $code "'[ _ + ] == [ + ] curry" }
+ { $code "'[ @ t ] == [ t ] compose" }
+ { $code "'[ _ nth @ ] == [ [ nth ] curry ] dip compose" }
+ { $code "'[ [ _ ] dip nth ] == [ [ ] curry dip nth ] curry" }
+ { "Fry and locals desugar to " { $link curry } ", " { $link compose } }
+ }
+ { $slide "Help system"
+ "Help markup is just literal data"
+ { "Look at the help for " { $link T{ link f + } } }
+ "These slides are built with the help system and a custom style sheet"
+ { $vocab-link "talks.galois-talk" }
+ }
+ { $slide "Why stack-based?"
+ "Because nobody else is doing it"
+ "Interesting properties: concatenation is composition, chaining functions together, \"fluent\" interfaces, new combinators"
+ { $vocab-link "smtp-example" }
+ { $code
+ "{ \"chicken\" \"beef\" \"pork\" \"turkey\" }"
+ "[ 5 short head ] map ."
+ }
+ }
+ { $slide "Implementation"
+ "VM: garbage collection, bignums, ..."
+ "Bootstrap image: parser, hashtables, object system, ..."
+ "Non-optimizing compiler"
+ "Stage 2 bootstrap: optimizing compiler, UI, ..."
+ "Full image contains machine code"
+ }
+ { $slide "Compiler"
+ { "Let's look at " { $vocab-link "benchmark.mandel" } }
+ "A naive implementation would be very slow"
+ "Combinators, partial application"
+ "Boxed complex numbers"
+ "Boxed floats"
+ { "Redundancy in " { $link absq } " and " { $link sq } }
+ }
+ { $slide "Compiler: high-level optimizer"
+ "High-level SSA IR"
+ "Type inference (classes, intervals, arrays with a fixed length, literals, ...)"
+ "Escape analysis and tuple unboxing"
+ }
+ { $slide "Compiler: high-level optimizer"
+ "Loop index becomes a fixnum, complex numbers unboxed, generic arithmetic inlined, higher-order code become first-order..."
+ { $code "[ c pixel ] optimized." }
+ }
+ { $slide "Compiler: low-level optimizer"
+ "Low-level SSA IR"
+ "Alias analysis"
+ "Value numbering"
+ "Linear scan register allocation"
+ }
+ { $slide "Compiler: low-level optimizer"
+ "Redundant stack operations eliminated, intermediate floats unboxed..."
+ { $code "[ c pixel ] regs." }
+ }
+ { $slide "Garbage collection"
+ "All roots are identified precisely"
+ "Generational copying for data"
+ "Mark sweep for native code"
+ }
+ { $slide "Project infrastructure"
+ { $url "http://factorcode.org" }
+ { $url "http://concatenative.org" }
+ { $url "http://docs.factorcode.org" }
+ { $url "http://planet.factorcode.org" }
+ "Uses our HTTP server, SSL, DB, Atom libraries..."
+ }
+ { $slide "Project infrastructure"
+ "Build farm, written in Factor"
+ "12 platforms"
+ "Builds Factor and all libraries, runs tests, makes binaries"
+ "Saves us from the burden of making releases by hand"
+ "Maintains stability"
+ }
+ { $slide "Community"
+ "#concatenative irc.freenode.net: 50-60 members"
+ "factor-talk@lists.sf.net: 180 subscribers"
+ "About 30 people have code in the Factor repository"
+ "Easy to get started: binaries, lots of docs, friendly community..."
+ }
+ { $slide "That's all, folks"
+ "It is hard to cover everything in a single talk"
+ "Factor has many cool things that I didn't talk about"
+ "Questions?"
+ }
+}
+
+: galois-talk ( -- ) galois-slides "Galois talk" slides-window ;
+
+MAIN: galois-talk
projects / factor-talks.git / blobdiff