diff --git a/markup/ml b/markup/ml
index 56e7863..006d3e0 100644
--- a/markup/ml
+++ b/markup/ml
@@ -2,14 +2,14 @@
 
 [#grammar-invocation grammar and invocation] | [#var-expr variables and expressions] | [#arithmetic-logic arithmetic and logic] | [#strings strings] | [#dates-time dates and time] | [#arrays arrays] | [#lists lists] | [#tuples tuples] | [#dictionaries dictionaries] | [#functions functions] | [#execution-control execution control] | [#exceptions exceptions] | [#concurrency concurrency] | [#file-handles file handles] | [#files files] | [#directories directories] | [#processes-environment processes and environment] | [#libraries-namespaces libraries and namespaces] | [#user-defined-types user-defined types] | [#objects objects] | [#inheritance-polymorphism inheritance and polymorphism] | [#net-web net and web] | [#unit-tests unit tests] | [#debugging-profiling debugging and profiling] | [#repl repl]
 
-||~ ||~ [#sml sml]||~ [#ocaml ocaml]||~ [#fsharp f#]||~ [#haskell haskell]||
+||~ ||~ [#sml sml]||~ [#ocaml ocaml]||~ [#fsharp f#]||~ [#haskell haskell]||~ [#loon loon]||
 ||[[# version-used]][#version-used-note version used] _
 @<&nbsp;>@||##gray|//SML NJ 110//##||##gray|//4.0//##||##gray|//F# 3.0//## _
-##gray|//Mono 3.2//##||##gray|//7.4//##||
+##gray|//Mono 3.2//##||##gray|//7.4//##||##gray|//Loon 0.6//##||
 ||[[# version]][#version-note show version] _
-@<&nbsp;>@||##gray|//displayed at startup//##||$ ocaml -version||$ fsharpi @@--@@help||$ ghc @@--@@version||
-||||||||||~ [[# grammar-invocation]][#grammar-invocation-note grammar and invocation]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+@<&nbsp;>@||##gray|//displayed at startup//##||$ ocaml -version||$ fsharpi @@--@@help||$ ghc @@--@@version||$ loon @@--@@version||
+||||||||||||~ [[# grammar-invocation]][#grammar-invocation-note grammar and invocation]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[[# interpreter]][#interpreter-note interpreter] _
 @<&nbsp;>@|| ||$ echo 'print_endline "hello"' > hello.ml _
  _
@@ -20,7 +20,8 @@ EOF _
  _
 $ fsharpi @@--@@quiet @@--@@exec hello.fs||$ echo 'main = putStrLn "hello"' > hello.hs _
  _
-$ runghc hello.hs||
+$ runghc hello.hs||$ echo '[fn main [] [println "hello"]]' > hello.oo _
+$ loon run hello.oo||
 ||[[# shebang]][#shebang-note shebang]|| ||$ cat @@<<@@EOF > hello.ml _
 #!/usr/bin/env ocaml _
  _
@@ -46,67 +47,70 @@ main = putStrLn "hello" _
 EOF _
  _
 $ chmod +x hello.hs _
-$ ./hello.hs||
+$ ./hello.hs||##gray|//none//##||
 ||[[# bytecode-compiler-interpreter]][#bytecode-compiler-interpreter-note bytecode compiler and interpreter]|| ||$ echo 'print_endline "hello";;' > hello.ml _
 $ ocamlc -o hello hello.ml _
 $ ocamlrun hello||$ echo 'printfn "hello"' > hello.fs _
 $ fsharpc hello.fs _
-$ mono hello.exe||##gray|//none//##||
+$ mono hello.exe||##gray|//none//##||##gray|//none//##||
 ||[[# native-compiler]][#native-compiler-note native compiler]|| ||$ echo 'print_endline "hello";;' > hello.ml _
 $ ocamlopt hello.ml -o hello _
 $ ./hello||##gray|//none//##||$ echo 'main = putStrLn "hello"' > hello.hs _
 $ ghc -o hello hello.hs _
-$ ./hello||
-||[[# library-always-imported]][#library-always-imported-note library which is always imported]|| ||Pervasives||Core||Prelude||
-||[[# statement-terminator]][#statement-terminator-note statement terminator]||;||;;||;;||##gray|//next line has equal or less indentation, or//## ;||
+$ ./hello||##gray|//compiles to WASM://## _
+$ loon build hello.oo||
+||[[# library-always-imported]][#library-always-imported-note library which is always imported]|| ||Pervasives||Core||Prelude||##gray|//prelude (builtins, IO, Fail)//##||
+||[[# statement-terminator]][#statement-terminator-note statement terminator]||;||;;||;;||##gray|//next line has equal or less indentation, or//## ;||##gray|//none; expression-based//##||
 ||[[# blocks]][#blocks-note blocks]||( ##gray|//expr//## ; ##gray|//…//## )||( ##gray|//expr//## ; ##gray|//...//## ) _
 begin  ##gray|//expr//## ; ##gray|//...//## end||( ##gray|//expr//## ; ##gray|//...//## ) _
-begin  ##gray|//expr//## ; ##gray|//...//## end||##gray|//offside rule or//## { }||
-||[[# end-of-line-comment]][#end-of-line-comment-note end-of-line comment]||##gray|//none//##||##gray|//none//##||@@//@@ ##gray|//comment//##||@@--@@ ##gray|//comment//##||
+begin  ##gray|//expr//## ; ##gray|//...//## end||##gray|//offside rule or//## { }||[do ##gray|//expr//## ##gray|//...//##]||
+||[[# end-of-line-comment]][#end-of-line-comment-note end-of-line comment]||##gray|//none//##||##gray|//none//##||@@//@@ ##gray|//comment//##||@@--@@ ##gray|//comment//##||; ##gray|//comment//##||
 ||[[# multiple-line-comment]][#multiple-line-comment-note multiple line comment]||(* ##gray|//comment//## _
 ##gray|//another comment//## *)||(* ##gray|//comment _
 another comment//## *)||(* ##gray|//comment _
 another comment//## *)||{- ##gray|//comment _
-another comment//## -}||
-||||||||||~ [[# var-expr]][#var-expr-note variables and expressions]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+another comment//## -}||##gray|//none//##||
+||||||||||||~ [[# var-expr]][#var-expr-note variables and expressions]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[[# value]][#value-note write-once variable] _
-@<&nbsp;>@||val a = 3;||let n = 1 + 2;;||let n = 1 + 2||n = 3||
+@<&nbsp;>@||val a = 3;||let n = 1 + 2;;||let n = 1 + 2||n = 3||[let n [+ 1 2]]||
 ||[[# variable]][#variable-note modifiable variable]||val a = ref 3; _
 a := 4; _
 !a + 7;||let n = ref 3;; _
 n := 4;; _
 !n + 7;;||let n = ref 3 _
 n := 4 _
-!n + 7||n <- return 3||
+!n + 7||n <- return 3||[let mut n 3] _
+[set! n 4]||
 ||[[# unit]][#unit-note unit type and value]||unit _
 ()||unit _
 ()||unit _
 ()||() _
-()||
+()||##gray|//type//## () ##gray|//; value//## ()||
 ||[[# conditional-expression]][#conditional-expression-note conditional expression]||val x = 3; _
 if x < 0 then ~x else x;||let n = -3;; _
 let absn = if n < 0 then -n else n;;||let n = -3 _
 let absn = if n < 0 then -n else n||n = -3 _
-let absn = if n < 0 then -n else n||
+let absn = if n < 0 then -n else n||[if [> x 0] "pos" "neg"]||
 ||[[# branch-type-mismatch]][#branch-type-mismatch-note branch type mismatch]||##gray|(* compilation error: *)## _
 if true then "hello" else 3;||##gray|(* compilation error: *)## _
 if true then "hello" else 3;;||##gray|(* compilation error: *)## _
 if true then "hello" else 3||##gray|@@--@@ compilation error:## _
-if True then "hello" else 3||
+if True then "hello" else 3||##gray|//compile error (type)//##||
 ||[[# null]][#null-note null] _
 @<&nbsp;>@||NONE||None||None _
  _
 ##gray|//Also this value returned by .NET library functions.  It has a type distinct from// None:## _
-null||Nothing||
+null||Nothing||##gray|//none//##||
 ||[[# nullable-type]][#nullable-type-note nullable type]||type list_option_int = int option list; _
  _
 val list = [SOME 3,NONE, SOME ~4];||type list_option_int = int option list;; _
  _
-let list = [Some 3; None; Some (-4)];;|| ||list = [Just(3), Nothing, Just(-4)]||
+let list = [Some 3; None; Some (-4)];;|| ||list = [Just(3), Nothing, Just(-4)]||[type Option [Some a] None] _
+##gray|//then://## [Some 3] ##gray|//or//## None||
 ||[[# null-test]][#null-test-note null test]|| ||match foo with _
 @<&nbsp;&nbsp;>@| None -> true _
-@<&nbsp;&nbsp;>@| _ -> false;;|| || ||
+@<&nbsp;&nbsp;>@| _ -> false;;|| || ||[match o [Some v] true None false]||
 ||[[# coalesce]][#coalesce-note coalesce]||val foo = SOME 3; _
  _
 ##gray|(* raises exception if NONE: *)## _
@@ -123,11 +127,11 @@ fromJust foo _
  _
 let intId x = x _
 ##gray|//evaluates to 0 if Nothing://## _
-maybe 0 intId foo||
+maybe 0 intId foo||[get m :key dflt]||
 ||[[# nullif]][#nullif-note nullif]|| ||match foo with _
 @<&nbsp;&nbsp;>@| -999 -> None _
-@<&nbsp;&nbsp;>@| n -> Some n;;|| || ||
-||[[# expr-type-declaration]][#expr-type-decl-note expression type declaration]|| ||float 1||float 1||1 :: Double||
+@<&nbsp;&nbsp;>@| n -> Some n;;|| || ||[if [= a b] None [Some a]]||
+||[[# expr-type-declaration]][#expr-type-decl-note expression type declaration]|| ||float 1||float 1||1 :: Double||[sig n : Int] ##gray|//; on bindings//##||
 ||[[# let-in]][#let-in-note let ... in ...]||val z = _
 let _
 @<&nbsp;&nbsp;>@val x = 3.0 _
@@ -142,29 +146,30 @@ end;||let z = _
 @<&nbsp;&nbsp;>@let y = 2.0 * x in _
 @<&nbsp;&nbsp;>@x * y||z = let x = 3.0 _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@y = 2.0 * x _
-@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@in x * y||
+@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@in x * y||[do [let n 3] [* n n]]||
 ||[[# where]][#where-note where]||##gray|//none//##||##gray|//none//##||##gray|//none//##||z = x * y _
 @<&nbsp;&nbsp;>@where x = 3.0 _
-@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@y = 2.0 * x||
-||||||||||~ [[# arithmetic-logic]][#arithmetic-logic-note arithmetic and logic]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@y = 2.0 * x||##gray|//none//##||
+||||||||||||~ [[# arithmetic-logic]][#arithmetic-logic-note arithmetic and logic]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[[# boolean-type]][#boolean-type-note boolean type] _
-@<&nbsp;>@||bool||bool||bool||Bool||
+@<&nbsp;>@||bool||bool||bool||Bool||Bool||
 ||[[# true-false]][#true-false-note true and false] _
-@<&nbsp;>@||true false||true false||true false||True False||
-||[[# logical-op]][#logical-op-note logical operators]||andalso orelse not||&& @@||@@ not||&& @@||@@ not||&& @@||@@ not||
-||[[# relational-op]][#relational-op-note relational operators]||@@=@@ <> < > <= >=||@@=@@ <> < > <= >=||@@=@@ <> < > <= >=||== /= < > <= >=||
+@<&nbsp;>@||true false||true false||true false||True False||true false||
+||[[# logical-op]][#logical-op-note logical operators]||andalso orelse not||&& @@||@@ not||&& @@||@@ not||&& @@||@@ not||[and a b] [or a b] [not a] _
+##gray|//eager, not short-circuiting//##||
+||[[# relational-op]][#relational-op-note relational operators]||@@=@@ <> < > <= >=||@@=@@ <> < > <= >=||@@=@@ <> < > <= >=||== /= < > <= >=||= != < > <= >=||
 ||[[# min-max]][#min-max-note min and max]|| ||min 1 2 _
 max 1 2||min 1 2 _
 max 1 2||min 1 2 _
-max 1 2||
+max 1 2||##gray|//of a collection://## [min xs] [max xs]||
 ||[[# int-type]][#int-type-note integer type]||int||int _
  _
 ##gray|//other integer types://## _
 int32 int64 nativeint||int _
  _
 ##gray|//other integer types://## _
-int32 int64 nativeint||Integer||
+int32 int64 nativeint||Integer||Int ##gray|//; 64-bit signed//##||
 ||[[# int-literal]][#int-literal-note integer literal]||##gray|negative integer://## _
 ~4||##gray|int, int64, and nativeint literals:## _
 12 12L 12n _
@@ -174,33 +179,34 @@ int32 int64 nativeint||Integer||
  _
 ##gray|//this parses as an expression://## _
 -4||-4||##gray|//an expression, not a literal://## _
--4||
-||[[# float-type]][#float-type-note float type]||real||float||float||Double||
+-4||7||
+||[[# float-type]][#float-type-note float type]||real||float||float||Double||Float ##gray|//; 64-bit//##||
 ||[[# int-op]][#int-op-note integer operators]||+ - * div mod||+ - * / mod _
 ##gray|mod //is an infix operator//##||+ - * / %||+ - * div rem _
-##gray|div //and// rem //are functions, not infix operators//##||
+##gray|div //and// rem //are functions, not infix operators//##||+ - * / %||
 ||[[# float-op]][#float-op-note float operators] _
-@<&nbsp;>@||+ - * /||+. -. *. /.||@@+@@ - * /||+ - * /||
-||[[# add-int-float]][#add-int-float-note add integer and float]||real 3 + 7.0;||float 3 +. 7.0||float 3 + 7.0||3 + 7.0||
+@<&nbsp;>@||+ - * /||+. -. *. /.||@@+@@ - * /||+ - * /||+ - * /||
+||[[# add-int-float]][#add-int-float-note add integer and float]||real 3 + 7.0;||float 3 +. 7.0||float 3 + 7.0||3 + 7.0||[+ [float 1] 2.0] _
+##gray|//no implicit coercion//##||
 ||[[# int-div]][#int-div-note integer division] _
 ##gray|//and remainder//##||7 div 3 _
 7 mod 3 _
 real 7 / real 3||7 / 3 _
 7 mod 3||7 / 3 _
 7 % 3||div 7 3 _
-rem 7 3||
-||[[# int-div-zero]][#int-div-zero-note integer division by zero]|| ||##gray|//raises//## Division_by_zero||System.DivideByZeroException||##gray|//Exception: divide by zero//##||
+rem 7 3||[/ 7 2] ##gray|//; 3//##||
+||[[# int-div-zero]][#int-div-zero-note integer division by zero]|| ||##gray|//raises//## Division_by_zero||System.DivideByZeroException||##gray|//Exception: divide by zero//##||##gray|//runtime error//##||
 ||[[# float-div]][#float-div-note float division] _
-@<&nbsp;>@|| ||float 7 /. float 3||float 7 / float 3||7 / 3||
-||[[# float-div-zero]][#float-div-zero-note float division by zero]|| ||infinity nan ##gray|//or//## neg_infinity||infinity nan ##gray|//or//## neg_infinity||##gray|//evaluates to// Infinity, NaN, //or// -Infinity, //values which do not have literals//##||
+@<&nbsp;>@|| ||float 7 /. float 3||float 7 / float 3||7 / 3||[/ 7.0 2.0] ##gray|//; 3.5//##||
+||[[# float-div-zero]][#float-div-zero-note float division by zero]|| ||infinity nan ##gray|//or//## neg_infinity||infinity nan ##gray|//or//## neg_infinity||##gray|//evaluates to// Infinity, NaN, //or// -Infinity, //values which do not have literals//##||[/ 1.0 0.0] ##gray|//; inf//##||
 ||[[# power]][#power-note power]||Math.pow (2.0, 32.0);||2.0 ** 32.0||2.0 ** 32.0||2 ** 32 _
  _
 ##gray|@@--@@ syntax error if exponent not an integer:## _
-2 ^ 32||
+2 ^ 32||##gray|//none//##||
 ||[[# sqrt]][#sqrt-note sqrt] _
-@<&nbsp;>@||Math.sqrt 2.0||sqrt 2.0||sqrt 2.0||sqrt 2||
+@<&nbsp;>@||Math.sqrt 2.0||sqrt 2.0||sqrt 2.0||sqrt 2||##gray|//none//##||
 ||[[# sqrt-negative-one]][#sqrt-negative-one-note sqrt -1]||##gray|//Math.sqrt ~1.0 evaluates to// nan##||##gray|sqrt (-1.0):## _
-nan||nan||##gray|sqrt (-1) //evaluates to// NaN, //a value which has no literal//##||
+nan||nan||##gray|sqrt (-1) //evaluates to// NaN, //a value which has no literal//##||##gray|//none//##||
 ||[[# transcendental-func]][#transcendental-func-note transcendental functions]||Math.exp Math.ln _
 Math.sin Math.cos Math.tan _
 Math.asin Math.acos Math.atan _
@@ -213,12 +219,12 @@ asin acos atan _
 atan2||exp log _
 sin cos tan _
 asin acos atan _
-atan2||
+atan2||##gray|//none//##||
 ||[[# transcendental-const]][#transcendental-const-note transcendental constants]||Math.pi _
 Math.e||4.0 *. atan 1.0 _
 exp 1.0||System.Math.PI _
 System.Math.E||pi _
-exp 1||
+exp 1||##gray|//none//##||
 ||[[# float-truncation]][#float-truncation-note float truncation]||round 3.14 _
 trunc 3.14 _
 floor 3.14 _
@@ -231,7 +237,7 @@ floor 3.14 ##gray|//returns float//## _
 ceil 3.14 ##gray|//returns float//##||truncate 3.14 _
 round 3.14 _
 floor 3.14 _
-ceiling 3.14||
+ceiling 3.14||[int 3.7] ##gray|//; 3//##||
 ||[[# abs-val]][#abs-val-note absolute value] _
 ##gray|//and signum//##|| ||abs (-7) _
 abs_float (-7.0) _
@@ -239,9 +245,9 @@ abs_float (-7.0) _
 abs -7.0 _
 sign -7 _
 sign -7.0||abs (-7) _
-signum (-7)||
-||[[# int-overflow]][#int-overflow-note integer overflow]||##gray|//Overflow exception//##||##gray|//modular arithmetic//##||##gray|//modular arithmetic//##||##gray|//has arbitrary length integers//##||
-||[[# float-overflow]][#float-overflow-note float overflow]|| ||infinity||infinity||##gray|//evaluates to// Infinity, //a value which has no literal//##||
+signum (-7)||[abs -4]||
+||[[# int-overflow]][#int-overflow-note integer overflow]||##gray|//Overflow exception//##||##gray|//modular arithmetic//##||##gray|//modular arithmetic//##||##gray|//has arbitrary length integers//##||##gray|//returns//## () ##gray|//(no wrap)//##||
+||[[# float-overflow]][#float-overflow-note float overflow]|| ||infinity||infinity||##gray|//evaluates to// Infinity, //a value which has no literal//##||##gray|//inf//##||
 ||[[# arbitrary-len-int]][#arbitrary-len-int-note arbitrary length integer]|| ||open Big_int;; _
  _
 let n = big_int_of_int 7;; _
@@ -249,7 +255,7 @@ let m = big_int_of_int 12;;||##gray|@@//@@ System.Numerics.BigInteger:## _
 let n = 7I _
 let m = 12I||##gray|@@--@@ Integer is arbitrary length type:## _
 let n = 7 _
-let m = 12||
+let m = 12||##gray|//none//##||
 ||[[# arbitrary-len-int-op]][#arbitrary-len-int-op-note arbitrary length integer operators]|| ||add_big_int n m _
 sub_big_int n m _
 mult_big_int n m _
@@ -280,26 +286,26 @@ n == m _
 n < m _
 n < m _
 n <= m _
-n >= m||
-||[[# rational-type]][#rational-type-note rational type]|| || || ||Ratio Integer||
+n >= m||##gray|//none//##||
+||[[# rational-type]][#rational-type-note rational type]|| || || ||Ratio Integer||##gray|//none//##||
 ||[[# rational-construction]][#rational-construction-note rational construction]|| || || ||import Data.Ratio _
  _
-1 % 7||
+1 % 7||##gray|//none//##||
 ||[[# rational-decomposition]][#rational-decomposition-note rational decomposition]|| || || ||import Data.Ratio _
  _
 numerator (1 % 7) _
-denominator (1 % 7)||
-||[[# complex-type]][#complex-type-note complex type]|| ||Complex.t|| ||Complex Double||
+denominator (1 % 7)||##gray|//none//##||
+||[[# complex-type]][#complex-type-note complex type]|| ||Complex.t|| ||Complex Double||##gray|//none//##||
 ||[[# complex-const]][#complex-const-note complex constants]|| ||Complex.zero _
 Complex.one _
-Complex.i|| || ||
+Complex.i|| || ||##gray|//none//##||
 ||[[# complex-op]][#complex-op-note complex operators]|| ||Complex.add z w;; _
 Complex.sub z w;; _
 Complex.mul z w;; _
-Complex.div z w;;|| || ||
+Complex.div z w;;|| || ||##gray|//none//##||
 ||[[# complex-construction]][#complex-construction-note complex construction]|| ||{Complex.re=1.0; Complex.im=2.0}||System.Numerics.Complex(1.0, 2.0)||import Data.Complex _
  _
-1 :+ 2.0||
+1 :+ 2.0||##gray|//none//##||
 ||[[# complex-decomposition]][#complex-decomposition-note complex decomposition]|| ||let z = {Complex.re=1.0; Complex.im=2.0};; _
  _
 z.Complex.re;; _
@@ -312,7 +318,7 @@ realPart (1 :+ 2) _
 imagPart (1 :+ 2) _
 phase (1 :+ 2) _
 magnitude (1 :+ 2) _
-conjugate (1 :+ 2)||
+conjugate (1 :+ 2)||##gray|//none//##||
 ||[[# random-num]][#random-num-note random number] _
 ##gray|//uniform int, uniform float, normal float//##|| ||Random.int 100 _
 Random.float 1.0 _
@@ -325,7 +331,7 @@ import System.Random _
  _
 getStdRandom (randomR (0, 99)) _
 getStdRandom (randomR (0.0, 1.0)) _
-##gray|//none//##||
+##gray|//none//##||##gray|//none//##||
 ||[[# random-seed]][#random-seed-note random seed] _
 ##gray|//set, get, restore//##|| ||Random.init 17;; _
 let seed = Random.get_state();; _
@@ -336,7 +342,7 @@ import System.Random _
  _
 setStdGen $ mkStdGen 17 _
 seed <- getStdGen _
-setStdGen seed||
+setStdGen seed||##gray|//none//##||
 ||[[# bit-op]][#bit-op-note bit operators]|| ||1 lsl 4 _
 1 lsr 4 _
 1 land 3 _
@@ -357,127 +363,128 @@ shiftR x 4 _
 x .&. y _
 x .|. y _
 xor x y _
-complement x||
+complement x||##gray|//none//##||
 ||[[# binary-octal-hex-literals]][#binary-octal-hex-literals-note binary, octal, and hex literals]|| ||0b101010 _
 0o52 _
 0x2a||0b101010 _
 0o52 _
 0x2a||##gray|//none//## _
 052 _
-0x2a||
-||[[# radix]][#radix-note radix]|| || || || ||
-||||||||||~ [[# strings]][#strings-note strings]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+0x2a||##gray|//none//##||
+||[[# radix]][#radix-note radix]|| || || || ||##gray|//none//##||
+||||||||||||~ [[# strings]][#strings-note strings]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[[# str-type]][#str-type-note string type] _
-@<&nbsp;>@||string||string||string||String||
+@<&nbsp;>@||string||string||string||String||Str||
 ||[[# str-literal]][#str-literal-note string literal] _
-@<&nbsp;>@||"Hello, World!"||"Hello, World!"||"Hello, World!"||"Hello, World!"||
-||[[# newline-in-str-literal]][#newline-in-str-literal-note newline in literal]|| ||##gray|//no//##||##gray|//yes//##||##gray|//no//##||
+@<&nbsp;>@||"Hello, World!"||"Hello, World!"||"Hello, World!"||"Hello, World!"||"hello"||
+||[[# newline-in-str-literal]][#newline-in-str-literal-note newline in literal]|| ||##gray|//no//##||##gray|//yes//##||##gray|//no//##||"line1\nline2"||
 ||[[# str-esc]][#str-esc-note literal escapes]||\000 \a \b \f \n \r \t \v \040||\b \n \r \t \" \' \\ _
 \##gray|//ooo//## \x##gray|//hh//##||\b \n \r\ t \" \' \\ _
 \u##gray|//hhhh//## \U##gray|//hhhhhhhh//##||\a \b \f \n \r \t \v \" \& \' \\ _
 \o##gray|//o@@...@@//## \##gray|//d@@...@@//## \x##gray|//h@@...@@//## _
  _
-##gray|//Octal, decimal, and hex escapes denote Unicode characters and can contain anywhere from 1 to 7 digits.  The max values are \o4177777, \1114111, and \x10ffff.  The \& escape does not represent a character, but can separate a numeric backslash escape sequence from a following digit.//##||
+##gray|//Octal, decimal, and hex escapes denote Unicode characters and can contain anywhere from 1 to 7 digits.  The max values are \o4177777, \1114111, and \x10ffff.  The \& escape does not represent a character, but can separate a numeric backslash escape sequence from a following digit.//##||\n \t \" \\||
 ||[[# format-str]][#format-str-note format string]|| || ||sprintf "foo %s %d %.2f" "bar" 7 3.1415||import Text.Printf _
  _
-printf "foo %s %d %.2f" "bar" 7 3.1415||
+printf "foo %s %d %.2f" "bar" 7 3.1415||"hi {name}, {[+ 1 2]}"||
 ||[[# str-concat]][#str-concat-note concatenate] _
-@<&nbsp;>@|| "Hello" ^ ", " ^ "World!"||"Hello" ^ ", " ^ "World!"||"Hello" + ", " + "World!"||"Hello" ++ ", " ++ "World!"||
+@<&nbsp;>@|| "Hello" ^ ", " ^ "World!"||"Hello" ^ ", " ^ "World!"||"Hello" + ", " + "World!"||"Hello" ++ ", " ++ "World!"||[str a b]||
 ||[[# str-replicate]][#str-replicate-note replicate] _
-@<&nbsp;>@|| ||String.make 80 '-'||String.replicate 80 "-"||concat ( replicate 80 "-" )||
+@<&nbsp;>@|| ||String.make 80 '-'||String.replicate 80 "-"||concat ( replicate 80 "-" )||##gray|//none//##||
 ||[[# translate-case]][#translate-case-note translate case] _
 ##gray|//to upper, to lower//##|| ||String.uppercase "hello" _
 String.lowercase "HELLO"||"hello".ToUpper() _
 "HELLO".ToLower()||import Data.Char _
  _
 map toUpper "hello" _
-map toLower "HELLO"||
+map toLower "HELLO"||[uppercase s] _
+[lowercase s]||
 ||[[# capitalize]][#capitalize-note capitalize] _
-@<&nbsp;>@|| ||String.capitalize "hello"|| || ||
+@<&nbsp;>@|| ||String.capitalize "hello"|| || ||##gray|//none//##||
 ||[[# trim]][#trim-note trim] _
 ##gray|//both sides, left, right//##|| ||String.trim " hello "||" hello ".Trim() _
 " hello".TrimStart() _
-"hello ".TrimEnd()|| ||
+"hello ".TrimEnd()|| ||[trim s]||
 ||[[# pad]][#pad-note pad] _
 ##gray|//on left, on right//##|| || ||"hello".PadLeft(10, ' ') _
-"hello".PadRight(10, ' ')|| ||
+"hello".PadRight(10, ' ')|| ||##gray|//none//##||
 ||[[# num-to-str]][#num-to-str-note number to string]|| ||"two: " ^ string_of_int 2 _
 "pi: " ^ float_of_string 3.14||"two: " + string 2 _
 "pi: " + string 3.14||"two: " ++ (show 2) _
-"pi: " ++ (show 3.14)||
+"pi: " ++ (show 3.14)||[str 42]||
 ||[[# str-to-num]][#str-to-num-note string to number]||Int.toString 3 _
 Real.toString 3.14||7 + int_of_string "12" _
 73.9 +. float_of_string ".037"||7 + int "12" _
 73.9 + float ".037||7 + (read "12")::Integer _
 73.9 + (read "0.037")::Double _
-##gray|//raises exception if string doesn't completely parse//##||
+##gray|//raises exception if string doesn't completely parse//##||##gray|//none//##||
 ||[[# join]][#join-note join] _
-@<&nbsp;>@|| || ||System.String.Join(" ", ["do"; "re"; "mi"])|| ||
+@<&nbsp;>@|| || ||System.String.Join(" ", ["do"; "re"; "mi"])|| ||[join ", " xs]||
 ||[[# split]][#split-note split] _
-@<&nbsp;>@|| || ||"do re mi".Split(' ')|| ||
+@<&nbsp;>@|| || ||"do re mi".Split(' ')|| ||[split s ","]||
 ||[[# char-type]][#char-type-note character type] _
-@<&nbsp;>@||char||char||char||Char||
-||[[# char-literal]][#char-literal-note character literal]||#"h"||'h'||'h'||'h'||
+@<&nbsp;>@||char||char||char||Char||##gray|//none; single-char Str//##||
+||[[# char-literal]][#char-literal-note character literal]||#"h"||'h'||'h'||'h'||##gray|//none; use//## "a"||
 ||[[# str-len]][#str-len-note length] _
-@<&nbsp;>@||size "hello"||String.length "hello"||"hello".Length||length "hello"||
-||[[# index-substr]][#index-substr-note index of substring]|| || ||"hello".IndexOf("hell")|| ||
-||[[# substr]][#substr-note extract substring]||substring ("hello",0,4)||String.sub "hello" 0 4||"hello".Substring(0, 4)||drop 0 (take 4 "hello")||
-||[[# extract-char]][#extract-char-note extract character]||String.sub ("hello", 0)||"hello".[0]||"hello".[0]||"hello" !! 0||
+@<&nbsp;>@||size "hello"||String.length "hello"||"hello".Length||length "hello"||[len s] ##gray|//; bytes//##||
+||[[# index-substr]][#index-substr-note index of substring]|| || ||"hello".IndexOf("hell")|| ||[index-of s "lo"] ##gray|//; -1 if absent//##||
+||[[# substr]][#substr-note extract substring]||substring ("hello",0,4)||String.sub "hello" 0 4||"hello".Substring(0, 4)||drop 0 (take 4 "hello")||[substring s 1 4]||
+||[[# extract-char]][#extract-char-note extract character]||String.sub ("hello", 0)||"hello".[0]||"hello".[0]||"hello" !! 0||[char-at s 0]||
 ||[[# chr-ord]][#chr-ord-note chr and ord]||ord #"a" _
 chr 97||Char.code 'a' _
 Char.chr 97||int 'a' _
 char 97||Char.ord 'a' _
-Char.chr 97||
-||||||||||~ [[# dates-time]][#dates-time-note dates and time]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||[[# dates-time-types]][#dates-time-types-note date and time types]|| || || ||ClockTime CalendarTime TimeDiff||
+Char.chr 97||##gray|//none//##||
+||||||||||||~ [[# dates-time]][#dates-time-note dates and time]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||[[# dates-time-types]][#dates-time-types-note date and time types]|| || || ||ClockTime CalendarTime TimeDiff||##gray|//none//##||
 ||[[# current-date-time]][#current-date-time-note current date and time]|| || || ||import Time _
  _
-t <- getClockTime||
+t <- getClockTime||##gray|//none//##||
 ||[[# current-unix-epoch]][#current-unix-epoch-note current unix epoch]|| ||open Unix;; _
  _
 ##gray|(* float: *)## _
 time();;|| ||import System.Time _
  _
-getClockTime @@>>@@= (\(TOD sec _) -> return sec)||
-||||||||||~ [[# arrays]][#arrays-note arrays]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||literal|| || || || ||
-||size|| || || || ||
-||lookup|| || || || ||
-||update|| || || || ||
-||out-of-bounds|| || || || ||
-||||||||||~ [[# lists]][#lists-note lists]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||[[# list-literal]][#list-literal-note literal]||[1, 2, 3]||[1; 2; 3]||[1; 2; 3]||[1, 2, 3]||
+getClockTime @@>>@@= (\(TOD sec _) -> return sec)||##gray|//none//##||
+||||||||||||~ [[# arrays]][#arrays-note arrays]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||literal|| || || || ||#[1 2 3]||
+||size|| || || || ||[len a]||
+||lookup|| || || || ||[nth a 0]||
+||update|| || || || ||##gray|//none//##||
+||out-of-bounds|| || || || ||[nth a 99] ##gray|//; runtime error//##||
+||||||||||||~ [[# lists]][#lists-note lists]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||[[# list-literal]][#list-literal-note literal]||[1, 2, 3]||[1; 2; 3]||[1; 2; 3]||[1, 2, 3]||#[1 2 3]||
 ||[[# empty-list]][#empty-list-note empty list] _
-@<&nbsp;>@|| ||[]|| ||[]||
+@<&nbsp;>@|| ||[]|| ||[]||#[]||
 ||[[# empty-list-test]][#empty-list-test-note empty list test]|| ||let list = [1; 2; 3];; _
  _
 list == []|| ||let list = [1, 2, 3] _
  _
 list == [] _
-null list||
+null list||[empty? xs]||
 ||[[# cons]][#cons-note cons] _
-@<&nbsp;>@||1 :: [2, 3]||1 :: [2; 3]||1 :: [2; 3]||1 : [2, 3]||
+@<&nbsp;>@||1 :: [2, 3]||1 :: [2; 3]||1 :: [2; 3]||1 : [2, 3]||[cons 0 xs]||
 ||[[# head]][#head-note head] _
-@<&nbsp;>@||List.hd [1, 2, 3]||List.hd [1; 2; 3]||List.head [1; 2; 3]||head [1, 2, 3]||
+@<&nbsp;>@||List.hd [1, 2, 3]||List.hd [1; 2; 3]||List.head [1; 2; 3]||head [1, 2, 3]||[first xs]||
 ||[[# tail]][#tail-note tail] _
-@<&nbsp;>@||List.tl [1, 2, 3]||List.tl [1; 2; 3]||List.tail [1; 2; 3]||tail [1, 2, 3]||
-||[[# head-tail-empty-list]][#head-tail-empty-list-note head and tail of empty list]|| ||##gray|//exceptions//##|| ||##gray|//exceptions//##||
+@<&nbsp;>@||List.tl [1, 2, 3]||List.tl [1; 2; 3]||List.tail [1; 2; 3]||tail [1, 2, 3]||[drop 1 xs]||
+||[[# head-tail-empty-list]][#head-tail-empty-list-note head and tail of empty list]|| ||##gray|//exceptions//##|| ||##gray|//exceptions//##||[first #[]] ##gray|//; ()//##||
 ||[[# list-length]][#list-length-note length] _
-@<&nbsp;>@||List.length [1, 2, 3]||List.length [1; 2; 3]||List.length [1; 2; 3]||length [1, 2, 3]||
+@<&nbsp;>@||List.length [1, 2, 3]||List.length [1; 2; 3]||List.length [1; 2; 3]||length [1, 2, 3]||[len xs]||
 ||[[# nth-elem-of-list]][#nth-elem-of-list-note nth element] _
-@<&nbsp;>@||List.nth ([1, 2, 3], 0)||List.nth [1; 2; 3] 0||List.nth [1; 2; 3] 0||[1, 2, 3] !! 0||
+@<&nbsp;>@||List.nth ([1, 2, 3], 0)||List.nth [1; 2; 3] 0||List.nth [1; 2; 3] 0||[1, 2, 3] !! 0||[nth xs 2]||
 ||[[# list-elem-index]][#list-elem-index-note element index]|| || || ||import Data.list _
  _
 ##gray|@@--@@ Just 1:## _
 elemIndex 8 [7, 8, 9] _
  _
 ##gray|@@--@@ Nothing:## _
-elemIndex 10 [7, 8, 9]||
-||[[# update-list]][#update-list-note update]|| || || || ||
+elemIndex 10 [7, 8, 9]||##gray|//none//##||
+||[[# update-list]][#update-list-note update]|| || || || ||##gray|//none//##||
 ||[[# concat-list]][#concat-list-note concatenate] _
 ##gray|//two lists, list of lists//##||[1, 2] @ [3, 4] _
 List.concat [[1, 2], [3, 4]]||[1; 2] @ [3; 4] _
@@ -488,14 +495,14 @@ List.append [1; 2] [3; 4] _
  _
 List.concat [[1; 2]; [3; 4]]||[1, 2] ++ [3, 4] _
  _
-concat [[1, 2], [3, 4]]||
+concat [[1, 2], [3, 4]]||[concat xs ys]||
 ||[[# list-last]][#list-last-note last] _
 ##gray|//and butlast//##|| || || ||last [1, 2, 3] _
-init [1, 2, 3]||
+init [1, 2, 3]||[last xs]||
 ||[[# list-take]][#list-take-note take] _
-@<&nbsp;>@|| || || ||take 2 [1, 2, 3]||
+@<&nbsp;>@|| || || ||take 2 [1, 2, 3]||[take 2 xs]||
 ||[[# list-drop]][#list-drop-note drop] _
-@<&nbsp;>@|| || || ||drop 2 [1, 2, 3]||
+@<&nbsp;>@|| || || ||drop 2 [1, 2, 3]||[drop 2 xs]||
 ||[[# iterate-over-list]][#iterate-over-list-note iterate]||fun f i = print ((Int.toString i) ^ "\n"); _
 List.app f [1, 2, 3];||let f i = _
 @<&nbsp;&nbsp;>@print_endline (string_of_int i);; _
@@ -503,43 +510,43 @@ List.app f [1, 2, 3];||let f i = _
 List.iter f [1; 2; 3];;||let f i = _
 @<&nbsp;&nbsp;>@System.Console.WriteLine(string i) _
  _
-List.iter f [1; 2; 3]||mapM_ print  [1, 2, 3]||
+List.iter f [1; 2; 3]||mapM_ print  [1, 2, 3]||[each [fn [x] [println x]] xs]||
 ||[[# reverse-list]][#reverse-list-note reverse] _
-@<&nbsp;>@||List.rev [1, 2, 3]||List.rev [1; 2; 3]||List.rev [1; 2; 3]||reverse [1, 2, 3]||
+@<&nbsp;>@||List.rev [1, 2, 3]||List.rev [1; 2; 3]||List.rev [1; 2; 3]||reverse [1, 2, 3]||[reverse xs]||
 ||[[# sort-list]][#sort-list-note sort]|| ||List.sort min [1; 3; 2; 4] _
 List.sort max [1; 3; 2; 4]||List.sort [1; 3; 2; 4]||import Data.List _
  _
-sort [1, 3, 2, 4]||
-||[[# map-list]][#map-list-note map]||List.map (fn (x) => x + 2) [1, 2, 3];||List.map (( * ) 2) [1; 2; 3]||List.map (( * ) 2) [1; 2; 3]||map (\x -> x * x) [1, 2, 3]||
+sort [1, 3, 2, 4]||[sort xs]||
+||[[# map-list]][#map-list-note map]||List.map (fn (x) => x + 2) [1, 2, 3];||List.map (( * ) 2) [1; 2; 3]||List.map (( * ) 2) [1; 2; 3]||map (\x -> x * x) [1, 2, 3]||[map [fn [x] [* x x]] xs]||
 ||[[# filter-list]][#filter-list-note filter] _
-@<&nbsp;>@||List.filter (fn (x) => x > 2) [1, 2, 3];||List.filter ((<) 2) [1; 2; 3]||List.filter ((<) 2) [1; 2; 3]||filter (\x -> x > 2) [1, 2, 3]||
-||[[# fold-list-left]][#fold-list-left-note fold from left]||List.foldl (op +) 0 [1, 2, 3];||List.fold_left (+) 0 [1; 2; 3]||List.fold (-) 0 [1; 2; 3]||foldl (+) 0 [1, 2, 3]||
+@<&nbsp;>@||List.filter (fn (x) => x > 2) [1, 2, 3];||List.filter ((<) 2) [1; 2; 3]||List.filter ((<) 2) [1; 2; 3]||filter (\x -> x > 2) [1, 2, 3]||[filter [fn [x] [> x 0]] xs]||
+||[[# fold-list-left]][#fold-list-left-note fold from left]||List.foldl (op +) 0 [1, 2, 3];||List.fold_left (+) 0 [1; 2; 3]||List.fold (-) 0 [1; 2; 3]||foldl (+) 0 [1, 2, 3]||[fold 0 [fn [a b] [+ a b]] xs]||
 ||[[# fold-list-right]][#fold-list-right-note fold from right] _
-@<&nbsp;>@|| ||List.fold_right (-) [1; 2; 3] 0||List.foldr (op -) 0 [1, 2, 3];||foldr (-) 0 [1, 2, 3]||
+@<&nbsp;>@|| ||List.fold_right (-) [1; 2; 3] 0||List.foldr (op -) 0 [1, 2, 3];||foldr (-) 0 [1, 2, 3]||[fold 0 [fn [a b] [+ a b]] [reverse xs]]||
 ||[[# list-member]][#list-member-note membership] _
-@<&nbsp;>@|| ||List.mem 3 [1; 2; 3]|| ||elem 3 [1, 2, 3]||
+@<&nbsp;>@|| ||List.mem 3 [1; 2; 3]|| ||elem 3 [1, 2, 3]||[contains? xs 3]||
 ||[[# universal-test-list]][#universal-test-list-note universal test] _
-@<&nbsp;>@|| ||List.for_all (fun x -> x > 2) [1; 2; 3];;||List.forall (fun x -> x > 2) [1; 2; 3]||all (\x -> x > 2) [1, 2, 3]||
+@<&nbsp;>@|| ||List.for_all (fun x -> x > 2) [1; 2; 3];;||List.forall (fun x -> x > 2) [1; 2; 3]||all (\x -> x > 2) [1, 2, 3]||[all? [fn [x] [> x 0]] xs]||
 ||[[# existential-test-list]][#existential-test-list-note existential test] _
-@<&nbsp;>@|| ||List.exists (fun x -> x > 2) [1; 2; 3];;||List.exists (fun x -> x > 2) [1; 2; 3]||any (\x -> x > 2) [1, 2, 3]||
+@<&nbsp;>@|| ||List.exists (fun x -> x > 2) [1; 2; 3];;||List.exists (fun x -> x > 2) [1; 2; 3]||any (\x -> x > 2) [1, 2, 3]||[any? [fn [x] [> x 0]] xs]||
 ||[[# zip-list]][#zip-list-note zip lists]|| ||##gray|@@(*@@ list of tuples *)## _
 List.combine [1; 2; 3] ['a'; 'b'; 'c'] _
 || ||##gray|@@--@@ list of tuples:## _
-zip [1, 2, 3] ['a', 'b', 'c']||
-||||||||||~ [[# tuples]][#tuples-note tuples]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||[[# tuple-literal]][#tuple-literal-note literal]||(1, "hello", true)||(1, "hello", true)||(1, "hello", true)||(1, "hello", True)||
-||[[# tuple-lookup]][#tuple-lookup-note lookup]||#1 (1, "hello", true)||match (1, "hello", true) with _, x, _ -> x||match (1, "hello", true) with _, x, _ -> x||(\(a, _, _) -> a) (1, "hello", True)||
+zip [1, 2, 3] ['a', 'b', 'c']||[zip xs ys]||
+||||||||||||~ [[# tuples]][#tuples-note tuples]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||[[# tuple-literal]][#tuple-literal-note literal]||(1, "hello", true)||(1, "hello", true)||(1, "hello", true)||(1, "hello", True)||##gray|//none; pairs via//## [zip xs ys]||
+||[[# tuple-lookup]][#tuple-lookup-note lookup]||#1 (1, "hello", true)||match (1, "hello", true) with _, x, _ -> x||match (1, "hello", true) with _, x, _ -> x||(\(a, _, _) -> a) (1, "hello", True)||##gray|//destructure://## [fn [[a b]] a]||
 ||[[# pair-lookup]][#pair-lookup-note pair lookup]||#1 (12,"December") _
 #2 (12,"December")||fst (12, "December") _
 snd (12, "December")||fst (12, "December") _
 snd (12, "December")||fst (12, "December") _
-snd (12, "December")||
-||||||||||~ [[# dictionaries]][#dictionaries-note dictionaries]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||||||||||~ [[# functions]][#functions-note functions]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||[[# def-func]][#def-func-note define function]||fun average a b = ( a + b ) / 2.0;||let average a b = ( a +. b ) /. 2.0;;||let average a b = ( a + b ) / 2.0||average a b = (a + b) / 2.0||
+snd (12, "December")||##gray|//destructure://## [fn [[a b]] b]||
+||||||||||||~ [[# dictionaries]][#dictionaries-note dictionaries]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||||||||||||~ [[# functions]][#functions-note functions]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||[[# def-func]][#def-func-note define function]||fun average a b = ( a + b ) / 2.0;||let average a b = ( a +. b ) /. 2.0;;||let average a b = ( a + b ) / 2.0||average a b = (a + b) / 2.0||[fn add [a b] [+ a b]]||
 ||[[# invoke-func]][#invoke-func-note invoke function]|| ||##gray|@@(*@@ 4.5: *)## _
 average 1.0 2.0 +. 3.0;; _
  _
@@ -553,52 +560,55 @@ average 1 2 + 3 _
  _
 ##gray|@@--@@ 3.0:## _
 average 1 (2 + 3) _
-average 1 $ 2 + 3||
+average 1 $ 2 + 3||[add 1 2]||
 ||[#named-parameter named parameter]|| ||let subtract ~m ~s = m - s;; _
  _
-subtract ~s: 3 ~m: 7;;|| ||##gray|//none//##||
+subtract ~s: 3 ~m: 7;;|| ||##gray|//none//##||##gray|//none//##||
 ||[#default-value named parameter default value]|| ||let logarithm ?(base = (exp 1.0)) x = log x /. (log base);; _
  _
 logarithm 2.718;; _
-logarithm ~base: 2.0 10.0;;|| ||##gray|//none//##||
+logarithm ~base: 2.0 10.0;;|| ||##gray|//none//##||##gray|//none; use multi-arity//##||
 ||[#piecewise-defined-function piecewise defined function]||val to_s = fn Red => "red" _
 @<&nbsp;&nbsp;>@| Green => "green" _
 @<&nbsp;&nbsp;>@| Blue => "blue";||let to_s = function Red -> "red" _
 @<&nbsp;&nbsp;>@| Green -> "green" _
 @<&nbsp;&nbsp;>@| Blue -> "blue";;|| ||to_s Red = "red" _
 to_s Green = "green" _
-to_s Blue = "blue"||
+to_s Blue = "blue"||[fn to-s [c] _
+  [match c Red "red" Green "green"]]||
 ||[#recursive-function recursive function]||fun range a b = _
 @<&nbsp;&nbsp;>@if a > b then [] _
 @<&nbsp;&nbsp;>@else a :: range (a + 1) b;||let rec range a b = _
 if a > b then [] _
-else a :: range (a+1) b;;|| ||range a b = if a > b then [] else a : range (a+1) b||
+else a :: range (a+1) b;;|| ||range a b = if a > b then [] else a : range (a+1) b||[fn fact [n] _
+  [if [< n 2] 1 [* n [fact [- n 1]]]]]||
 ||[#mutually-recursive-functions mutually-recursive-functions]|| ||let rec even n = if n = 0 then true else odd (n-1) _
-and odd n = if n = 0 then false else even (n-1);;|| || ||
-||[#anonymous-func anonymous function]||fn x => fn y => (x + y) / 2.0||fun x -> fun y -> (x +. y) /. 2.0||fun x -> fun y -> (x + y) / 2.0||\x y -> (x+y) / 2.0||
-||[#infix-prefix infix operator in prefix position]||(op * ) (3, 4)||( * ) 3 4;;|| ||( * ) 3 4||
+and odd n = if n = 0 then false else even (n-1);;|| || ||[fn ev? [n] [if [= n 0] true [od? [- n 1]]]] _
+[fn od? [n] [if [= n 0] false [ev? [- n 1]]]]||
+||[#anonymous-func anonymous function]||fn x => fn y => (x + y) / 2.0||fun x -> fun y -> (x +. y) /. 2.0||fun x -> fun y -> (x + y) / 2.0||\x y -> (x+y) / 2.0||[fn [x y] [/ [+ x y] 2.0]]||
+||[#infix-prefix infix operator in prefix position]||(op * ) (3, 4)||( * ) 3 4;;|| ||( * ) 3 4||##gray|//operators are prefix://## [* 3 4]||
 ||[#function-infix function in infix position]|| ||##gray|//none//##|| ||add x y = x + y _
-3 `add` 4||
+3 `add` 4||##gray|//none; all calls are prefix//##||
 ||[#currying currying]||un plus x y = x + y; _
 val plus2 = plus 2; _
-plus2 7;||let plus2 = (+) 2;;|| ||plus2 = (+) 2||
+plus2 7;||let plus2 = (+) 2;;|| ||plus2 = (+) 2||##gray|//none; use a closure://## [fn [x] [+ 2 x]]||
 ||[#composition composition]|| || || ||f x = x + 2 _
 g x = x * 3 _
-(f . g ) 4||
+(f . g ) 4||[fn [x] [f [g x]]]||
 ||[#function-composition function composition operator]||fun double x = 2 * x; _
 val quadruple = double o double;||##gray|//none//##|| ||double x = 2 * x _
-quadruple x = double . double||
+quadruple x = double . double||[pipe x g f] ##gray|//; via pipe//##||
 ||[#lazy-evaluation lazy evaluation]|| ||let arg1 x y = x;; _
  _
 arg1 7 (lazy (1/0) );;|| ||##gray|//lazy evaluation is default://## _
 arg1 x y = x _
  _
-arg1 7 (error "bam!")||
+arg1 7 (error "bam!")||##gray|//none; strict evaluation//##||
 ||[#strict-evaluation strict evaluation]|| ||##gray|//default behavior//##||##gray|//default behavior//##||arg1 x y = seq y x _
  _
-arg1 7 (error "bam!")||
-||||||||||~ [[# execution-control]][#execution-control-note execution control]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+arg1 7 (error "bam!")||##gray|//default (strict)//##||
+||||||||||||~ [[# execution-control]][#execution-control-note execution control]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#if if]||f x > 0 then _
 @<&nbsp;&nbsp;>@print "pos\n" _
 else _
@@ -606,7 +616,7 @@ else _
 @<&nbsp;&nbsp;>@print_endline "pos";;||if x > 0 then _
 @<&nbsp;&nbsp;>@printfn "pos"||if x > 0 _
 @<&nbsp;&nbsp;>@then putStrLn "pos" _
-@<&nbsp;&nbsp;>@else return ()||
+@<&nbsp;&nbsp;>@else return ()||[if [> x 0] [println "pos"] [println "neg"]]||
 ||[#if-else-if-else if else-if else]||if x > 0 then print "pos" else if x < 0 then print "neg" else print "zero";||if x > 0 then _
 @<&nbsp;&nbsp;>@print_endline "pos" _
 else _
@@ -623,7 +633,8 @@ else _
 @<&nbsp;&nbsp;>@then putStrLn "pos" _
 @<&nbsp;&nbsp;>@else if x < 0 _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@then putStrLn "neg" _
-@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@else putStrLn "zero"||
+@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@else putStrLn "zero"||[if [> x 0] "pos" _
+  [if [< x 0] "neg" "zero"]]||
 ||[#sequencing sequencing]|| ||print_endline "one"; _
 print_endline "two"; _
 print_endline "three";;||printfn "one" _
@@ -631,7 +642,7 @@ printfn "two" _
 printfn "three"||do _
 @<&nbsp;&nbsp;>@putStrLn "one" _
 @<&nbsp;&nbsp;>@putStrLn  "two" _
-@<&nbsp;&nbsp;>@putStrLn  "three"||
+@<&nbsp;&nbsp;>@putStrLn  "three"||[do [println "one"] [println "two"]]||
 ||[#while while]|| ||let i = ref 0;; _
  _
 while !i < 10 do _
@@ -641,31 +652,31 @@ done;;||let i = ref 0 _
  _
 while !i < 10 do _
 @<&nbsp;&nbsp;>@printfn "%d" !i _
-@<&nbsp;&nbsp;>@i := !i + 1|| ||
+@<&nbsp;&nbsp;>@i := !i + 1|| ||##gray|//none; use//## [loop [i 0] [if [< i 3] [recur [+ i 1]] i]]||
 ||[#for for]|| ||for i = 1 to 10 do _
 @<&nbsp;&nbsp;>@let s = string_of_int i in _
 @<&nbsp;&nbsp;>@print_endline s _
-done;;|| || ||
+done;;|| || ||[each [fn [i] [println i]] [range 5]]||
 ||[#reverse-for for in reverse]|| ||for i = 10 downto 1 do _
 @<&nbsp;&nbsp;>@let s = string_of_int i in _
 @<&nbsp;&nbsp;>@print_endline s _
-done;;|| || ||
-||[#list-iteration list iteration]|| ||##gray|//none//##|| || ||
+done;;|| || ||[each [fn [i] [println i]] [reverse [range 5]]]||
+||[#list-iteration list iteration]|| ||##gray|//none//##|| || ||[each [fn [x] [println x]] xs]||
 ||[#loop loop]|| ||let rec loop i = _
 @<&nbsp;&nbsp;>@if i <= 10 then begin _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@print_endline (string_of_int i); _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@loop (i+1) _
 @<&nbsp;&nbsp;>@end in _
-loop 0;;|| || ||
-||||||||||~ [[# exceptions]][#exceptions-note exceptions]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+loop 0;;|| || ||[loop [i 0] [if [< i 5] [recur [+ i 1]] i]]||
+||||||||||||~ [[# exceptions]][#exceptions-note exceptions]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#raise-error raise error]|| ||raise (Failure "bam!");; _
 ##gray|//or//## _
-failwith "bam!";;|| ||error "bam!"||
-||[#handle-error handle error]|| ||let x = try 1 / 0 with Division_by_zero -> 0;;|| || ||
-||[#exception-type type of exceptions]|| ||exn|| || ||
+failwith "bam!";;|| ||error "bam!"||[Fail.raise "bam"]||
+||[#handle-error handle error]|| ||let x = try 1 / 0 with Division_by_zero -> 0;;|| || ||[try [risky]] ##gray|//; -> Result//##||
+||[#exception-type type of exceptions]|| ||exn|| || ||##gray|//none; Result a Str or Fail effect//##||
 ||[#user-exception user defined exception]|| ||exception Foo of string;; _
-raise (Foo "invalid input");;|| || ||
+raise (Foo "invalid input");;|| || ||[effect Err [oops [String] a]]||
 ||[#standard-exceptions standard exceptions]|| ||Division_by_zero _
 Failure ##gray|//string//## _
 Not_found _
@@ -673,33 +684,33 @@ Invalid_argument ##gray|//string//## _
 Match_failure (##gray|//string//##, ##gray|//int//##, ##gray|//int//##) _
 Assert_failure (##gray|//string//##, ##gray|//int//##, ##gray|//int//##) _
 Out_of_memory _
-Stack_overflow|| || ||
-||[#assert assert]|| ||assert(1 = 0);;|| || ||
-||||||||||~ [[# concurrency]][#concurrency-note concurrency]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||||||||||~ [[# file-handles]][#file-handles-note file handles]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+Stack_overflow|| || ||##gray|//none; Fail effect//##||
+||[#assert assert]|| ||assert(1 = 0);;|| || ||[assert-eq got 1] ##gray|//; in a test//##||
+||||||||||||~ [[# concurrency]][#concurrency-note concurrency]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||||||||||||~ [[# file-handles]][#file-handles-note file handles]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||standard file handles|| ||stdin stdout stderr||stdin stdout stderr||import System.Posix.IO _
  _
-stdInput stdOutput stdError||
-||read line from stdin|| ||let line = read_line();;|| ||line <- getLine||
-||end-of-file behavior|| ||##gray|//raises// End_of_file##|| ||##gray|//when last data is returned,// hIsEOF //will return True.  Reading after end-of-file throws an exception.//##||
-||chomp|| || || || ||
-||[#write-line-stdout write line to stdout]|| ||print_endline "lorem ipsum";;||printfn "lorem ipsum"||putStrLn "lorem ipsum"||
-||write formatted string to stdout|| || || || ||
+stdInput stdOutput stdError||##gray|//none//##||
+||read line from stdin|| ||let line = read_line();;|| ||line <- getLine||[IO.read-line]||
+||end-of-file behavior|| ||##gray|//raises// End_of_file##|| ||##gray|//when last data is returned,// hIsEOF //will return True.  Reading after end-of-file throws an exception.//##||##gray|//none//##||
+||chomp|| || || || ||[trim s]||
+||[#write-line-stdout write line to stdout]|| ||print_endline "lorem ipsum";;||printfn "lorem ipsum"||putStrLn "lorem ipsum"||[IO.println "lorem ipsum"]||
+||write formatted string to stdout|| || || || ||[IO.println "x = {x}"]||
 ||open file for reading|| ||let f = open_in "/etc/passwd";;|| ||import System.IO _
  _
-f <- openFile "/etc/hosts" ReadMode||
+f <- openFile "/etc/hosts" ReadMode||##gray|//none; whole-file://## [IO.read-file p]||
 ||open file for writing|| ||let f = open_out "/tmp/ocaml.out";;|| ||import System.IO _
  _
-f <- openFile "/tmp/test" WriteMode||
+f <- openFile "/tmp/test" WriteMode||##gray|//none; whole-file://## [IO.write-file p s]||
 ||open file for appending|| || || ||import System.IO _
  _
-f <- openFile "/tmp/err.log" AppendMode||
+f <- openFile "/tmp/err.log" AppendMode||##gray|//none//##||
 ||close file|| || || ||import System.IO _
  _
-hClose f||
-||i/o errors|| || || || ||
+hClose f||##gray|//n/a; no handles//##||
+||i/o errors|| || || || ||[IO.read-file p]? ##gray|//; propagates Err//##||
 ||[#read-line read line]||fun displayFile(file: string) = _
 @<&nbsp;&nbsp;>@let _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@val f = TextIO.openIn file _
@@ -728,11 +739,11 @@ readAndPrintLines h = do _
  _
 main = do _
 @<&nbsp;&nbsp;>@h <- openFile "/etc/passwd" ReadMode _
-@<&nbsp;&nbsp;>@readAndPrintLines h||
-||iterate over file by line|| || || || ||
-||read file into array of strings|| || || || ||
-||read file into string|| || || || ||
-||write string|| || || || ||
+@<&nbsp;&nbsp;>@readAndPrintLines h||[IO.read-line] ##gray|//; stdin//##||
+||iterate over file by line|| || || || ||[each f [split [IO.read-file p] "\n"]]||
+||read file into array of strings|| || || || ||[split [IO.read-file p] "\n"]||
+||read file into string|| || || || ||[IO.read-file p]||
+||write string|| || || || ||[IO.write-file p s]||
 ||[#write-file write line]||val file = "/tmp/test-sml"; _
 val f = TextIO.openOut file; _
 TextIO.output(f, "hello out\n"); _
@@ -741,12 +752,12 @@ let oc = open_out "/tmp/test-ocaml" in _
 fprintf oc "hello out\n"; _
 close_out oc;;|| ||s = "hello out\n" _
 f = "/tmp/test-haskell" _
-main = writeFile f s||
-||flush file handle|| || || || ||
-||end-of-file test|| || || || ||
-||get and set filehandle position|| || || || ||
-||||||||||~ [[# files]][#files-note files]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+main = writeFile f s||[IO.write-file p "hello\n"]||
+||flush file handle|| || || || ||##gray|//n/a//##||
+||end-of-file test|| || || || ||##gray|//none//##||
+||get and set filehandle position|| || || || ||##gray|//none//##||
+||||||||||||~ [[# files]][#files-note files]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||file test, regular file test|| ||open Unix _
  _
 try Some (stat "/etc/hosts") with _
@@ -759,11 +770,11 @@ Directory.doesFileExist "/etc/hosts" _
 import Control.Monad _
 import System.Posix.Files _
  _
-liftM isRegularFile (getFileStatus "/etc/hosts")||
+liftM isRegularFile (getFileStatus "/etc/hosts")||##gray|//none//##||
 ||file size|| ||(stat "/etc/hosts").st_size|| ||import Control.Monad _
 import System.Posix.Files _
  _
-liftM fileSize (getFileStatus "/etc/hosts")||
+liftM fileSize (getFileStatus "/etc/hosts")||##gray|//none//##||
 ||is file readable, writable, executable|| ||open Unix _
  _
 try access "/tmp/bar" [R_OK]; true with _
@@ -778,7 +789,7 @@ liftM readable _
 liftM writable _
 @<&nbsp;&nbsp;>@(getPermissions "/etc/hosts") _
 liftM executable _
-@<&nbsp;&nbsp;>@(getPermissions "/etc/hosts")||
+@<&nbsp;&nbsp;>@(getPermissions "/etc/hosts")||##gray|//none//##||
 ||set file permissions|| ||open Unix _
  _
 chmod "/tmp/foo" 0o755|| ||import System.Posix.Files _
@@ -787,7 +798,7 @@ setFileMode "/tmp/foo" ownerModes _
 setFileMode "/tmp/foo" groupReadMode _
 setFileMode "/tmp/foo" groupExecuteMode _
 setFileMode "/tmp/foo" otherReadMode _
-setFileMode "/tmp/foo" otherExecuteMode||
+setFileMode "/tmp/foo" otherExecuteMode||##gray|//none//##||
 ||copy file, remove file, rename file|| ||open Unix _
  _
 ##gray|//??//## _
@@ -796,7 +807,7 @@ rename "/tmp/bar" "/tmp/foo"|| ||import System.Directory _
  _
 copyFile "/tmp/foo" "/tmp/bar" _
 removeFile "/tmp/foo" _
-renameFile "/tmp/bar" "/tmp/foo"||
+renameFile "/tmp/bar" "/tmp/foo"||##gray|//none//##||
 ||create symlink, symlink test, readlink|| ||open Unix _
  _
 symlink "/etc/hosts" "/tmp/hosts" _
@@ -805,50 +816,50 @@ readlink "/tmp/hosts"|| ||import System.Posix.Files _
  _
 createSymbolicLink "/etc/hosts" "/tmp/hosts" _
 ##gray|//??//## _
-readSymbolicLink "/tmp/hosts"||
+readSymbolicLink "/tmp/hosts"||##gray|//none//##||
 ||generate unused file name|| ||open Filename _
  _
 ##gray|(* prefix and suffix: *)## _
-temp_file "foo" ".txt"|| || ||
-||||||||||~ [[# directories]][#directories-note directories]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+temp_file "foo" ".txt"|| || ||##gray|//none//##||
+||||||||||||~ [[# directories]][#directories-note directories]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||build pathname|| ||open Filename _
  _
 concat "/etc" "hosts"|| ||import System.FilePath ((</>)) _
  _
-let path = "/etc" </> "hosts"||
+let path = "/etc" </> "hosts"||[join "/" #["dir" "file"]]||
 ||dirname and basename|| ||open Filename _
  _
 dirname "/etc/hosts" _
 basename "/etc/hosts"|| ||import System.FilePath _
  _
 takeFileName "/etc/hosts" _
-takeDirectory "/etc/hosts"||
+takeDirectory "/etc/hosts"||##gray|//none//##||
 ||iterate over directory by file|| || || ||import System _
  _
 ##gray|@@--@@ returns IO [FilePath]## _
-Directory.getDirectoryContents "/etc"||
+Directory.getDirectoryContents "/etc"||##gray|//none//##||
 ||make directory|| ||##gray|(* opam install fileutils *)## _
 open FileUtil _
  _
 mkdir ~parent:true "/tmp/foo/bar"|| ||import System.Directory _
  _
 createDirectoryIfMissing True _
-@<&nbsp;&nbsp;>@"/tmp/foo/bar"||
+@<&nbsp;&nbsp;>@"/tmp/foo/bar"||##gray|//none//##||
 ||remove empty directory|| ||open Unix _
  _
 rmdir "/tmp/foodir"|| ||import System.Directory _
  _
-removeDirectory "/tmp/foodir"||
+removeDirectory "/tmp/foodir"||##gray|//none//##||
 ||remove directory and contents|| || || ||import System.Directory _
  _
-removeDirectoryRecursive "/tmp/foodir"||
+removeDirectoryRecursive "/tmp/foodir"||##gray|//none//##||
 ||directory test|| || || ||import System _
  _
-Directory.doesDirectoryExist "/tmp"||
-||temporary directory|| || || || ||
-||||||||||~ [[# processes-environment]][#processes-environment-note processes and environment]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+Directory.doesDirectoryExist "/tmp"||##gray|//none//##||
+||temporary directory|| || || || ||##gray|//none//##||
+||||||||||||~ [[# processes-environment]][#processes-environment-note processes and environment]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#command-line-arg command line arguments]|| ||for i = 0 to Array.length Sys.argv - 1 do _
 @<&nbsp;&nbsp;>@print_endline i Sys.argv.(i) _
 done|| ||import System _
@@ -861,12 +872,12 @@ printArgs args = do _
 @<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@@<&nbsp;&nbsp;>@printArgs (tail args) _
 main = do _
 @<&nbsp;&nbsp;>@a <- getArgs _
-@<&nbsp;&nbsp;>@printArgs a||
+@<&nbsp;&nbsp;>@printArgs a||[IO.args] ##gray|//; #[Str]//##||
 ||[[# program-name]][#program-name-note program name] _
 @<&nbsp;>@|| || || ||import System _
  _
-s <-  getProgName||
-||[[# getopt]][#getopt-note getopt]|| || || || ||
+s <-  getProgName||[nth [IO.args] 0]||
+||[[# getopt]][#getopt-note getopt]|| || || || ||##gray|//none//##||
 ||[[# env-var]][#env-var-note get and set environment variable] _
 @<&nbsp;>@|| ||open Unix _
  _
@@ -874,20 +885,21 @@ s = getenv "HOME" _
 putenv "PATH" "/bin"|| ||import System.Posix.Env _
  _
 s <- getEnv "HOME" _
-putEnv "PATH=/bin"||
+putEnv "PATH=/bin"||[IO.env "HOME"] _
+##gray|//set: none//##||
 ||[[# pid]][#pid-note get pid, parent pid]|| ||open Unix _
  _
 let pid = getpid() _
 let ppid = getppid()|| ||import System.Posix.Process _
  _
 pid <- getProcessID _
-ppid <- getParentProcessID||
+ppid <- getParentProcessID||##gray|//none//##||
 ||[[# user-id-name]][#user-id-name-note get user id and name]|| ||let uid = getuid() _
 let username = _
 @<&nbsp;&nbsp;>@(getpwuid (getuid())).pw_name|| ||import System.Posix.User _
  _
 uid <- getRealUserID _
-username <- getLoginName||
+username <- getLoginName||##gray|//none//##||
 ||[[# exit]][#exit-note exit] _
 @<&nbsp;>@|| ||exit 0 _
  _
@@ -896,19 +908,20 @@ exit 1|| ||import System.Exit _
 exitWith ExitSuccess _
  _
 ##gray|//to return nonzero status://## _
-exitWith (ExitFailure 1)||
+exitWith (ExitFailure 1)||##gray|//none//##||
 ||[[# signal-handler]][#signal-handler-note set signal handler] _
-@<&nbsp;>@|| || || || ||
+@<&nbsp;>@|| || || || ||##gray|//none//##||
 ||[[# external-cmd]][#external-cmd-note external command] _
 @<&nbsp;>@|| || || ||import System.Cmd _
  _
-rawSystem "ls" ["-l", "/tmp"]||
+rawSystem "ls" ["-l", "/tmp"]||[IO.exec "ls" #["-l"]]||
 ||[[# escaped-external-cmd]][#escaped-external-cmd-note escaped external command] _
-@<&nbsp;>@|| || || || ||
+@<&nbsp;>@|| || || || ||[IO.exec "ls" #["-l"]] _
+##gray|//args are a vector//##||
 ||[[# backticks]][#backticks-note backticks] _
-@<&nbsp;>@|| || || || ||
-||||||||||~ [[# libraries-namespaces]][#libraries-namespaces-note libraries and namespaces]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+@<&nbsp;>@|| || || || ||[IO.exec "date" #[]] ##gray|//; Result Str//##||
+||||||||||||~ [[# libraries-namespaces]][#libraries-namespaces-note libraries and namespaces]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#namespace-example namespace example]|| || || ||##gray|//Foo/Bar.hs//## _
 module Foo.Bar where _
 @<&nbsp;&nbsp;>@data Baz = Baz _
@@ -924,13 +937,13 @@ main = say baz _
 $ ghc -c Foo/Bar.hs _
 $ ghc Main.hs _
 $ ./Main _
-hello||
-||[#namespaces namespaces]|| || || ||values, constructors, type variables, type constructors, type classes, modules||
-||[#file-name file name restrictions]|| ||##gray|//module// Foo.Bar //must be in// Foo.ml##|| ||##gray|//module// Foo.Bar //must be in// Foo/Bar.hs##||
-||[#import namespace]|| ||open Graphics;;|| ||import Data.Bytestring||
-||[#namespace-creation namespace creation]|| ||##gray|//put code in file// MODULE_NAME//.ml//##|| || ||
-||[#namespace-alias namespace alias]|| ||module Gr = Graphics;;|| ||import qualified Data.Bytestring as B||
-||[#namespace-separator namespace separator]|| ||.|| ||.||
+hello||##gray|//math.oo://## [pub fn add [a b] [+ a b]]||
+||[#namespaces namespaces]|| || || ||values, constructors, type variables, type constructors, type classes, modules||##gray|//one module per file//##||
+||[#file-name file name restrictions]|| ||##gray|//module// Foo.Bar //must be in// Foo.ml##|| ||##gray|//module// Foo.Bar //must be in// Foo/Bar.hs##||##gray|//module name = file name//##||
+||[#import namespace]|| ||open Graphics;;|| ||import Data.Bytestring||[use math]||
+||[#namespace-creation namespace creation]|| ||##gray|//put code in file// MODULE_NAME//.ml//##|| || ||##gray|//implicit (the file)//##||
+||[#namespace-alias namespace alias]|| ||module Gr = Graphics;;|| ||import qualified Data.Bytestring as B||[use math as m]||
+||[#namespace-separator namespace separator]|| ||.|| ||.||. ##gray|//; e.g. math.add//##||
 ||[#subnamespace subnamespace]|| ||##gray|//in A.ml://## _
 module B = _
 sig _
@@ -941,23 +954,24 @@ struct _
 @<&nbsp;&nbsp;>@let display_instruction () = print_endline msg _
 end _
 ##gray|//in client source://## _
-A.B.display_instruction;;|| || ||
+A.B.display_instruction;;|| || ||[use utils/string]||
 ||[[# pkg-manager-setup]][#pkg-manager-setup-note package manager setup]|| ||##gray|//do this once://## _
 $ opam init _
  _
 ##gray|//for each shell session://## _
-$ eval $(opam config env)|| || ||
+$ eval $(opam config env)|| || ||$ loon init||
 ||[[# pkg-manager]][#pkg-manager-note package manager] _
 ##gray|//search; install; list installed//##|| ||$ opam search utop _
 $ opam install utop _
 $ opam list @@--@@installed|| ||$ cabal list parsec _
 $ cabal install parsec _
-$ cabal list @@--@@installed||
-||[[# pkg-compile]][#pkg-compile-note compile app using package]|| || || || ||
-||||||||||~ [[# user-defined-types]][#user-defined-types-note user-defined types]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+$ cabal list @@--@@installed||$ loon add ##gray|//pkg//## _
+$ loon update||
+||[[# pkg-compile]][#pkg-compile-note compile app using package]|| || || || ||$ loon build||
+||||||||||||~ [[# user-defined-types]][#user-defined-types-note user-defined types]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[[# type-synonym]][#type-synonym-note type synonym] _
-@<&nbsp;>@||type name = string;||type name = string;;||type name = string||type Name = String||
+@<&nbsp;>@||type name = string;||type name = string;;||type name = string||type Name = String||##gray|//none//##||
 ||[[# sum-type]][#sum-type-note sum type]||datatype color = Red | Green | Blue;||type color = Red | Green | Blue;; _
  _
 let col = Red;; _
@@ -973,7 +987,7 @@ col < Green||data Color = Red | Green | Blue _
 col = Red _
  _
 ##gray|@@--@@ this won't compile:## _
-col < Green||
+col < Green||[type Color Red Green Blue]||
 ||tuple product type with one field||datatype special_int = SpecialInt of int; _
  _
 val x = SpecialInt 7;||type special_int = SpecialInt of int;; _
@@ -982,7 +996,7 @@ let n = SpecialInt 7;;||type special_int = SpecialInt of int _
  _
 let n = SpecialInt 7||data SpecialIntType = SpecialInt Integer _
  _
-n = SpecialInt 7||
+n = SpecialInt 7||[type Id [Id Int]]||
 ||tuple product type with two fields||datatype int_pair = IntPair of int * int; _
  _
 val y = IntPair (7, 11);||type int_pair = IntPair of int * int;; _
@@ -991,7 +1005,7 @@ let p = IntPair (7, 11);;||type int_pair = IntPair of int * int _
  _
 let p = IntPair (7, 11)||data IntPairType = IntPair Integer Integer _
  _
-p = IntPair 7 11||
+p = IntPair 7 11||[type Pair [Pair Int Int]]||
 ||record product type||type customer = {id:int, name:string, address:string}||type customer = { _
 @<&nbsp;&nbsp;>@id: int; _
 @<&nbsp;&nbsp;>@name: string; _
@@ -1004,7 +1018,7 @@ p = IntPair 7 11||
 @<&nbsp;&nbsp;>@customerId :: Integer, _
 @<&nbsp;&nbsp;>@name :: String, _
 @<&nbsp;&nbsp;>@address :: String _
-}||
+}||##gray|//use a map (row-typed)//##||
 ||record product type literal||{id=7, name="John", address="Topeka, KS"}||let cust = { _
 @<&nbsp;&nbsp;>@id=7; _
 @<&nbsp;&nbsp;>@name="John"; _
@@ -1012,7 +1026,7 @@ p = IntPair 7 11||
 };;||{id=7; name="John"; address="Topeka, KS"}||Customer { _
 @<&nbsp;&nbsp;>@customerId=7, _
 @<&nbsp;&nbsp;>@name="John", _
-@<&nbsp;&nbsp;>@address="Topeka, KS" }||
+@<&nbsp;&nbsp;>@address="Topeka, KS" }||{:id 7 :name "ada"}||
 ||[[# generic-type]][#generic-type-note generic type]||datatype ('a, 'b) twosome = _
 @<&nbsp;&nbsp;>@Twosome of 'a * 'b; _
  _
@@ -1024,14 +1038,17 @@ let p = Twosome ("pi", 3.14);;||type ('a, 'b) twosome = _
  _
 let p = Twosome ("pi", 3.14)||data TwosomeType a b = Twosome a b _
  _
-p = Twosome ("pi", 3.14)||
+p = Twosome ("pi", 3.14)||[type Tree _
+  [Leaf a] _
+  [Node [Tree a] [Tree a]]]||
 ||[#recursive-type recursive type]||datatype binary_tree = _
 @<&nbsp;&nbsp;>@Leaf of int _
 @<&nbsp;&nbsp;>@| Tree of binary_tree * binary_tree;||type binary_tree = _
 @<&nbsp;&nbsp;>@| Leaf of int _
 @<&nbsp;&nbsp;>@| Tree of binary_tree * binary_tree;;||type binary_tree = _
 @<&nbsp;&nbsp;>@| Leaf of int _
-@<&nbsp;&nbsp;>@| Tree of binary_tree * binary_tree||data BinaryTree = Leaf Integer | Tree BinaryTree BinaryTree||
+@<&nbsp;&nbsp;>@| Tree of binary_tree * binary_tree||data BinaryTree = Leaf Integer | Tree BinaryTree BinaryTree||[type Tree _
+  [Leaf Int] [Node Tree Tree]]||
 ||pattern match sum type||val c = Red; _
  _
 case c of Red => "red" _
@@ -1044,35 +1061,35 @@ let s = match col with _
 @<&nbsp;&nbsp;>@| Green -> "green";;|| ||c = Red _
 case c of Red -> "red" _
 @<&nbsp;&nbsp;>@Green -> "green" _
-@<&nbsp;&nbsp;>@Blue -> "blue"||
-||pattern match product type|| || || || ||
-||[#match-guard pattern match guard]||##gray|//none; use// if##||match i with j when i < 0 -> -j | j -> j;;|| ||##gray|//none, use if or piecewise function definition//##||
+@<&nbsp;&nbsp;>@Blue -> "blue"||[match c Red "red" Green "green"]||
+||pattern match product type|| || || || ||[match p [Pair a b] [+ a b]]||
+||[#match-guard pattern match guard]||##gray|//none; use// if##||match i with j when i < 0 -> -j | j -> j;;|| ||##gray|//none, use if or piecewise function definition//##||[match n x [if [> x 0] "pos" "neg"]]||
 ||[#match-catchall pattern match catchall]||fun to_s c = case c of Red => "red" | _ => "not red";||let to_s c = match c with Red -> "red" | _ -> "not red";; _
 to_s Green;;|| ||c = Green _
-case c of Red -> "red"; _ -> "not red"||
-||||||||||~ [[# objects]][#objects-note objects]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+case c of Red -> "red"; _ -> "not red"||[match c Red "red" _ "other"]||
+||||||||||||~ [[# objects]][#objects-note objects]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#class-definition class definition]|| ||class counter = object _
 @<&nbsp;&nbsp;>@val mutable n = 0 _
 @<&nbsp;&nbsp;>@method incr = n <- n+1 _
 @<&nbsp;&nbsp;>@method get = n _
-end;;|| || ||
-||[#object-creation object creation]|| ||let c = new counter;;|| || ||
+end;;|| || ||##gray|//none; use type + functions//##||
+||[#object-creation object creation]|| ||let c = new counter;;|| || ||##gray|//none; construct a value//##||
 ||[#method-invocation method invocation]|| ||c#incr;; _
-c#get;;|| || ||
-||[#field-access field access]|| ||##gray|//none//##|| || ||
-||||||||||~ [[# inheritance-polymorphism]][#inheritance-polymorphism-note inheritance and polymorphism]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||overload function|| || || || ||
-||[#inheritance inheritance]|| || || || ||
-||||||||||~ [[# net-web]][#net-web-note net and web]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||||||||||~ [[# unit-tests]][#unit-tests-note unit test]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||||||||||~ [[# debugging-profiling]][#debugging-profiling-note debugging and profiling]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
-||||||||||~ [[# repl]][#repl-note repl]||
-||~ ||~ sml||~ ocaml||~ f#||~ haskell||
+c#get;;|| || ||##gray|//none; call a function//##||
+||[#field-access field access]|| ||##gray|//none//##|| || ||[get rec :field] ##gray|//; map field//##||
+||||||||||||~ [[# inheritance-polymorphism]][#inheritance-polymorphism-note inheritance and polymorphism]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||overload function|| || || || ||[fn f ([a] ...) ([a b] ...)] ##gray|//; multi-arity//##||
+||[#inheritance inheritance]|| || || || ||##gray|//none//##||
+||||||||||||~ [[# net-web]][#net-web-note net and web]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||||||||||||~ [[# unit-tests]][#unit-tests-note unit test]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||||||||||||~ [[# debugging-profiling]][#debugging-profiling-note debugging and profiling]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
+||||||||||||~ [[# repl]][#repl-note repl]||
+||~ ||~ sml||~ ocaml||~ f#||~ haskell||~ loon||
 ||[#invoke-repl invoke repl]||$ sml||$ ocaml _
  _
 ##gray|//Use this if you want history://## _
@@ -1081,23 +1098,24 @@ $ rlwrap ocaml _
 ##gray|//The utop toplevel, which can be installed via opam, also provides history.//##||##gray|//Mono://## _
 $ fsharpi _
  _
-##gray|//In visual studio, highlight code and press ALT+ENTER.//##||$ ghci||
-||[#repl-limitations repl limitations]|| || || ||##gray|//Must use let to define values and functions; when defining functions with multiple equations the equations must be separated by semicolons; the clauses of case/of statements must be separated by semicolons; it is not possible to define data types.//##||
-||[#repl-last-value repl last value]||it||##gray|//none//##||it||it||
-||[#help help]|| ||##gray|//none//##|| ||:?||
-||[#quit quit]|| ||^D||#quit;;|| ||
+##gray|//In visual studio, highlight code and press ALT+ENTER.//##||$ ghci||$ loon repl||
+||[#repl-limitations repl limitations]|| || || ||##gray|//Must use let to define values and functions; when defining functions with multiple equations the equations must be separated by semicolons; the clauses of case/of statements must be separated by semicolons; it is not possible to define data types.//##||##gray|//none//##||
+||[#repl-last-value repl last value]||it||##gray|//none//##||it||it||##gray|//none//##||
+||[#help help]|| ||##gray|//none//##|| ||:?||##gray|//none//##||
+||[#quit quit]|| ||^D||#quit;;|| ||:quit||
 ||[#inspect-type inspect type]|| ||##gray|//repl displays the type of any expression entered//##|| ||let a = 3 _
-:type a||
-||[#inspect-namespace inspect namespace]|| ||module Unix = Unix;;|| || ||
+:type a||##gray|//LSP hover, or//## $ loon check||
+||[#inspect-namespace inspect namespace]|| ||module Unix = Unix;;|| || ||##gray|//none//##||
 ||[#load-source load source file]||use "hello.ml";||#use "hello";;|| ||:edit hello.hs _
-:load hello||
+:load hello||$ loon run file.oo||
 ||[#load-pkg-note load package]|| ||##gray|//consider adding to// .ocamlinit:## _
 #use "topfind";; _
 # thread;; _
 #require "core";; _
-open Core.Std;;|| || ||
-||[#search-path search path]|| ||#directory "libdir";;|| || ||
-||[#search-path-command-line set search path on command line]|| ||ocaml -Ilibdir|| || ||
+open Core.Std;;|| || ||$ loon add pkg _
+[use pkg]||
+||[#search-path search path]|| ||#directory "libdir";;|| || ||##gray|//none//##||
+||[#search-path-command-line set search path on command line]|| ||ocaml -Ilibdir|| || ||##gray|//none//##||
 ||~ ||~ ##EFEFEF|@@_______________________________________________@@##||~ ##EFEFEF|@@_______________________________________________@@##||~ ##EFEFEF|@@_______________________________________________@@##||~ ##EFEFEF|@@_______________________________________________@@##||