diff --git a/prelude.md b/prelude.md
index c0c3c1d..b0473c6 100644
--- a/prelude.md
+++ b/prelude.md
@@ -65,7 +65,7 @@ You can see what this looks like in the last clause of `add`: `((x1, y1), (x2, y
 [any?](#any)&nbsp;&nbsp;&nbsp; [append](#append)&nbsp;&nbsp;&nbsp; [coll?](#coll)&nbsp;&nbsp;&nbsp; [concat](#concat)&nbsp;&nbsp;&nbsp; [contains?](#contains)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [omit](#omit)&nbsp;&nbsp;&nbsp; [random](#random)&nbsp;&nbsp;&nbsp; [set](#set)&nbsp;&nbsp;&nbsp; [set?](#set)
 
 ### Strings
-[any?](#any)&nbsp;&nbsp;&nbsp; [concat](#concat)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [downcase](#downcase)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [join](#join)&nbsp;&nbsp;&nbsp; [sentence](#sentence)&nbsp;&nbsp;&nbsp; [show](#show)&nbsp;&nbsp;&nbsp; [slice](#slice)&nbsp;&nbsp;&nbsp; [split](#split)&nbsp;&nbsp;&nbsp; [string](#string)&nbsp;&nbsp;&nbsp; [string?](#string)&nbsp;&nbsp;&nbsp; [strip](#strip)&nbsp;&nbsp;&nbsp; [trim](#trim)&nbsp;&nbsp;&nbsp; [upcase](#upcase)&nbsp;&nbsp;&nbsp; [words](#words)
+[any?](#any)&nbsp;&nbsp;&nbsp; [chars](#chars)&nbsp;&nbsp;&nbsp; [chars/safe](#chars/safe)&nbsp;&nbsp;&nbsp; [concat](#concat)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [downcase](#downcase)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [join](#join)&nbsp;&nbsp;&nbsp; [sentence](#sentence)&nbsp;&nbsp;&nbsp; [show](#show)&nbsp;&nbsp;&nbsp; [slice](#slice)&nbsp;&nbsp;&nbsp; [split](#split)&nbsp;&nbsp;&nbsp; [string](#string)&nbsp;&nbsp;&nbsp; [string?](#string)&nbsp;&nbsp;&nbsp; [strip](#strip)&nbsp;&nbsp;&nbsp; [trim](#trim)&nbsp;&nbsp;&nbsp; [upcase](#upcase)&nbsp;&nbsp;&nbsp; [words](#words)
 
 ### Tuples
 [any?](#any)&nbsp;&nbsp;&nbsp; [at](#at)&nbsp;&nbsp;&nbsp; [coll?](#coll)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [first](#first)&nbsp;&nbsp;&nbsp; [last](#last)&nbsp;&nbsp;&nbsp; [ordered?](#ordered)&nbsp;&nbsp;&nbsp; [rest](#rest)&nbsp;&nbsp;&nbsp; [second](#second)&nbsp;&nbsp;&nbsp; [tuple?](#tuple)
@@ -77,7 +77,7 @@ You can see what this looks like in the last clause of `add`: `((x1, y1), (x2, y
 [assoc?](#assoc)&nbsp;&nbsp;&nbsp; [bool?](#bool)&nbsp;&nbsp;&nbsp; [box?](#box)&nbsp;&nbsp;&nbsp; [coll?](#coll)&nbsp;&nbsp;&nbsp; [dict?](#dict)&nbsp;&nbsp;&nbsp; [eq?](#eq)&nbsp;&nbsp;&nbsp; [fn?](#fn)&nbsp;&nbsp;&nbsp; [keyword?](#keyword)&nbsp;&nbsp;&nbsp; [list?](#list)&nbsp;&nbsp;&nbsp; [neq?](#neq)&nbsp;&nbsp;&nbsp; [nil?](#nil)&nbsp;&nbsp;&nbsp; [number?](#number)&nbsp;&nbsp;&nbsp; [ordered?](#ordered)&nbsp;&nbsp;&nbsp; [set?](#set)&nbsp;&nbsp;&nbsp; [show](#show)&nbsp;&nbsp;&nbsp; [some](#some)&nbsp;&nbsp;&nbsp; [some?](#some)&nbsp;&nbsp;&nbsp; [string?](#string)&nbsp;&nbsp;&nbsp; [tuple?](#tuple)&nbsp;&nbsp;&nbsp; [type](#type)
     
 ## All functions, alphabetically
-[abs](#abs)&nbsp;&nbsp;&nbsp; [add](#add)&nbsp;&nbsp;&nbsp; [and](#and)&nbsp;&nbsp;&nbsp; [angle](#angle)&nbsp;&nbsp;&nbsp; [any?](#any)&nbsp;&nbsp;&nbsp; [append](#append)&nbsp;&nbsp;&nbsp; [assert!](#assert)&nbsp;&nbsp;&nbsp; [assoc](#assoc)&nbsp;&nbsp;&nbsp; [assoc?](#assoc)&nbsp;&nbsp;&nbsp; [at](#at)&nbsp;&nbsp;&nbsp; [atan/2](#atan/2)&nbsp;&nbsp;&nbsp; [back!](#back)&nbsp;&nbsp;&nbsp; [background!](#background)&nbsp;&nbsp;&nbsp; [between?](#between)&nbsp;&nbsp;&nbsp; [bg!](#bg)&nbsp;&nbsp;&nbsp; [bgcolor](#bgcolor)&nbsp;&nbsp;&nbsp; [bk!](#bk)&nbsp;&nbsp;&nbsp; [bool](#bool)&nbsp;&nbsp;&nbsp; [bool?](#bool)&nbsp;&nbsp;&nbsp; [box?](#box)&nbsp;&nbsp;&nbsp; [butlast](#butlast)&nbsp;&nbsp;&nbsp; [ceil](#ceil)&nbsp;&nbsp;&nbsp; [clear!](#clear)&nbsp;&nbsp;&nbsp; [coll?](#coll)&nbsp;&nbsp;&nbsp; [colors](#colors)&nbsp;&nbsp;&nbsp; [concat](#concat)&nbsp;&nbsp;&nbsp; [contains?](#contains)&nbsp;&nbsp;&nbsp; [cos](#cos)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [dec](#dec)&nbsp;&nbsp;&nbsp; [deg/rad](#deg/rad)&nbsp;&nbsp;&nbsp; [deg/turn](#deg/turn)&nbsp;&nbsp;&nbsp; [dict](#dict)&nbsp;&nbsp;&nbsp; [dict?](#dict)&nbsp;&nbsp;&nbsp; [diff](#diff)&nbsp;&nbsp;&nbsp; [dissoc](#dissoc)&nbsp;&nbsp;&nbsp; [dist](#dist)&nbsp;&nbsp;&nbsp; [div](#div)&nbsp;&nbsp;&nbsp; [div/0](#div/0)&nbsp;&nbsp;&nbsp; [div/safe](#div/safe)&nbsp;&nbsp;&nbsp; [doc!](#doc)&nbsp;&nbsp;&nbsp; [downcase](#downcase)&nbsp;&nbsp;&nbsp; [each!](#each)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [eq?](#eq)&nbsp;&nbsp;&nbsp; [err](#err)&nbsp;&nbsp;&nbsp; [err?](#err)&nbsp;&nbsp;&nbsp; [even?](#even)&nbsp;&nbsp;&nbsp; [false?](#false)&nbsp;&nbsp;&nbsp; [fd!](#fd)&nbsp;&nbsp;&nbsp; [filter](#filter)&nbsp;&nbsp;&nbsp; [first](#first)&nbsp;&nbsp;&nbsp; [floor](#floor)&nbsp;&nbsp;&nbsp; [fn?](#fn)&nbsp;&nbsp;&nbsp; [fold](#fold)&nbsp;&nbsp;&nbsp; [forward!](#forward)&nbsp;&nbsp;&nbsp; [get](#get)&nbsp;&nbsp;&nbsp; [goto!](#goto)&nbsp;&nbsp;&nbsp; [gt?](#gt)&nbsp;&nbsp;&nbsp; [gte?](#gte)&nbsp;&nbsp;&nbsp; [heading](#heading)&nbsp;&nbsp;&nbsp; [heading/vector](#heading/vector)&nbsp;&nbsp;&nbsp; [home!](#home)&nbsp;&nbsp;&nbsp; [inc](#inc)&nbsp;&nbsp;&nbsp; [inv](#inv)&nbsp;&nbsp;&nbsp; [inv/0](#inv/0)&nbsp;&nbsp;&nbsp; [inv/safe](#inv/safe)&nbsp;&nbsp;&nbsp; [join](#join)&nbsp;&nbsp;&nbsp; [keep](#keep)&nbsp;&nbsp;&nbsp; [keys](#keys)&nbsp;&nbsp;&nbsp; [keyword?](#keyword)&nbsp;&nbsp;&nbsp; [last](#last)&nbsp;&nbsp;&nbsp; [left!](#left)&nbsp;&nbsp;&nbsp; [list](#list)&nbsp;&nbsp;&nbsp; [list?](#list)&nbsp;&nbsp;&nbsp; [load\_turtle_state!](#load\_turtle_state)&nbsp;&nbsp;&nbsp; [lt!](#lt)&nbsp;&nbsp;&nbsp; [lt?](#lt)&nbsp;&nbsp;&nbsp; [lte?](#lte)&nbsp;&nbsp;&nbsp; [map](#map)&nbsp;&nbsp;&nbsp; [max](#max)&nbsp;&nbsp;&nbsp; [min](#min)&nbsp;&nbsp;&nbsp; [mod](#mod)&nbsp;&nbsp;&nbsp; [mod/0](#mod/0)&nbsp;&nbsp;&nbsp; [mod/safe](#mod/safe)&nbsp;&nbsp;&nbsp; [mult](#mult)&nbsp;&nbsp;&nbsp; [neg](#neg)&nbsp;&nbsp;&nbsp; [neg?](#neg)&nbsp;&nbsp;&nbsp; [neq?](#neq)&nbsp;&nbsp;&nbsp; [nil?](#nil)&nbsp;&nbsp;&nbsp; [not](#not)&nbsp;&nbsp;&nbsp; [odd?](#odd)&nbsp;&nbsp;&nbsp; [ok](#ok)&nbsp;&nbsp;&nbsp; [ok?](#ok)&nbsp;&nbsp;&nbsp; [omit](#omit)&nbsp;&nbsp;&nbsp; [or](#or)&nbsp;&nbsp;&nbsp; [ordered?](#ordered)&nbsp;&nbsp;&nbsp; [p5\_calls](#p5\_calls)&nbsp;&nbsp;&nbsp; [pc!](#pc)&nbsp;&nbsp;&nbsp; [pd!](#pd)&nbsp;&nbsp;&nbsp; [pencolor](#pencolor)&nbsp;&nbsp;&nbsp; [pencolor!](#pencolor)&nbsp;&nbsp;&nbsp; [pendown!](#pendown)&nbsp;&nbsp;&nbsp; [pendown?](#pendown)&nbsp;&nbsp;&nbsp; [penup!](#penup)&nbsp;&nbsp;&nbsp; [penwidth](#penwidth)&nbsp;&nbsp;&nbsp; [penwidth!](#penwidth)&nbsp;&nbsp;&nbsp; [pi](#pi)&nbsp;&nbsp;&nbsp; [pos?](#pos)&nbsp;&nbsp;&nbsp; [position](#position)&nbsp;&nbsp;&nbsp; [print!](#print)&nbsp;&nbsp;&nbsp; [pu!](#pu)&nbsp;&nbsp;&nbsp; [pw!](#pw)&nbsp;&nbsp;&nbsp; [rad/deg](#rad/deg)&nbsp;&nbsp;&nbsp; [rad/turn](#rad/turn)&nbsp;&nbsp;&nbsp; [random](#random)&nbsp;&nbsp;&nbsp; [random\_int](#random\_int)&nbsp;&nbsp;&nbsp; [range](#range)&nbsp;&nbsp;&nbsp; [render\_turtle!](#render\_turtle)&nbsp;&nbsp;&nbsp; [report!](#report)&nbsp;&nbsp;&nbsp; [reset\_turtle!](#reset\_turtle)&nbsp;&nbsp;&nbsp; [rest](#rest)&nbsp;&nbsp;&nbsp; [right!](#right)&nbsp;&nbsp;&nbsp; [round](#round)&nbsp;&nbsp;&nbsp; [rt!](#rt)&nbsp;&nbsp;&nbsp; [second](#second)&nbsp;&nbsp;&nbsp; [sentence](#sentence)&nbsp;&nbsp;&nbsp; [set](#set)&nbsp;&nbsp;&nbsp; [set?](#set)&nbsp;&nbsp;&nbsp; [show](#show)&nbsp;&nbsp;&nbsp; [sin](#sin)&nbsp;&nbsp;&nbsp; [slice](#slice)&nbsp;&nbsp;&nbsp; [some](#some)&nbsp;&nbsp;&nbsp; [some?](#some)&nbsp;&nbsp;&nbsp; [split](#split)&nbsp;&nbsp;&nbsp; [sqrt](#sqrt)&nbsp;&nbsp;&nbsp; [sqrt/safe](#sqrt/safe)&nbsp;&nbsp;&nbsp; [square](#square)&nbsp;&nbsp;&nbsp; [state](#state)&nbsp;&nbsp;&nbsp; [store!](#store)&nbsp;&nbsp;&nbsp; [string](#string)&nbsp;&nbsp;&nbsp; [string?](#string)&nbsp;&nbsp;&nbsp; [strip](#strip)&nbsp;&nbsp;&nbsp; [sub](#sub)&nbsp;&nbsp;&nbsp; [sum\_of_squares](#sum\_of_squares)&nbsp;&nbsp;&nbsp; [tan](#tan)&nbsp;&nbsp;&nbsp; [tau](#tau)&nbsp;&nbsp;&nbsp; [trim](#trim)&nbsp;&nbsp;&nbsp; [tuple?](#tuple)&nbsp;&nbsp;&nbsp; [turn/deg](#turn/deg)&nbsp;&nbsp;&nbsp; [turn/rad](#turn/rad)&nbsp;&nbsp;&nbsp; [turtle\_commands](#turtle\_commands)&nbsp;&nbsp;&nbsp; [turtle\_state](#turtle\_state)&nbsp;&nbsp;&nbsp; [turtle\_states](#turtle\_states)&nbsp;&nbsp;&nbsp; [type](#type)&nbsp;&nbsp;&nbsp; [unbox](#unbox)&nbsp;&nbsp;&nbsp; [unwrap!](#unwrap)&nbsp;&nbsp;&nbsp; [unwrap\_or](#unwrap\_or)&nbsp;&nbsp;&nbsp; [upcase](#upcase)&nbsp;&nbsp;&nbsp; [update](#update)&nbsp;&nbsp;&nbsp; [update!](#update)&nbsp;&nbsp;&nbsp; [values](#values)&nbsp;&nbsp;&nbsp; [words](#words)&nbsp;&nbsp;&nbsp; [ws?](#ws)&nbsp;&nbsp;&nbsp; [zero?](#zero)
+[abs](#abs)&nbsp;&nbsp;&nbsp; [add](#add)&nbsp;&nbsp;&nbsp; [and](#and)&nbsp;&nbsp;&nbsp; [angle](#angle)&nbsp;&nbsp;&nbsp; [any?](#any)&nbsp;&nbsp;&nbsp; [append](#append)&nbsp;&nbsp;&nbsp; [assert!](#assert)&nbsp;&nbsp;&nbsp; [assoc](#assoc)&nbsp;&nbsp;&nbsp; [assoc?](#assoc)&nbsp;&nbsp;&nbsp; [at](#at)&nbsp;&nbsp;&nbsp; [atan/2](#atan/2)&nbsp;&nbsp;&nbsp; [back!](#back)&nbsp;&nbsp;&nbsp; [background!](#background)&nbsp;&nbsp;&nbsp; [between?](#between)&nbsp;&nbsp;&nbsp; [bg!](#bg)&nbsp;&nbsp;&nbsp; [bk!](#bk)&nbsp;&nbsp;&nbsp; [bool](#bool)&nbsp;&nbsp;&nbsp; [bool?](#bool)&nbsp;&nbsp;&nbsp; [box?](#box)&nbsp;&nbsp;&nbsp; [butlast](#butlast)&nbsp;&nbsp;&nbsp; [ceil](#ceil)&nbsp;&nbsp;&nbsp; [chars](#chars)&nbsp;&nbsp;&nbsp; [clear!](#clear)&nbsp;&nbsp;&nbsp; [coll?](#coll)&nbsp;&nbsp;&nbsp; [colors](#colors)&nbsp;&nbsp;&nbsp; [concat](#concat)&nbsp;&nbsp;&nbsp; [contains?](#contains)&nbsp;&nbsp;&nbsp; [cos](#cos)&nbsp;&nbsp;&nbsp; [count](#count)&nbsp;&nbsp;&nbsp; [dec](#dec)&nbsp;&nbsp;&nbsp; [deg/rad](#deg/rad)&nbsp;&nbsp;&nbsp; [deg/turn](#deg/turn)&nbsp;&nbsp;&nbsp; [dict](#dict)&nbsp;&nbsp;&nbsp; [dict?](#dict)&nbsp;&nbsp;&nbsp; [diff](#diff)&nbsp;&nbsp;&nbsp; [dissoc](#dissoc)&nbsp;&nbsp;&nbsp; [dist](#dist)&nbsp;&nbsp;&nbsp; [div](#div)&nbsp;&nbsp;&nbsp; [div/0](#div/0)&nbsp;&nbsp;&nbsp; [div/safe](#div/safe)&nbsp;&nbsp;&nbsp; [doc!](#doc)&nbsp;&nbsp;&nbsp; [downcase](#downcase)&nbsp;&nbsp;&nbsp; [each!](#each)&nbsp;&nbsp;&nbsp; [empty?](#empty)&nbsp;&nbsp;&nbsp; [eq?](#eq)&nbsp;&nbsp;&nbsp; [err](#err)&nbsp;&nbsp;&nbsp; [err?](#err)&nbsp;&nbsp;&nbsp; [even?](#even)&nbsp;&nbsp;&nbsp; [false?](#false)&nbsp;&nbsp;&nbsp; [fd!](#fd)&nbsp;&nbsp;&nbsp; [filter](#filter)&nbsp;&nbsp;&nbsp; [first](#first)&nbsp;&nbsp;&nbsp; [floor](#floor)&nbsp;&nbsp;&nbsp; [fn?](#fn)&nbsp;&nbsp;&nbsp; [fold](#fold)&nbsp;&nbsp;&nbsp; [forward!](#forward)&nbsp;&nbsp;&nbsp; [get](#get)&nbsp;&nbsp;&nbsp; [goto!](#goto)&nbsp;&nbsp;&nbsp; [gt?](#gt)&nbsp;&nbsp;&nbsp; [gte?](#gte)&nbsp;&nbsp;&nbsp; [heading](#heading)&nbsp;&nbsp;&nbsp; [heading/vector](#heading/vector)&nbsp;&nbsp;&nbsp; [hideturtle!](#hideturtle)&nbsp;&nbsp;&nbsp; [home!](#home)&nbsp;&nbsp;&nbsp; [inc](#inc)&nbsp;&nbsp;&nbsp; [inv](#inv)&nbsp;&nbsp;&nbsp; [inv/0](#inv/0)&nbsp;&nbsp;&nbsp; [inv/safe](#inv/safe)&nbsp;&nbsp;&nbsp; [join](#join)&nbsp;&nbsp;&nbsp; [keep](#keep)&nbsp;&nbsp;&nbsp; [keys](#keys)&nbsp;&nbsp;&nbsp; [keyword?](#keyword)&nbsp;&nbsp;&nbsp; [last](#last)&nbsp;&nbsp;&nbsp; [left!](#left)&nbsp;&nbsp;&nbsp; [list](#list)&nbsp;&nbsp;&nbsp; [list?](#list)&nbsp;&nbsp;&nbsp; [loadstate!](#loadstate)&nbsp;&nbsp;&nbsp; [lt!](#lt)&nbsp;&nbsp;&nbsp; [lt?](#lt)&nbsp;&nbsp;&nbsp; [lte?](#lte)&nbsp;&nbsp;&nbsp; [map](#map)&nbsp;&nbsp;&nbsp; [max](#max)&nbsp;&nbsp;&nbsp; [min](#min)&nbsp;&nbsp;&nbsp; [mod](#mod)&nbsp;&nbsp;&nbsp; [mod/0](#mod/0)&nbsp;&nbsp;&nbsp; [mod/safe](#mod/safe)&nbsp;&nbsp;&nbsp; [mult](#mult)&nbsp;&nbsp;&nbsp; [neg](#neg)&nbsp;&nbsp;&nbsp; [neg?](#neg)&nbsp;&nbsp;&nbsp; [neq?](#neq)&nbsp;&nbsp;&nbsp; [nil?](#nil)&nbsp;&nbsp;&nbsp; [not](#not)&nbsp;&nbsp;&nbsp; [odd?](#odd)&nbsp;&nbsp;&nbsp; [ok](#ok)&nbsp;&nbsp;&nbsp; [ok?](#ok)&nbsp;&nbsp;&nbsp; [omit](#omit)&nbsp;&nbsp;&nbsp; [or](#or)&nbsp;&nbsp;&nbsp; [ordered?](#ordered)&nbsp;&nbsp;&nbsp; [pc!](#pc)&nbsp;&nbsp;&nbsp; [pd!](#pd)&nbsp;&nbsp;&nbsp; [pencolor](#pencolor)&nbsp;&nbsp;&nbsp; [pencolor!](#pencolor)&nbsp;&nbsp;&nbsp; [pendown!](#pendown)&nbsp;&nbsp;&nbsp; [pendown?](#pendown)&nbsp;&nbsp;&nbsp; [penup!](#penup)&nbsp;&nbsp;&nbsp; [penwidth](#penwidth)&nbsp;&nbsp;&nbsp; [penwidth!](#penwidth)&nbsp;&nbsp;&nbsp; [pi](#pi)&nbsp;&nbsp;&nbsp; [pos?](#pos)&nbsp;&nbsp;&nbsp; [position](#position)&nbsp;&nbsp;&nbsp; [print!](#print)&nbsp;&nbsp;&nbsp; [pu!](#pu)&nbsp;&nbsp;&nbsp; [pw!](#pw)&nbsp;&nbsp;&nbsp; [rad/deg](#rad/deg)&nbsp;&nbsp;&nbsp; [rad/turn](#rad/turn)&nbsp;&nbsp;&nbsp; [random](#random)&nbsp;&nbsp;&nbsp; [random\_int](#random\_int)&nbsp;&nbsp;&nbsp; [range](#range)&nbsp;&nbsp;&nbsp; [report!](#report)&nbsp;&nbsp;&nbsp; [rest](#rest)&nbsp;&nbsp;&nbsp; [right!](#right)&nbsp;&nbsp;&nbsp; [round](#round)&nbsp;&nbsp;&nbsp; [rt!](#rt)&nbsp;&nbsp;&nbsp; [second](#second)&nbsp;&nbsp;&nbsp; [sentence](#sentence)&nbsp;&nbsp;&nbsp; [set](#set)&nbsp;&nbsp;&nbsp; [set?](#set)&nbsp;&nbsp;&nbsp; [setheading!](#setheading)&nbsp;&nbsp;&nbsp; [show](#show)&nbsp;&nbsp;&nbsp; [showturtle!](#showturtle)&nbsp;&nbsp;&nbsp; [sin](#sin)&nbsp;&nbsp;&nbsp; [slice](#slice)&nbsp;&nbsp;&nbsp; [some](#some)&nbsp;&nbsp;&nbsp; [some?](#some)&nbsp;&nbsp;&nbsp; [split](#split)&nbsp;&nbsp;&nbsp; [sqrt](#sqrt)&nbsp;&nbsp;&nbsp; [sqrt/safe](#sqrt/safe)&nbsp;&nbsp;&nbsp; [square](#square)&nbsp;&nbsp;&nbsp; [state](#state)&nbsp;&nbsp;&nbsp; [store!](#store)&nbsp;&nbsp;&nbsp; [string](#string)&nbsp;&nbsp;&nbsp; [string?](#string)&nbsp;&nbsp;&nbsp; [strip](#strip)&nbsp;&nbsp;&nbsp; [sub](#sub)&nbsp;&nbsp;&nbsp; [sum\_of_squares](#sum\_of_squares)&nbsp;&nbsp;&nbsp; [tan](#tan)&nbsp;&nbsp;&nbsp; [tau](#tau)&nbsp;&nbsp;&nbsp; [trim](#trim)&nbsp;&nbsp;&nbsp; [tuple?](#tuple)&nbsp;&nbsp;&nbsp; [turn/deg](#turn/deg)&nbsp;&nbsp;&nbsp; [turn/rad](#turn/rad)&nbsp;&nbsp;&nbsp; [turtle\_commands](#turtle\_commands)&nbsp;&nbsp;&nbsp; [turtle\_init](#turtle\_init)&nbsp;&nbsp;&nbsp; [turtle\_state](#turtle\_state)&nbsp;&nbsp;&nbsp; [type](#type)&nbsp;&nbsp;&nbsp; [unbox](#unbox)&nbsp;&nbsp;&nbsp; [unwrap!](#unwrap)&nbsp;&nbsp;&nbsp; [unwrap\_or](#unwrap\_or)&nbsp;&nbsp;&nbsp; [upcase](#upcase)&nbsp;&nbsp;&nbsp; [update](#update)&nbsp;&nbsp;&nbsp; [update!](#update)&nbsp;&nbsp;&nbsp; [values](#values)&nbsp;&nbsp;&nbsp; [words](#words)&nbsp;&nbsp;&nbsp; [ws?](#ws)&nbsp;&nbsp;&nbsp; [zero?](#zero)
 ## Function documentation
 
 ### abs
@@ -95,7 +95,7 @@ Adds numbers or vectors.
 ()
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ((x1, y1), (x2, y2))
 ```
 [Back to top.](#ludus-prelude-documentation)
@@ -107,7 +107,7 @@ Returns true if all values passed in are truthy. Note that this does not short-c
 ()
 (x)
 (x, y)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -158,9 +158,9 @@ Asserts a condition: returns the value if the value is truthy, panics if the val
 Takes a dict, key, and value, and returns a new dict with the key set to value.
 ```
 ()
-(dict as :dict)
-(dict as :dict, key as :keyword, value)
-(dict as :dict, (key as :keyword, value))
+(d as :dict)
+(d as :dict, k as :keyword, val)
+(d as :dict, (k as :keyword, val))
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -168,8 +168,8 @@ Takes a dict, key, and value, and returns a new dict with the key set to value.
 ### assoc?
 Returns true if a value is an associative collection: a dict or a pkg.
 ```
-(assoc as :dict)
-(assoc as :pkg)
+(d as :dict)
+(p as :pkg)
 (_)
 ```
 [Back to top.](#ludus-prelude-documentation)
@@ -210,6 +210,7 @@ Moves the turtle backward by a number of steps. Alias: bk!
 ### background!
 Sets the background color behind the turtle and path. Alias: bg!
 ```
+(color as :keyword)
 (gray as :number)
 ((r as :number, g as :number, b as :number))
 ((r as :number, g as :number, b as :number, a as :number))
@@ -228,16 +229,13 @@ Returns true if a number is in the range [lower, higher): greater than or equal
 ### bg!
 Sets the background color behind the turtle and path. Alias: bg!
 ```
+(color as :keyword)
 (gray as :number)
 ((r as :number, g as :number, b as :number))
 ((r as :number, g as :number, b as :number, a as :number))
 ```
 [Back to top.](#ludus-prelude-documentation)
 
----
-### bgcolor
-No documentation available.
-
 ---
 ### bk!
 Moves the turtle backward by a number of steps. Alias: bk!
@@ -291,6 +289,14 @@ Truncates a number towards positive infinity. With negative numbers, it returns
 ```
 [Back to top.](#ludus-prelude-documentation)
 
+---
+### chars
+Takes a string and returns its characters as a list. Works only for strings with only ascii characters. Panics on any non-ascii characters.
+```
+(str as :string)
+```
+[Back to top.](#ludus-prelude-documentation)
+
 ---
 ### clear!
 Clears the canvas and sends the turtle home.
@@ -322,7 +328,7 @@ Combines two lists, strings, or sets.
 (x as :string, y as :string)
 (xs as :list, ys as :list)
 (xs as :set, ys as :set)
-(xs, ys, ...)
+(xs, ys, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -330,8 +336,8 @@ Combines two lists, strings, or sets.
 ### contains?
 Returns true if a set or list contains a value.
 ```
-(value, set as :set)
-(value, list as :list)
+(value, s as :set)
+(value, l as :list)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -386,9 +392,9 @@ Converts an angle in degrees to an angle in turns.
 ### dict
 Takes a list or tuple of (key, value) tuples and returns it as a dict. Returns dicts unharmed.
 ```
-(dict as :dict)
-(list as :list)
-(tup as :tuple)
+(d as :dict)
+(l as :list)
+(t as :tuple)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -396,7 +402,7 @@ Takes a list or tuple of (key, value) tuples and returns it as a dict. Returns d
 ### dict?
 Returns true if a value is a dict.
 ```
-(dict as :dict)
+(d as :dict)
 (_)
 ```
 [Back to top.](#ludus-prelude-documentation)
@@ -413,8 +419,8 @@ Takes two dicts and returns a dict describing their differences. Does this shall
 ### dissoc
 Takes a dict and a key, and returns a new dict with the key and associated value omitted.
 ```
-(dict as :dict)
-(dict as :dict, key as :keyword)
+(d as :dict)
+(d as :dict, k as :keyword)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -434,7 +440,7 @@ Divides numbers. Panics on division by zero.
 (x as :number)
 (_, 0)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -445,7 +451,7 @@ Divides numbers. Returns 0 on division by zero.
 (x as :number)
 (_, 0)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -456,7 +462,7 @@ Divides a number. Returns a result tuple.
 (x as :number)
 (_, 0)
 (x, y)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -483,7 +489,7 @@ Takes a list and applies a function, presumably with side effects, to each eleme
 ```
 (f! as :fn, [])
 (f! as :fn, [x])
-(f! as :fn, [x, ...])
+(f! as :fn, [x, ...xs])
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -506,7 +512,7 @@ Returns true if all arguments have the same value.
 ```
 (x)
 (x, y)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -590,7 +596,9 @@ Returns true if an argument is a function.
 ### fold
 Folds a list.
 ```
+(f as :fn, [])
 (f as :fn, xs as :list)
+(f as :fn, [], root)
 (f as :fn, xs as :list, root)
 ```
 [Back to top.](#ludus-prelude-documentation)
@@ -607,9 +615,9 @@ Moves the turtle forward by a number of steps. Alias: fd!
 ### get
 Takes a key, dict, and optional default value; returns the value at key. If the value is not found, returns nil or the default value.
 ```
-(key as :keyword)
-(key as :keyword, dict as :dict)
-(key as :keyword, dict as :dict, default)
+(k as :keyword)
+(k as :keyword, d as :dict)
+(k as :keyword, d as :dict, default)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -628,7 +636,7 @@ Returns true if numbers are in decreasing order.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -638,7 +646,7 @@ Returns true if numbers are in decreasing or flat order.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -658,6 +666,14 @@ Takes a turtle heading, and returns a unit vector of that heading.
 ```
 [Back to top.](#ludus-prelude-documentation)
 
+---
+### hideturtle!
+If the turtle is visible, hides it. If the turtle is already hidden, does nothing.
+```
+()
+```
+[Back to top.](#ludus-prelude-documentation)
+
 ---
 ### home!
 Sends the turtle home: to the centre of the screen, pointing up. If the pen is down, the turtle will draw a path to home.
@@ -705,8 +721,9 @@ Takes a list of strings, and joins them into a single string, interposing an opt
 ([])
 ([str as :string])
 (strs as :list)
+([], separator as :string)
 ([str as :string], separator as :string)
-([str, ...], separator as :string)
+([str, ...strs], separator as :string)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -722,7 +739,7 @@ Takes a list and returns a new list with any `nil` values omitted.
 ### keys
 Takes a dict and returns a list of keys in that dict.
 ```
-(dict as :dict)
+(d as :dict)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -769,8 +786,8 @@ Returns true if the value is a list.
 [Back to top.](#ludus-prelude-documentation)
 
 ---
-### load_turtle_state!
-Sets the turtle state to a previously saved state. Returns the state.
+### loadstate!
+Sets the turtle state to a previously saved state.
 ```
 (state)
 ```
@@ -790,7 +807,7 @@ Returns true if numbers are in increasing order.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -800,7 +817,7 @@ Returns true if numbers are in increasing or flat order.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -819,7 +836,7 @@ Returns the number in its arguments that is closest to positive infinity.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -829,34 +846,34 @@ Returns the number in its arguments that is closest to negative infinity.
 ```
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
 ---
 ### mod
-Returns the modulus of num and div. Truncates towards negative infinity. Panics if div is 0.
+Returns the modulus of x and y. Truncates towards negative infinity. Panics if y is 0.
 ```
-(num as :number, 0)
-(num as :number, div as :number)
+(x as :number, 0)
+(x as :number, y as :number)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
 ---
 ### mod/0
-Returns the modulus of num and div. Truncates towards negative infinity. Returns 0 if div is 0.
+Returns the modulus of x and y. Truncates towards negative infinity. Returns 0 if y is 0.
 ```
-(num as :number, 0)
-(num as :number, div as :number)
+(x as :number, 0)
+(x as :number, y as :number)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
 ---
 ### mod/safe
-Returns the modulus of num and div in a result tuple, or an error if div is 0. Truncates towards negative infinity.
+Returns the modulus of x and y in a result tuple, or an error if y is 0. Truncates towards negative infinity.
 ```
-(num as :number, 0)
-(num as :number, div as :number)
+(x as :number, 0)
+(x as :number, y as :number)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -867,7 +884,7 @@ Multiplies numbers or vectors.
 ()
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 (scalar as :number, (x, y))
 ((x, y), scalar as :number)
 ```
@@ -896,7 +913,7 @@ Returns true if none of the arguments have the same value.
 ```
 (x)
 (x, y)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -960,7 +977,7 @@ Returns true if any value passed in is truthy. Note that this does not short-cir
 ()
 (x)
 (x, y)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -970,18 +987,16 @@ Returns true if a value is an indexed collection: list or tuple.
 ```
 (coll as :list)
 (coll as :tuple)
+(coll as :string)
 (_)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
----
-### p5_calls
-No documentation available.
-
 ---
 ### pc!
 Changes the turtle's pen color. Takes a single grayscale value, an rgb tuple, or an rgba tuple. Alias: pc!
 ```
+(color as :keyword)
 (gray as :number)
 ((r as :number, g as :number, b as :number))
 ((r as :number, g as :number, b as :number, a as :number))
@@ -998,7 +1013,7 @@ Lowers the turtle's pen, causing it to draw. Alias: pd!
 
 ---
 ### pencolor
-Returns the turtle's pen color as an (r, g, b, a) tuple.
+Returns the turtle's pen color as an (r, g, b, a) tuple or keyword.
 ```
 ()
 ```
@@ -1008,6 +1023,7 @@ Returns the turtle's pen color as an (r, g, b, a) tuple.
 ### pencolor!
 Changes the turtle's pen color. Takes a single grayscale value, an rgb tuple, or an rgba tuple. Alias: pc!
 ```
+(color as :keyword)
 (gray as :number)
 ((r as :number, g as :number, b as :number))
 ((r as :number, g as :number, b as :number, a as :number))
@@ -1079,7 +1095,7 @@ Returns the turtle's current position.
 ### print!
 Sends a text representation of Ludus values to the console.
 ```
-(...)
+(...args)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -1146,14 +1162,6 @@ Returns the set of integers between start (inclusive) and end (exclusive) as a l
 ```
 [Back to top.](#ludus-prelude-documentation)
 
----
-### render_turtle!
-No docstring available.
-```
-()
-```
-[Back to top.](#ludus-prelude-documentation)
-
 ---
 ### report!
 Prints a value, then returns it.
@@ -1163,20 +1171,15 @@ Prints a value, then returns it.
 ```
 [Back to top.](#ludus-prelude-documentation)
 
----
-### reset_turtle!
-Resets the turtle to its original state.
-```
-()
-```
-[Back to top.](#ludus-prelude-documentation)
-
 ---
 ### rest
 Returns all but the first element of a list or tuple, as a list.
 ```
+([])
+(())
 (xs as :list)
 (xs as :tuple)
+(xs as :string)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -1238,6 +1241,14 @@ Returns true if a value is a set.
 ```
 [Back to top.](#ludus-prelude-documentation)
 
+---
+### setheading!
+Sets the turtle's heading. The angle is specified in turns, with 0 pointing up. Increasing values rotate the turtle counter-clockwise.
+```
+(heading as :number)
+```
+[Back to top.](#ludus-prelude-documentation)
+
 ---
 ### show
 Returns a text representation of a Ludus value as a string.
@@ -1246,6 +1257,14 @@ Returns a text representation of a Ludus value as a string.
 ```
 [Back to top.](#ludus-prelude-documentation)
 
+---
+### showturtle!
+If the turtle is hidden, shows the turtle. If the turtle is already visible, does nothing.
+```
+()
+```
+[Back to top.](#ludus-prelude-documentation)
+
 ---
 ### sin
 Returns the sine of an angle. Default angle measure is turns. An optional keyword argument specifies the units of the angle passed in.
@@ -1336,7 +1355,7 @@ Converts a value to a string by using `show`. If it is a string, returns it unha
 ```
 (x as :string)
 (x)
-(x, ...)
+(x, ...xs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -1370,7 +1389,7 @@ Subtracts numbers or vectors.
 ()
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ((x1, y1), (x2, y2))
 ```
 [Back to top.](#ludus-prelude-documentation)
@@ -1382,7 +1401,7 @@ Returns the sum of squares of numbers.
 ()
 (x as :number)
 (x as :number, y as :number)
-(x, y, ...)
+(x, y, ...zs)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -1441,15 +1460,11 @@ Converts an angle in turns to an angle in radians.
 No documentation available.
 
 ---
-### turtle_state
-Returns the turtle's current state.
-```
-()
-```
-[Back to top.](#ludus-prelude-documentation)
+### turtle_init
+No documentation available.
 
 ---
-### turtle_states
+### turtle_state
 No documentation available.
 
 ---
@@ -1499,8 +1514,8 @@ Takes a string and returns it in all uppercase. Works only for ascii characters.
 ### update
 Takes a dict, key, and function, and returns a new dict with the key set to the result of applying the function to original value held at the key.
 ```
-(dict as :dict)
-(dict as :dict, key as :keyword, updater as :fn)
+(d as :dict)
+(d as :dict, k as :keyword, updater as :fn)
 ```
 [Back to top.](#ludus-prelude-documentation)
 
@@ -1516,7 +1531,7 @@ Updates a box by applying a function to its value. Returns the new value.
 ### values
 Takes a dict and returns a list of values in that dict.
 ```
-(dict)
+(d as :dict)
 ```
 [Back to top.](#ludus-prelude-documentation)