diff --git a/README.md b/README.md
index ec648fe..a376fc3 100644
--- a/README.md
+++ b/README.md
@@ -66,12 +66,6 @@ Positional values can be gotten out of lists using the `at` operator, and keys u
 20
 ```
 
-A shortcut for a key whose value is `true` looks like this, called a flag:
-```
-> (list :yes)
-(yes: true)
-```
-
 #### Variables
 Variables are declared using `define` and `define-global`. Variables declared with `define` are available for use anywhere in subsequent expressions in the same scope, and `define-global` makes them globally available.
 ```
@@ -227,22 +221,12 @@ A function's parameter list can contain both positional and key parameters, wher
 15
 ```
 
-If the key's value is `true`, the same name as the key is used to bind the parameter's value. This makes it easy to define named parameters with flags:
-```
-> (let f (fn (a b: true) (+ a b))
-    (f 1 b: 2))
-3
-> (let f (fn (a :b) (+ a b)) ; use a flag
-    (f 10 b: 20))
-30
-```
-
 Parameters in Lumen are always optional, and those without a supplied argument have the value `nil`:
 ```
 > (let f (fn (a) a)
     (f))
 >
-> (let f (fn (:b) (if (= b nil) 10 20))
+> (let f (fn (b: b) (if (= b nil) 10 20))
     (f a: 99))
 10
 ```
@@ -270,7 +254,7 @@ Variables can be bound to values in a list at certain positions or key:
 2
 > ((fn ((a b: my-b)) (list a my-b)) (list 1 b: 2))
 (1 2)
-> (let ((a :b) (list 1 b: 2))
+> (let ((a b: b) (list 1 b: 2))
     b)
 2
 ```
@@ -279,7 +263,7 @@ The `rest` key works with destructuring as it does with function parameters, whi
 > (let ((a rest: as) (list 1 2 3))
     (list a as))
 (1 (2 3))
-> (let ((a :rest) (list 1 2 3))
+> (let ((a rest: rest) (list 1 2 3))
     (list a rest))
 (1 (2 3))
 ```
diff --git a/bin/compiler.js b/bin/compiler.js
index f0ca439..89f179d 100644
--- a/bin/compiler.js
+++ b/bin/compiler.js
@@ -503,22 +503,22 @@ ____x69.js = "!";
 ____x69.lua = "not";
 ____x68["not"] = ____x69;
 var ____x70 = [];
-____x70["*"] = true;
-____x70["/"] = true;
-____x70["%"] = true;
+____x70["*"] = "*";
+____x70["/"] = "/";
+____x70["%"] = "%";
 var ____x71 = [];
 var ____x72 = [];
 ____x72.js = "+";
 ____x72.lua = "..";
 ____x71.cat = ____x72;
 var ____x73 = [];
-____x73["+"] = true;
-____x73["-"] = true;
+____x73["+"] = "+";
+____x73["-"] = "-";
 var ____x74 = [];
-____x74["<"] = true;
-____x74[">"] = true;
-____x74["<="] = true;
-____x74[">="] = true;
+____x74["<"] = "<";
+____x74[">"] = ">";
+____x74["<="] = "<=";
+____x74[">="] = ">=";
 var ____x75 = [];
 var ____x76 = [];
 ____x76.js = "===";
@@ -567,8 +567,12 @@ var getop = function (op) {
     if (__x82 === true) {
       return op;
     } else {
-      if (is63(__x82)) {
-        return __x82[target];
+      if (string63(__x82)) {
+        return __x82;
+      } else {
+        if (is63(__x82)) {
+          return __x82[target];
+        }
       }
     }
   }, infix);
diff --git a/bin/compiler.lua b/bin/compiler.lua
index 6768275..e34a2e3 100644
--- a/bin/compiler.lua
+++ b/bin/compiler.lua
@@ -454,22 +454,22 @@ ____x69.js = "!"
 ____x69.lua = "not"
 ____x68["not"] = ____x69
 local ____x70 = {}
-____x70["*"] = true
-____x70["/"] = true
-____x70["%"] = true
+____x70["*"] = "*"
+____x70["/"] = "/"
+____x70["%"] = "%"
 local ____x71 = {}
 local ____x72 = {}
 ____x72.js = "+"
 ____x72.lua = ".."
 ____x71.cat = ____x72
 local ____x73 = {}
-____x73["+"] = true
-____x73["-"] = true
+____x73["+"] = "+"
+____x73["-"] = "-"
 local ____x74 = {}
-____x74["<"] = true
-____x74[">"] = true
-____x74["<="] = true
-____x74[">="] = true
+____x74["<"] = "<"
+____x74[">"] = ">"
+____x74["<="] = "<="
+____x74[">="] = ">="
 local ____x75 = {}
 local ____x76 = {}
 ____x76.js = "==="
@@ -513,8 +513,12 @@ local function getop(op)
     if __x82 == true then
       return op
     else
-      if is63(__x82) then
-        return __x82[target]
+      if string63(__x82) then
+        return __x82
+      else
+        if is63(__x82) then
+          return __x82[target]
+        end
       end
     end
   end, infix)
diff --git a/bin/reader.js b/bin/reader.js
index b98c64e..b7b9dc6 100644
--- a/bin/reader.js
+++ b/bin/reader.js
@@ -71,9 +71,6 @@ read_string = function (str, more) {
 var key63 = function (atom) {
   return string63(atom) && _35(atom) > 1 && char(atom, edge(atom)) === ":";
 };
-var flag63 = function (atom) {
-  return string63(atom) && _35(atom) > 1 && char(atom, 0) === ":";
-};
 var expected = function (s, c) {
   var ____id1 = s;
   var __more = ____id1.more;
@@ -146,17 +143,17 @@ read_table[""] = function (s) {
 };
 read_table["("] = function (s) {
   read_char(s);
-  var __r16 = undefined;
+  var __r15 = undefined;
   var __l1 = [];
-  while (nil63(__r16)) {
+  while (nil63(__r15)) {
     skip_non_code(s);
     var __c4 = peek_char(s);
     if (__c4 === ")") {
       read_char(s);
-      __r16 = __l1;
+      __r15 = __l1;
     } else {
       if (nil63(__c4)) {
-        __r16 = expected(s, ")");
+        __r15 = expected(s, ")");
       } else {
         var __x2 = read(s);
         if (key63(__x2)) {
@@ -164,31 +161,27 @@ read_table["("] = function (s) {
           var __v = read(s);
           __l1[__k] = __v;
         } else {
-          if (flag63(__x2)) {
-            __l1[clip(__x2, 1)] = true;
-          } else {
-            add(__l1, __x2);
-          }
+          add(__l1, __x2);
         }
       }
     }
   }
-  return __r16;
+  return __r15;
 };
 read_table[")"] = function (s) {
   return error("Unexpected ) at " + s.pos);
 };
 read_table["\""] = function (s) {
   read_char(s);
-  var __r19 = undefined;
+  var __r18 = undefined;
   var __str1 = "\"";
-  while (nil63(__r19)) {
+  while (nil63(__r18)) {
     var __c5 = peek_char(s);
     if (__c5 === "\"") {
-      __r19 = __str1 + read_char(s);
+      __r18 = __str1 + read_char(s);
     } else {
       if (nil63(__c5)) {
-        __r19 = expected(s, "\"");
+        __r18 = expected(s, "\"");
       } else {
         if (__c5 === "\\") {
           __str1 = __str1 + read_char(s);
@@ -197,25 +190,25 @@ read_table["\""] = function (s) {
       }
     }
   }
-  return __r19;
+  return __r18;
 };
 read_table["|"] = function (s) {
   read_char(s);
-  var __r21 = undefined;
+  var __r20 = undefined;
   var __str2 = "|";
-  while (nil63(__r21)) {
+  while (nil63(__r20)) {
     var __c6 = peek_char(s);
     if (__c6 === "|") {
-      __r21 = __str2 + read_char(s);
+      __r20 = __str2 + read_char(s);
     } else {
       if (nil63(__c6)) {
-        __r21 = expected(s, "|");
+        __r20 = expected(s, "|");
       } else {
         __str2 = __str2 + read_char(s);
       }
     }
   }
-  return __r21;
+  return __r20;
 };
 read_table["'"] = function (s) {
   read_char(s);
diff --git a/bin/reader.lua b/bin/reader.lua
index 6ccf399..eaca7e1 100644
--- a/bin/reader.lua
+++ b/bin/reader.lua
@@ -71,9 +71,6 @@ end
 local function key63(atom)
   return string63(atom) and _35(atom) > 1 and char(atom, edge(atom)) == ":"
 end
-local function flag63(atom)
-  return string63(atom) and _35(atom) > 1 and char(atom, 0) == ":"
-end
 local function expected(s, c)
   local ____id1 = s
   local __more = ____id1.more
@@ -146,17 +143,17 @@ read_table[""] = function (s)
 end
 read_table["("] = function (s)
   read_char(s)
-  local __r16 = nil
+  local __r15 = nil
   local __l1 = {}
-  while nil63(__r16) do
+  while nil63(__r15) do
     skip_non_code(s)
     local __c4 = peek_char(s)
     if __c4 == ")" then
       read_char(s)
-      __r16 = __l1
+      __r15 = __l1
     else
       if nil63(__c4) then
-        __r16 = expected(s, ")")
+        __r15 = expected(s, ")")
       else
         local __x2 = read(s)
         if key63(__x2) then
@@ -164,31 +161,27 @@ read_table["("] = function (s)
           local __v = read(s)
           __l1[__k] = __v
         else
-          if flag63(__x2) then
-            __l1[clip(__x2, 1)] = true
-          else
-            add(__l1, __x2)
-          end
+          add(__l1, __x2)
         end
       end
     end
   end
-  return __r16
+  return __r15
 end
 read_table[")"] = function (s)
   return error("Unexpected ) at " .. s.pos)
 end
 read_table["\""] = function (s)
   read_char(s)
-  local __r19 = nil
+  local __r18 = nil
   local __str1 = "\""
-  while nil63(__r19) do
+  while nil63(__r18) do
     local __c5 = peek_char(s)
     if __c5 == "\"" then
-      __r19 = __str1 .. read_char(s)
+      __r18 = __str1 .. read_char(s)
     else
       if nil63(__c5) then
-        __r19 = expected(s, "\"")
+        __r18 = expected(s, "\"")
       else
         if __c5 == "\\" then
           __str1 = __str1 .. read_char(s)
@@ -197,25 +190,25 @@ read_table["\""] = function (s)
       end
     end
   end
-  return __r19
+  return __r18
 end
 read_table["|"] = function (s)
   read_char(s)
-  local __r21 = nil
+  local __r20 = nil
   local __str2 = "|"
-  while nil63(__r21) do
+  while nil63(__r20) do
     local __c6 = peek_char(s)
     if __c6 == "|" then
-      __r21 = __str2 .. read_char(s)
+      __r20 = __str2 .. read_char(s)
     else
       if nil63(__c6) then
-        __r21 = expected(s, "|")
+        __r20 = expected(s, "|")
       else
         __str2 = __str2 .. read_char(s)
       end
     end
   end
-  return __r21
+  return __r20
 end
 read_table["'"] = function (s)
   read_char(s)
diff --git a/compiler.l b/compiler.l
index bdaa4e7..3e9517a 100644
--- a/compiler.l
+++ b/compiler.l
@@ -121,7 +121,7 @@
        (= (hd x) 'unquote-splicing)))
 
 (define expand-local ((x name value))
-  (setenv name :variable)
+  (setenv name variable: true)
   `(%local ,name ,(macroexpand value)))
 
 (define expand-function ((x args rest: body))
@@ -276,14 +276,14 @@
           (add o x))))))
 
 (define infix
-  `((not: (js: ! lua: ,"not"))
-    (:* :/ :%)
+  `((not: (js: ! lua: not))
+    (*: * /: / %: %)
     (cat: (js: + lua: ..))
-    (:+ :-)
-    (:< :> :<= :>=)
+    (+: + -: -)
+    (<: < >: > <=: <= >=: >=)
     (=: (js: === lua: ==))
     (and: (js: && lua: and))
-    (or: (js: ,"||" lua: or))))
+    (or: (js: || lua: or))))
 
 (define unary? (form)
   (and (two? form) (in? (hd form) '(not -))))
@@ -301,6 +301,7 @@
   (find (fn (level)
           (let x (get level op)
             (if (= x true) op
+                (string? x) x
                 (is? x) (get x target))))
         infix))
 
@@ -345,7 +346,7 @@
 
 (define compile-special (form stmt?)
   (let ((x rest: args) form
-        (:special :stmt tr: self-tr?) (getenv x)
+        (special: special stmt: stmt tr: self-tr?) (getenv x)
         tr (terminator (and stmt? (not self-tr?))))
     (cat (apply special args) tr)))
 
@@ -362,7 +363,7 @@
         (cat "(" f1 ")" args)
       (cat f1 args))))
 
-(define op-delims (parent child :right)
+(define op-delims (parent child right: right)
   (if ((if right >= >)
        (precedence child)
        (precedence parent))
@@ -372,7 +373,7 @@
 (define compile-infix (form)
   (let ((op rest: (a b)) form
         (ao ac) (op-delims form a)
-        (bo bc) (op-delims form b :right)
+        (bo bc) (op-delims form b right: true)
         a (compile a)
         b (compile b)
         op (getop op))
@@ -380,14 +381,14 @@
         (cat op ao " " a ac)
       (cat ao a ac " " op " " bo b bc))))
 
-(define-global compile-function (args body :name :prefix)
+(define-global compile-function (args body name: name prefix: prefix)
   (let (id (if name (compile name) "")
         args1 (if (and (= target 'lua)
                        (get args 'rest))
                   `(,@args |...|)
                 args)
         args (compile-args args1)
-        body (with-indent (compile body :stmt))
+        body (with-indent (compile body stmt: true))
         ind (indentation)
         p (if prefix (cat prefix " ") "")
         tr (if (= target 'js) "" "end"))
@@ -402,7 +403,7 @@
            (and (not (= (hd form) 'return))
                 (not (statement? (hd form)))))))
 
-(define-global compile (form :stmt)
+(define-global compile (form stmt: stmt)
   (if (nil? form) ""
       (special-form? form)
       (compile-special form stmt)
@@ -593,23 +594,23 @@
 (define-global immediate-call? (x)
   (and (obj? x) (obj? (hd x)) (= (hd (hd x)) '%function)))
 
-(define-special do forms :stmt :tr
+(define-special do forms stmt: true tr: true
   (with s ""
     (step x forms
       (when (and (= target 'lua)
                  (immediate-call? x)
                  (= "\n" (char s (edge s))))
         (set s (cat (clip s 0 (edge s)) ";\n")))
-      (cat! s (compile x :stmt))
+      (cat! s (compile x stmt: true))
       (unless (atom? x)
         (if (or (= (hd x) 'return)
                 (= (hd x) 'break))
             (break))))))
 
-(define-special %if (cond cons alt) :stmt :tr
+(define-special %if (cond cons alt) stmt: true tr: true
   (let (cond (compile cond)
-        cons (with-indent (compile cons :stmt))
-        alt (if alt (with-indent (compile alt :stmt)))
+        cons (with-indent (compile cons stmt: true))
+        alt (if alt (with-indent (compile alt stmt: true)))
         ind (indentation)
         s "")
     (if (= target 'js)
@@ -622,53 +623,53 @@
         (cat s ind "end\n")
       (cat s "\n"))))
 
-(define-special while (cond form) :stmt :tr
+(define-special while (cond form) stmt: true tr: true
   (let (cond (compile cond)
-        body (with-indent (compile form :stmt))
+        body (with-indent (compile form stmt: true))
         ind (indentation))
     (if (= target 'js)
         (cat ind "while (" cond ") {\n" body ind "}\n")
       (cat ind "while " cond " do\n" body ind "end\n"))))
 
-(define-special %for (t k form) :stmt :tr
+(define-special %for (t k form) stmt: true tr: true
   (let (t (compile t)
         ind (indentation)
-        body (with-indent (compile form :stmt)))
+        body (with-indent (compile form stmt: true)))
     (if (= target 'lua)
         (cat ind "for " k " in next, " t " do\n" body ind "end\n")
       (cat ind "for (" k " in " t ") {\n" body ind "}\n"))))
 
-(define-special %try (form) :stmt :tr
+(define-special %try (form) stmt: true tr: true
   (let-unique (e)
     (let (ind (indentation)
-          body (with-indent (compile form :stmt))
+          body (with-indent (compile form stmt: true))
           hf `(return (%array false ,e))
-          h (with-indent (compile hf :stmt)))
+          h (with-indent (compile hf stmt: true)))
       (cat ind "try {\n" body ind "}\n"
            ind "catch (" e ") {\n" h ind "}\n"))))
 
-(define-special %delete (place) :stmt
+(define-special %delete (place) stmt: true
   (cat (indentation) "delete " (compile place)))
 
-(define-special break () :stmt
+(define-special break () stmt: true
   (cat (indentation) "break"))
 
 (define-special %function (args body)
   (compile-function args body))
 
-(define-special %global-function (name args body) :stmt :tr
+(define-special %global-function (name args body) stmt: true tr: true
   (if (= target 'lua)
       (let x (compile-function args body name: name)
         (cat (indentation) x))
-    (compile `(%set ,name (%function ,args ,body)) :stmt)))
+    (compile `(%set ,name (%function ,args ,body)) stmt: true)))
 
-(define-special %local-function (name args body) :stmt :tr
+(define-special %local-function (name args body) stmt: true tr: true
   (if (= target 'lua)
       (let x (compile-function args body name: name prefix: 'local)
         (cat (indentation) x))
-    (compile `(%local ,name (%function ,args ,body)) :stmt)))
+    (compile `(%local ,name (%function ,args ,body)) stmt: true)))
 
-(define-special return (x) :stmt
+(define-special return (x) stmt: true
   (let x (if (nil? x)
              "return"
            (cat "return " (compile x)))
@@ -680,13 +681,13 @@
 (define-special typeof (x)
   (cat "typeof(" (compile x) ")"))
 
-(define-special throw (x) :stmt
+(define-special throw (x) stmt: true
   (let e (if (= target 'js)
              (cat "throw " (compile x))
            (cat "error(" (compile x) ")"))
     (cat (indentation) e)))
 
-(define-special %local (name value) :stmt
+(define-special %local (name value) stmt: true
   (let (id (compile name)
         value1 (compile value)
         rh (if (is? value) (cat " = " value1) "")
@@ -694,7 +695,7 @@
         ind (indentation))
     (cat ind keyword id rh)))
 
-(define-special %set (lh rh) :stmt
+(define-special %set (lh rh) stmt: true
   (let (lh (compile lh)
         rh (compile (if (nil? rh) 'nil rh)))
     (cat (indentation) lh " = " rh)))
diff --git a/macros.l b/macros.l
index bac6bd6..087ab3d 100644
--- a/macros.l
+++ b/macros.l
@@ -96,13 +96,13 @@
   `(set (get read-table ,char) (fn (,s) ,@body)))
 
 (define-macro define (name x rest: body)
-  (setenv name :variable)
+  (setenv name variable: true)
   (if (some? body)
       `(%local-function ,name ,@(bind* x body))
     `(%local ,name ,x)))
 
 (define-macro define-global (name x rest: body)
-  (setenv name :toplevel :variable)
+  (setenv name toplevel: true variable: true)
   (if (some? body)
       `(%global-function ,name ,@(bind* x body))
     `(set ,name ,x)))
@@ -117,7 +117,7 @@
   (let-unique (x)
    `(with-frame
       (each ,x ,names
-        (setenv ,x :variable))
+        (setenv ,x variable: true))
       ,@body)))
 
 (define-macro let-macro (definitions rest: body)
diff --git a/main.l b/main.l
index 743303a..3751e82 100644
--- a/main.l
+++ b/main.l
@@ -36,7 +36,7 @@
   (let (s ((get reader 'stream) ((get system 'read-file) path))
         body ((get reader 'read-all) s)
         form ((get compiler 'expand) `(do ,@body)))
-    ((get compiler 'compile) form :stmt)))
+    ((get compiler 'compile) form stmt: true)))
 
 (define-global load (path)
   (let previous target
diff --git a/reader.l b/reader.l
index 9deb5d1..e483eee 100644
--- a/reader.l
+++ b/reader.l
@@ -5,7 +5,7 @@
   (obj pos: 0 string: str len: (# str) more: more))
 
 (define peek-char (s)
-  (let ((:pos :len :string) s)
+  (let ((pos: pos len: len string: string) s)
     (when (< pos len)
       (char string pos))))
 
@@ -52,13 +52,8 @@
        (> (# atom) 1)
        (= (char atom (edge atom)) ":")))
 
-(define flag? (atom)
-  (and (string? atom)
-       (> (# atom) 1)
-       (= (char atom 0) ":")))
-
 (define expected (s c)
-  (let ((:more :pos) s)
+  (let ((more: more pos: pos) s)
     (or more (error (cat "Expected " c " at " pos)))))
 
 (define wrap (s x)
@@ -108,7 +103,6 @@
                   (let (k (clip x 0 (edge x))
                         v (read s))
                     (set (get l k) v))
-                  (flag? x) (set (get l (clip x 1)) true)
                 (add l x)))))))))
 
 (define-reader (")" s)
diff --git a/test.l b/test.l
index 30a6d0b..12d69c6 100755
--- a/test.l
+++ b/test.l
@@ -57,7 +57,6 @@
     (test= '(quasiquote (unquote-splicing a)) (read "`,@a"))
     (test= 2 (# (read "(1 2 a: 7)")))
     (test= 7 (get (read "(1 2 a: 7)") 'a))
-    (test= true (get (read "(:a)") 'a))
     (test= 1 (- -1))
     (test= "0?" (read "0?"))
     (test= "0!" (read "0!"))
@@ -249,10 +248,6 @@ c"
   (test= '(1 2 3) (list 1 2 3))
   (test= 17 (get (list foo: 17) 'foo))
   (test= 17 (get (list 1 foo: 17) 'foo))
-  (test= true (get (list :foo) 'foo))
-  (test= true (get '(:foo) 'foo))
-  (test= true (get (hd '((:foo))) 'foo))
-  (test= '(:a) (list :a))
   (test= '(b: false) (list b: false))
   (test= '(c: 0) (list c: 0)))
 
@@ -287,7 +282,6 @@ c"
   (let a 42
     (test= '(quasiquote ((unquote-splicing (list a)))) ``(,@(list a)))
     (test= '(quasiquote ((unquote-splicing (list 42)))) ``(,@(list ,a))))
-  (test= true (get `(:foo) 'foo))
   (let (a 17
         b '(1 2)
         c (obj a: 10)
@@ -296,13 +290,8 @@ c"
     (test= 2 (# `(foo: ,a ,@b)))
     (test= 17 (get `(foo: ,@a) 'foo))
     (test= '(1 a: 10) `(1 ,@c))
-    (test= '(1 a: 10) `(1 ,@d))
-    (test= true (get (hd `((:foo))) 'foo))
-    (test= true (get (hd `(,(list :foo))) 'foo))
-    (test= true (get `(,@(list :foo)) 'foo))
-    (test= true (get `(1 2 3 ,@'(:foo)) 'foo)))
+    (test= '(1 a: 10) `(1 ,@d)))
   (let-macro ((a keys `(obj ,@keys)))
-    (test= true (get (a :foo) 'foo))
     (test= 17 (get (a bar: 17) 'bar)))
   (let-macro ((a () `(obj baz: (fn () 17))))
     (test= 17 ((get (a) 'baz)))))
@@ -379,7 +368,7 @@ c"
     (test= nil a)))
 
 (define-test wipe
-  (let x '(:a :b :c)
+  (let x '(a: true b: true c: true)
     (wipe (get x 'a))
     (test= nil (get x 'a))
     (test= true (get x 'b))
@@ -480,15 +469,14 @@ c"
     (test= 3 n)))
 
 (define-test table
-  (test= 10 (get (obj a: 10) 'a))
-  (test= true (get (obj :a) 'a)))
+  (test= 10 (get (obj a: 10) 'a)))
 
 (define-test empty
   (test= true (empty? ()))
   (test= true (empty? (obj)))
   (test= false (empty? '(1)))
-  (test= false (empty? '(:a)))
-  (test= false (empty? (obj :a)))
+  (test= false (empty? '(a: true)))
+  (test= false (empty? (obj a: true)))
   (test= false (empty? '(b: false))))
 
 (define-test at
@@ -514,7 +502,7 @@ c"
     (test= nil (get t2 'foo))))
 
 (define-test each
-  (let t '(1 2 3 :a b: false)
+  (let t '(1 2 3 a: true b: false)
     (let (a 0 b 0)
       (each (k v) t
         (if (number? k)
@@ -543,7 +531,7 @@ c"
     (test= 10 n))
   (let xs ()
     (let l (list (obj a: 1 b: 2) (obj a: 2 b: 4))
-      (step (:a :b) l
+      (step (a: a b: b) l
         (add xs (+ a b))))
     (test= '(3 6) xs))
   (let l '(a b)
@@ -718,20 +706,20 @@ c"
   (let ((w (x rest: y) rest: z) '(1 (2 3 4) 5 6 7))
     (test= '(3 4) y)
     (test= '(5 6 7) z))
-  (let ((:foo) (obj foo: 99))
+  (let ((foo: foo) (obj foo: 99))
     (test= 99 foo))
-  (let ((:foo) (list foo: 99))
+  (let ((foo: foo) (list foo: 99))
     (test= 99 foo))
   (let ((foo: a) (obj foo: 99))
     (test= 99 a))
   (let ((foo: (a b)) (obj foo: '(98 99)))
     (test= 98 a)
     (test= 99 b))
-  (let ((:foo bar: (:baz))
-        (obj foo: 42 bar: '(99 :baz)))
+  (let ((foo: foo bar: (baz: baz))
+        (obj foo: 42 bar: '(99 baz: true)))
     (test= 42 foo)
     (test= true baz))
-  (let ((a (b :foo) :bar)
+  (let ((a (b foo: foo) bar: bar)
         (list 10 (list 20 foo: 17) bar: '(1 2 3)))
     (test= 10 a)
     (test= 20 b)
@@ -866,10 +854,10 @@ c"
   (test= '(a) (join '(a) ()))
   (test= '(a) (join nil '(a)))
   (test= '(a) (join '(a)))
-  (test= '(a :b) (join '(a) (obj :b)))
-  (test= '(a b :b) (join '(a) '(b :b)))
-  (test= '(a b: 10) (join '(a :b) (obj b: 10)))
-  (test= '(b: 10) (join (obj :b) '(b: 10)))
+  (test= '(a b: true) (join '(a) (obj b: true)))
+  (test= '(a b b: true) (join '(a) '(b b: true)))
+  (test= '(a b: 10) (join '(a b: true) (obj b: 10)))
+  (test= '(b: 10) (join (obj b: true) '(b: 10)))
   (let t (join '(a b: 1) '(b c: 2))
     (test= 1 (get t 'b))
     (test= 2 (get t 'c))
@@ -878,16 +866,16 @@ c"
 (define-test reverse
   (test= () (reverse ()))
   (test= '(3 2 1) (reverse '(1 2 3)))
-  (test= '(3 2 1 :a) (reverse '(1 2 3 :a))))
+  (test= '(3 2 1 a: true) (reverse '(1 2 3 a: true))))
 
 (define-test map
   (test= () (map (fn (x) x) ()))
   (test= '(1) (map (fn (x) x) '(1)))
   (test= '(2 3 4) (map (fn (x) (+ x 1)) '(1 2 3)))
   (test= '(2 3 4 a: 5) (map (fn (x) (+ x 1)) (list 1 2 3 a: 4)))
-  (test= '(:a) (map (fn (x) x) '(:a)))
+  (test= '(a: true) (map (fn (x) x) '(a: true)))
   (test= '(b: false) (map (fn (x) x) '(b: false)))
-  (test= '(:a b: false) (map (fn (x) x) '(:a b: false)))
+  (test= '(a: true b: false) (map (fn (x) x) '(a: true b: false)))
   (let evens (fn (x) (when (= (% x 2) 0) x))
     (test= '(2 4 6) (map evens '(1 2 3 4 5 6)))
     (test= '(2 4 6 b: 8) (map evens '(1 2 3 4 5 6 a: 7 b: 8)))))
@@ -900,12 +888,12 @@ c"
   (test= '(1 2 3) (cut '(1 2 3) 0 10))
   (test= '(1) (cut '(1 2 3) -4 1))
   (test= '(1 2 3) (cut '(1 2 3) -4))
-  (test= '(2 :a) (cut '(1 2 :a) 1))
-  (test= '(:a b: 2) (cut '(:a b: 2)))
+  (test= '(2 a: true) (cut '(1 2 a: true) 1))
+  (test= '(a: true b: 2) (cut '(a: true b: 2)))
   (let t '(1 2 3)
     (test= () (cut t (# t))))
-  (let t '(1 2 3 :a)
-    (test= '(:a) (cut t (# t)))))
+  (let t '(1 2 3 a: true)
+    (test= '(a: true) (cut t (# t)))))
 
 (define-test clip
   (test= "uux" (clip "quux" 1))
@@ -966,10 +954,10 @@ c"
   (test= 7 (find (fn (x) x) '(7)))
   (test= true (find (fn (x) (= x 7)) '(2 4 7)))
   (test= true (find (fn (x) (= x 7)) '(2 4 foo: 7)))
-  (test= true (find (fn (x) (= x true)) '(2 4 :bar)))
+  (test= true (find (fn (x) (= x true)) '(2 4 bar: true)))
   (test= true (in? 7 '(2 4 7)))
   (test= true (in? 7 '(2 4 foo: 7)))
-  (test= true (in? true '(2 4 :bar))))
+  (test= true (in? true '(2 4 bar: true))))
 
 (define-test first
   (test= nil (first (fn (x) x) ()))
@@ -1025,8 +1013,8 @@ c"
   (let t '(1)
     (set (get t 'foo) 17)
     (test= 17 (apply (fn a (get a 'foo)) t)))
-  (test= 42 (apply (fn (:foo) foo) (list foo: 42)))
-  (test= 42 (apply (fn ((:foo)) foo) (list (list foo: 42))))
+  (test= 42 (apply (fn (foo: foo) foo) (list foo: 42)))
+  (test= 42 (apply (fn ((foo: foo)) foo) (list (list foo: 42))))
   (test= 116 (apply + 1 5 '(100 10))))
 
 (define-test eval
@@ -1055,22 +1043,22 @@ c"
   (test= '(3 4) ((fn (a b rest: c) c) 1 2 3 4))
   (let f (fn (w (x rest: y) rest: z) (list y z))
     (test= '((3 4) (5 6 7)) (f 1 '(2 3 4) 5 6 7)))
-  (test= 42 ((fn (:foo) foo) foo: 42))
-  (test= 42 (apply (fn (:foo) foo) '(foo: 42)))
-  (test= 42 ((fn ((:foo)) foo) (list foo: 42)))
-  (let f (fn (a bar: b (:foo)) (list a b foo))
+  (test= 42 ((fn (foo: foo) foo) foo: 42))
+  (test= 42 (apply (fn (foo: foo) foo) '(foo: 42)))
+  (test= 42 ((fn ((foo: foo)) foo) (list foo: 42)))
+  (let f (fn (a bar: b (foo: foo)) (list a b foo))
     (test= '(10 20 42) (f 10 bar: 20 (list foo: 42))))
-  (let f (fn (a bar: b (:foo)) (list a b foo))
+  (let f (fn (a bar: b (foo: foo)) (list a b foo))
     (test= '(10 20 42) (apply f '(10 bar: 20 (foo: 42)))))
-  (test= 1 ((fn (a :b) (+ (or a 0) b)) b: 1))
-  (test= 1 (apply (fn (a :b) (+ (or a 0) b)) (list b: 1)))
+  (test= 1 ((fn (a b: b) (+ (or a 0) b)) b: 1))
+  (test= 1 (apply (fn (a b: b) (+ (or a 0) b)) (list b: 1)))
   (let f (fn args args)
     (test= '(1 2 3) (f 1 2 3)))
   (let f (fn args args)
     (test= '(1 2 3) (apply f (list 1 2 3))))
   (let l ()
-    (define f (:a) (add l a) a)
-    (define g (a b :c) (add l (list a b c)) c)
+    (define f (a: a) (add l a) a)
+    (define g (a b c: c) (add l (list a b c)) c)
     (test= 42 (f a: (g (f a: 10) (f a: 20) c: (f a: 42))))
     (test= '(10 20 42 (10 20 42) 42) l))
   (let l nil