diff --git a/extra/peg/ebnf/ebnf-tests.factor b/extra/peg/ebnf/ebnf-tests.factor
index dea549eb37..c2c0a50a59 100644
--- a/extra/peg/ebnf/ebnf-tests.factor
+++ b/extra/peg/ebnf/ebnf-tests.factor
@@ -144,30 +144,65 @@ IN: peg.ebnf.tests
   "Z" [EBNF foo=[^A-Z] EBNF] call  
 ] unit-test
 
-[ 
-  #! Test direct left recursion. Currently left recursion should cause a
-  #! failure of that parser.
-  #! Not using packrat, so recursion causes data stack overflow  
-  "1+1" [EBNF num=([0-9])+ expr=expr "+" num | num EBNF] call
-] must-fail
-
-{ V{ 49 } } [ 
-  #! Test direct left recursion. Currently left recursion should cause a
-  #! failure of that parser.
+{ V{ V{ 49 } "+" V{ 49 } } } [ 
+  #! Test direct left recursion. 
   #! Using packrat, so first part of expr fails, causing 2nd choice to be used  
-  "1+1" [ [EBNF num=([0-9])+ expr=expr "+" num | num EBNF] call ] with-packrat parse-result-ast
+  "1+1" [EBNF num=([0-9])+ expr=expr "+" num | num EBNF] call parse-result-ast
 ] unit-test
 
-[ 
-  #! Test indirect left recursion. Currently left recursion should cause a
-  #! failure of that parser.
-  #! Not using packrat, so recursion causes data stack overflow  
-  "1+1" [EBNF num=([0-9])+ x=expr expr=x "+" num | num EBNF] call
-] must-fail
-
-{ V{ 49 } } [ 
-  #! Test indirect left recursion. Currently left recursion should cause a
-  #! failure of that parser.
+{ V{ V{ V{ 49 } "+" V{ 49 } } "+" V{ 49 } } } [ 
+  #! Test direct left recursion. 
   #! Using packrat, so first part of expr fails, causing 2nd choice to be used  
-  "1+1" [ [EBNF num=([0-9])+ x=expr expr=x "+" num | num EBNF] call ] with-packrat parse-result-ast
+  "1+1+1" [EBNF num=([0-9])+ expr=expr "+" num | num EBNF] call parse-result-ast
+] unit-test
+
+{ V{ V{ V{ 49 } "+" V{ 49 } } "+" V{ 49 } } } [ 
+  #! Test indirect left recursion. 
+  #! Using packrat, so first part of expr fails, causing 2nd choice to be used  
+  "1+1+1" [EBNF num=([0-9])+ x=expr expr=x "+" num | num EBNF] call parse-result-ast
+] unit-test
+
+EBNF: primary 
+Primary = PrimaryNoNewArray
+PrimaryNoNewArray =  ClassInstanceCreationExpression 
+                   | MethodInvocation
+                   | FieldAccess
+                   | ArrayAccess
+                   | "this"
+ClassInstanceCreationExpression =  "new" ClassOrInterfaceType "(" ")"
+                                 | Primary "." "new" Identifier "(" ")"
+MethodInvocation =  Primary "." MethodName "(" ")"
+                  | MethodName "(" ")"
+FieldAccess =  Primary "." Identifier
+             | "super" "." Identifier  
+ArrayAccess =  Primary "[" Expression "]"
+             | ExpressionName "[" Expression "]"
+ClassOrInterfaceType = ClassName | InterfaceTypeName
+ClassName = "C" | "D"
+InterfaceTypeName = "I" | "J"
+Identifier = "x" | "y" | ClassOrInterfaceType
+MethodName = "m" | "n"
+ExpressionName = Identifier
+Expression = "i" | "j"
+main = Primary
+;EBNF 
+
+{ "this" } [
+  "this" primary parse-result-ast
+] unit-test
+
+{ V{ "this" "." "x" } } [
+  "this.x" primary parse-result-ast
+] unit-test
+
+{ V{ V{ "this" "." "x" } "." "y" } } [
+  "this.x.y" primary parse-result-ast
+] unit-test
+
+{ V{ V{ "this" "." "x" } "." "m" "(" ")" } } [
+  "this.x.m()" primary parse-result-ast
+] unit-test
+
+{ V{ V{ V{ "x" "[" "i" "]" } "[" "j" "]" } "." "y" } } [
+  "x[i][j].y" primary parse-result-ast
 ] unit-test
diff --git a/extra/peg/ebnf/ebnf.factor b/extra/peg/ebnf/ebnf.factor
index ed0dea0410..3efe2d6979 100644
--- a/extra/peg/ebnf/ebnf.factor
+++ b/extra/peg/ebnf/ebnf.factor
@@ -266,7 +266,7 @@ M: ebnf-non-terminal (transform) ( ast -- parser )
   ] [ ] make delay sp ;
 
 : transform-ebnf ( string -- object )
-  'ebnf' packrat-parse parse-result-ast transform ;
+  'ebnf' parse parse-result-ast transform ;
 
 : check-parse-result ( result -- result )
   dup [
@@ -281,8 +281,8 @@ M: ebnf-non-terminal (transform) ( ast -- parser )
   ] if ;
 
 : ebnf>quot ( string -- hashtable quot )
-  'ebnf' packrat-parse check-parse-result 
-  parse-result-ast transform dup main swap at compile 1quotation ;
+  'ebnf' parse check-parse-result 
+  parse-result-ast transform dup main swap at compile [ parse ] curry ;
 
 : [EBNF "EBNF]" parse-multiline-string ebnf>quot nip parsed ; parsing
 
diff --git a/extra/peg/parsers/parsers.factor b/extra/peg/parsers/parsers.factor
index fa6801dc1c..7a82418c27 100755
--- a/extra/peg/parsers/parsers.factor
+++ b/extra/peg/parsers/parsers.factor
@@ -7,7 +7,6 @@ USING: kernel sequences strings namespaces math assocs shuffle
 IN: peg.parsers
 
 TUPLE: just-parser p1 ;
-M: just-parser equal? 2drop f ;
 
 : just-pattern
   [
@@ -21,7 +20,7 @@ M: just-parser (compile) ( parser -- quot )
   just-parser-p1 compiled-parser just-pattern curry ;
 
 MEMO: just ( parser -- parser )
-  just-parser construct-boa ;
+  just-parser construct-boa init-parser ;
 
 : 1token ( ch -- parser ) 1string token ;
 
diff --git a/extra/peg/peg-docs.factor b/extra/peg/peg-docs.factor
index c93d1af830..d2ca353ba1 100644
--- a/extra/peg/peg-docs.factor
+++ b/extra/peg/peg-docs.factor
@@ -12,41 +12,7 @@ HELP: parse
 { $description 
     "Given the input string, parse it using the given parser. The result is a <parse-result> object if "
     "the parse was successful, otherwise it is f." } 
-{ $see-also compile with-packrat packrat-parse } ;
-
-HELP: with-packrat
-{ $values 
-  { "quot" "a quotation with stack effect ( input -- result )" } 
-  { "result" "the result of the quotation" } 
-}
-{ $description 
-    "Calls the quotation with a packrat cache in scope. Usually the quotation will "
-    "call " { $link parse } " or call a word produced by " { $link compile } "."
-    "The cache is used to avoid the possible exponential time performace that pegs "
-    "can have, instead giving linear time at the cost of increased memory usage. "
-    "Use of this packrat option also allows direct and indirect recursion to "
-    "be handled in the parser without entering an infinite loop."  } 
-{ $see-also compile parse packrat-parse packrat-call } ;
-
-HELP: packrat-parse
-{ $values 
-  { "input" "a string" } 
-  { "parser" "a parser" } 
-  { "result" "a parse-result or f" } 
-}
-{ $description 
-    "Compiles and calls the parser with a packrat cache in scope."  } 
-{ $see-also compile parse packrat-call with-packrat } ;
-
-HELP: packrat-call
-{ $values 
-  { "input" "a string" } 
-  { "quot" "a quotation with stack effect ( input -- result )" } 
-  { "result" "a parse-result or f" } 
-}
-{ $description 
-    "Calls the compiled parser with a packrat cache in scope."  } 
-{ $see-also compile packrat-call packrat-parse with-packrat } ;
+{ $see-also compile } ;
 
 HELP: compile
 { $values 
@@ -54,11 +20,12 @@ HELP: compile
   { "word" "a word" } 
 }
 { $description 
-    "Compile the parser to a word. The word will have stack effect ( input -- result )."
+    "Compile the parser to a word. The word will have stack effect ( -- result )."
     "The mapping from parser to compiled word is kept in a cache. If you later change "
     "the definition of a parser you'll need to clear this cache with " 
-    { $link reset-compiled-parsers } " before using " { $link compile } " on that parser again." } 
-{ $see-also compile with-packrat reset-compiled-parsers packrat-call packrat-parse } ;
+    { $link reset-compiled-parsers } " before using " { $link compile } " on that parser again." 
+} 
+{ $see-also parse } ;
 
 HELP: reset-compiled-parsers
 { $description 
diff --git a/extra/peg/peg-tests.factor b/extra/peg/peg-tests.factor
index cd95bd3b93..f57fe83220 100644
--- a/extra/peg/peg-tests.factor
+++ b/extra/peg/peg-tests.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2007 Chris Double.
 ! See http://factorcode.org/license.txt for BSD license.
 !
-USING: kernel tools.test strings namespaces arrays sequences peg peg.private ;
+USING: kernel tools.test strings namespaces arrays sequences peg peg.private accessors words ;
 IN: peg.tests
 
 { f } [
@@ -168,31 +168,18 @@ IN: peg.tests
   "1+1" swap parse parse-result-ast
 ] unit-test
 
-{ V{ "1" "-" "1" } V{ "1" "+" "1" } } [
-  [ 
-    [
-      [ "1" token , "-" token , "1" token , ] seq* ,
-      [ "1" token , "+" token , "1" token , ] seq* ,
-    ] choice* 
-    "1-1" over parse parse-result-ast swap
-  ] with-packrat
-  [
-    "1+1" swap parse parse-result-ast
-  ] with-packrat 
-] unit-test
-
 : expr ( -- parser ) 
   #! Test direct left recursion. Currently left recursion should cause a
   #! failure of that parser.
   [ expr ] delay "+" token "1" token 3seq "1" token 2choice ;
 
-[
-  #! Not using packrat, so recursion causes data stack overflow  
-  "1+1" expr parse parse-result-ast   
-] must-fail
-
-{ "1" } [
-  #! Using packrat, so expr fails, causing the 2nd choice to be used.  
-  "1+1" expr [ parse ] with-packrat parse-result-ast   
+{ V{ V{ "1" "+" "1" } "+" "1" } } [
+  "1+1+1" expr parse parse-result-ast   
 ] unit-test
 
+{ t } [
+  #! Ensure a circular parser doesn't loop infinitely
+  [ f , "a" token , ] seq*
+  dup parsers>>
+  dupd 0 swap set-nth compile word?
+] unit-test
\ No newline at end of file
diff --git a/extra/peg/peg.factor b/extra/peg/peg.factor
index 709052b7dd..8f7522bda9 100755
--- a/extra/peg/peg.factor
+++ b/extra/peg/peg.factor
@@ -7,6 +7,8 @@ USING: kernel sequences strings namespaces math assocs shuffle
        combinators.cleave locals ;
 IN: peg
 
+USE: prettyprint
+
 TUPLE: parse-result remaining ast ;
 
 SYMBOL: ignore 
@@ -15,6 +17,183 @@ SYMBOL: ignore
   parse-result construct-boa ;
 
 SYMBOL: packrat
+SYMBOL: pos
+SYMBOL: input
+SYMBOL: fail
+SYMBOL: lrstack
+SYMBOL: heads
+
+TUPLE: memo-entry ans pos ;
+C: <memo-entry> memo-entry
+
+TUPLE: left-recursion seed rule head next ;
+C: <left-recursion> left-recursion
+ 
+TUPLE: peg-head rule involved-set eval-set ;
+C: <head> peg-head
+
+: rule-parser ( rule -- parser ) 
+  #! A rule is the parser compiled down to a word. It has
+  #! a "peg" property containing the original parser.
+  "peg" word-prop ;
+
+: input-slice ( -- slice )
+  #! Return a slice of the input from the current parse position
+  input get pos get tail-slice ;
+
+: input-from ( input -- n )
+  #! Return the index from the original string that the
+  #! input slice is based on.
+  dup slice? [ slice-from ] [ drop 0 ] if ;
+
+: input-cache ( parser -- cache )
+  #! From the packrat cache, obtain the cache for the parser 
+  #! that maps the position to the parser result.
+  id>> packrat get [ drop H{ } clone ] cache ;
+
+: eval-rule ( rule -- ast )
+  #! Evaluate a rule, return an ast resulting from it.
+  #! Return fail if the rule failed. The rule has
+  #! stack effect ( input -- parse-result )
+  pos get swap 
+  execute 
+!  drop f f <parse-result>
+  [
+    nip
+    [ ast>> ] [ remaining>> ] bi
+    input-from pos set    
+  ] [ 
+    pos set   
+    fail
+  ] if* ; inline
+
+: memo ( pos rule -- memo-entry )
+  #! Return the result from the memo cache. 
+  rule-parser input-cache at ;
+
+: set-memo ( memo-entry pos rule -- )
+  #! Store an entry in the cache
+  rule-parser input-cache set-at ;
+
+:: (grow-lr) ( r p m h -- )
+  p pos set
+  h involved-set>> clone h (>>eval-set)
+  r eval-rule
+  dup fail = pos get m pos>> <= or [
+    drop
+  ] [
+    m (>>ans)
+    pos get m (>>pos)
+    r p m h (grow-lr)
+  ] if ; inline
+ 
+:: grow-lr ( r p m h -- ast )
+  h p heads get set-at
+  r p m h (grow-lr) 
+  p heads get delete-at
+  m pos>> pos set m ans>>
+  ; inline
+
+:: (setup-lr) ( r l s -- )
+  s head>> l head>> eq? [
+    l head>> s (>>head)
+    l head>> [ s rule>> add ] change-involved-set drop
+    r l s next>> (setup-lr)
+  ] unless ;
+
+:: setup-lr ( r l -- )
+  l head>> [
+    r V{ } clone V{ } clone <head> l (>>head)
+  ] unless
+  r l lrstack get (setup-lr) ;
+
+:: lr-answer ( r p m -- ast )
+  [let* |
+          h [ m ans>> head>> ]
+        |
+    h rule>> r eq? [
+      m ans>> seed>> m (>>ans)
+      m ans>> fail = [
+        fail
+      ] [
+        r p m h grow-lr
+      ] if
+    ] [
+      m ans>> seed>>
+    ] if
+  ] ; inline
+
+:: recall ( r p -- memo-entry )
+  [let* |
+          m [ p r memo ]
+          h [ p heads get at ]
+        |
+    h [
+      m r h involved-set>> h rule>> add member? not and [
+        fail p <memo-entry>
+      ] [
+        r h eval-set>> member? [
+          h [ r swap remove ] change-eval-set drop
+          r eval-rule
+          m (>>ans)
+          pos get m (>>pos)
+          m
+        ] [ 
+          m
+        ] if
+      ] if
+    ] [
+      m
+    ] if
+  ] ; inline
+
+:: apply-non-memo-rule ( r p -- ast )
+  [let* |
+          lr  [ fail r f lrstack get <left-recursion> ]
+          m   [ lr lrstack set lr p <memo-entry> dup p r set-memo ]
+          ans [ r eval-rule ]
+        |
+    lrstack get next>> lrstack set
+    pos get m (>>pos)
+    lr head>> [
+      ans lr (>>seed)
+      r p m lr-answer
+    ] [
+      ans m (>>ans)
+      ans
+    ] if
+  ] ; inline
+
+:: apply-memo-rule ( r m -- ast )
+  m pos>> pos set 
+  m ans>> left-recursion? [ 
+    r m ans>> setup-lr
+    m ans>> seed>>
+  ] [
+    m ans>>
+  ] if ;
+
+:: apply-rule ( r p -- ast )
+  [let* |
+          m [ r p recall ]
+        | 
+    m [
+      r m apply-memo-rule
+    ] [
+      r p apply-non-memo-rule
+    ] if 
+  ] ; inline
+
+: with-packrat ( input quot -- result )
+  #! Run the quotation with a packrat cache active.
+  swap [ 
+    input set
+    0 pos set
+    f lrstack set
+    H{ } clone heads set
+    H{ } clone packrat set
+  ] H{ } make-assoc swap bind ;
+
 
 : compiled-parsers ( -- cache )
   \ compiled-parsers get-global [ H{ } clone dup \ compiled-parsers set-global ] unless* ;
@@ -22,67 +201,77 @@ SYMBOL: packrat
 : reset-compiled-parsers ( -- )
   H{ } clone \ compiled-parsers set-global ;
 
+reset-compiled-parsers
+
 GENERIC: (compile) ( parser -- quot )
 
-: input-from ( input -- n )
-  #! Return the index from the original string that the
-  #! input slice is based on.
-  dup slice? [ slice-from ] [ drop 0 ] if ;
-
-: input-cache ( quot cache -- cache )
-  #! From the packrat cache, obtain the cache for the parser quotation 
-  #! that maps the input string position to the parser result.
-  [ drop H{ } clone ] cache ;
-
-:: cached-result ( n input-cache input quot -- result )
-  #! Get the cached result for input position n
-  #! from the input cache. If the item is not in the cache,
-  #! call 'quot' with 'input' on the stack to get the result
-  #! and store that in the cache and return it.
-  n input-cache [ 
-    drop
-    f n input-cache set-at
-    input quot call 
-  ] cache ; inline
-
-:: run-packrat-parser ( input quot c -- result )
-  input input-from
-  quot c input-cache 
-  input quot cached-result ; inline
-
-: run-parser ( input quot -- result )
-  #! If a packrat cache is available, use memoization for
-  #! packrat parsing, otherwise do a standard peg call.
-  packrat get [ run-packrat-parser ] [ call ] if* ; inline
 
+:: parser-body ( parser -- quot )
+  #! Return the body of the word that is the compiled version
+  #! of the parser.
+  [let* | rule [ parser (compile) define-temp dup parser "peg" set-word-prop ] 
+        |
+    [
+      rule pos get apply-rule dup fail = [ 
+        drop f 
+      ] [
+        input-slice swap <parse-result>
+      ] if
+    ] 
+  ] ;
+ 
 : compiled-parser ( parser -- word )
   #! Look to see if the given parser has been compiled.
   #! If not, compile it to a temporary word, cache it,
   #! and return it. Otherwise return the existing one.
-  compiled-parsers [
-    (compile) [ run-parser ] curry define-temp
-  ] cache ;
+  #! Circular parsers are supported by getting the word
+  #! name and storing it in the cache, before compiling, 
+  #! so it is picked up when re-entered.
+  dup id>> compiled-parsers [
+    drop dup gensym swap 2dup id>> compiled-parsers set-at
+    2dup parser-body define 
+    dupd "peg" set-word-prop
+  ] cache nip ;
 
 : compile ( parser -- word )
   [ compiled-parser ] with-compilation-unit ;
 
 : parse ( state parser -- result )
-  compile execute ; inline
-
-: with-packrat ( quot -- result )
-  #! Run the quotation with a packrat cache active.
-  [ H{ } clone packrat ] dip with-variable ; inline
-
-: packrat-parse ( state parser -- result )
-  [ parse ] with-packrat ;
-
-: packrat-call ( state quot -- result )
-  with-packrat ; inline
+  dup word? [ compile ] unless
+  [ execute ] curry with-packrat ;
 
 <PRIVATE
 
+SYMBOL: id 
+
+: next-id ( -- n )
+  #! Return the next unique id for a parser
+  id get-global [
+    dup 1+ id set-global
+  ] [
+    1 id set-global 0
+  ] if* ;
+
+TUPLE: parser id ;
+M: parser equal? [ id>> ] 2apply = ;
+C: <parser> parser
+
+: delegates ( -- cache )
+  \ delegates get-global [ H{ } clone dup \ delegates set-global ] unless* ;
+
+: reset-delegates ( -- )
+  H{ } clone \ delegates set-global ;
+
+reset-delegates 
+
+: init-parser ( parser -- parser )
+  #! Set the delegate for the parser. Equivalent parsers
+  #! get a delegate with the same id.
+  dup clone delegates [
+    drop next-id <parser> 
+  ] cache over set-delegate ;
+
 TUPLE: token-parser symbol ;
-M: token-parser equal? 2drop f ;
 
 MATCH-VARS: ?token ;
 
@@ -95,16 +284,15 @@ MATCH-VARS: ?token ;
   ] if ;
 
 M: token-parser (compile) ( parser -- quot )
-  symbol>> [ parse-token ] curry ;
-      
+  [ \ input-slice , symbol>> , \ parse-token , ] [ ] make ;
+   
 TUPLE: satisfy-parser quot ;
-M: satisfy-parser equal? 2drop f ;
 
 MATCH-VARS: ?quot ;
 
 : satisfy-pattern ( -- quot )
   [
-    dup empty? [
+    input-slice dup empty? [
       drop f 
     ] [
       unclip-slice dup ?quot call [  
@@ -119,13 +307,12 @@ M: satisfy-parser (compile) ( parser -- quot )
   quot>> \ ?quot satisfy-pattern match-replace ;
 
 TUPLE: range-parser min max ;
-M: range-parser equal? 2drop f ;
 
 MATCH-VARS: ?min ?max ;
 
 : range-pattern ( -- quot )
   [
-    dup empty? [
+    input-slice dup empty? [
       drop f
     ] [
       0 over nth dup 
@@ -141,12 +328,11 @@ M: range-parser (compile) ( parser -- quot )
   T{ range-parser _ ?min ?max } range-pattern match-replace ;
 
 TUPLE: seq-parser parsers ;
-M: seq-parser equal? 2drop f ;
 
 : seq-pattern ( -- quot )
   [
     dup [
-      dup remaining>> ?quot [
+      ?quot [
         [ remaining>> swap (>>remaining) ] 2keep
         ast>> dup ignore = [ 
           drop  
@@ -163,34 +349,27 @@ M: seq-parser equal? 2drop f ;
 
 M: seq-parser (compile) ( parser -- quot )
   [
-    [ V{ } clone <parse-result> ] %
+    [ input-slice V{ } clone <parse-result> ] %
     parsers>> [ compiled-parser \ ?quot seq-pattern match-replace % ] each 
   ] [ ] make ;
 
 TUPLE: choice-parser parsers ;
-M: choice-parser equal? 2drop f ;
 
 : choice-pattern ( -- quot )
   [
-    dup [
-          
-    ] [
-      drop dup ?quot 
-    ] if
+    [ ?quot ] unless* 
   ] ;
 
 M: choice-parser (compile) ( parser -- quot )
-  [
+  [ 
     f ,
     parsers>> [ compiled-parser \ ?quot choice-pattern match-replace % ] each
-    \ nip ,
   ] [ ] make ;
 
 TUPLE: repeat0-parser p1 ;
-M: repeat0-parser equal? 2drop f ;
 
 : (repeat0) ( quot result -- result )
-  2dup remaining>> swap call [
+  over call [
     [ remaining>> swap (>>remaining) ] 2keep 
     ast>> swap [ ast>> push ] keep
     (repeat0) 
@@ -205,12 +384,11 @@ M: repeat0-parser equal? 2drop f ;
 
 M: repeat0-parser (compile) ( parser -- quot )
   [
-    [ V{ } clone <parse-result> ] %
+    [ input-slice V{ } clone <parse-result> ] %
     p1>> compiled-parser \ ?quot repeat0-pattern match-replace %        
   ] [ ] make ;
 
 TUPLE: repeat1-parser p1 ;
-M: repeat1-parser equal? 2drop f ;
 
 : repeat1-pattern ( -- quot )
   [
@@ -225,27 +403,25 @@ M: repeat1-parser equal? 2drop f ;
 
 M: repeat1-parser (compile) ( parser -- quot )
   [
-    [ V{ } clone <parse-result> ] %
+    [ input-slice V{ } clone <parse-result> ] %
     p1>> compiled-parser \ ?quot repeat1-pattern match-replace % 
   ] [ ] make ;
 
 TUPLE: optional-parser p1 ;
-M: optional-parser equal? 2drop f ;
 
 : optional-pattern ( -- quot )
   [
-    dup ?quot swap f <parse-result> or 
+    ?quot [ input-slice f <parse-result> ] unless* 
   ] ;
 
 M: optional-parser (compile) ( parser -- quot )
   p1>> compiled-parser \ ?quot optional-pattern match-replace ;
 
 TUPLE: ensure-parser p1 ;
-M: ensure-parser equal? 2drop f ;
 
 : ensure-pattern ( -- quot )
   [
-    dup ?quot [
+    input-slice ?quot [
       ignore <parse-result>
     ] [
       drop f
@@ -256,11 +432,10 @@ M: ensure-parser (compile) ( parser -- quot )
   p1>> compiled-parser \ ?quot ensure-pattern match-replace ;
 
 TUPLE: ensure-not-parser p1 ;
-M: ensure-not-parser equal? 2drop f ;
 
 : ensure-not-pattern ( -- quot )
   [
-    dup ?quot [
+    input-slice ?quot [
       drop f
     ] [
       ignore <parse-result>
@@ -271,7 +446,6 @@ M: ensure-not-parser (compile) ( parser -- quot )
   p1>> compiled-parser \ ?quot ensure-not-pattern match-replace ;
 
 TUPLE: action-parser p1 quot ;
-M: action-parser equal? 2drop f ;
 
 MATCH-VARS: ?action ;
 
@@ -284,7 +458,7 @@ MATCH-VARS: ?action ;
   ] ;
 
 M: action-parser (compile) ( parser -- quot )
-  { [ p1>> ] [ quot>> ] } cleave [ compiled-parser ] dip 
+  [ p1>> compiled-parser ] [ quot>> ] bi  
   2array { ?quot ?action } action-pattern match-replace ;
 
 : left-trim-slice ( string -- string )
@@ -295,15 +469,13 @@ M: action-parser (compile) ( parser -- quot )
   ] unless ;
 
 TUPLE: sp-parser p1 ;
-M: sp-parser equal? 2drop f ;
 
 M: sp-parser (compile) ( parser -- quot )
   [
-    \ left-trim-slice , p1>> compiled-parser , 
+    \ input-slice , \ left-trim-slice , \ input-from , \ pos , \ set , p1>> compiled-parser , 
   ] [ ] make ;
 
 TUPLE: delay-parser quot ;
-M: delay-parser equal? 2drop f ;
 
 M: delay-parser (compile) ( parser -- quot )
   #! For efficiency we memoize the quotation.
@@ -317,71 +489,71 @@ M: delay-parser (compile) ( parser -- quot )
 
 PRIVATE>
 
-MEMO: token ( string -- parser )
-  token-parser construct-boa ;      
+: token ( string -- parser )
+  token-parser construct-boa init-parser ;      
 
-MEMO: satisfy ( quot -- parser )
-  satisfy-parser construct-boa ;
+: satisfy ( quot -- parser )
+  satisfy-parser construct-boa init-parser ;
 
-MEMO: range ( min max -- parser )
-  range-parser construct-boa ;
+: range ( min max -- parser )
+  range-parser construct-boa init-parser ;
 
-MEMO: seq ( seq -- parser )
-  seq-parser construct-boa ;
+: seq ( seq -- parser )
+  seq-parser construct-boa init-parser ;
 
-MEMO: 2seq ( parser1 parser2 -- parser )
+: 2seq ( parser1 parser2 -- parser )
   2array seq ;
 
-MEMO: 3seq ( parser1 parser2 parser3 -- parser )
+: 3seq ( parser1 parser2 parser3 -- parser )
   3array seq ;
 
-MEMO: 4seq ( parser1 parser2 parser3 parser4 -- parser )
+: 4seq ( parser1 parser2 parser3 parser4 -- parser )
   4array seq ;
 
 : seq* ( quot -- paser )
   { } make seq ; inline 
 
-MEMO: choice ( seq -- parser )
-  choice-parser construct-boa ;
+: choice ( seq -- parser )
+  choice-parser construct-boa init-parser ;
 
-MEMO: 2choice ( parser1 parser2 -- parser )
+: 2choice ( parser1 parser2 -- parser )
   2array choice ;
 
-MEMO: 3choice ( parser1 parser2 parser3 -- parser )
+: 3choice ( parser1 parser2 parser3 -- parser )
   3array choice ;
 
-MEMO: 4choice ( parser1 parser2 parser3 parser4 -- parser )
+: 4choice ( parser1 parser2 parser3 parser4 -- parser )
   4array choice ;
 
 : choice* ( quot -- paser )
   { } make choice ; inline 
 
-MEMO: repeat0 ( parser -- parser )
-  repeat0-parser construct-boa ;
+: repeat0 ( parser -- parser )
+  repeat0-parser construct-boa init-parser ;
 
-MEMO: repeat1 ( parser -- parser )
-  repeat1-parser construct-boa ;
+: repeat1 ( parser -- parser )
+  repeat1-parser construct-boa init-parser ;
 
-MEMO: optional ( parser -- parser )
-  optional-parser construct-boa ;
+: optional ( parser -- parser )
+  optional-parser construct-boa init-parser ;
 
-MEMO: ensure ( parser -- parser )
-  ensure-parser construct-boa ;
+: ensure ( parser -- parser )
+  ensure-parser construct-boa init-parser ;
 
-MEMO: ensure-not ( parser -- parser )
-  ensure-not-parser construct-boa ;
+: ensure-not ( parser -- parser )
+  ensure-not-parser construct-boa init-parser ;
 
-MEMO: action ( parser quot -- parser )
-  action-parser construct-boa ;
+: action ( parser quot -- parser )
+  action-parser construct-boa init-parser ;
 
-MEMO: sp ( parser -- parser )
-  sp-parser construct-boa ;
+: sp ( parser -- parser )
+  sp-parser construct-boa init-parser ;
 
 : hide ( parser -- parser )
   [ drop ignore ] action ;
 
-MEMO: delay ( quot -- parser )
-  delay-parser construct-boa ;
+: delay ( quot -- parser )
+  delay-parser construct-boa init-parser ;
 
 : PEG:
   (:) [