From 166817bd45d49ad94034222efb78c8e537733a3e Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@factorcode.org>
Date: Thu, 4 Nov 2004 04:37:08 +0000
Subject: [PATCH] add infix parser library

---
 contrib/infix.factor        | 33 ++++++++++++++++++++++
 contrib/stack-effect.factor | 56 -------------------------------------
 2 files changed, 33 insertions(+), 56 deletions(-)
 create mode 100644 contrib/infix.factor
 delete mode 100644 contrib/stack-effect.factor

diff --git a/contrib/infix.factor b/contrib/infix.factor
new file mode 100644
index 0000000000..f3d71f3cad
--- /dev/null
+++ b/contrib/infix.factor
@@ -0,0 +1,33 @@
+USE: combinators
+USE: lists
+USE: math
+USE: namespaces
+USE: stack
+USE: test
+USE: vectors
+USE: words
+
+SYMBOL: exprs
+DEFER: infix
+: >e exprs get vector-push ;
+: e> exprs get vector-pop ;
+: e@ exprs get dup vector-empty? [ drop f ] [ vector-peek ] ifte ;
+: e, ( obj -- ) dup cons? [ [ e, ] each ] [ , ] ifte ;
+: end ( -- ) exprs get [ e, ] vector-each ;
+: >postfix ( op -- ) e@ word? [ e> e> -rot 3list ] when >e ;
+: token ( obj -- ) dup cons? [ infix ] when >postfix ;
+: (infix) ( list -- ) [ unswons token (infix) ] when* ;
+
+: infix ( list -- quot )
+    #! Convert an infix expression (passed in as a list) to
+    #! postfix.
+    [, 10 <vector> exprs set (infix) end ,] ;
+
+[ [ ] ] [ [ ] infix ] unit-test
+[ [ 1 ] ] [ [ 1 ] infix ] unit-test
+[ [ 2 3 + ] ] [ [ 2 + 3 ] infix ] unit-test
+[ [ 2 3 * 4 + ] ] [ [ 2 * 3 + 4 ] infix ] unit-test
+[ [ 2 3 * 4 + 5 + ] ] [ [ 2 * 3 + 4 + 5 ] infix ] unit-test
+[ [ 2 3 * 4 + ] ] [ [ [ 2 * 3 ] + 4 ] infix ] unit-test
+[ [ 2 3 4 + * ] ] [ [ 2 * [ 3 + 4 ] ] infix ] unit-test
+[ [ 2 3 2 / 4 + * ] ] [ [ 2 * [ [ 3 / 2 ] + 4 ] ] infix ] unit-test
diff --git a/contrib/stack-effect.factor b/contrib/stack-effect.factor
deleted file mode 100644
index 99fcca65b2..0000000000
--- a/contrib/stack-effect.factor
+++ /dev/null
@@ -1,56 +0,0 @@
-IN: stack-effect
-USE: lists
-USE: stack
-USE: math
-USE: combinators
-USE: kernel
-USE: test
-USE: errors
-
-: s* ( [ a | b ] [ c | d ] )
-    #! Stack effect composition.
-    >r uncons r> uncons >r -
-    dup 0 < [ neg + r> cons ] [ r> + cons ] ifte ;
-
-: list* ( list [ a | b ] -- list )
-    #! Right composition with a list and stack effect.
-    swap [ over s* ] map nip prune ;
-
-: *list ( [ a | b ] list -- list )
-    #! Left composition with a list and stack effect.
-    [ dupd s* ] map nip prune ;
-
-: <> ( [ a | b ] )
-    #! Stack height equivelence.
-    uncons - ;
-
-: balanced? ( list -- ? )
-    #! Is this a balanced set?
-    [ unswons <> swap [ <> over = ] all? nip ] [ t ] ifte* ;
-
-: car> ( [ a | b ] [ c | d ] )
-    swap car swap car > ;
-
-: car-max ( [ a | b ] [ c | d ] )
-    2dup car> [ drop ] [ nip ] ifte ;
-
-: point ( list -- [ a | b ] )
-    #! The point of a balanced set.
-    [ -1 | -1 ] swap [ car-max ] each ;
-
-: s+ ( [ a | b ] [ c | d ] -- )
-    #! Stack effect addition.
-    2list dup balanced? [ point ] [ "Not balanced" throw ] ifte ;
-
-[ t ] [ [ [ 1 | 2 ] [ 3 | 4 ] ] balanced? ] unit-test
-[ f ] [ [ [ 4 | 2 ] [ 3 | 4 ] ] balanced? ] unit-test
-[ t ] [ [ [ 1 | 5 ] ] balanced? ] unit-test
-[ t ] [ [ ] balanced? ] unit-test
-[ [ 3 | 4 ] ] [ [ [ 1 | 2 ] [ 3 | 4 ] ] point ] unit-test
-
-[ [ [ 1 | 1 ] [ 2 | 2 ] [ 3 | 3 ] ] ]
-[ [ [ 1 | 2 ] [ 2 | 3 ] [ 3 | 4 ] ] [ 1 | 0 ] list* ] unit-test
-
-[ [ 1 | 1 ] ] [ [ 1 | 2 ] [ 2 | 1 ] s* ] unit-test
-
-[ [ 4 | 5 ] ] [ [ 4 | 5 ] [ 3 | 4 ] s+ ] unit-test