Fix lin2string and pass all unittests and Phrasebook

testsuite/lpgf/unittests/Bind.gf

@@ -9,4 +9,6 @@ abstract Bind = {
     softspace : S -> S -> S ;
     capit : S -> S ;
     allcapit : S -> S ;
+    prebind : S -> S ;
+    precapit : S -> S ;
 }

testsuite/lpgf/unittests/Bind.treebank

@@ -18,3 +18,15 @@ BindCnc: hello there goodbye
 
 Bind: concat (capit f1) (allcapit f2)
 BindCnc: Hello there GOODBYE
+
+Bind: prebind f1
+BindCnc: |hello there
+
+Bind: prebind f2
+BindCnc: > goodbye
+
+Bind: precapit f1
+BindCnc: |Hello there
+
+Bind: precapit f2
+BindCnc: > Goodbye

testsuite/lpgf/unittests/BindCnc.gf

@@ -10,4 +10,12 @@ concrete BindCnc of Bind = open Prelude in {
     softspace a b = ss (a.s ++ SOFT_SPACE ++ b.s) ;
     capit a = ss (CAPIT ++ a.s) ;
     allcapit a = ss (ALL_CAPIT ++ a.s) ;
+    prebind a = ss (p ++ a.s) ;
+    precapit a = ss (p ++ CAPIT ++ a.s) ;
+  oper
+    p = pre {
+      "he" => "|" ++ BIND;
+      "H"|"G" => "^" ++ BIND;
+      _ => ">"
+    } ;
 }