* algebra/syntax.spad.pamphlet (Syntax): Now belong to

	RetractableTo Integer, RetractableTo DoubleFloat, RetractableTo
	Symbol, and RetractableTo String.

4 files changed, 37 insertions, 25 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 8cd268ff..f725401e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,11 @@
 2008-10-18  Gabriel Dos Reis  <gdr@cs.tamu.edu>
 
+	* algebra/syntax.spad.pamphlet (Syntax): Now belong to
+	RetractableTo Integer, RetractableTo DoubleFloat, RetractableTo
+	Symbol, and RetractableTo String.
+
+2008-10-18  Gabriel Dos Reis  <gdr@cs.tamu.edu>
+
 	* algebra/syntax.spad.pamphlet (Syntax): Simplify.
 
 2008-10-17  Gabriel Dos Reis  <gdr@cs.tamu.edu>
diff --git a/src/algebra/Makefile.in b/src/algebra/Makefile.in
index 46e59144..f3521c0a 100644
--- a/src/algebra/Makefile.in
+++ b/src/algebra/Makefile.in
@@ -374,7 +374,7 @@ axiom_algebra_layer_0_objects = \
 axiom_algebra_layer_1 = \
   AGG      AGG-     IEVALAB  IEVALAB- FORTCAT   ITUPLE   \
   PATAB    PPCURVE  PSCURVE  REAL     RESLATC   RETRACT  \
-  RETRACT- SEGCAT   BINDING  SYNTAX   BMODULE   LOGIC    \
+  RETRACT- SEGCAT   BINDING           BMODULE   LOGIC    \
   LOGIC-   EVALAB   EVALAB-  FEVALAB  FEVALAB-  BYTE     \
   OSGROUP  MAYBE    DATABUF  PROPLOG
 
@@ -386,7 +386,7 @@ axiom_algebra_layer_1_objects = \
 	   $(addsuffix .$(FASLEXT),$(axiom_algebra_layer_1)))
 axiom_algebra_layer_2 = \
   ELTAGG   ELTAGG- FMC      FMFUN   FORTFN   FVC     \
-  CTORCALL FVFUN   INTRET   IXAGG   IXAGG-   SEGXCAT \
+  SYNTAX   FVFUN   INTRET   IXAGG   IXAGG-   SEGXCAT \
   CONTOUR  LIST3   MKFUNC   OASGP   KTVLOGIC
 
 axiom_algebra_layer_2_nrlibs = \
@@ -397,7 +397,7 @@ axiom_algebra_layer_2_objects = \
 	   $(addsuffix .$(FASLEXT),$(axiom_algebra_layer_2)))
 axiom_algebra_layer_3 = \
    GRDEF     SCOPE    MAPHACK1 MAPHACK2 MAPHACK3 MAPPKG1  \
-   MAPPKG2   MAPPKG3  INTBIT   MONAD    MONAD-   
+   MAPPKG2   MAPPKG3  INTBIT   MONAD    MONAD-   CTORCALL
 
 
 
diff --git a/src/algebra/Makefile.pamphlet b/src/algebra/Makefile.pamphlet
index 63c8c402..609786e6 100644
--- a/src/algebra/Makefile.pamphlet
+++ b/src/algebra/Makefile.pamphlet
@@ -217,7 +217,7 @@ coerce.spad.pamphlet   (TYPE KOERCE KONVERT RETRACT)
 axiom_algebra_layer_1 = \
   AGG      AGG-     IEVALAB  IEVALAB- FORTCAT   ITUPLE   \
   PATAB    PPCURVE  PSCURVE  REAL     RESLATC   RETRACT  \
-  RETRACT- SEGCAT   BINDING  SYNTAX   BMODULE   LOGIC    \
+  RETRACT- SEGCAT   BINDING           BMODULE   LOGIC    \
   LOGIC-   EVALAB   EVALAB-  FEVALAB  FEVALAB-  BYTE     \
   OSGROUP  MAYBE    DATABUF  PROPLOG
 
@@ -236,7 +236,7 @@ axiom_algebra_layer_1_objects = \
 <<layer2>>=
 axiom_algebra_layer_2 = \
   ELTAGG   ELTAGG- FMC      FMFUN   FORTFN   FVC     \
-  CTORCALL FVFUN   INTRET   IXAGG   IXAGG-   SEGXCAT \
+  SYNTAX   FVFUN   INTRET   IXAGG   IXAGG-   SEGXCAT \
   CONTOUR  LIST3   MKFUNC   OASGP   KTVLOGIC
 
 axiom_algebra_layer_2_nrlibs = \
@@ -258,7 +258,7 @@ grdef.spad.pamphlet (GRDEF)
 <<layer3>>=
 axiom_algebra_layer_3 = \
    GRDEF     SCOPE    MAPHACK1 MAPHACK2 MAPHACK3 MAPPKG1  \
-   MAPPKG2   MAPPKG3  INTBIT   MONAD    MONAD-   
+   MAPPKG2   MAPPKG3  INTBIT   MONAD    MONAD-   CTORCALL
 
 
 
diff --git a/src/algebra/syntax.spad.pamphlet b/src/algebra/syntax.spad.pamphlet
index 380748d8..be0fc84b 100644
--- a/src/algebra/syntax.spad.pamphlet
+++ b/src/algebra/syntax.spad.pamphlet
@@ -34,11 +34,13 @@ import SExpression
 ++   while InputForm may contain atoms like vectors and other Lisp
 ++   objects, the Syntax domain is supposed to contain only that
 ++   initial algebra build from the primitives listed above.
-++ Related Constructors: Boolean, Integer, Float, Symbol, String, SExpression.
+++ Related Constructors: Integer, DoubleFloat, Symbol, String, SExpression.
 ++ See Also: SExpression.
 ++ The equality supported by this domain is structural.
 Syntax(): Public == Private where
-  Public == Join(UnionType, SetCategory) with
+  Public == Join(UnionType, SetCategory, RetractableTo Integer,
+              RetractableTo DoubleFloat, RetractableTo Symbol,
+                RetractableTo String) with
     convert: % -> SExpression
       ++ convert(s) returns the s-expression representation of a syntax.
 
@@ -47,8 +49,6 @@ Syntax(): Public == Private where
       ++ is not an atom, it is expected that it designates a proper list,
       ++ e.g. a sequence of cons cells ending with nil.
 
-    coerce: Integer -> %
-      ++ coerce(i) injects the integer value `i' into the Syntax domain.
     coerce: % -> Integer
       ++ coerce(s) extracts and integer value from the syntax `s'
     autoCoerce: % -> Integer
@@ -56,8 +56,6 @@ Syntax(): Public == Private where
       ++ the syntax `s'; no check performed.  To be called only
       ++ at the discretion of the compiler.
 
-    coerce: DoubleFloat -> %
-      ++ coerce(f) injects the float value `f' into the Syntax domain
     coerce: % -> DoubleFloat
       ++ coerce(s) extracts a float value from the syntax `s'.
     autoCoerce: % -> DoubleFloat
@@ -65,8 +63,6 @@ Syntax(): Public == Private where
       ++ no check performed.  To be called only at the discretion of
       ++ the compiler
 
-    coerce: Symbol -> %
-      ++ coerce(s) injects the symbol `s' into the Syntax domain.
     coerce: % -> Symbol
       ++ coerce(s) extracts a symbol from the syntax `s'.
     autoCoerce: % -> Symbol
@@ -74,8 +70,6 @@ Syntax(): Public == Private where
       ++ domain `s'; no check performed.  To be called only at
       ++ at the discretion of the compiler.
 
-    coerce: String -> %
-      ++ coerce(s) injects the string value `s' into the syntax domain
     coerce: % -> String
       ++ coerce(s) extracts a string value from the syntax `s'.
     autoCoerce: % -> String
@@ -150,9 +144,12 @@ Syntax(): Public == Private where
     autoCoerce(i: %): Integer ==                -- used for hard coercion
       i : Integer
 
-    coerce(i: %): Integer ==
-      i case Integer => i
-      userError "invalid conversion target type"
+    retractIfCan(x: %): Union(Integer,"failed") ==
+      x case Integer => x@Integer
+      "failed"
+
+    coerce(i: %): Integer == 
+      retract(i)@Integer
 
     coerce(f: DoubleFloat): % ==
       f pretend %
@@ -160,9 +157,12 @@ Syntax(): Public == Private where
     autoCoerce(f: %): DoubleFloat ==            -- used for hard coercion
       f : DoubleFloat
 
+    retractIfCan(x: %): Union(DoubleFloat,"failed") ==
+      x case DoubleFloat => x@DoubleFloat
+      "failed"
+
     coerce(f: %): DoubleFloat ==
-      f case DoubleFloat => f
-      userError "invalid conversion target type"
+      retract(f)@DoubleFloat
 
     coerce(s: Symbol): % ==
       s pretend %
@@ -170,9 +170,12 @@ Syntax(): Public == Private where
     autoCoerce(s: %): Symbol ==                 -- used for hard coercion
       s : Symbol
 
+    retractIfCan(x: %): Union(Symbol,"failed") ==
+      x case Symbol => x@Symbol
+      "failed"
+
     coerce(s: %): Symbol ==
-      s case Symbol => s
-      userError "invalid conversion target type"
+      retract(s)@Symbol
 
     coerce(s: String): % ==
       s pretend %
@@ -180,9 +183,12 @@ Syntax(): Public == Private where
     autoCoerce(s: %): String ==                 -- used for hard coercion
       s : String
 
+    retractIfCan(x: %): Union(String,"failed") ==
+      x case String => x@String
+      "failed"
+
     coerce(s: %): String ==
-      s case String => s
-      userError "invalid conversion target type"
+      retract(s)@String
 
     buildSyntax(s: Symbol, l: List %): % ==
       CONS(s,l)$Lisp