* Refactoring to support domain checks.

src/libexpr/eval.cc

@@ -37,15 +37,17 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
     ATermVector defsUsed;
     ATermList recAttrs = ATempty;
     for (ATermIterator i(formals); i; ++i) {
-        Expr name, def = 0;
-        if (!matchNoDefFormal(*i, name) && !matchDefFormal(*i, name, def))
-            abort(); /* can't happen */
+        Expr name, def; DefaultValue def2; ATerm dummy;
+        if (!matchFormal(*i, name, dummy, def2)) abort(); /* can't happen */
+        if (!matchDefaultValue(def2, def)) def = 0;
         if (subs[name] == 0) {
             if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
                 % aterm2String(name));
             defsUsed.push_back(name);
             recAttrs = ATinsert(recAttrs, makeBind(name, def, makeNoPos()));
         }
+        /* !!! check that the argument are in the valid values list,
+           if present */
     }
 
     /* Make a recursive attribute set out of the (argument-name,
@@ -64,8 +66,8 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
         /* One or more actual arguments were not declared as formal
            arguments.  Find out which. */
         for (ATermIterator i(formals); i; ++i) {
-            Expr name, def;
-            matchNoDefFormal(*i, name) || matchDefFormal(*i, name, def);
+            Expr name; ATerm d1, d2;
+            matchFormal(*i, name, d1, d2);
             subs.remove(name);
         }
         throw TypeError(format("the function does not expect an argument named `%1%'")

src/libexpr/get-drvs.cc

@@ -121,12 +121,11 @@ static void getDerivations(EvalState & state, Expr e,
     ATerm body, pos;
     if (matchFunction(e, formals, body, pos)) {
         for (ATermIterator i(formals); i; ++i) {
-            Expr name, def;
-            if (matchNoDefFormal(*i, name))
+            Expr name, def; ATerm values, def2;
+            if (!matchFormal(*i, name, values, def2)) abort();
+            if (!matchDefaultValue(def2, def)) 
                 throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
                     % aterm2String(name));
-            else if (!matchDefFormal(*i, name, def))
-                abort(); /* can't happen */
         }
         getDerivations(state,
             makeCall(e, makeAttrs(ATermMap(0))),

src/libexpr/nixexpr-ast.def

@@ -45,8 +45,13 @@ Inherit | Expr ATermList Pos | ATerm |
 
 Scope | | Expr |
 
-NoDefFormal | string | ATerm |
-DefFormal | string Expr | ATerm |
+Formal | string ValidValues DefaultValue | ATerm |
+
+ValidValues | ATermList | ValidValues |
+UnrestrictedValues | | ValidValues |
+
+DefaultValue | Expr | DefaultValue |
+NoDefaultValue | | DefaultValue |
 
 True | | ATerm |
 False | | ATerm |

src/libexpr/nixexpr.cc

@@ -134,9 +134,8 @@ Expr substitute(const Substitution & subs, Expr e)
     if (matchFunction(e, formals, body, pos)) {
         ATermMap map(ATgetLength(formals));
         for (ATermIterator i(formals); i; ++i) {
-            if (!matchNoDefFormal(*i, name) &&
-                !matchDefFormal(*i, name, def))
-                abort();
+            ATerm d1, d2;
+            if (!matchFormal(*i, name, d1, d2)) abort();
             map.set(name, makeRemoved());
         }
         Substitution subs2(&subs, &map);
@@ -221,16 +220,14 @@ static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e)
     else if (matchFunction(e, formals, body, pos)) {
         ATermMap defs2(defs);
         for (ATermIterator i(formals); i; ++i) {
-            Expr deflt;
-            if (!matchNoDefFormal(*i, name) &&
-                !matchDefFormal(*i, name, deflt))
-                abort();
+            Expr d1, d2;
+            if (!matchFormal(*i, name, d1, d2)) abort();
             defs2.set(name, (ATerm) ATempty);
         }
         for (ATermIterator i(formals); i; ++i) {
-            Expr deflt;
+            Expr dummy, deflt;
             set<Expr> done2;
-            if (matchDefFormal(*i, name, deflt))
+            if (matchFormal(*i, name, dummy, deflt)) /* !!! check dummy */
                 checkVarDefs2(done2, defs2, deflt);
         }
         set<Expr> done2;

src/libexpr/nixexpr.hh

@@ -19,6 +19,9 @@ MakeError(TypeError, EvalError)
    normals forms efficiently. */
 typedef ATerm Expr;
 
+typedef ATerm DefaultValue;
+typedef ATerm ValidValues;
+
 typedef ATerm Pos;
 
 

src/libexpr/parser.cc

@@ -118,10 +118,8 @@ static void checkAttrSets(ATerm e)
         ATermMap names(ATgetLength(formals));
         for (ATermIterator i(formals); i; ++i) {
             ATerm name;
-            Expr deflt;
-            if (!matchNoDefFormal(*i, name) &&
-                !matchDefFormal(*i, name, deflt))
-                abort();
+            ATerm d1, d2;
+            if (!matchFormal(*i, name, d1, d2)) abort();
             if (names.get(name))
                 throw EvalError(format("duplicate formal function argument `%1%' at %2%")
                     % aterm2String(name) % showPos(pos));

src/libexpr/parser.y

@@ -16,6 +16,8 @@
 #include "lexer-tab.h"
 
 typedef ATerm Expr;
+typedef ATerm ValidValues;
+typedef ATerm DefaultValue;
 typedef ATerm Pos;
     
 #include "nixexpr-ast.hh"
@@ -203,8 +205,9 @@ formals
   ;
 
 formal
-  : ID { $$ = makeNoDefFormal($1); }
-  | ID '?' expr { $$ = makeDefFormal($1, $3); }
+  : ID { $$ = makeFormal($1, makeUnrestrictedValues(), makeNoDefaultValue()); }
+//  | ID ':' '[' expr_list ']' { $$ = makeDefFormal($1, $3); }
+  | ID '?' expr { $$ = makeFormal($1, makeUnrestrictedValues(), makeDefaultValue($3)); }
   ;
   
 %%