* Allow function argument default values to refer to other arguments
of the function. Implements NIX-45.
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					 5 changed files with 51 additions and 39 deletions
				
			
		|  | @ -24,49 +24,54 @@ void EvalState::addPrimOp(const string & name, | |||
| /* Substitute an argument set into the body of a function. */ | ||||
| static Expr substArgs(Expr body, ATermList formals, Expr arg) | ||||
| { | ||||
|     ATermMap subs(ATgetLength(formals) * 2); | ||||
|     unsigned int nrFormals = ATgetLength(formals); | ||||
|     ATermMap subs(nrFormals); | ||||
| 
 | ||||
|     /* ({x ? E1; y ? E2, z}: E3) {x = E4; z = E5;}
 | ||||
| 
 | ||||
|        => let {x = E4; y = E2; z = E5; body = E3; } | ||||
| 
 | ||||
|        => subst(E3, s) | ||||
|           s = { | ||||
|             R = rec {x = E4; y = E2; z = E5} | ||||
|             x -> R.x | ||||
|             y -> R.y | ||||
|             z -> R.z | ||||
|           } | ||||
|     */ | ||||
|      | ||||
|     /* Get the formal arguments. */ | ||||
|     for (ATermIterator i(formals); i; ++i) { | ||||
|         Expr name, def; | ||||
|         if (matchNoDefFormal(*i, name)) | ||||
|             subs.set(name, makeUndefined()); | ||||
|         else if (matchDefFormal(*i, name, def)) | ||||
|             subs.set(name, def); | ||||
|         else abort(); /* can't happen */ | ||||
|     } | ||||
| 
 | ||||
|     /* Get the actual arguments, and check that they match with the
 | ||||
|        formals. */ | ||||
|     /* Get the actual arguments and put them in the substitution. */ | ||||
|     ATermMap args(128); /* !!! fix */ | ||||
|     queryAllAttrs(arg, args); | ||||
|     for (ATermMap::const_iterator i = args.begin(); i != args.end(); ++i) { | ||||
|         Expr cur = subs.get(i->key); | ||||
|         if (!subs.get(i->key)) | ||||
|             throw Error(format("unexpected function argument `%1%'") | ||||
|                 % aterm2String(i->key)); | ||||
|     for (ATermMap::const_iterator i = args.begin(); i != args.end(); ++i) | ||||
|         subs.set(i->key, i->value); | ||||
|      | ||||
|     /* Get the formal arguments. */ | ||||
|     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 */ | ||||
|         if (subs[name] == 0) { | ||||
|             if (def == 0) throw Error(format("required function argument `%1%' missing") | ||||
|                 % aterm2String(name)); | ||||
|             defsUsed.push_back(name); | ||||
|             recAttrs = ATinsert(recAttrs, makeBind(name, def, makeNoPos())); | ||||
|         } | ||||
|     } | ||||
| 
 | ||||
|     /* Check that all arguments are defined. */ | ||||
|     for (ATermMap::const_iterator i = subs.begin(); i != subs.end(); ++i) | ||||
|         if (i->value == makeUndefined()) | ||||
|             throw Error(format("required function argument `%1%' missing") | ||||
|                 % aterm2String(i->key)); | ||||
|     /* Make a recursive attribute set out of the (argument-name,
 | ||||
|        value) tuples.  This is so that we can support default | ||||
|        parameters that refer to each other, e.g.  ({x, y ? x + x}: y) | ||||
|        {x = "foo";} evaluates to "foofoo". */ | ||||
|     if (defsUsed.size() != 0) { | ||||
|         for (ATermMap::const_iterator i = args.begin(); i != args.end(); ++i) | ||||
|             recAttrs = ATinsert(recAttrs, makeBind(i->key, i->value, makeNoPos())); | ||||
|         Expr rec = makeRec(recAttrs, ATempty); | ||||
|         for (ATermVector::iterator i = defsUsed.begin(); i != defsUsed.end(); ++i) | ||||
|             subs.set(*i, makeSelect(rec, *i)); | ||||
|     } | ||||
|      | ||||
|     if (subs.size() != nrFormals) { | ||||
|         /* 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); | ||||
|             subs.remove(name); | ||||
|         } | ||||
|         throw Error(format("unexpected function argument `%1%'") | ||||
|             % aterm2String(subs.begin()->key)); | ||||
|     } | ||||
| 
 | ||||
|     return substitute(Substitution(0, &subs), body); | ||||
| } | ||||
| 
 | ||||
|  |  | |||
|  | @ -217,17 +217,17 @@ unsigned int ATermMap::size() | |||
| 
 | ||||
| void printATermMapStats() | ||||
| { | ||||
|     cout << "RESIZES: " << nrResizes << " " | ||||
|     cerr << "RESIZES: " << nrResizes << " " | ||||
|          << sizeTotalAlloc << " " | ||||
|          << sizeCurAlloc << " " | ||||
|          << sizeMaxAlloc << endl; | ||||
|          | ||||
|     cout << "SET: " | ||||
|     cerr << "SET: " | ||||
|          << nrItemsSet << " " | ||||
|          << nrSetProbes << " " | ||||
|          << (double) nrSetProbes / nrItemsSet << endl; | ||||
| 
 | ||||
|     cout << "GET: " | ||||
|     cerr << "GET: " | ||||
|          << nrItemsGet << " " | ||||
|          << nrGetProbes << " " | ||||
|          << (double) nrGetProbes / nrItemsGet << endl; | ||||
|  |  | |||
|  | @ -50,6 +50,11 @@ public: | |||
| 
 | ||||
|     ATerm get(ATerm key) const; | ||||
| 
 | ||||
|     ATerm operator [](ATerm key) const | ||||
|     { | ||||
|         return get(key); | ||||
|     } | ||||
| 
 | ||||
|     void remove(ATerm key); | ||||
| 
 | ||||
|     unsigned int size(); | ||||
|  |  | |||
							
								
								
									
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								tests/lang/eval-fail-missing-arg.nix
									
										
									
									
									
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								tests/lang/eval-fail-missing-arg.nix
									
										
									
									
									
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							|  | @ -0,0 +1 @@ | |||
| ({x, y, z}: x + y + z) {x = "foo"; z = "bar";} | ||||
							
								
								
									
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								tests/lang/eval-fail-undeclared-arg.nix
									
										
									
									
									
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								tests/lang/eval-fail-undeclared-arg.nix
									
										
									
									
									
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							|  | @ -0,0 +1 @@ | |||
| ({x, z}: x + z) {x = "foo"; y = "bla"; z = "bar";} | ||||
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