* Added an experimental feature suggested by Andres: ellipses ("...")
in attribute set pattern matches. This allows defining a function that takes *at least* the listed attributes, while ignoring additional attributes. For instance, {stdenv, fetchurl, fuse, ...}: stdenv.mkDerivation { ... }; defines a function that requires an attribute set that contains the specified attributes but ignores others. The main advantage is that we can then write in all-packages.nix aefs = import ../bla/aefs pkgs; instead of aefs = import ../bla/aefs { inherit stdenv fetchurl fuse; }; This saves a lot of typing (not to mention not having to update all-packages.nix with purely mechanical changes). It saves as much typing as the "args: with args;" style, but has the advantage that the function arguments are properly declared (not implicit in what the body of the "with" uses).
This commit is contained in:
parent
db4f4a8425
commit
9279174dde
14 changed files with 57 additions and 23 deletions
|
@ -84,11 +84,12 @@ static void patternMatch(EvalState & state,
|
|||
ATerm name;
|
||||
ATermList formals;
|
||||
Pattern pat1, pat2;
|
||||
ATermBool ellipsis;
|
||||
|
||||
if (matchVarPat(pat, name))
|
||||
subs.set(name, arg);
|
||||
|
||||
else if (matchAttrsPat(pat, formals)) {
|
||||
else if (matchAttrsPat(pat, formals, ellipsis)) {
|
||||
|
||||
arg = evalExpr(state, arg);
|
||||
|
||||
|
@ -122,8 +123,8 @@ static void patternMatch(EvalState & state,
|
|||
}
|
||||
|
||||
/* Check that each actual argument is listed as a formal
|
||||
argument. */
|
||||
if (attrsUsed != nrAttrs)
|
||||
argument (unless the attribute match specifies a `...'). */
|
||||
if (ellipsis == eFalse && attrsUsed != nrAttrs)
|
||||
throw TypeError(format("the function does not expect an argument named `%1%'")
|
||||
% aterm2String(attrs.begin()->key));
|
||||
}
|
||||
|
@ -402,9 +403,10 @@ Expr autoCallFunction(Expr e, const ATermMap & args)
|
|||
Pattern pat;
|
||||
ATerm body, pos;
|
||||
ATermList formals;
|
||||
|
||||
ATermBool ellipsis;
|
||||
|
||||
/* !!! this should be more general */
|
||||
if (matchFunction(e, pat, body, pos) && matchAttrsPat(pat, formals)) {
|
||||
if (matchFunction(e, pat, body, pos) && matchAttrsPat(pat, formals, ellipsis)) {
|
||||
ATermMap actualArgs(ATgetLength(formals));
|
||||
|
||||
for (ATermIterator i(formals); i; ++i) {
|
||||
|
|
|
@ -45,15 +45,17 @@ static void printPatternAsXML(Pattern pat, XMLWriter & doc)
|
|||
ATerm name;
|
||||
ATermList formals;
|
||||
Pattern pat1, pat2;
|
||||
ATermBool ellipsis;
|
||||
if (matchVarPat(pat, name))
|
||||
doc.writeEmptyElement("varpat", singletonAttrs("name", aterm2String(name)));
|
||||
else if (matchAttrsPat(pat, formals)) {
|
||||
else if (matchAttrsPat(pat, formals, ellipsis)) {
|
||||
XMLOpenElement _(doc, "attrspat");
|
||||
for (ATermIterator i(formals); i; ++i) {
|
||||
Expr name; ATerm dummy;
|
||||
if (!matchFormal(*i, name, dummy)) abort();
|
||||
doc.writeEmptyElement("attr", singletonAttrs("name", aterm2String(name)));
|
||||
}
|
||||
if (ellipsis == eTrue) doc.writeEmptyElement("ellipsis");
|
||||
}
|
||||
else if (matchAtPat(pat, pat1, pat2)) {
|
||||
XMLOpenElement _(doc, "at");
|
||||
|
|
|
@ -95,6 +95,7 @@ let { return LET; }
|
|||
in { return IN; }
|
||||
rec { return REC; }
|
||||
inherit { return INHERIT; }
|
||||
\.\.\. { return ELLIPSIS; }
|
||||
|
||||
\=\= { return EQ; }
|
||||
\!\= { return NEQ; }
|
||||
|
|
|
@ -66,7 +66,7 @@ PrimOp | int ATermBlob ATermList | Expr |
|
|||
Attrs | ATermList | Expr |
|
||||
Closed | Expr | Expr |
|
||||
Rec | ATermList ATermList | Expr |
|
||||
Bool | ATerm | Expr |
|
||||
Bool | ATermBool | Expr |
|
||||
Null | | Expr |
|
||||
|
||||
Bind | string Expr Pos | ATerm |
|
||||
|
@ -76,7 +76,7 @@ Inherit | Expr ATermList Pos | ATerm |
|
|||
Scope | | Expr |
|
||||
|
||||
VarPat | string | Pattern |
|
||||
AttrsPat | ATermList | Pattern |
|
||||
AttrsPat | ATermList ATermBool | Pattern | # bool = `...'
|
||||
AtPat | Pattern Pattern | Pattern |
|
||||
|
||||
Formal | string DefaultValue | ATerm |
|
||||
|
@ -84,8 +84,8 @@ Formal | string DefaultValue | ATerm |
|
|||
DefaultValue | Expr | DefaultValue |
|
||||
NoDefaultValue | | DefaultValue |
|
||||
|
||||
True | | ATerm |
|
||||
False | | ATerm |
|
||||
True | | ATermBool |
|
||||
False | | ATermBool |
|
||||
|
||||
PrimOpDef | int ATermBlob | ATerm |
|
||||
|
||||
|
|
|
@ -114,12 +114,13 @@ static void varsBoundByPattern(ATermMap & map, Pattern pat)
|
|||
{
|
||||
ATerm name;
|
||||
ATermList formals;
|
||||
Pattern pat1, pat2;
|
||||
Pattern pat1, pat2;
|
||||
ATermBool ellipsis;
|
||||
/* Use makeRemoved() so that it can be used directly in
|
||||
substitute(). */
|
||||
if (matchVarPat(pat, name))
|
||||
map.set(name, makeRemoved());
|
||||
else if (matchAttrsPat(pat, formals)) {
|
||||
else if (matchAttrsPat(pat, formals, ellipsis)) {
|
||||
for (ATermIterator i(formals); i; ++i) {
|
||||
ATerm d1;
|
||||
if (!matchFormal(*i, name, d1)) abort();
|
||||
|
|
|
@ -24,6 +24,7 @@ typedef ATerm Expr;
|
|||
typedef ATerm DefaultValue;
|
||||
typedef ATerm Pos;
|
||||
typedef ATerm Pattern;
|
||||
typedef ATerm ATermBool;
|
||||
|
||||
|
||||
/* A STL vector of ATerms. Should be used with great care since it's
|
||||
|
|
|
@ -208,16 +208,22 @@ static void freeAndUnprotect(void * p)
|
|||
%union {
|
||||
ATerm t;
|
||||
ATermList ts;
|
||||
struct {
|
||||
ATermList formals;
|
||||
bool ellipsis;
|
||||
} formals;
|
||||
}
|
||||
|
||||
%type <t> start expr expr_function expr_if expr_op
|
||||
%type <t> expr_app expr_select expr_simple bind inheritsrc formal
|
||||
%type <t> pattern pattern2
|
||||
%type <ts> binds ids expr_list formals string_parts ind_string_parts
|
||||
%type <ts> binds ids expr_list string_parts ind_string_parts
|
||||
%type <formals> formals
|
||||
%token <t> ID INT STR IND_STR PATH URI
|
||||
%token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL
|
||||
%token DOLLAR_CURLY /* == ${ */
|
||||
%token IND_STRING_OPEN IND_STRING_CLOSE
|
||||
%token ELLIPSIS
|
||||
|
||||
%nonassoc IMPL
|
||||
%left OR
|
||||
|
@ -326,7 +332,7 @@ pattern
|
|||
|
||||
pattern2
|
||||
: ID { $$ = makeVarPat($1); }
|
||||
| '{' formals '}' { $$ = makeAttrsPat($2); }
|
||||
| '{' formals '}' { $$ = makeAttrsPat($2.formals, $2.ellipsis ? eTrue : eFalse); }
|
||||
;
|
||||
|
||||
binds
|
||||
|
@ -357,9 +363,14 @@ expr_list
|
|||
;
|
||||
|
||||
formals
|
||||
: formal ',' formals { $$ = ATinsert($3, $1); } /* idem - right recursive */
|
||||
| formal { $$ = ATinsert(ATempty, $1); }
|
||||
| { $$ = ATempty; }
|
||||
: formal ',' formals /* idem - right recursive */
|
||||
{ $$.formals = ATinsert($3.formals, $1); $$.ellipsis = $3.ellipsis; }
|
||||
| formal
|
||||
{ $$.formals = ATinsert(ATempty, $1); $$.ellipsis = false; }
|
||||
|
|
||||
{ $$.formals = ATempty; $$.ellipsis = false; }
|
||||
| ELLIPSIS
|
||||
{ $$.formals = ATempty; $$.ellipsis = true; }
|
||||
;
|
||||
|
||||
formal
|
||||
|
@ -401,13 +412,14 @@ static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
|
|||
ATerm name;
|
||||
ATermList formals;
|
||||
Pattern pat1, pat2;
|
||||
ATermBool ellipsis;
|
||||
if (matchVarPat(pat, name)) {
|
||||
if (map.get(name))
|
||||
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
|
||||
% aterm2String(name) % showPos(pos));
|
||||
map.set(name, name);
|
||||
}
|
||||
else if (matchAttrsPat(pat, formals)) {
|
||||
else if (matchAttrsPat(pat, formals, ellipsis)) {
|
||||
for (ATermIterator i(formals); i; ++i) {
|
||||
ATerm d1;
|
||||
if (!matchFormal(*i, name, d1)) abort();
|
||||
|
|
|
@ -1 +1 @@
|
|||
Str("abcxyzDDDDEFgh",[])
|
||||
Str("abcxyzDDDDEFghijk",[])
|
||||
|
|
|
@ -8,9 +8,12 @@ let
|
|||
|
||||
i = args@args2: args.x + args2.y;
|
||||
|
||||
j = {x, y, z, ...}: x + y + z;
|
||||
|
||||
in
|
||||
f {x = "a"; y = "b"; z = "c";} +
|
||||
g {x = "x"; y = "y"; z = "z";} +
|
||||
h {x = "D";} +
|
||||
h {x = "D"; y = "E"; z = "F";} +
|
||||
i {x = "g"; y = "h";}
|
||||
i {x = "g"; y = "h";} +
|
||||
j {x = "i"; y = "j"; z = "k"; bla = "bla"; foo = "bar";}
|
||||
|
|
|
@ -22,6 +22,16 @@
|
|||
<attr name="c">
|
||||
<string value="foobar" />
|
||||
</attr>
|
||||
<attr name="ellipsis">
|
||||
<function>
|
||||
<attrspat>
|
||||
<attr name="x" />
|
||||
<attr name="y" />
|
||||
<attr name="z" />
|
||||
<ellipsis />
|
||||
</attrspat>
|
||||
</function>
|
||||
</attr>
|
||||
<attr name="f">
|
||||
<function>
|
||||
<attrspat>
|
||||
|
|
|
@ -14,4 +14,6 @@ rec {
|
|||
|
||||
at = args@{x, y, z}: x;
|
||||
|
||||
ellipsis = {x, y, z, ...}: x;
|
||||
|
||||
}
|
||||
|
|
|
@ -1 +1 @@
|
|||
Function(AttrsPat([Formal("x",NoDefaultValue),Formal("y",NoDefaultValue),Formal("z",NoDefaultValue)]),OpPlus(OpPlus(Var("x"),Var("y")),Var("z")),NoPos)
|
||||
Function(AttrsPat([Formal("x",NoDefaultValue),Formal("y",NoDefaultValue),Formal("z",NoDefaultValue)],Bool(False)),OpPlus(OpPlus(Var("x"),Var("y")),Var("z")),NoPos)
|
||||
|
|
|
@ -1 +1 @@
|
|||
Function(AttrsPat([Formal("stdenv",NoDefaultValue),Formal("fetchurl",NoDefaultValue)]),Call(Select(Var("stdenv"),"mkDerivation"),Attrs([Bind("name",Str("libXi-6.0.1",[]),NoPos),Bind("src",Call(Var("fetchurl"),Attrs([Bind("md5",Str("7e935a42428d63a387b3c048be0f2756",[]),NoPos),Bind("url",Str("http://freedesktop.org/~xlibs/release/libXi-6.0.1.tar.bz2",[]),NoPos)])),NoPos)])),NoPos)
|
||||
Function(AttrsPat([Formal("stdenv",NoDefaultValue),Formal("fetchurl",NoDefaultValue)],Bool(False)),Call(Select(Var("stdenv"),"mkDerivation"),Attrs([Bind("name",Str("libXi-6.0.1",[]),NoPos),Bind("src",Call(Var("fetchurl"),Attrs([Bind("md5",Str("7e935a42428d63a387b3c048be0f2756",[]),NoPos),Bind("url",Str("http://freedesktop.org/~xlibs/release/libXi-6.0.1.tar.bz2",[]),NoPos)])),NoPos)])),NoPos)
|
||||
|
|
|
@ -1 +1 @@
|
|||
Function(AttrsPat([Formal("localServer",DefaultValue(Var("false"))),Formal("httpServer",DefaultValue(Var("false"))),Formal("sslSupport",DefaultValue(Var("false"))),Formal("pythonBindings",DefaultValue(Var("false"))),Formal("javaSwigBindings",DefaultValue(Var("false"))),Formal("javahlBindings",DefaultValue(Var("false"))),Formal("stdenv",NoDefaultValue),Formal("fetchurl",NoDefaultValue),Formal("openssl",DefaultValue(Var("null"))),Formal("httpd",DefaultValue(Var("null"))),Formal("db4",DefaultValue(Var("null"))),Formal("expat",NoDefaultValue),Formal("swig",DefaultValue(Var("null"))),Formal("j2sdk",DefaultValue(Var("null")))]),Assert(OpNEq(Var("expat"),Var("null")),Assert(OpImpl(Var("localServer"),OpNEq(Var("db4"),Var("null"))),Assert(OpImpl(Var("httpServer"),OpAnd(OpNEq(Var("httpd"),Var("null")),OpEq(Select(Var("httpd"),"expat"),Var("expat")))),Assert(OpImpl(Var("sslSupport"),OpAnd(OpNEq(Var("openssl"),Var("null")),OpImpl(Var("httpServer"),OpEq(Select(Var("httpd"),"openssl"),Var("openssl"))))),Assert(OpImpl(Var("pythonBindings"),OpAnd(OpNEq(Var("swig"),Var("null")),Select(Var("swig"),"pythonSupport"))),Assert(OpImpl(Var("javaSwigBindings"),OpAnd(OpNEq(Var("swig"),Var("null")),Select(Var("swig"),"javaSupport"))),Assert(OpImpl(Var("javahlBindings"),OpNEq(Var("j2sdk"),Var("null"))),Call(Select(Var("stdenv"),"mkDerivation"),Attrs([Bind("builder",Path("/foo/bar"),NoPos),Bind("db4",If(Var("localServer"),Var("db4"),Var("null")),NoPos),Bind("expat",Var("expat"),NoPos),Bind("httpServer",Var("httpServer"),NoPos),Bind("httpd",If(Var("httpServer"),Var("httpd"),Var("null")),NoPos),Bind("j2sdk",If(Var("javaSwigBindings"),Select(Var("swig"),"j2sdk"),If(Var("javahlBindings"),Var("j2sdk"),Var("null"))),NoPos),Bind("javaSwigBindings",Var("javaSwigBindings"),NoPos),Bind("javahlBindings",Var("javahlBindings"),NoPos),Bind("localServer",Var("localServer"),NoPos),Bind("name",Str("subversion-1.1.1",[]),NoPos),Bind("openssl",If(Var("sslSupport"),Var("openssl"),Var("null")),NoPos),Bind("patches",If(Var("javahlBindings"),List([Path("/javahl.patch")]),List([])),NoPos),Bind("python",If(Var("pythonBindings"),Select(Var("swig"),"python"),Var("null")),NoPos),Bind("pythonBindings",Var("pythonBindings"),NoPos),Bind("src",Call(Var("fetchurl"),Attrs([Bind("md5",Str("a180c3fe91680389c210c99def54d9e0",[]),NoPos),Bind("url",Str("http://subversion.tigris.org/tarballs/subversion-1.1.1.tar.bz2",[]),NoPos)])),NoPos),Bind("sslSupport",Var("sslSupport"),NoPos),Bind("swig",If(OpOr(Var("pythonBindings"),Var("javaSwigBindings")),Var("swig"),Var("null")),NoPos)])),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos)
|
||||
Function(AttrsPat([Formal("localServer",DefaultValue(Var("false"))),Formal("httpServer",DefaultValue(Var("false"))),Formal("sslSupport",DefaultValue(Var("false"))),Formal("pythonBindings",DefaultValue(Var("false"))),Formal("javaSwigBindings",DefaultValue(Var("false"))),Formal("javahlBindings",DefaultValue(Var("false"))),Formal("stdenv",NoDefaultValue),Formal("fetchurl",NoDefaultValue),Formal("openssl",DefaultValue(Var("null"))),Formal("httpd",DefaultValue(Var("null"))),Formal("db4",DefaultValue(Var("null"))),Formal("expat",NoDefaultValue),Formal("swig",DefaultValue(Var("null"))),Formal("j2sdk",DefaultValue(Var("null")))],Bool(False)),Assert(OpNEq(Var("expat"),Var("null")),Assert(OpImpl(Var("localServer"),OpNEq(Var("db4"),Var("null"))),Assert(OpImpl(Var("httpServer"),OpAnd(OpNEq(Var("httpd"),Var("null")),OpEq(Select(Var("httpd"),"expat"),Var("expat")))),Assert(OpImpl(Var("sslSupport"),OpAnd(OpNEq(Var("openssl"),Var("null")),OpImpl(Var("httpServer"),OpEq(Select(Var("httpd"),"openssl"),Var("openssl"))))),Assert(OpImpl(Var("pythonBindings"),OpAnd(OpNEq(Var("swig"),Var("null")),Select(Var("swig"),"pythonSupport"))),Assert(OpImpl(Var("javaSwigBindings"),OpAnd(OpNEq(Var("swig"),Var("null")),Select(Var("swig"),"javaSupport"))),Assert(OpImpl(Var("javahlBindings"),OpNEq(Var("j2sdk"),Var("null"))),Call(Select(Var("stdenv"),"mkDerivation"),Attrs([Bind("builder",Path("/foo/bar"),NoPos),Bind("db4",If(Var("localServer"),Var("db4"),Var("null")),NoPos),Bind("expat",Var("expat"),NoPos),Bind("httpServer",Var("httpServer"),NoPos),Bind("httpd",If(Var("httpServer"),Var("httpd"),Var("null")),NoPos),Bind("j2sdk",If(Var("javaSwigBindings"),Select(Var("swig"),"j2sdk"),If(Var("javahlBindings"),Var("j2sdk"),Var("null"))),NoPos),Bind("javaSwigBindings",Var("javaSwigBindings"),NoPos),Bind("javahlBindings",Var("javahlBindings"),NoPos),Bind("localServer",Var("localServer"),NoPos),Bind("name",Str("subversion-1.1.1",[]),NoPos),Bind("openssl",If(Var("sslSupport"),Var("openssl"),Var("null")),NoPos),Bind("patches",If(Var("javahlBindings"),List([Path("/javahl.patch")]),List([])),NoPos),Bind("python",If(Var("pythonBindings"),Select(Var("swig"),"python"),Var("null")),NoPos),Bind("pythonBindings",Var("pythonBindings"),NoPos),Bind("src",Call(Var("fetchurl"),Attrs([Bind("md5",Str("a180c3fe91680389c210c99def54d9e0",[]),NoPos),Bind("url",Str("http://subversion.tigris.org/tarballs/subversion-1.1.1.tar.bz2",[]),NoPos)])),NoPos),Bind("sslSupport",Var("sslSupport"),NoPos),Bind("swig",If(OpOr(Var("pythonBindings"),Var("javaSwigBindings")),Var("swig"),Var("null")),NoPos)])),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos),NoPos)
|
||||
|
|
Loading…
Reference in a new issue