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-rw-r--r--src/libexpr/eval.cc89
-rw-r--r--src/libexpr/expr-to-xml.cc10
-rw-r--r--src/libexpr/nixexpr-ast.def1
-rw-r--r--src/libexpr/nixexpr.cc7
-rw-r--r--src/libexpr/parser.y13
-rw-r--r--tests/lang/eval-okay-patterns.exp1
-rw-r--r--tests/lang/eval-okay-patterns.nix16
-rw-r--r--tests/lang/eval-okay-xml.exp.xml12
-rw-r--r--tests/lang/eval-okay-xml.nix2
-rw-r--r--tests/lang/parse-fail-patterns-1.nix1
10 files changed, 106 insertions, 46 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 95a70ac27..ebcbac539 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -74,11 +74,16 @@ LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2,
}
+/* Pattern-match `pat' against `arg'. The result is a set of
+ substitutions (`subs') and a set of recursive substitutions
+ (`subsRecursive'). The latter can refer to the variables bound by
+ both `subs' and `subsRecursive'. */
static void patternMatch(EvalState & state,
- Pattern pat, Expr arg, ATermMap & subs)
+ Pattern pat, Expr arg, ATermMap & subs, ATermMap & subsRecursive)
{
ATerm name;
ATermList formals;
+ Pattern pat1, pat2;
if (matchVarPat(pat, name))
subs.set(name, arg);
@@ -87,60 +92,45 @@ static void patternMatch(EvalState & state,
arg = evalExpr(state, arg);
- unsigned int nrFormals = ATgetLength(formals);
+ /* Get the actual arguments. */
+ ATermMap attrs;
+ queryAllAttrs(arg, attrs);
+ unsigned int nrAttrs = attrs.size();
- /* Get the actual arguments and put them in the substitution.
- !!! shouldn't do this once we add `...'.*/
- ATermMap args;
- queryAllAttrs(arg, args);
- 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 each formal argument, get the actual argument. If
+ there is no matching actual argument but the formal
+ argument has a default, use the default. */
+ unsigned int attrsUsed = 0;
for (ATermIterator i(formals); i; ++i) {
Expr name, def;
DefaultValue def2;
if (!matchFormal(*i, name, def2)) abort(); /* can't happen */
- Expr value = subs[name];
-
+ Expr value = attrs[name];
+
if (value == 0) {
if (!matchDefaultValue(def2, def)) def = 0;
if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
% aterm2String(name));
- value = def;
- defsUsed.push_back(name);
- recAttrs = ATinsert(recAttrs, makeBind(name, def, makeNoPos()));
+ subsRecursive.set(name, def);
+ } else {
+ attrsUsed++;
+ attrs.remove(name);
+ subs.set(name, value);
}
}
-
- /* 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; ATerm d1;
- if (!matchFormal(*i, name, d1)) abort();
- subs.remove(name);
- }
+
+ /* Check that each actual argument is listed as a formal
+ argument. */
+ if (attrsUsed != nrAttrs)
throw TypeError(format("the function does not expect an argument named `%1%'")
- % aterm2String(subs.begin()->key));
- }
+ % aterm2String(attrs.begin()->key));
+ }
+ else if (matchAtPat(pat, pat1, pat2)) {
+ patternMatch(state, pat1, arg, subs, subsRecursive);
+ patternMatch(state, pat2, arg, subs, subsRecursive);
}
else abort();
@@ -151,9 +141,24 @@ static void patternMatch(EvalState & state,
static Expr substArgs(EvalState & state,
Expr body, Pattern pat, Expr arg)
{
- ATermMap subs(16);
+ ATermMap subs(16), subsRecursive(16);
- patternMatch(state, pat, arg, subs);
+ patternMatch(state, pat, arg, subs, subsRecursive);
+
+ /* If we used any default values, make a recursive attribute set
+ out of the (argument-name, value) tuples. This is so that we
+ can support default values that refer to each other, e.g. ({x,
+ y ? x + x}: y) {x = "foo";} evaluates to "foofoo". */
+ if (subsRecursive.size() != 0) {
+ ATermList recAttrs = ATempty;
+ foreach (ATermMap::const_iterator, i, subs)
+ recAttrs = ATinsert(recAttrs, makeBind(i->key, i->value, makeNoPos()));
+ foreach (ATermMap::const_iterator, i, subsRecursive)
+ recAttrs = ATinsert(recAttrs, makeBind(i->key, i->value, makeNoPos()));
+ Expr rec = makeRec(recAttrs, ATempty);
+ foreach (ATermMap::const_iterator, i, subsRecursive)
+ subs.set(i->key, makeSelect(rec, i->key));
+ }
return substitute(Substitution(0, &subs), body);
}
diff --git a/src/libexpr/expr-to-xml.cc b/src/libexpr/expr-to-xml.cc
index 5aa537b20..6ec906356 100644
--- a/src/libexpr/expr-to-xml.cc
+++ b/src/libexpr/expr-to-xml.cc
@@ -40,10 +40,11 @@ static void showAttrs(const ATermMap & attrs, XMLWriter & doc,
}
-static void printPatternAsXML(Pattern pat, XMLWriter & doc, PathSet & context)
+static void printPatternAsXML(Pattern pat, XMLWriter & doc)
{
ATerm name;
ATermList formals;
+ Pattern pat1, pat2;
if (matchVarPat(pat, name))
doc.writeEmptyElement("varpat", singletonAttrs("name", aterm2String(name)));
else if (matchAttrsPat(pat, formals)) {
@@ -54,6 +55,11 @@ static void printPatternAsXML(Pattern pat, XMLWriter & doc, PathSet & context)
doc.writeEmptyElement("attr", singletonAttrs("name", aterm2String(name)));
}
}
+ else if (matchAtPat(pat, pat1, pat2)) {
+ XMLOpenElement _(doc, "at");
+ printPatternAsXML(pat1, doc);
+ printPatternAsXML(pat2, doc);
+ }
}
@@ -128,7 +134,7 @@ static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context,
else if (matchFunction(e, pat, body, pos)) {
XMLOpenElement _(doc, "function");
- printPatternAsXML(pat, doc, context);
+ printPatternAsXML(pat, doc);
}
else
diff --git a/src/libexpr/nixexpr-ast.def b/src/libexpr/nixexpr-ast.def
index 6b9cf95fa..670db1976 100644
--- a/src/libexpr/nixexpr-ast.def
+++ b/src/libexpr/nixexpr-ast.def
@@ -77,6 +77,7 @@ Scope | | Expr |
VarPat | string | Pattern |
AttrsPat | ATermList | Pattern |
+AtPat | Pattern Pattern | Pattern |
Formal | string DefaultValue | ATerm |
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index 4744cdde3..b2d775abb 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -114,6 +114,7 @@ static void varsBoundByPattern(ATermMap & map, Pattern pat)
{
ATerm name;
ATermList formals;
+ Pattern pat1, pat2;
/* Use makeRemoved() so that it can be used directly in
substitute(). */
if (matchVarPat(pat, name))
@@ -125,6 +126,10 @@ static void varsBoundByPattern(ATermMap & map, Pattern pat)
map.set(name, makeRemoved());
}
}
+ else if (matchAtPat(pat, pat1, pat2)) {
+ varsBoundByPattern(map, pat1);
+ varsBoundByPattern(map, pat2);
+ }
else abort();
}
@@ -354,7 +359,7 @@ Expr makeStr(const string & s, const PathSet & context)
string showType(Expr e)
{
- ATerm t1, t2, t3;
+ ATerm t1, t2;
ATermList l1;
ATermBlob b1;
int i1;
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 7713021a9..c48aa34aa 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -211,7 +211,8 @@ static void freeAndUnprotect(void * p)
}
%type <t> start expr expr_function expr_if expr_op
-%type <t> expr_app expr_select expr_simple bind inheritsrc formal pattern
+%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
%token <t> ID INT STR IND_STR PATH URI
%token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL
@@ -319,6 +320,11 @@ ind_string_parts
;
pattern
+ : pattern2 '@' pattern { $$ = makeAtPat($1, $3); }
+ | pattern2
+ ;
+
+pattern2
: ID { $$ = makeVarPat($1); }
| '{' formals '}' { $$ = makeAttrsPat($2); }
;
@@ -394,6 +400,7 @@ static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
{
ATerm name;
ATermList formals;
+ Pattern pat1, pat2;
if (matchVarPat(pat, name)) {
if (map.get(name))
throw EvalError(format("duplicate formal function argument `%1%' at %2%")
@@ -410,6 +417,10 @@ static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat)
map.set(name, name);
}
}
+ else if (matchAtPat(pat, pat1, pat2)) {
+ checkPatternVars(pos, map, pat1);
+ checkPatternVars(pos, map, pat2);
+ }
else abort();
}
diff --git a/tests/lang/eval-okay-patterns.exp b/tests/lang/eval-okay-patterns.exp
new file mode 100644
index 000000000..382a0bd26
--- /dev/null
+++ b/tests/lang/eval-okay-patterns.exp
@@ -0,0 +1 @@
+Str("abcxyzDDDDEFgh",[])
diff --git a/tests/lang/eval-okay-patterns.nix b/tests/lang/eval-okay-patterns.nix
new file mode 100644
index 000000000..bcb9f3842
--- /dev/null
+++ b/tests/lang/eval-okay-patterns.nix
@@ -0,0 +1,16 @@
+let
+
+ f = args@{x, y, z}: x + args.y + z;
+
+ g = {x, y, z}@args: f args;
+
+ h = {x ? "d", y ? x, z ? args.x}@args: x + y + z;
+
+ i = args@args2: args.x + args2.y;
+
+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";}
diff --git a/tests/lang/eval-okay-xml.exp.xml b/tests/lang/eval-okay-xml.exp.xml
index 4798e87f8..4f55c69a7 100644
--- a/tests/lang/eval-okay-xml.exp.xml
+++ b/tests/lang/eval-okay-xml.exp.xml
@@ -4,6 +4,18 @@
<attr name="a">
<string value="foo" />
</attr>
+ <attr name="at">
+ <function>
+ <at>
+ <varpat name="args" />
+ <attrspat>
+ <attr name="x" />
+ <attr name="y" />
+ <attr name="z" />
+ </attrspat>
+ </at>
+ </function>
+ </attr>
<attr name="b">
<string value="bar" />
</attr>
diff --git a/tests/lang/eval-okay-xml.nix b/tests/lang/eval-okay-xml.nix
index 75420316d..44afbff1e 100644
--- a/tests/lang/eval-okay-xml.nix
+++ b/tests/lang/eval-okay-xml.nix
@@ -12,4 +12,6 @@ rec {
id = x: x;
+ at = args@{x, y, z}: x;
+
}
diff --git a/tests/lang/parse-fail-patterns-1.nix b/tests/lang/parse-fail-patterns-1.nix
new file mode 100644
index 000000000..7b4061641
--- /dev/null
+++ b/tests/lang/parse-fail-patterns-1.nix
@@ -0,0 +1 @@
+args@{args, x, y, z}: x
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 13:32:21 +0000