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* Some utility functions for working with ATerms.

This commit is contained in:
Eelco Dolstra 2003-11-16 17:46:31 +00:00
parent 06ae269c7c
commit 3e5a019a07
14 changed files with 362 additions and 174 deletions
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108
src/fix-ng/eval.cc
View File

@ -16,6 +16,7 @@ EvalState::EvalState()
/* Substitute an argument set into the body of a function. */
static Expr substArgs(Expr body, ATermList formals, Expr arg)
{
ATMatcher m;
ATermMap subs;
Expr undefined = ATmake("Undefined");
@ -23,9 +24,9 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
while (!ATisEmpty(formals)) {
ATerm t = ATgetFirst(formals);
Expr name, def;
if (ATmatch(t, "NoDefFormal(<term>)", &name))
if (atMatch(m, t) >> "NoDefFormal" >> name)
subs.set(name, undefined);
else if (ATmatch(t, "DefFormal(<term>, <term>)", &name, &def))
else if (atMatch(m, t) >> "DefFormal" >> name >> def)
subs.set(name, def);
else abort(); /* can't happen */
formals = ATgetNext(formals);
@ -67,15 +68,17 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
(e.x) (e.y), y = e.x}'. */
ATerm expandRec(ATerm e, ATermList bnds)
{
ATMatcher m;
/* Create the substitution list. */
ATermMap subs;
ATermList bs = bnds;
while (!ATisEmpty(bs)) {
char * s;
string s;
Expr e2;
if (!ATmatch(ATgetFirst(bs), "Bind(<str>, <term>)", &s, &e2))
if (!(atMatch(m, ATgetFirst(bs)) >> "Bind" >> s >> e2))
abort(); /* can't happen */
subs.set(s, ATmake("Select(<term>, <str>)", e, s));
subs.set(s, ATmake("Select(<term>, <str>)", e, s.c_str()));
bs = ATgetNext(bs);
}
@ -83,9 +86,9 @@ ATerm expandRec(ATerm e, ATermList bnds)
ATermMap as;
bs = bnds;
while (!ATisEmpty(bs)) {
char * s;
string s;
Expr e2;
if (!ATmatch(ATgetFirst(bs), "Bind(<str>, <term>)", &s, &e2))
if (!(atMatch(m, ATgetFirst(bs)) >> "Bind" >> s >> e2))
abort(); /* can't happen */
as.set(s, substitute(subs, e2));
bs = ATgetNext(bs);
@ -98,8 +101,9 @@ ATerm expandRec(ATerm e, ATermList bnds)
string evalString(EvalState & state, Expr e)
{
e = evalExpr(state, e);
char * s;
if (!ATmatch(e, "Str(<str>)", &s))
ATMatcher m;
string s;
if (!(atMatch(m, e) >> "Str" >> s))
throw badTerm("string expected", e);
return s;
}
@ -108,8 +112,9 @@ string evalString(EvalState & state, Expr e)
Path evalPath(EvalState & state, Expr e)
{
e = evalExpr(state, e);
char * s;
if (!ATmatch(e, "Path(<str>)", &s))
ATMatcher m;
string s;
if (!(atMatch(m, e) >> "Path" >> s))
throw badTerm("path expected", e);
return s;
}
@ -118,78 +123,79 @@ Path evalPath(EvalState & state, Expr e)
bool evalBool(EvalState & state, Expr e)
{
e = evalExpr(state, e);
if (ATmatch(e, "Bool(True)")) return true;
else if (ATmatch(e, "Bool(False)")) return false;
ATMatcher m;
if (atMatch(m, e) >> "Bool" >> "True") return true;
else if (atMatch(m, e) >> "Bool" >> "False") return false;
else throw badTerm("expecting a boolean", e);
}
Expr evalExpr2(EvalState & state, Expr e)
{
ATMatcher m;
Expr e1, e2, e3, e4;
char * s1;
string s1;
/* Normal forms. */
if (ATmatch(e, "Str(<str>)", &s1) ||
ATmatch(e, "Path(<str>)", &s1) ||
ATmatch(e, "Uri(<str>)", &s1) ||
ATmatch(e, "Bool(<term>)", &e1) ||
ATmatch(e, "Function([<list>], <term>)", &e1, &e2) ||
ATmatch(e, "Attrs([<list>])", &e1) ||
ATmatch(e, "List([<list>])", &e1))
if (atMatch(m, e) >> "Str" ||
atMatch(m, e) >> "Path" ||
atMatch(m, e) >> "Uri" ||
atMatch(m, e) >> "Bool" ||
atMatch(m, e) >> "Function" ||
atMatch(m, e) >> "Attrs" ||
atMatch(m, e) >> "List")
return e;
/* Any encountered variables must be undeclared or primops. */
if (ATmatch(e, "Var(<str>)", &s1)) {
if ((string) s1 == "null") return primNull(state);
if (atMatch(m, e) >> "Var" >> s1) {
if (s1 == "null") return primNull(state);
return e;
}
/* Function application. */
if (ATmatch(e, "Call(<term>, <term>)", &e1, &e2)) {
if (atMatch(m, e) >> "Call" >> e1 >> e2) {
ATermList formals;
/* Evaluate the left-hand side. */
e1 = evalExpr(state, e1);
/* Is it a primop or a function? */
if (ATmatch(e1, "Var(<str>)", &s1)) {
string primop(s1);
if (primop == "import") return primImport(state, e2);
if (primop == "derivation") return primDerivation(state, e2);
if (primop == "toString") return primToString(state, e2);
if (primop == "baseNameOf") return primBaseNameOf(state, e2);
if (primop == "isNull") return primIsNull(state, e2);
if (atMatch(m, e1) >> "Var" >> s1) {
if (s1 == "import") return primImport(state, e2);
if (s1 == "derivation") return primDerivation(state, e2);
if (s1 == "toString") return primToString(state, e2);
if (s1 == "baseNameOf") return primBaseNameOf(state, e2);
if (s1 == "isNull") return primIsNull(state, e2);
else throw badTerm("undefined variable/primop", e1);
}
else if (ATmatch(e1, "Function([<list>], <term>)", &e3, &e4)) {
else if (atMatch(m, e1) >> "Function" >> formals >> e4)
return evalExpr(state,
substArgs(e4, (ATermList) e3, evalExpr(state, e2)));
}
substArgs(e4, formals, evalExpr(state, e2)));
else throw badTerm("expecting a function or primop", e1);
}
/* Attribute selection. */
if (ATmatch(e, "Select(<term>, <str>)", &e1, &s1)) {
string name(s1);
Expr a = queryAttr(evalExpr(state, e1), name);
if (!a) throw badTerm(format("missing attribute `%1%'") % name, e);
if (atMatch(m, e) >> "Select" >> e1 >> s1) {
Expr a = queryAttr(evalExpr(state, e1), s1);
if (!a) throw badTerm(format("missing attribute `%1%'") % s1, e);
return evalExpr(state, a);
}
/* Mutually recursive sets. */
ATermList bnds;
if (ATmatch(e, "Rec([<list>])", &bnds))
return expandRec(e, (ATermList) bnds);
if (atMatch(m, e) >> "Rec" >> bnds)
return expandRec(e, bnds);
/* Let expressions `let {..., body = ...}' are just desugared
into `(rec {..., body = ...}).body'. */
if (ATmatch(e, "LetRec(<term>)", &e1))
return evalExpr(state, ATmake("Select(Rec(<term>), \"body\")", e1));
if (atMatch(m, e) >> "LetRec" >> bnds)
return evalExpr(state, ATmake("Select(Rec(<term>), \"body\")", bnds));
/* Conditionals. */
if (ATmatch(e, "If(<term>, <term>, <term>)", &e1, &e2, &e3)) {
if (atMatch(m, e) >> "If" >> e1 >> e2 >> e3) {
if (evalBool(state, e1))
return evalExpr(state, e2);
else
@ -197,33 +203,33 @@ Expr evalExpr2(EvalState & state, Expr e)
}
/* Assertions. */
if (ATmatch(e, "Assert(<term>, <term>)", &e1, &e2)) {
if (atMatch(m, e) >> "Assert" >> e1 >> e2) {
if (!evalBool(state, e1)) throw badTerm("guard failed", e);
return evalExpr(state, e2);
}
/* Generic equality. */
if (ATmatch(e, "OpEq(<term>, <term>)", &e1, &e2))
if (atMatch(m, e) >> "OpEq" >> e1 >> e2)
return makeBool(evalExpr(state, e1) == evalExpr(state, e2));
/* Generic inequality. */
if (ATmatch(e, "OpNEq(<term>, <term>)", &e1, &e2))
if (atMatch(m, e) >> "OpNEq" >> e1 >> e2)
return makeBool(evalExpr(state, e1) != evalExpr(state, e2));
/* Negation. */
if (ATmatch(e, "OpNot(<term>)", &e1))
if (atMatch(m, e) >> "OpNot" >> e1)
return makeBool(!evalBool(state, e1));
/* Implication. */
if (ATmatch(e, "OpImpl(<term>, <term>)", &e1, &e2))
if (atMatch(m, e) >> "OpImpl" >> e1 >> e2)
return makeBool(!evalBool(state, e1) || evalBool(state, e2));
/* Conjunction (logical AND). */
if (ATmatch(e, "OpAnd(<term>, <term>)", &e1, &e2))
if (atMatch(m, e) >> "OpAnd" >> e1 >> e2)
return makeBool(evalBool(state, e1) && evalBool(state, e2));
/* Disjunction (logical OR). */
if (ATmatch(e, "OpOr(<term>, <term>)", &e1, &e2))
if (atMatch(m, e) >> "OpOr" >> e1 >> e2)
return makeBool(evalBool(state, e1) || evalBool(state, e2));
/* Barf. */
@ -234,7 +240,7 @@ Expr evalExpr2(EvalState & state, Expr e)
Expr evalExpr(EvalState & state, Expr e)
{
startNest(nest, lvlVomit,
format("evaluating expression: %1%") % printTerm(e));
format("evaluating expression: %1%") % e);
state.nrEvaluated++;

22
src/fix-ng/fix-expr.cc
View File

@ -118,14 +118,15 @@ ATerm bottomupRewrite(TermFun & f, ATerm e)
void queryAllAttrs(Expr e, ATermMap & attrs)
{
ATMatcher m;
ATermList bnds;
if (!ATmatch(e, "Attrs([<list>])", &bnds))
if (!(atMatch(m, e) >> "Attrs" >> bnds))
throw badTerm("expected attribute set", e);
while (!ATisEmpty(bnds)) {
char * s;
string s;
Expr e;
if (!ATmatch(ATgetFirst(bnds), "Bind(<str>, <term>)", &s, &e))
if (!(atMatch(m, ATgetFirst(bnds)) >> "Bind" >> s >> e))
abort(); /* can't happen */
attrs.set(s, e);
bnds = ATgetNext(bnds);
@ -156,9 +157,10 @@ Expr makeAttrs(const ATermMap & attrs)
Expr substitute(const ATermMap & subs, Expr e)
{
char * s;
ATMatcher m;
string s;
if (ATmatch(e, "Var(<str>)", &s)) {
if (atMatch(m, e) >> "Var" >> s) {
Expr sub = subs.get(s);
return sub ? sub : e;
}
@ -167,13 +169,13 @@ Expr substitute(const ATermMap & subs, Expr e)
function. */
ATermList formals;
ATerm body;
if (ATmatch(e, "Function([<list>], <term>)", &formals, &body)) {
if (atMatch(m, e) >> "Function" >> formals >> body) {
ATermMap subs2(subs);
ATermList fs = formals;
while (!ATisEmpty(fs)) {
Expr def;
if (!ATmatch(ATgetFirst(fs), "NoDefFormal(<str>)", &s) &&
!ATmatch(ATgetFirst(fs), "DefFormal(<str>, <term>)", &s))
if (!(atMatch(m, ATgetFirst(fs)) >> "NoDefFormal" >> s) &&
!(atMatch(m, ATgetFirst(fs)) >> "DefFormal" >> s >> def))
abort();
subs2.remove(s);
fs = ATgetNext(fs);
@ -184,12 +186,12 @@ Expr substitute(const ATermMap & subs, Expr e)
/* Idem for a mutually recursive attribute set. */
ATermList bindings;
if (ATmatch(e, "Rec([<list>])", &bindings)) {
if (atMatch(m, e) >> "Rec" >> bindings) {
ATermMap subs2(subs);
ATermList bnds = bindings;
while (!ATisEmpty(bnds)) {
Expr e;
if (!ATmatch(ATgetFirst(bnds), "Bind(<str>, <term>)", &s, &e))
if (!(atMatch(m, ATgetFirst(bnds)) >> "Bind" >> s >> e))
abort(); /* can't happen */
subs2.remove(s);
bnds = ATgetNext(bnds);

36
src/fix-ng/fix.cc
View File

@ -27,37 +27,6 @@ static Path searchPath(const Paths & searchDirs, const Path & relPath)
#endif
#if 0
static Expr evalExpr2(EvalState & state, Expr e)
{
/* Ad-hoc function for string matching. */
if (ATmatch(e, "HasSubstr(<term>, <term>)", &e1, &e2)) {
e1 = evalExpr(state, e1);
e2 = evalExpr(state, e2);
char * s1, * s2;
if (!ATmatch(e1, "<str>", &s1))
throw badTerm("expecting a string", e1);
if (!ATmatch(e2, "<str>", &s2))
throw badTerm("expecting a string", e2);
return
string(s1).find(string(s2)) != string::npos ?
ATmake("True") : ATmake("False");
}
/* BaseName primitive function. */
if (ATmatch(e, "BaseName(<term>)", &e1)) {
e1 = evalExpr(state, e1);
if (!ATmatch(e1, "<str>", &s1))
throw badTerm("string expected", e1);
return ATmake("<str>", baseNameOf(s1).c_str());
}
}
#endif
static Expr evalStdin(EvalState & state)
{
startNest(nest, lvlTalkative, format("evaluating standard input"));
@ -70,9 +39,10 @@ static Expr evalStdin(EvalState & state)
static void printNixExpr(EvalState & state, Expr e)
{
ATMatcher m;
ATermList es;
if (ATmatch(e, "Attrs([<list>])", &es)) {
if (atMatch(m, e) >> "Attrs" >> es) {
Expr a = queryAttr(e, "type");
if (a && evalString(state, a) == "derivation") {
a = queryAttr(e, "drvPath");
@ -83,7 +53,7 @@ static void printNixExpr(EvalState & state, Expr e)
}
}
if (ATmatch(e, "[<list>]", &es)) {
if (ATgetType(e) == AT_LIST) {
while (!ATisEmpty(es)) {
printNixExpr(state, evalExpr(state, ATgetFirst(es)));
es = ATgetNext(es);

36
src/fix-ng/parser.cc
View File

@ -28,40 +28,40 @@ struct Cleanup : TermFun
virtual ATerm operator () (ATerm e)
{
char * s;
ATMatcher m;
string s;
if (ATmatch(e, "Str(<str>)", &s)) {
string s2(s);
if (atMatch(m, e) >> "Str" >> s) {
return ATmake("Str(<str>)",
string(s2, 1, s2.size() - 2).c_str());
string(s, 1, s.size() - 2).c_str());
}
if (ATmatch(e, "Path(<str>)", &s)) {
string path(s);
if (path[0] != '/')
path = basePath + "/" + path;
return ATmake("Path(<str>)", canonPath(path).c_str());
if (atMatch(m, e) >> "Path" >> s) {
if (s[0] != '/')
s = basePath + "/" + s;
return ATmake("Path(<str>)", canonPath(s).c_str());
}
if (ATmatch(e, "Int(<str>)", &s)) {
if (atMatch(m, e) >> "Int" >> s) {
istringstream s2(s);
int n;
s2 >> n;
return ATmake("Int(<int>)", n);
}
if (ATmatch(e, "Bool(\"true\")", &s))
if (atMatch(m, e) >> "Bool" >> "true")
return ATmake("Bool(True)");
if (ATmatch(e, "Bool(\"false\")", &s))
if (atMatch(m, e) >> "Bool" >> "false")
return ATmake("Bool(False)");
if (ATmatch(e, "ExprNil"))
if (atMatch(m, e) >> "ExprNil")
return (ATerm) ATempty;
ATerm e1, e2;
if (ATmatch(e, "ExprCons(<term>, [<list>])", &e1, &e2))
return (ATerm) ATinsert((ATermList) e2, e1);
ATerm e1;
ATermList e2;
if (atMatch(m, e) >> "ExprCons" >> e1 >> e2)
return (ATerm) ATinsert(e2, e1);
return e;
}
@ -133,7 +133,7 @@ Expr parseExprFromFile(Path path)
throw SysError(format("parse failed in `%1%'") % path);
if (SGisParseError(result))
throw Error(format("parse error in `%1%': %2%")
% path % printTerm(result));
% path % result);
/* Implode it. */
PT_ParseTree tree = PT_makeParseTreeFromTerm(result);
@ -156,7 +156,7 @@ Expr parseExprFromFile(Path path)
throw Error(format("cannot implode parse tree"));
debug(format("imploded parse tree of `%1%': %2%")
% path % printTerm(imploded));
% path % imploded);
/* Finally, clean it up. */
Cleanup cleanup;

43
src/fix-ng/primops.cc
View File

@ -5,8 +5,9 @@
Expr primImport(EvalState & state, Expr arg)
{
char * path;
if (!ATmatch(arg, "Path(<str>)", &path))
ATMatcher m;
string path;
if (!(atMatch(m, arg) >> "Path" >> path))
throw badTerm("path expected", arg);
return evalFile(state, path);
}
@ -79,15 +80,16 @@ static string processBinding(EvalState & state, Expr e, NixExpr & ne)
{
e = evalExpr(state, e);
char * s;
ATMatcher m;
string s;
ATermList es;
if (ATmatch(e, "Str(<str>)", &s)) return s;
if (ATmatch(e, "Uri(<str>)", &s)) return s;
if (ATmatch(e, "Bool(True)")) return "1";
if (ATmatch(e, "Bool(False)")) return "";
if (atMatch(m, e) >> "Str" >> s) return s;
if (atMatch(m, e) >> "Uri" >> s) return s;
if (atMatch(m, e) >> "Bool" >> "True") return "1";
if (atMatch(m, e) >> "Bool" >> "False") return "";
if (ATmatch(e, "Attrs([<list>])", &es)) {
if (atMatch(m, e) >> "Attrs" >> es) {
Expr a = queryAttr(e, "type");
if (a && evalString(state, a) == "derivation") {
a = queryAttr(e, "drvPath");
@ -98,12 +100,12 @@ static string processBinding(EvalState & state, Expr e, NixExpr & ne)
}
}
if (ATmatch(e, "Path(<str>)", &s)) {
if (atMatch(m, e) >> "Path" >> s) {
Path drvPath = copyAtom(state, s);
return addInput(state, drvPath, ne);
}
if (ATmatch(e, "List([<list>])", &es)) {
if (atMatch(m, e) >> "List" >> es) {
string s;
bool first = true;
while (!ATisEmpty(es)) {
@ -115,7 +117,7 @@ static string processBinding(EvalState & state, Expr e, NixExpr & ne)
return s;
}
if (ATmatch(e, "Null")) return "";
if (atMatch(m, e) >> "Null") return "";
throw badTerm("invalid derivation binding", e);
}
@ -148,14 +150,17 @@ Expr primDerivation(EvalState & state, Expr args)
/* The `args' attribute is special: it supplies the
command-line arguments to the builder. */
if (key == "args") {
throw Error("args not implemented");
#if 0
ATermList args;
if (!ATmatch(value, "[<list>]", &args))
if (!(ATmatch(value, "[<list>]", &args))
throw badTerm("list expected", value);
while (!ATisEmpty(args)) {
Expr arg = evalExpr(state, ATgetFirst(args));
ne.derivation.args.push_back(processBinding(state, arg, ne));
args = ATgetNext(args);
}
#endif
}
/* All other attributes are passed to the builder through the
@ -220,11 +225,12 @@ Expr primBaseNameOf(EvalState & state, Expr arg)
Expr primToString(EvalState & state, Expr arg)
{
arg = evalExpr(state, arg);
char * s;
if (ATmatch(arg, "Str(<str>)", &s) ||
ATmatch(arg, "Path(<str>)", &s) ||
ATmatch(arg, "Uri(<str>)", &s))
return ATmake("Str(<str>)", s);
ATMatcher m;
string s;
if (atMatch(m, arg) >> "Str" >> s ||
atMatch(m, arg) >> "Path" >> s ||
atMatch(m, arg) >> "Uri" >> s)
return ATmake("Str(<str>)", s.c_str());
else throw badTerm("cannot coerce to string", arg);
}
@ -238,5 +244,6 @@ Expr primNull(EvalState & state)
Expr primIsNull(EvalState & state, Expr arg)
{
arg = evalExpr(state, arg);
return makeBool(ATmatch(arg, "Null"));
ATMatcher m;
return makeBool(atMatch(m, arg) >> "Null");
}

2
src/fix/fix.cc
View File

@ -384,7 +384,7 @@ static Expr evalExpr2(EvalState & state, Expr e)
static Expr evalExpr(EvalState & state, Expr e)
{
startNest(nest, lvlVomit,
format("evaluating expression: %1%") % printTerm(e));
format("evaluating expression: %1%") % e);
/* Consult the memo table to quickly get the normal form of
previously evaluated expressions. */

9
src/libnix/Makefile.am
View File

@ -2,8 +2,15 @@ noinst_LIBRARIES = libnix.a
libnix_a_SOURCES = util.cc hash.cc archive.cc md5.c \
store.cc expr.cc normalise.cc exec.cc \
globals.cc db.cc references.cc pathlocks.cc
globals.cc db.cc references.cc pathlocks.cc aterm.cc
AM_CXXFLAGS = -DSYSTEM=\"@host@\" -Wall -I.. -I../../externals/inst/include
EXTRA_DIST = *.hh *.h test-builder-*.sh
check_PROGRAMS = test-aterm
test_aterm_SOURCES = test-aterm.cc
test_aterm_LDADD = libnix.a $(LDADD) ../boost/format/libformat.a \
-L../../externals/inst/lib -ldb_cxx -lATerm

93
src/libnix/aterm.cc Normal file
View File

@ -0,0 +1,93 @@
#include "aterm.hh"
string atPrint(ATerm t)
{
if (!t) throw Error("attempt to print null aterm");
char * s = ATwriteToString(t);
if (!s) throw Error("cannot print term");
return s;
}
ostream & operator << (ostream & stream, ATerm e)
{
return stream << atPrint(e);
}
ATMatcher & atMatch(ATMatcher & pos, ATerm t)
{
pos.t = t;
pos.pos = ATMatcher::funPos;
return pos;
}
static inline bool failed(const ATMatcher & pos)
{
return pos.pos == ATMatcher::failPos;
}
static inline ATMatcher & fail(ATMatcher & pos)
{
pos.pos = ATMatcher::failPos;
return pos;
}
ATMatcher & operator >> (ATMatcher & pos, ATerm & out)
{
out = 0;
if (failed(pos)) return pos;
if (pos.pos == ATMatcher::funPos ||
ATgetType(pos.t) != AT_APPL ||
pos.pos >= (int) ATgetArity(ATgetAFun(pos.t)))
return fail(pos);
out = ATgetArgument(pos.t, pos.pos);
pos.pos++;
return pos;
}
ATMatcher & operator >> (ATMatcher & pos, string & out)
{
out = "";
if (pos.pos == ATMatcher::funPos) {
if (ATgetType(pos.t) != AT_APPL) return fail(pos);
out = ATgetName(ATgetAFun(pos.t));
pos.pos = 0;
} else {
ATerm t;
pos = pos >> t;
if (failed(pos)) return pos;
if (ATgetType(t) != AT_APPL ||
ATgetArity(ATgetAFun(t)) != 0)
return fail(pos);
out = ATgetName(ATgetAFun(t));
}
return pos;
}
ATMatcher & operator >> (ATMatcher & pos, const string & s)
{
string s2;
pos = pos >> s2;
if (failed(pos)) return pos;
if (s != s2) return fail(pos);
return pos;
}
ATMatcher & operator >> (ATMatcher & pos, ATermList & out)
{
out = 0;
ATerm t;
pos = pos >> t;
if (failed(pos)) return pos;
if (ATgetType(t) != AT_LIST) return fail(pos);
out = (ATermList) t;
return pos;
}

55
src/libnix/aterm.hh Normal file
View File

@ -0,0 +1,55 @@
#ifndef __ATERM_H
#define __ATERM_H
extern "C" {
#include <aterm2.h>
}
#include "util.hh"
/* Print an ATerm. */
string atPrint(ATerm t);
/* Write an ATerm to an output stream. */
ostream & operator << (ostream & stream, ATerm e);
/* Type-safe matching. */
struct ATMatcher
{
ATerm t;
int pos;
const static int failPos = -2;
const static int funPos = -1;
ATMatcher() : t(0), pos(failPos)
{
}
operator bool() const
{
return pos != failPos;
}
};
/* Initiate matching of a term. */
ATMatcher & atMatch(ATMatcher & pos, ATerm t);
/* Get the next argument of an application. */
ATMatcher & operator >> (ATMatcher & pos, ATerm & out);
/* Get the name of the function symbol of an applicatin, or the next
argument of an application as a string. */
ATMatcher & operator >> (ATMatcher & pos, string & out);
/* Like the previous, but check that the string is equal to the given
string. */
ATMatcher & operator >> (ATMatcher & pos, const string & s);
/* Get the next argument of an application, and verify that it is a
list. */
ATMatcher & operator >> (ATMatcher & pos, ATermList & out);
#endif /* !__ATERM_H */

50
src/libnix/expr.cc
View File

@ -3,14 +3,6 @@
#include "store.hh"
string printTerm(ATerm t)
{
char * s = ATwriteToString(t);
if (!s) throw Error("cannot print term");
return s;
}
Error badTerm(const format & f, ATerm t)
{
char * s = ATwriteToString(t);
@ -26,7 +18,7 @@ Error badTerm(const format & f, ATerm t)
Hash hashTerm(ATerm t)
{
return hashString(printTerm(t));
return hashString(atPrint(t));
}
@ -50,10 +42,11 @@ Path writeTerm(ATerm t, const string & suffix)
static void parsePaths(ATermList paths, PathSet & out)
{
ATMatcher m;
while (!ATisEmpty(paths)) {
char * s;
string s;
ATerm t = ATgetFirst(paths);
if (!ATmatch(t, "<str>", &s))
if (!(atMatch(m, t) >> s))
throw badTerm("not a path", t);
out.insert(s);
paths = ATgetNext(paths);
@ -91,21 +84,22 @@ static void checkClosure(const Closure & closure)
static bool parseClosure(ATerm t, Closure & closure)
{
ATermList roots, elems;
if (!ATmatch(t, "Closure([<list>], [<list>])", &roots, &elems))
ATMatcher m;
if (!(atMatch(m, t) >> "Closure" >> roots >> elems))
return false;
parsePaths(roots, closure.roots);
while (!ATisEmpty(elems)) {
char * s1;
string path;
ATermList refs;
ATerm t = ATgetFirst(elems);
if (!ATmatch(t, "(<str>, [<list>])", &s1, &refs))
if (!(atMatch(m, t) >> "" >> path >> refs))
throw badTerm("not a closure element", t);
ClosureElem elem;
parsePaths(refs, elem.refs);
closure.elems[s1] = elem;
closure.elems[path] = elem;
elems = ATgetNext(elems);
}
@ -116,19 +110,13 @@ static bool parseClosure(ATerm t, Closure & closure)
static bool parseDerivation(ATerm t, Derivation & derivation)
{
ATMatcher m;
ATermList outs, ins, args, bnds;
char * builder;
char * platform;
string builder, platform;
if (!ATmatch(t, "Derive([<list>], [<list>], <str>, <str>, [<list>], [<list>])",
&outs, &ins, &platform, &builder, &args, &bnds))
{
/* !!! compatibility -> remove eventually */
if (!ATmatch(t, "Derive([<list>], [<list>], <str>, <str>, [<list>])",
&outs, &ins, &builder, &platform, &bnds))
return false;
args = ATempty;
}
if (!(atMatch(m, t) >> "Derive" >> outs >> ins >> platform
>> builder >> args >> bnds))
return false;
parsePaths(outs, derivation.outputs);
parsePaths(ins, derivation.inputs);
@ -137,18 +125,18 @@ static bool parseDerivation(ATerm t, Derivation & derivation)
derivation.platform = platform;
while (!ATisEmpty(args)) {
char * s;
string s;
ATerm arg = ATgetFirst(args);
if (!ATmatch(arg, "<str>", &s))
if (!(atMatch(m, arg) >> s))
throw badTerm("string expected", arg);
derivation.args.push_back(s);
args = ATgetNext(args);
}
while (!ATisEmpty(bnds)) {
char * s1, * s2;
string s1, s2;
ATerm bnd = ATgetFirst(bnds);
if (!ATmatch(bnd, "(<str>, <str>)", &s1, &s2))
if (!(atMatch(m, bnd) >> "" >> s1 >> s2))
throw badTerm("tuple of strings expected", bnd);
derivation.env[s1] = s2;
bnds = ATgetNext(bnds);

8
src/libnix/expr.hh
View File

@ -1,10 +1,7 @@
#ifndef __FSTATE_H
#define __FSTATE_H
extern "C" {
#include <aterm2.h>
}
#include "aterm.hh"
#include "store.hh"
@ -43,9 +40,6 @@ struct NixExpr
};
/* Return a canonical textual representation of an expression. */
string printTerm(ATerm t);
/* Throw an exception with an error message containing the given
aterm. */
Error badTerm(const format & f, ATerm t);

2
src/libnix/normalise.cc
View File

@ -239,7 +239,7 @@ Path normaliseNixExpr(const Path & _nePath, PathSet pending)
/* Write the normal form. This does not have to occur in the
transaction below because writing terms is idem-potent. */
ATerm nfTerm = unparseNixExpr(nf);
printMsg(lvlVomit, format("normal form: %1%") % printTerm(nfTerm));
printMsg(lvlVomit, format("normal form: %1%") % atPrint(nfTerm));
Path nfPath = writeTerm(nfTerm, "-s");
/* Register each outpat path, and register the normal form. This

6
src/libnix/references.hh
View File

@ -1,5 +1,5 @@
#ifndef __VALUES_H
#define __VALUES_H
#ifndef __REFERENCES_H
#define __REFERENCES_H
#include "util.hh"
@ -7,4 +7,4 @@
Strings filterReferences(const Path & path, const Strings & refs);
#endif /* !__VALUES_H */
#endif /* !__REFERENCES_H */

66
src/libnix/test-aterm.cc Normal file
View File

@ -0,0 +1,66 @@
#include "aterm.hh"
#include <iostream>
void runTests()
{
verbosity = lvlDebug;
ATMatcher pos;
ATerm t = ATmake("Call(Foo, Bar, \"xyz\")");
debug(format("term: %1%") % t);
string fun, arg3;
ATerm lhs, rhs;
if (!(atMatch(pos, t) >> "Call" >> lhs >> rhs >> arg3))
throw Error("should succeed");
if (arg3 != "xyz") throw Error("bad 1");
if (!(atMatch(pos, t) >> fun >> lhs >> rhs >> arg3))
throw Error("should succeed");
if (fun != "Call") throw Error("bad 2");
if (arg3 != "xyz") throw Error("bad 3");
if (!(atMatch(pos, t) >> fun >> lhs >> rhs >> "xyz"))
throw Error("should succeed");
if (atMatch(pos, t) >> fun >> lhs >> rhs >> "abc")
throw Error("should fail");
if (atMatch(pos, t) >> "Call" >> lhs >> rhs >> "abc")
throw Error("should fail");
t = ATmake("X([A, B, C], \"abc\")");
ATerm t1, t2, t3;
if (atMatch(pos, t) >> "X" >> t1 >> t2 >> t3)
throw Error("should fail");
if (!(atMatch(pos, t) >> "X" >> t1 >> t2))
throw Error("should succeed");
ATermList ts;
if (!(atMatch(pos, t) >> "X" >> ts >> t2))
throw Error("should succeed");
if (ATgetLength(ts) != 3)
throw Error("bad");
if (atMatch(pos, t) >> "X" >> t1 >> ts)
throw Error("should fail");
}
int main(int argc, char * * argv)
{
ATerm bottomOfStack;
ATinit(argc, argv, &bottomOfStack);
try {
runTests();
} catch (Error & e) {
printMsg(lvlError, format("error: %1%") % e.msg());
return 1;
}
return 0;
}