diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/eval.cc | 51 | ||||
| -rw-r--r-- | src/eval.hh | 54 | ||||
| -rw-r--r-- | src/test.cc | 6 |
3 files changed, 49 insertions, 62 deletions
diff --git a/src/eval.cc b/src/eval.cc index e6a3478a1551..ad6f5ae2a2a7 100644 --- a/src/eval.cc +++ b/src/eval.cc @@ -186,30 +186,31 @@ static void checkPlatform(string platform) } +string printExpr(Expr e) +{ + char * s = ATwriteToString(e); + return s; +} + + /* Throw an exception with an error message containing the given aterm. */ static Error badTerm(const string & msg, Expr e) { - char * s = ATwriteToString(e); - return Error(msg + ", in `" + s + "'"); + return Error(msg + ", in `" + printExpr(e) + "'"); } -/* Hash an expression. Hopefully the representation used by - ATwriteToString() won't change, otherwise all hashes will - change. */ -static Hash hashExpr(Expr e) +Hash hashExpr(Expr e) { - char * s = ATwriteToString(e); - debug(s); - return hashString(s); + return hashString(printExpr(e)); } /* Evaluate an expression; the result must be a string. */ static string evalString(Expr e) { - e = evalValue(e).e; + e = evalValue(e); char * s; if (ATmatch(e, "Str(<str>)", &s)) return s; else throw badTerm("string value expected", e); @@ -220,10 +221,10 @@ static string evalString(Expr e) non-expression reference. */ static Hash evalExternal(Expr e) { - EvalResult r = evalValue(e); + e = evalValue(e); char * s; - if (ATmatch(r.e, "External(<str>)", &s)) return r.h; - else throw badTerm("external non-expression value expected", r.e); + if (ATmatch(e, "External(<str>)", &s)) return parseHash(s); + else throw badTerm("external non-expression value expected", e); } @@ -238,7 +239,7 @@ void evalArgs(ATermList args, ATermList & argsNF, Environment & env) throw badTerm("invalid argument", arg); string name = evalString(eName); - eVal = evalValue(eVal).e; + eVal = evalValue(eVal); char * s; if (ATmatch(eVal, "Str(<str>)", &s)) { @@ -256,9 +257,8 @@ void evalArgs(ATermList args, ATermList & argsNF, Environment & env) /* Evaluate an expression. */ -EvalResult evalValue(Expr e) +Expr evalValue(Expr e) { - EvalResult r; char * s; Expr eBuildPlatform, eProg; ATermList args; @@ -267,21 +267,19 @@ EvalResult evalValue(Expr e) if (ATmatch(e, "Str(<str>)", &s) || ATmatch(e, "Bool(True)") || ATmatch(e, "Bool(False)")) - { - r.e = e; - } + return e; /* External expressions. */ /* External non-expressions. */ - else if (ATmatch(e, "External(<str>)", &s)) { - r.e = e; - r.h = parseHash(s); + if (ATmatch(e, "External(<str>)", &s)) { + parseHash(s); /* i.e., throw exception if not valid */ + return e; } /* Execution primitive. */ - else if (ATmatch(e, "Exec(<term>, <term>, [<list>])", + if (ATmatch(e, "Exec(<term>, <term>, [<list>])", &eBuildPlatform, &eProg, &args)) { string buildPlatform = evalString(eBuildPlatform); @@ -312,12 +310,9 @@ EvalResult evalValue(Expr e) (string) sourceHash + "-nf", buildPlatform, prog, env); } - r.e = ATmake("External(<str>)", ((string) targetHash).c_str()); - r.h = targetHash; + return ATmake("External(<str>)", ((string) targetHash).c_str()); } /* Barf. */ - else throw badTerm("invalid expression", e); - - return r; + throw badTerm("invalid expression", e); } diff --git a/src/eval.hh b/src/eval.hh index bddc9f5d9578..1a8edcfdea9e 100644 --- a/src/eval.hh +++ b/src/eval.hh @@ -18,69 +18,63 @@ using namespace std; | Bool(b) -- boolean constant | App(e, e) -- application | Lam(x, e) -- lambda abstraction - | Exec(platform, e, [(s, e)]) + | Exec(platform, e, [Arg(e, e)]) -- primitive; execute e with args e* on platform ; Semantics - Each rules given as eval(e) => (e', h'), i.e., expression e has a - normal form e' with hash code h'. evalE = fst . eval. evalH = snd - . eval. + Each rule given as eval(e) => e', i.e., expression e has a normal + form e'. eval(Hash(h)) => eval(loadExpr(h)) - eval(External(h)) => (External(h), h) - - eval(Str(s)@e) => (e, 0) # idem for Bool + eval(External(h)) => External(h) # idem for Str, Bool eval(App(e1, e2)) => eval(App(e1', e2)) - where e1' = evalE(e1) + where e1' = eval(e1) - eval(App(Lam(var, body), arg)@in) => - eval(subst(var, arg, body))@out - [AND write out to storage, and dbNFs[hash(in)] = hash(out) ???] + eval(App(Lam(var, body), arg)) => + eval(subst(var, arg, body)) - eval(Exec(platform, prog, args)@e) => + eval(Exec(platform, prog, args)) => (External(h), h) where - hIn = hashExpr(e) - - fn = ... form name involving hIn ... - + fn = ... name of the output (random or by hashing expr) ... h = - if exec(evalE(platform) => Str(...) - , getFile(evalH(prog)) + if exec( fn + , eval(platform) => Str(...) + , getFile(eval(prog)) , map(makeArg . eval, args) ) then hashExternal(fn) else undef + ... register ... - makeArg((argn, (External(h), h))) => (argn, getFile(h)) - makeArg((argn, (Str(s), _))) => (argn, s) - makeArg((argn, (Bool(True), _))) => (argn, "1") - makeArg((argn, (Bool(False), _))) => (argn, undef) + makeArg(Arg(Str(nm), (External(h), h))) => (nm, getFile(h)) + makeArg(Arg(Str(nm), (Str(s), _))) => (nm, s) + makeArg(Arg(Str(nm), (Bool(True), _))) => (nm, "1") + makeArg(Arg(Str(nm), (Bool(False), _))) => (nm, undef) getFile :: Hash -> FileName loadExpr :: Hash -> FileName hashExpr :: Expr -> Hash hashExternal :: FileName -> Hash - exec :: Platform -> FileName -> [(String, String)] -> Status + exec :: FileName -> Platform -> FileName -> [(String, String)] -> Status */ typedef ATerm Expr; -struct EvalResult -{ - Expr e; - Hash h; -}; +/* Evaluate an expression. */ +Expr evalValue(Expr e); +/* Return a canonical textual representation of an expression. */ +string printExpr(Expr e); -/* Evaluate an expression. */ -EvalResult evalValue(Expr e); +/* Hash an expression. */ +Hash hashExpr(Expr e); #endif /* !__EVAL_H */ diff --git a/src/test.cc b/src/test.cc index bf7ee191f0b7..56414956202c 100644 --- a/src/test.cc +++ b/src/test.cc @@ -12,10 +12,8 @@ void evalTest(Expr e) { - EvalResult r = evalValue(e); - - char * s = ATwriteToString(r.e); - cout << (string) r.h << ": " << s << endl; + e = evalValue(e); + cout << (string) hashExpr(e) << ": " << printExpr(e) << endl; } |