diff options
| -rw-r--r-- | src/libexpr/eval-test.cc | 130 |
1 files changed, 66 insertions, 64 deletions
diff --git a/src/libexpr/eval-test.cc b/src/libexpr/eval-test.cc index ee95fc1e780c..68a7380e5da9 100644 --- a/src/libexpr/eval-test.cc +++ b/src/libexpr/eval-test.cc @@ -9,15 +9,15 @@ using namespace nix; -typedef struct Env_ * Env; -typedef struct Value_ * Value; +struct Env; +struct Value; typedef std::map<string, Value> Bindings; -struct Env_ +struct Env { - Env up; + Env * up; Bindings bindings; }; @@ -30,7 +30,7 @@ typedef enum { } ValueType; -struct Value_ +struct Value { ValueType type; union @@ -38,11 +38,11 @@ struct Value_ int integer; Bindings * attrs; struct { - Env env; + Env * env; Expr expr; } thunk; struct { - Env env; + Env * env; Pattern pat; Expr body; } lambda; @@ -50,7 +50,7 @@ struct Value_ }; -std::ostream & operator << (std::ostream & str, Value_ & v) +std::ostream & operator << (std::ostream & str, Value & v) { switch (v.type) { case tInt: @@ -58,9 +58,8 @@ std::ostream & operator << (std::ostream & str, Value_ & v) break; case tAttrs: str << "{ "; - foreach (Bindings::iterator, i, *v.attrs) { - str << i->first << " = " << *i->second << "; "; - } + foreach (Bindings::iterator, i, *v.attrs) + str << i->first << " = " << i->second << "; "; str << "}"; break; case tThunk: @@ -73,21 +72,21 @@ std::ostream & operator << (std::ostream & str, Value_ & v) } -void eval(Env env, Expr e, Value v); +void eval(Env * env, Expr e, Value & v); -void forceValue(Value v) +void forceValue(Value & v) { - if (v->type != tThunk) return; - eval(v->thunk.env, v->thunk.expr, v); + if (v.type != tThunk) return; + eval(v.thunk.env, v.thunk.expr, v); } -Value lookupVar(Env env, const string & name) +Value * lookupVar(Env * env, const string & name) { for ( ; env; env = env->up) { - Value v = env->bindings[name]; - if (v) return v; + Bindings::iterator i = env->bindings.find(name); + if (i != env->bindings.end()) return &i->second; } throw Error("undefined variable"); } @@ -95,63 +94,65 @@ Value lookupVar(Env env, const string & name) unsigned long nrValues = 0; -Value allocValue() +unsigned long nrEnvs = 0; + +Env * allocEnv() { - nrValues++; - return new Value_; + nrEnvs++; + return new Env; } -void eval(Env env, Expr e, Value v) +void eval(Env * env, Expr e, Value & v) { printMsg(lvlError, format("eval: %1%") % e); ATerm name; if (matchVar(e, name)) { - Value v2 = lookupVar(env, aterm2String(name)); - forceValue(v2); - *v = *v2; + Value * v2 = lookupVar(env, aterm2String(name)); + forceValue(*v2); + v = *v2; return; } int n; if (matchInt(e, n)) { - v->type = tInt; - v->integer = n; + v.type = tInt; + v.integer = n; return; } ATermList es; if (matchAttrs(e, es)) { - v->type = tAttrs; - v->attrs = new Bindings; + v.type = tAttrs; + v.attrs = new Bindings; ATerm e2, pos; for (ATermIterator i(es); i; ++i) { if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */ - Value v2 = allocValue(); - v2->type = tThunk; - v2->thunk.env = env; - v2->thunk.expr = e2; - (*v->attrs)[aterm2String(name)] = v2; + Value & v2 = (*v.attrs)[aterm2String(name)]; + nrValues++; + v2.type = tThunk; + v2.thunk.env = env; + v2.thunk.expr = e2; } return; } ATermList rbnds, nrbnds; if (matchRec(e, rbnds, nrbnds)) { - Env env2 = new Env_; + Env * env2 = allocEnv(); env2->up = env; - v->type = tAttrs; - v->attrs = &env2->bindings; + v.type = tAttrs; + v.attrs = &env2->bindings; ATerm name, e2, pos; for (ATermIterator i(rbnds); i; ++i) { if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */ - Value v2 = allocValue(); - v2->type = tThunk; - v2->thunk.env = env2; - v2->thunk.expr = e2; - env2->bindings[aterm2String(name)] = v2; + Value & v2 = env2->bindings[aterm2String(name)]; + nrValues++; + v2.type = tThunk; + v2.thunk.env = env2; + v2.thunk.expr = e2; } return; @@ -160,39 +161,39 @@ void eval(Env env, Expr e, Value v) Expr e2; if (matchSelect(e, e2, name)) { eval(env, e2, v); - if (v->type != tAttrs) throw TypeError("expected attribute set"); - Value v2 = (*v->attrs)[aterm2String(name)]; - if (!v2) throw TypeError("attribute not found"); - forceValue(v2); - *v = *v2; + if (v.type != tAttrs) throw TypeError("expected attribute set"); + Bindings::iterator i = v.attrs->find(aterm2String(name)); + if (i == v.attrs->end()) throw TypeError("attribute not found"); + forceValue(i->second); + v = i->second; return; } Pattern pat; Expr body; Pos pos; if (matchFunction(e, pat, body, pos)) { - v->type = tLambda; - v->lambda.env = env; - v->lambda.pat = pat; - v->lambda.body = body; + v.type = tLambda; + v.lambda.env = env; + v.lambda.pat = pat; + v.lambda.body = body; return; } Expr fun, arg; if (matchCall(e, fun, arg)) { eval(env, fun, v); - if (v->type != tLambda) throw TypeError("expected function"); - if (!matchVarPat(v->lambda.pat, name)) throw Error("not implemented"); + if (v.type != tLambda) throw TypeError("expected function"); + if (!matchVarPat(v.lambda.pat, name)) throw Error("not implemented"); - Value arg_ = allocValue(); - arg_->type = tThunk; - arg_->thunk.env = env; - arg_->thunk.expr = arg; - - Env env2 = new Env_; + Env * env2 = allocEnv(); env2->up = env; - env2->bindings[aterm2String(name)] = arg_; + + Value & arg_ = env2->bindings[aterm2String(name)]; + nrValues++; + arg_.type = tThunk; + arg_.thunk.env = env; + arg_.thunk.expr = arg; - eval(env2, v->lambda.body, v); + eval(env2, v.lambda.body, v); return; } @@ -205,15 +206,15 @@ void doTest(string s) EvalState state; Expr e = parseExprFromString(state, s, "/"); printMsg(lvlError, format("%1%") % e); - Value_ v; - eval(0, e, &v); + Value v; + eval(0, e, v); printMsg(lvlError, format("result: %1%") % v); } void run(Strings args) { - printMsg(lvlError, format("size of value: %1% bytes") % sizeof(Value_)); + printMsg(lvlError, format("size of value: %1% bytes") % sizeof(Value)); doTest("123"); doTest("{ x = 1; y = 2; }"); @@ -228,6 +229,7 @@ void run(Strings args) //Expr e = parseExprFromString(state, "\"a\" + \"b\"", "/"); printMsg(lvlError, format("alloced %1% values") % nrValues); + printMsg(lvlError, format("alloced %1% environments") % nrEnvs); } |