diff options
Diffstat (limited to 'src/libexpr')
| -rw-r--r-- | src/libexpr/eval.cc | 152 | ||||
| -rw-r--r-- | src/libexpr/expr-to-xml.cc | 30 | ||||
| -rw-r--r-- | src/libexpr/nixexpr-ast.def | 6 | ||||
| -rw-r--r-- | src/libexpr/nixexpr.cc | 67 | ||||
| -rw-r--r-- | src/libexpr/nixexpr.hh | 4 | ||||
| -rw-r--r-- | src/libexpr/parser.y | 33 | ||||
| -rw-r--r-- | src/libexpr/primops.cc | 8 |
7 files changed, 165 insertions, 135 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 15cccc6b7..95a70ac27 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -74,63 +74,87 @@ LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2, } -/* Substitute an argument set into the body of a function. */ -static Expr substArgs(EvalState & state, - Expr body, ATermList formals, Expr arg) +static void patternMatch(EvalState & state, + Pattern pat, Expr arg, ATermMap & subs) { - unsigned int nrFormals = ATgetLength(formals); - ATermMap subs(nrFormals); - - /* Get the actual arguments and put them in the substitution. */ - ATermMap args; - queryAllAttrs(arg, args); - for (ATermMap::const_iterator i = args.begin(); i != args.end(); ++i) - subs.set(i->key, i->value); + ATerm name; + ATermList formals; - /* Get the formal arguments. */ - ATermVector defsUsed; - ATermList recAttrs = ATempty; - for (ATermIterator i(formals); i; ++i) { - Expr name, def; - DefaultValue def2; - if (!matchFormal(*i, name, def2)) abort(); /* can't happen */ - - Expr value = subs[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())); - } - } + if (matchVarPat(pat, name)) + subs.set(name, arg); + + else if (matchAttrsPat(pat, formals)) { + + arg = evalExpr(state, arg); + + unsigned int nrFormals = ATgetLength(formals); - /* 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) { + /* 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) - 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. */ + subs.set(i->key, i->value); + + /* Get the formal arguments. */ + ATermVector defsUsed; + ATermList recAttrs = ATempty; for (ATermIterator i(formals); i; ++i) { - Expr name; ATerm d1; - if (!matchFormal(*i, name, d1)) abort(); - subs.remove(name); + Expr name, def; + DefaultValue def2; + if (!matchFormal(*i, name, def2)) abort(); /* can't happen */ + + Expr value = subs[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())); + } + + } + + /* 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); + } + throw TypeError(format("the function does not expect an argument named `%1%'") + % aterm2String(subs.begin()->key)); } - throw TypeError(format("the function does not expect an argument named `%1%'") - % aterm2String(subs.begin()->key)); + } + else abort(); +} + + +/* Substitute an argument set into the body of a function. */ +static Expr substArgs(EvalState & state, + Expr body, Pattern pat, Expr arg) +{ + ATermMap subs(16); + + patternMatch(state, pat, arg, subs); + return substitute(Substitution(0, &subs), body); } @@ -370,10 +394,12 @@ Path coerceToPath(EvalState & state, Expr e, PathSet & context) Expr autoCallFunction(Expr e, const ATermMap & args) { - ATermList formals; + Pattern pat; ATerm body, pos; - - if (matchFunction(e, formals, body, pos)) { + ATermList formals; + + /* !!! this should be more general */ + if (matchFunction(e, pat, body, pos) && matchAttrsPat(pat, formals)) { ATermMap actualArgs(ATgetLength(formals)); for (ATermIterator i(formals); i; ++i) { @@ -418,8 +444,8 @@ LocalNoInline(Expr evalVar(EvalState & state, ATerm name)) LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg)) { - ATermList formals; - ATerm pos, name; + Pattern pat; + ATerm pos; Expr body; /* Evaluate the left-hand side. */ @@ -445,10 +471,9 @@ LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg)) return makePrimOp(arity, funBlob, args); } - else if (matchFunction(fun, formals, body, pos)) { - arg = evalExpr(state, arg); + else if (matchFunction(fun, pat, body, pos)) { try { - return evalExpr(state, substArgs(state, body, formals, arg)); + return evalExpr(state, substArgs(state, body, pat, arg)); } catch (Error & e) { addErrorPrefix(e, "while evaluating the function at %1%:\n", showPos(pos)); @@ -456,18 +481,6 @@ LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg)) } } - else if (matchFunction1(fun, name, body, pos)) { - try { - ATermMap subs(1); - subs.set(name, arg); - return evalExpr(state, substitute(Substitution(0, &subs), body)); - } catch (Error & e) { - addErrorPrefix(e, "while evaluating the function at %1%:\n", - showPos(pos)); - throw; - } - } - else throwTypeError( "attempt to call something which is neither a function nor a primop (built-in operation) but %1%", showType(fun)); @@ -624,7 +637,6 @@ Expr evalExpr2(EvalState & state, Expr e) sym == symInt || sym == symBool || sym == symFunction || - sym == symFunction1 || sym == symAttrs || sym == symList || sym == symPrimOp) diff --git a/src/libexpr/expr-to-xml.cc b/src/libexpr/expr-to-xml.cc index c47f24e6c..5aa537b20 100644 --- a/src/libexpr/expr-to-xml.cc +++ b/src/libexpr/expr-to-xml.cc @@ -40,6 +40,23 @@ static void showAttrs(const ATermMap & attrs, XMLWriter & doc, } +static void printPatternAsXML(Pattern pat, XMLWriter & doc, PathSet & context) +{ + ATerm name; + ATermList formals; + if (matchVarPat(pat, name)) + doc.writeEmptyElement("varpat", singletonAttrs("name", aterm2String(name))); + else if (matchAttrsPat(pat, formals)) { + 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))); + } + } +} + + static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context, ExprSet & drvsSeen) { @@ -47,8 +64,8 @@ static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context, string s; ATerm s2; int i; - ATermList as, es, formals; - ATerm body, pos; + ATermList as, es; + ATerm pat, body, pos; checkInterrupt(); @@ -109,14 +126,9 @@ static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context, printTermAsXML(*i, doc, context, drvsSeen); } - else if (matchFunction(e, formals, body, pos)) { + else if (matchFunction(e, pat, body, pos)) { XMLOpenElement _(doc, "function"); - - for (ATermIterator i(formals); i; ++i) { - Expr name; ATerm dummy; - if (!matchFormal(*i, name, dummy)) abort(); - XMLOpenElement _(doc, "arg", singletonAttrs("name", aterm2String(name))); - } + printPatternAsXML(pat, doc, context); } else diff --git a/src/libexpr/nixexpr-ast.def b/src/libexpr/nixexpr-ast.def index a57a48613..6b9cf95fa 100644 --- a/src/libexpr/nixexpr-ast.def +++ b/src/libexpr/nixexpr-ast.def @@ -3,8 +3,7 @@ init initNixExprHelpers Pos | string int int | Pos | NoPos | | Pos | -Function | ATermList Expr Pos | Expr | -Function1 | string Expr Pos | Expr | +Function | Pattern Expr Pos | Expr | Assert | Expr Expr Pos | Expr | With | Expr Expr Pos | Expr | If | Expr Expr Expr | Expr | @@ -76,6 +75,9 @@ Inherit | Expr ATermList Pos | ATerm | Scope | | Expr | +VarPat | string | Pattern | +AttrsPat | ATermList | Pattern | + Formal | string DefaultValue | ATerm | DefaultValue | Expr | DefaultValue | diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc index 310f71471..4744cdde3 100644 --- a/src/libexpr/nixexpr.cc +++ b/src/libexpr/nixexpr.cc @@ -110,6 +110,25 @@ Expr makeAttrs(const ATermMap & attrs) } +static void varsBoundByPattern(ATermMap & map, Pattern pat) +{ + ATerm name; + ATermList formals; + /* Use makeRemoved() so that it can be used directly in + substitute(). */ + if (matchVarPat(pat, name)) + map.set(name, makeRemoved()); + else if (matchAttrsPat(pat, formals)) { + for (ATermIterator i(formals); i; ++i) { + ATerm d1; + if (!matchFormal(*i, name, d1)) abort(); + map.set(name, makeRemoved()); + } + } + else abort(); +} + + Expr substitute(const Substitution & subs, Expr e) { checkInterrupt(); @@ -135,27 +154,17 @@ Expr substitute(const Substitution & subs, Expr e) /* In case of a function, filter out all variables bound by this function. */ - ATermList formals; + Pattern pat; ATerm body; - if (matchFunction(e, formals, body, pos)) { - ATermMap map(ATgetLength(formals)); - for (ATermIterator i(formals); i; ++i) { - ATerm d1; - if (!matchFormal(*i, name, d1)) abort(); - map.set(name, makeRemoved()); - } + if (matchFunction(e, pat, body, pos)) { + ATermMap map(16); + varsBoundByPattern(map, pat); Substitution subs2(&subs, &map); return makeFunction( - (ATermList) substitute(subs2, (ATerm) formals), + (Pattern) substitute(subs2, (Expr) pat), substitute(subs2, body), pos); } - if (matchFunction1(e, name, body, pos)) { - ATermMap map(1); - map.set(name, makeRemoved()); - return makeFunction1(name, substitute(Substitution(&subs, &map), body), pos); - } - /* Idem for a mutually recursive attribute set. */ ATermList rbnds, nrbnds; if (matchRec(e, rbnds, nrbnds)) { @@ -213,9 +222,9 @@ static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e) done.insert(e); ATerm name, pos, value; - ATermList formals; ATerm with, body; ATermList rbnds, nrbnds; + Pattern pat; /* Closed terms don't have free variables, so we don't have to check by definition. */ @@ -227,27 +236,11 @@ static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e) % aterm2String(name)); } - else if (matchFunction(e, formals, body, pos)) { - ATermMap defs2(defs); - for (ATermIterator i(formals); i; ++i) { - ATerm d1; - if (!matchFormal(*i, name, d1)) abort(); - defs2.set(name, (ATerm) ATempty); - } - for (ATermIterator i(formals); i; ++i) { - ATerm deflt; - set<Expr> done2; - if (!matchFormal(*i, name, deflt)) abort(); - checkVarDefs2(done2, defs2, deflt); - } - set<Expr> done2; - checkVarDefs2(done2, defs2, body); - } - - else if (matchFunction1(e, name, body, pos)) { + else if (matchFunction(e, pat, body, pos)) { ATermMap defs2(defs); - defs2.set(name, (ATerm) ATempty); + varsBoundByPattern(defs2, pat); set<Expr> done2; + checkVarDefs2(done2, defs2, pat); checkVarDefs2(done2, defs2, body); } @@ -365,13 +358,13 @@ string showType(Expr e) ATermList l1; ATermBlob b1; int i1; + Pattern p1; if (matchStr(e, t1, l1)) return "a string"; if (matchPath(e, t1)) return "a path"; if (matchNull(e)) return "null"; if (matchInt(e, i1)) return "an integer"; if (matchBool(e, t1)) return "a boolean"; - if (matchFunction(e, l1, t1, t2)) return "a function"; - if (matchFunction1(e, t1, t2, t3)) return "a function"; + if (matchFunction(e, p1, t1, t2)) return "a function"; if (matchAttrs(e, l1)) return "an attribute set"; if (matchList(e, l1)) return "a list"; if (matchPrimOp(e, i1, b1, l1)) return "a partially applied built-in function"; diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh index dabbaa323..320d1dc97 100644 --- a/src/libexpr/nixexpr.hh +++ b/src/libexpr/nixexpr.hh @@ -21,11 +21,9 @@ MakeError(TypeError, EvalError) property of the ATerm library allows us to implement caching of normals forms efficiently. */ typedef ATerm Expr; - typedef ATerm DefaultValue; -typedef ATerm ValidValues; - typedef ATerm Pos; +typedef ATerm Pattern; /* A STL vector of ATerms. Should be used with great care since it's diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 9c941bb7d..067a0f8d5 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -237,9 +237,9 @@ expr: expr_function; expr_function : '{' formals '}' ':' expr_function - { $$ = makeFunction($2, $5, CUR_POS); } + { $$ = makeFunction(makeAttrsPat($2), $5, CUR_POS); } | ID ':' expr_function - { $$ = makeFunction1($1, $3, CUR_POS); } + { $$ = makeFunction(makeVarPat($1), $3, CUR_POS); } | ASSERT expr ';' expr_function { $$ = makeAssert($2, $4, CUR_POS); } | WITH expr ';' expr_function @@ -387,22 +387,37 @@ static void checkAttrs(ATermMap & names, ATermList bnds) } -static void checkAttrSets(ATerm e) +static void checkPatternVars(ATerm pos, ATermMap & map, Pattern pat) { + ATerm name; ATermList formals; - ATerm body, pos; - if (matchFunction(e, formals, body, pos)) { - ATermMap names(ATgetLength(formals)); + 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)) { for (ATermIterator i(formals); i; ++i) { - ATerm name; ATerm d1; if (!matchFormal(*i, name, d1)) abort(); - if (names.get(name)) + if (map.get(name)) throw EvalError(format("duplicate formal function argument `%1%' at %2%") % aterm2String(name) % showPos(pos)); - names.set(name, name); + map.set(name, name); } } + else abort(); +} + + +static void checkAttrSets(ATerm e) +{ + ATerm pat, body, pos; + if (matchFunction(e, pat, body, pos)) { + ATermMap map(16); + checkPatternVars(pos, map, pat); + } ATermList bnds; if (matchAttrs(e, bnds)) { diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index c747f46c4..50a641670 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -120,11 +120,9 @@ static Expr prim_isNull(EvalState & state, const ATermVector & args) static Expr prim_isFunction(EvalState & state, const ATermVector & args) { Expr e = evalExpr(state, args[0]); - ATermList formals; - ATerm name, body, pos; - return makeBool( - matchFunction(e, formals, body, pos) || - matchFunction1(e, name, body, pos)); + Pattern pat; + ATerm body, pos; + return makeBool(matchFunction(e, pat, body, pos)); } |