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* Implement `...' and default function arguments.

This commit is contained in:
Eelco Dolstra 2010-03-25 12:45:23 +00:00
parent 8a10360c91
commit ef8bd919fc
1 changed files with 31 additions and 7 deletions
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38
src/libexpr/eval-test.cc
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@ -215,20 +215,40 @@ static void eval(Env * env, Expr e, Value & v)
eval(env, arg, *vArg);
if (vArg->type != tAttrs) throw TypeError("expected attribute set");
/* 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 */
Bindings::iterator j = vArg->attrs->find(aterm2String(name));
if (j == vArg->attrs->end())
throw TypeError(format("the argument named `%1%' required by the function is missing")
% aterm2String(name));
Value & v = env2->bindings[aterm2String(name)];
v.type = tCopy;
v.val = &j->second;
}
if (j == vArg->attrs->end()) {
if (!matchDefaultValue(def2, def)) def = 0;
if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
% aterm2String(name));
v.type = tThunk;
v.thunk.env = env2;
v.thunk.expr = def;
} else {
attrsUsed++;
v.type = tCopy;
v.val = &j->second;
}
}
/* Check that each actual argument is listed as a formal
argument (unless the attribute match specifies a
`...'). TODO: show the names of the
expected/unexpected arguments. */
if (ellipsis == eFalse && attrsUsed != vArg->attrs->size())
throw TypeError("function called with unexpected argument");
}
else abort();
@ -266,6 +286,10 @@ void run(Strings args)
doTest("({x, y}: x) { x = 1; y = 2; }");
doTest("({x, y}@args: args.x) { x = 1; y = 2; }");
doTest("(args@{x, y}: args.x) { x = 1; y = 2; }");
doTest("({x ? 1}: x) { }");
doTest("({x ? 1, y ? x}: y) { x = 2; }");
doTest("({x, y, ...}: x) { x = 1; y = 2; z = 3; }");
doTest("({x, y, ...}@args: args.z) { x = 1; y = 2; z = 3; }");
//Expr e = parseExprFromString(state, "let x = \"a\"; in x + \"b\"", "/");
//Expr e = parseExprFromString(state, "(x: x + \"b\") \"a\"", "/");