* Primops: baseNameOf, toString.

This commit is contained in:
Eelco Dolstra 2003-11-02 16:31:35 +00:00
parent c8268ca991
commit adf9a45469
4 changed files with 30 additions and 4 deletions

View file

@ -145,6 +145,8 @@ Expr evalExpr2(EvalState & state, Expr e)
string primop(s1); string primop(s1);
if (primop == "import") return primImport(state, e2); if (primop == "import") return primImport(state, e2);
if (primop == "derivation") return primDerivation(state, e2); if (primop == "derivation") return primDerivation(state, e2);
if (primop == "toString") return primToString(state, e2);
if (primop == "baseNameOf") return primBaseNameOf(state, e2);
else throw badTerm("undefined variable/primop", e1); else throw badTerm("undefined variable/primop", e1);
} }

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@ -30,10 +30,6 @@ static Path searchPath(const Paths & searchDirs, const Path & relPath)
#if 0 #if 0
static Expr evalExpr2(EvalState & state, Expr e) static Expr evalExpr2(EvalState & state, Expr e)
{ {
/* Conditional. */
if (ATmatch(e, "If(<term>, <term>, <term>)", &e1, &e2, &e3)) {
}
/* Ad-hoc function for string matching. */ /* Ad-hoc function for string matching. */
if (ATmatch(e, "HasSubstr(<term>, <term>)", &e1, &e2)) { if (ATmatch(e, "HasSubstr(<term>, <term>)", &e1, &e2)) {
e1 = evalExpr(state, e1); e1 = evalExpr(state, e1);

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@ -204,3 +204,22 @@ Expr primDerivation(EvalState & state, Expr args)
return makeAttrs(attrs); return makeAttrs(attrs);
} }
Expr primBaseNameOf(EvalState & state, Expr arg)
{
string s = evalString(state, arg);
return ATmake("Str(<str>)", baseNameOf(s).c_str());
}
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);
else throw badTerm("cannot coerce to string", arg);
}

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@ -19,4 +19,13 @@ Expr primImport(EvalState & state, Expr arg);
Expr primDerivation(EvalState & state, Expr args); Expr primDerivation(EvalState & state, Expr args);
/* Return the base name of the given string, i.e., everything
following the last slash. */
Expr primBaseNameOf(EvalState & state, Expr arg);
/* Convert the argument (which can be a path or a uri) to a string. */
Expr primToString(EvalState & state, Expr arg);
#endif /* !__PRIMOPS_H */ #endif /* !__PRIMOPS_H */