diff options
| -rw-r--r-- | doc/concepts/expressions.md | 5 | ||||
| -rw-r--r-- | src/buildtool/build_engine/expression/evaluator.cpp | 10 | ||||
| -rw-r--r-- | test/buildtool/build_engine/expression/expression.test.cpp | 16 |
3 files changed, 31 insertions, 0 deletions
diff --git a/doc/concepts/expressions.md b/doc/concepts/expressions.md index aead2c31..c5d120e4 100644 --- a/doc/concepts/expressions.md +++ b/doc/concepts/expressions.md @@ -74,6 +74,11 @@ the value `null` is taken as default for `"default"`) and evaluated. The value obtained this way is the result of the evaluation. +##### Quoting: `"'"` + +The value is the value of the key `"$1"` uninterpreted, if present, +and `null` otherwise. + ##### Sequential binding: `"let*"` The key `"bindings"` (default `[]`) has to be (syntactically) a diff --git a/src/buildtool/build_engine/expression/evaluator.cpp b/src/buildtool/build_engine/expression/evaluator.cpp index 2256a040..673b80b3 100644 --- a/src/buildtool/build_engine/expression/evaluator.cpp +++ b/src/buildtool/build_engine/expression/evaluator.cpp @@ -499,6 +499,15 @@ auto VarExpr(SubExprEvaluator&& eval, return result; } +auto QuoteExpr(SubExprEvaluator&& /*eval*/, + ExpressionPtr const& expr, + Configuration const& /*env*/) -> ExpressionPtr { + if (auto const literal = expr->At("$1")) { + return *literal; + } + return Expression::kNone; +} + auto IfExpr(SubExprEvaluator&& eval, ExpressionPtr const& expr, Configuration const& env) -> ExpressionPtr { @@ -1089,6 +1098,7 @@ auto AssertNonEmptyExpr(SubExprEvaluator&& eval, auto const kBuiltInFunctions = FunctionMap::MakePtr({{"var", VarExpr}, + {"'", QuoteExpr}, {"if", IfExpr}, {"cond", CondExpr}, {"case", CaseExpr}, diff --git a/test/buildtool/build_engine/expression/expression.test.cpp b/test/buildtool/build_engine/expression/expression.test.cpp index 8dd0aa92..888e7216 100644 --- a/test/buildtool/build_engine/expression/expression.test.cpp +++ b/test/buildtool/build_engine/expression/expression.test.cpp @@ -389,6 +389,22 @@ TEST_CASE("Expression Evaluation", "[expression]") { // NOLINT CHECK(overwrite == Expression::FromJson(R"(["bar"])"_json)); } + SECTION("quote expression") { + auto expr = Expression::FromJson(R"( + {"type": "'", "$1": {"type": "var", "name": "this is literal"}} + )"_json); + REQUIRE(expr); + + auto result = expr.Evaluate(env, fcts); + CHECK(result == Expression::FromJson(R"( + {"type": "var", "name": "this is literal"})"_json)); + + auto expr_empty = Expression::FromJson(R"({"type": "'"})"_json); + REQUIRE(expr_empty); + auto result_empty = expr_empty.Evaluate(env, fcts); + CHECK(result_empty == Expression::FromJson(R"(null)"_json)); + } + SECTION("if expression") { auto expr = Expression::FromJson(R"( { "type": "if" |