Add remove_unused_variables_and_functions()

Blake-Madden · Blake-Madden · commit 3476100e4738 · 2025-06-19T08:37:35.000-04:00
Minor version bump #24
diff --git a/tests/tetests.cpp b/tests/tetests.cpp
@@ -2425,6 +2425,101 @@ TEST_CASE("Is variable used", "[functions]")
     CHECK_FALSE(p.is_variable_used(("zz")));
     CHECK_FALSE(p.is_variable_used(("TRESS_L")));
     }
+
+TEST_CASE("Remove unused variables", "[variables]")
+    {
+    te_parser p;
+    // nothing in here yet
+    p.remove_unused_variables_and_functions();
+
+    p.set_variables_and_functions({
+        {"STRESS_L", static_cast<te_type>(10.1) },
+        {"P_LEVEL", static_cast<te_type>(.5) },
+        {"z", static_cast<te_type>(.75) } });
+    CHECK(p.get_variables_and_functions().size() == 3);
+
+    p.compile(("z + P_LEVEL"));
+    CHECK(p.is_variable_used(("Z")));
+    CHECK_FALSE(p.is_variable_used(("STRESS_L")));
+    CHECK(p.is_variable_used(("P_LEVEL")));
+    CHECK(p.success());
+    CHECK(p.get_variables_and_functions().size() == 3);
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().size() == 2);
+
+    p.compile(("P_LEVEL"));
+    CHECK(p.success());
+    CHECK_FALSE(p.is_variable_used(("Z")));
+    CHECK_FALSE(p.is_variable_used(("STRESS_L")));
+    CHECK(p.is_variable_used(("P_LEVEL")));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().size() == 1);
+
+    p.compile(("5 + 2"));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().empty());
+
+    // remove all at once
+    p.set_variables_and_functions({
+        {"STRESS_L", static_cast<te_type>(10.1) },
+        {"P_LEVEL", static_cast<te_type>(.5) },
+        {"z", static_cast<te_type>(.75) } });
+    p.compile(("5 + 2"));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().empty());
+
+    // shouldn't do anything
+    p.remove_unused_variables_and_functions();
+    }
+
+TEST_CASE("Remove unused functions", "[functions]")
+    {
+    te_parser p;
+    // nothing in here yet
+    p.remove_unused_variables_and_functions();
+
+    p.set_variables_and_functions({
+        {"STRESS_L", return5 },
+        {"P_LEVEL", __mult },
+        {"z", AddEm } });
+    CHECK(p.get_variables_and_functions().size() == 3);
+
+    p.compile(("z(2,5) + P_LEVEL(2,30,4,5)"));
+    CHECK(p.is_function_used(("Z")));
+    CHECK_FALSE(p.is_function_used(("STRESS_L")));
+    CHECK(p.is_function_used(("P_LEVEL")));
+    CHECK(p.success());
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().size() == 2);
+
+    p.compile(("P_LEVEL(2,30,4,5)"));
+    CHECK(p.success());
+    CHECK_FALSE(p.is_function_used(("Z")));
+    CHECK_FALSE(p.is_function_used(("STRESS_L")));
+    CHECK(p.is_function_used(("P_LEVEL")));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().size() == 1);
+
+    p.compile(("5 + 2"));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().empty());
+
+    // remove all at once
+    p.set_variables_and_functions({
+        {"STRESS_L", return5 },
+        {"P_LEVEL", __mult },
+        {"z", AddEm } });
+    p.compile(("5 + 2"));
+    p.remove_unused_variables_and_functions();
+    CHECK(p.get_variables_and_functions().empty());
+
+    // function shouldn't be recognized now
+    p.compile(("P_LEVEL(2,30,4,5)"));
+    CHECK_FALSE(p.success());
+
+    // shouldn't do anything
+    p.remove_unused_variables_and_functions();
+    }
 #endif
 
 TEST_CASE("Custom test", "[functions]")
diff --git a/tinyexpr.h b/tinyexpr.h
@@ -81,8 +81,9 @@
 constexpr int TINYEXPR_CPP_MAJOR_VERSION = 1;
 constexpr int TINYEXPR_CPP_MINOR_VERSION = 0;
 constexpr int TINYEXPR_CPP_PATCH_VERSION = 0;
-constexpr int TINYEXPR_CPP_TWEAK_VERSION = 0;
-constexpr wchar_t TINYEXPR_CPP_COPYRIGHT[] = L"TinyExpr: Copyright (c) 2015-2020 Lewis Van Winkle\nTinyExpr++: Copyright (c) 2020-2025 Blake Madden";
+constexpr int TINYEXPR_CPP_TWEAK_VERSION = 1;
+constexpr wchar_t TINYEXPR_CPP_COPYRIGHT[] = L"TinyExpr: Copyright (c) 2015-2020 Lewis Van Winkle\n"
+                                             "TinyExpr++: Copyright (c) 2020-2025 Blake Madden";
 
 class te_parser;
 
@@ -567,6 +568,24 @@ class te_parser
             }
         }
 
+#ifndef TE_NO_BOOKKEEPING
+    /// @brief Removes any custom variables and functions that weren't used in the last compilation.
+    /// @details This can be useful if the parser is pre-loaded with a large number of
+    ///     variables and functions that needs to be pruned after the first expression is parsed.
+    /// @warning After calling this, any custom variables and functions that weren't found
+    ///     in the previously parsed expression will no longer be available.
+    void remove_unused_variables_and_functions()
+        {
+        for (auto funcIter = m_customFuncsAndVars.cbegin(); funcIter != m_customFuncsAndVars.cend();
+             /* in loop*/)
+            {
+            funcIter = (is_function_used(funcIter->m_name) || is_variable_used(funcIter->m_name)) ?
+                           ++funcIter :
+                           m_customFuncsAndVars.erase(funcIter);
+            }
+        }
+#endif
+
     /** @brief Sets a custom function to resolve unknown symbols in an expression.
         @param usr The function to use to resolve unknown symbols.
         @param keepResolvedVariables @c true to cache any resolved variables into the parser.
