+ README.md

README.md

@@ -0,0 +1,42 @@
+# callback-set with reentrant invocation
+
+Reentrant:
+1. A callback can modify parent callback-set (for example to remove itself),
+   even while being invoked.
+2. Any such re-entrant operations are deferred until callback invocation completes.
+
+# build + install
+```
+$ cd xo-callback
+$ mkdir build
+$ cd build
+$ INSTALL_PREFIX=/usr/local  # or wherever you prefer, e.g. ~/local
+$ cmake \
+    -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake \
+    -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} \
+    -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} ..
+$ make
+$ make install
+```
+(also see .github/workflows/main.yml)
+
+# build for unit test coverage
+```
+$ cd xo-callback
+$ mkdir build-ccov
+$ cd build-ccov
+$ cmake \
+    -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake \
+    -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} \
+    -DCODE_COVERAGE=ON \
+    -DCMAKE_BUILD_TYPE=Debug ..
+```
+
+# LSP (language server) support
+
+LSP looks for compile commands in the root of the source tree;
+cmake creates them in the root of its build directory.
+```
+$ cd xo-callback
+$ ln -s build/compile_commands.json
+```