+ README.md

README.md

@@ -0,0 +1,73 @@
+# python bindings for llvm JIT for EGAD (xo-pyjit)
+
+## Getting Started
+
+### Build + install dependencies
+
+- [github/Rconybea/xo-jit](https://github.com/Rconybea/xo-jit)
+- [github/Rconybea/xo-pyexpression](https://github.com/Rconybea/xo-pyexpression)
+
+### build + isntall
+
+```
+$ cd xo-pyjit
+$ PREFIX=/usr/local         # or preferred install location
+$ cmake -DCMAKE_INSTALL_PREFIX=$PREFIX -S . -B .build
+$ cmake --build .build -j
+$ cmake --install .build
+```
+(also see .github/workflows/main.yml)
+
+## Examples
+
+Assumes `xo-pyjit` installed to `~/local2/lib`,
+i.e. built with `PREFIX=~/local2`.
+```
+PYTHONPATH=~/local2/lib:$PYTHONPATH python
+>>> from xo_pyexpression import *
+>>> from xo_pyjit import *
+>>> x=make_constant(3.14159)
+>>> jit=Jit.make()
+>>> code=jit.codegen(x)
+>>> x.print
+double 3.141600e+00
+```
+
+## Development
+
+### use from build tree
+
+Limited utility: requires that supporting libraries (e.g. `xo_pyexpression`) appear in PYTHONPATH
+```
+$ cd xo-pyjit/.build/src/pyjit
+$ python
+>>> import xo_pyjit
+```
+
+### build for unit test coverage
+```
+$ cd xo-pyexpression
+$ cmake -DCMAKE_BUILD_TYPE=coverage -DENABLE_TESTING=on -S . -B .build-ccov
+$ cmake --build .build-ccov -j
+```
+
+### LSP (language server) support
+
+LSP looks for compile commands in the root of the source tree;
+while Cmake creates them in the root of its build directory.
+
+```
+$ cd xo-pyexpression
+$ ln -s .build/compile_commands.json  # supply compile commands to LSP
+```
+
+### display cmake variables
+
+- `-L` list variables
+- `-A` include 'advanced' variables
+- `-H` include help text
+
+```
+$ cd xo-pyjit/.build
+$ cmake -LAH
+```