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| -rw-r--r-- | README.md | 28 |
1 files changed, 19 insertions, 9 deletions
@@ -20,6 +20,8 @@ nimpb_build is modeled somewhat after [prost-build](https://github.com/danburker # Usage +## As a binary + Using the tool is simple: $ nimpb_build -I. --out=. my.proto @@ -35,14 +37,22 @@ file and create a task for generating code: task proto, "Process .proto files": exec "nimpb_build -I. --out=. my.proto" -# How it works +## As a library + +It's also possible to use nimpb_build as a library: + +```nim +import nimpb_build -nimpb_build includes functionality to invoke the protoc compiler. It also -includes a built-in protoc plugin, that protoc will use to generate the Nim -code. +let protos = @["my.proto"] +let incdirs = @["."] +let outdir = "." + +compileProtos(protos, incdirs, outdir) +``` + +# How it works -First, nimpb_build will execute protoc with correct arguments. It will also -pass itself as a plugin using the --plugin argument to protoc. nimpb_build -will set the NIMPB_BUILD_PLUGIN=1 environment variable when executing protoc, -so that when protoc executes nimpb_build, the new nimpb_build instance knows -to work in protoc plugin mode. +nimpb_build invokes the protoc compiler with `--descriptor_set_out` parameter, +which makes protoc output a `FileDescriptorSet` (defined [here](src/nimpb_buildpkg/protobuf/include/google/protobuf/descriptor.proto)) into a file. nimpb_build then reads and parses the file, +and generates Nim code from the parsed definitions. |