Merge pull request fortran-lang#94 from certik/workflow

Document workflow based on the discussion in #5

Author: certik

WORKFLOW.md

@@ -1,5 +1,57 @@
 # Workflow for the Fortran stdlib contributors
 
-This document will describe the workflow we'll follow when developing the Fortran stdlib.
-It's largely to be discussed and decided.
-For now, take a look at the [issues](https://github.com/fortran-lang/stdlib).
+This document describes our current workflow.
+
+We welcome everyone and anyone to participate and propose additions to stdlib.
+It is okay if you do not have experience for specification or implementation,
+but have an idea for stdlib. If the idea is popular among the community, more
+experienced contributors will help it through all 5 steps.
+
+
+1. **Idea**: You have an idea or a proposal. Open an
+   [issue](https://github.com/fortran-lang/stdlib/issues) to discuss it. This
+   is on the level of "is there interest in having image reader/writer
+   functions in stdlib?" The goal of this step is to find out if the community
+   is interested in having this functionality as part of stdlib.
+
+2. **API**: When there seems to be significant interest in the proposal (vast
+   majority of participants think it is a good idea), move on to discuss the
+   specific API. It's OK to propose the API off the bat if you already have an
+   idea for it. This step is exploratory and its goal is to find out what the
+   API should *look* and *feel* like.
+
+3. **Specification**: Discuss the API and iterate. When there is vast majority
+   approval for the API, move on to implement it and submit a PR. Small PRs are
+   always better than large.  It is OK to implement only a few functions of a
+   new module, and continue work on the others in a later PR. All new
+   functionality goes into an "experimental" namespace
+   (`stdlib_experimental_*.f90`).  As part of the PR, when submitting a new
+   public facing API, please provide the initial draft of the specification
+   document as well as the the initial reference implementation of this
+   specification.  The specification is a document that describes the API and
+   the functionality, so that anyone can use it to create an implementation
+   from scratch without looking at `stdlib`. The `stdlib` library then provides
+   the reference implementation.
+
+4. **Implementation** in experimental: When opening a PR, request reviews from
+   one or more people that are most relevant to it. These are likely to be
+   people involved in prior steps of the workflow. Other contributors (not
+   explicitly invited) are encouraged to provide reviews and suggestions as
+   well. Iterate until all (or most) participants are on the same page.
+   We can merge when there is vast majority approval of the PR.
+
+5. **Release**: Moving from experimental to release. The experimental
+   "namespace" contains new functionality together with its specification. In
+   order to move from experimental to release, the specification document must
+   be approved by the wide community and the standards committee (informally).
+   If that happens, it has now been blessed for broad use and we can move the
+   code into the main section of `stdlib`, and the particular specification
+   document becomes part of the Fortran Standard Library.
+
+
+Note: the general term "vast majority" above means at least 80%, but ultimately
+it is left to our best judgement to ensure that the community agrees that each
+PR and proposal was approved by "vast majority".
+
+You are welcome to propose changes to this workflow by opening an
+[issue](https://github.com/fortran-lang/stdlib/issues).