Implement string-builder.
authorChris Hanson <org/chris-hanson/cph>
Sun, 19 Feb 2017 21:03:34 +0000 (13:03 -0800)
committerChris Hanson <org/chris-hanson/cph>
Sun, 19 Feb 2017 21:03:34 +0000 (13:03 -0800)
commit418f64fcc7603cb727c0ec7915be55fcf5f896d9
treedd9b4d028acecd1c083139f07d89c7fa9a3ddf9c
parent9bc826be19d82d44da8b8f5ec5e3ba5ed04008e2
Implement string-builder.

This hides most of the details of building strings, and continues to work even
if we add immutable strings.
src/runtime/runtime.pkg
src/runtime/ustring.scm
tests/runtime/test-string.scm