Write a compiler from Scrapscript to C (#120)

Emit straight C, no IR. Includes a GC and small runtime.

Has immediate small integers (no bignum), small strings and heap
strings, and immediate empty list.

Author: tekknolagi

.clang-format

@@ -0,0 +1,12 @@
+BasedOnStyle: Google
+AlignEscapedNewlinesLeft: false
+DerivePointerAlignment: false
+PointerAlignment: Left
+IncludeBlocks: Regroup
+IncludeCategories:
+  # C system headers
+  - Regex:           '^<.*\.h?>'
+    Priority:        1
+  # Scrapscript headers
+  - Regex:           '.*'
+    Priority:        2

.clang-tidy

@@ -0,0 +1,23 @@
+Checks: >
+  -*,
+  bugprone-argument-comment,
+  google-readability-casting,
+  google-readability-todo,
+  modernize-use-nullptr,
+  readability-braces-around-statements,
+  readability-else-after-return,
+  readability-identifier-naming,
+  readability-inconsistent-declaration-parameter-name,
+  readability-static-accessed-through-instance,
+FormatStyle: file
+CheckOptions:
+  - { key: readability-identifier-naming.ClassCase, value: CamelCase }
+  - { key: readability-identifier-naming.ClassMemberCase, value: lower_case }
+  - { key: readability-identifier-naming.ClassMemberSuffix, value: '_' }
+  - { key: readability-identifier-naming.GlobalConstantCase, value: CamelCase }
+  - { key: readability-identifier-naming.GlobalConstantPrefix, value: 'k' }
+  - { key: readability-identifier-naming.LocalVariableCase, value: lower_case }
+  - { key: readability-identifier-naming.MethodCase, value: camelBack }
+  - { key: readability-identifier-naming.NamespaceCase, value: lower_case }
+  - { key: readability-identifier-naming.ParameterCase, value: lower_case }
+  - { key: readability-braces-around-statements.ShortStatementLines, value: 1 }

.github/workflows/ci.yml

@@ -42,8 +42,10 @@ jobs:
       run: sudo apt update
     - name: Install Python
       run: sudo apt install --yes ${{matrix.PYTHON}}
-    - name: Run tests
+    - name: Run interpreter tests
       run: ${{matrix.PYTHON}} scrapscript.py test
+    - name: Run compiler tests
+      run: ${{matrix.PYTHON}} compiler_tests.py
   build_docker_image:
     runs-on: ubuntu-latest
     permissions:

README.md

@@ -53,6 +53,30 @@ docker run -i -t ghcr.io/tekknolagi/scrapscript:trunk apply "1 + 2"
 docker run -i -t ghcr.io/tekknolagi/scrapscript:trunk repl
 ```
 
+### The experimental compiler:
+
+#### Normal ELF
+
+```bash
+./compiler.py some.scrap  # produces output.c
+./compiler.py some.scrap --compile  # produces a.out
+```
+
+#### Cosmopolitan
+
+```bash
+CC=~/Downloads/cosmos/bin/cosmocc ./compiler.py some.scrap  --compile # produces a.out
+```
+
+#### Wasm
+
+```bash
+CC=/opt/wasi-sdk/bin/clang \
+CFLAGS=-D_WASI_EMULATED_MMAN \
+LDFLAGS=-lwasi-emulated-mman \
+./compiler.py some.scrap --compile  # produces a.out
+```
+
 ## Running Tests
 
 ```bash