New syntax

README.md

@@ -7,21 +7,28 @@
 
 Try it in the [online playground](https://solcore-rs-preview.solcore-rs-team.workers.dev/).
 
-## Compatibility target
+## Language and compatibility targets
 
-The current compatibility target is the Haskell reference implementation at
+The canonical source-language target is [`syntax.md`](syntax.md). It
+intentionally replaces legacy Haskell Solcore spellings with the new Core
+surface, so source-syntax compatibility with the Haskell implementation is not
+a language goal. The compiler, standard library, examples, and fixtures use the
+new `.sol` surface.
+
+For semantics already supported by Core, the comparison baseline remains the
+Haskell reference implementation at
 [`argotorg/solcore@2f372bde`](https://github.com/argotorg/solcore/tree/2f372bde2801612814015a22319d0bc51486cbf0).
-The standard library and the complete 499-source reference frontend corpus are
-vendored from that exact revision. See
+The standard library and the complete 499-source frontend corpus are semantic
+ports of that exact revision to the canonical syntax. See
 [`SEMANTIC_DIFFERENCES.md`](SEMANTIC_DIFFERENCES.md) for intentional Rust
 extensions, shared upstream limitations, and phase-sensitive differences, and
 the [corpus README](crates/parser/tests/fixtures/corpus/README.md) for the
 reproducible reference verdict configuration.
 
-Compatibility does not imply production readiness or byte-for-byte compiler
-output. Rust deliberately keeps structured diagnostics and several safety
-checks that are stricter than the reference target, while shared upstream
-limitations remain explicitly unsupported.
+Semantic compatibility does not imply source-syntax compatibility, production
+readiness, or byte-for-byte compiler output. Rust deliberately keeps structured
+diagnostics and several safety checks that are stricter than the reference
+target, while shared upstream limitations remain explicitly unsupported.
 
 ## Build and test
 

benchmarks/README.md

@@ -10,7 +10,7 @@ The fixed cases cover distinct compiler workloads:
 
 | Case | Fixture | Purpose |
 | --- | --- | --- |
-| `std-free` | `SingleFun.solc` | Small frontend run without reachable std/runtime |
+| `std-free` | `SingleFun.sol` | Small frontend run without reachable std/runtime |
 | `dispatch-small` | `tests/e2e/022add` | Small contract with compiler-owned dispatch |
 | `erc20-large` | `tests/e2e/128minierc20` | Larger std- and storage-heavy contract |
 | `multi-file` | `tests/e2e/ltimp` | Main module plus a local import |

benchmarks/tofu/materialize.py

@@ -11,18 +11,18 @@
 REPOSITORY = HERE.parents[1]
 CASES = {
     "std-free": {
-        "main.solc": REPOSITORY
-        / "crates/parser/tests/fixtures/corpus/ok/test/examples/cases/SingleFun.solc",
+        "main.sol": REPOSITORY
+        / "crates/parser/tests/fixtures/corpus/ok/test/examples/cases/SingleFun.sol",
     },
     "dispatch-small": {
-        "main.solc": REPOSITORY / "tests/e2e/022add/main.solc",
+        "main.sol": REPOSITORY / "tests/e2e/022add/main.sol",
     },
     "erc20-large": {
-        "main.solc": REPOSITORY / "tests/e2e/128minierc20/main.solc",
+        "main.sol": REPOSITORY / "tests/e2e/128minierc20/main.sol",
     },
     "multi-file": {
-        "main.solc": REPOSITORY / "tests/e2e/ltimp/main.solc",
-        "ltproxy.solc": REPOSITORY / "tests/e2e/ltimp/ltproxy.solc",
+        "main.sol": REPOSITORY / "tests/e2e/ltimp/main.sol",
+        "ltproxy.sol": REPOSITORY / "tests/e2e/ltimp/ltproxy.sol",
     },
 }
 
@@ -36,7 +36,7 @@ def standard_json(sources):
         },
         "settings": {
             "solcore": {
-                "entrypoint": "main.solc",
+                "entrypoint": "main.sol",
                 "stage": "hull",
             },
             "outputSelection": {"*": {"*": []}},

crates/compiler/src/lib.rs

@@ -415,7 +415,7 @@ mod tests {
     #[test]
     fn frontend_diagnostics_are_lowered() {
         let mut db = TestDb::default();
-        let key = load_main_source(&mut db, "function main() -> word { return true; }\n");
+        let key = load_main_source(&mut db, "function main() returns (word) { return true; }\n");
         let entry = module_id_from_key(&db, &key);
 
         let diagnostics = collect_frontend_diagnostics(&db, entry);
@@ -432,7 +432,7 @@ mod tests {
         let mut db = TestDb::default();
         let key = load_main_source(
             &mut db,
-            "contract Main { public function answer() -> word { return 42; } }\n",
+            "contract Main { function answer() public returns (word) { return 42; } }\n",
         );
         let entry = module_id_from_key(&db, &key);
 
@@ -449,7 +449,7 @@ mod tests {
     #[test]
     fn clean_source_builds_checked_hull() {
         let mut db = TestDb::default();
-        let key = load_main_source(&mut db, "function main() -> word { return 42; }\n");
+        let key = load_main_source(&mut db, "function main() returns (word) { return 42; }\n");
         let entry = module_id_from_key(&db, &key);
         let file = db.module_file(entry).expect("entry source");
 
@@ -465,17 +465,17 @@ mod tests {
         let mut db = TestDb::default();
         let entry_key = load_main_source(
             &mut db,
-            "import a; import b;\nfunction main() -> word { return 0; }\n",
+            "import a; import b;\nfunction main() returns (word) { return 0; }\n",
         );
         insert_main_module(
             &mut db,
             "a",
-            "contract Token { public function main() -> word { return 1; } }\n",
+            "contract Token { function main() public returns (word) { return 1; } }\n",
         );
         insert_main_module(
             &mut db,
             "b",
-            "contract Token { public function main() -> word { return 2; } }\n",
+            "contract Token { function main() public returns (word) { return 2; } }\n",
         );
         set_main_module_paths(&mut db, &["main", "a", "b"]);
         let entry = module_id_from_key(&db, &entry_key);
@@ -512,7 +512,7 @@ mod tests {
             library: LibraryId::Main,
             logical_path: vec![name.to_owned()],
         };
-        let url = Url::parse(&format!("memory:///main/{name}.solc")).expect("module URL");
+        let url = Url::parse(&format!("memory:///main/{name}.sol")).expect("module URL");
         let file = SourceFile::new(db, url, Some(source.to_owned()));
         db.insert_module_file(key, file);
     }
@@ -521,7 +521,7 @@ mod tests {
         let root = PathBuf::from("/main");
         let existing_files = stems
             .iter()
-            .map(|stem| root.join(format!("{stem}.solc")))
+            .map(|stem| root.join(format!("{stem}.sol")))
             .collect::<BTreeSet<_>>();
         let sibling_stems =
             BTreeMap::from([(root, stems.iter().map(|stem| (*stem).to_owned()).collect())]);

crates/driver/src/args.rs

@@ -391,6 +391,12 @@ pub(crate) fn parse_args(args: Vec<OsString>) -> Result<ParsedArgs, String> {
     let Some(input) = input else {
         return Err("missing input file".to_owned());
     };
+    if input.extension() != Some(OsStr::new("sol")) {
+        return Err(format!(
+            "input source file `{}` must use the `.sol` extension",
+            input.display()
+        ));
+    }
     if emit_yul_object.is_some() && emit_yul.is_none() {
         return Err("--emit-yul-object requires --emit-yul".to_owned());
     }
@@ -600,15 +606,15 @@ pub(crate) fn default_diagnostic_width() -> usize {
 }
 
 pub(crate) fn usage_text(program: &str) -> String {
-    format!("usage: {program} [OPTIONS] <input.solc>\ntry `{program} --help` for more information")
+    format!("usage: {program} [OPTIONS] <input.sol>\ntry `{program} --help` for more information")
 }
 
 pub(crate) fn help_text(program: &str) -> String {
     format!(
         "\
 Solcore Rust driver
 
-Usage: {program} [OPTIONS] [<input.solc>]
+Usage: {program} [OPTIONS] [<input.sol>]
 
 Options:
   -f, --file FILE                    Input source file (alternative to positional input)

crates/driver/src/paths.rs

@@ -117,7 +117,7 @@ fn collect_module_fs_snapshot(
     };
     for entry in entries.flatten() {
         let path = entry.path();
-        if path.extension().and_then(|extension| extension.to_str()) == Some("solc") {
+        if path.extension().and_then(|extension| extension.to_str()) == Some("sol") {
             if path.is_file() {
                 existing_files.insert(path.clone());
             }
@@ -180,8 +180,8 @@ mod tests {
 
     #[test]
     fn lexical_normalization_removes_dot_and_parent_components() {
-        let normalized = normalize_lexically(Path::new("alpha/./beta/../gamma/main.solc"));
-        assert_eq!(normalized, PathBuf::from("alpha/gamma/main.solc"));
+        let normalized = normalize_lexically(Path::new("alpha/./beta/../gamma/main.sol"));
+        assert_eq!(normalized, PathBuf::from("alpha/gamma/main.sol"));
     }
 
     #[test]

crates/driver/src/standard_json.rs

@@ -14,7 +14,7 @@ use std::{
 use serde_json::{Map, Value, json};
 use vfs::{Diagnostic, DiagnosticSeverity, Workspace, WorkspaceFileChange};
 
-const DEFAULT_ENTRYPOINT: &str = "main.solc";
+const DEFAULT_ENTRYPOINT: &str = "main.sol";
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 enum Stage {
@@ -154,10 +154,10 @@ fn validate_source_name(name: &str) -> Result<(), String> {
         || name.contains('\\')
         || name.contains(':')
         || !has_only_normal_components
-        || path.extension().and_then(|extension| extension.to_str()) != Some("solc")
+        || path.extension().and_then(|extension| extension.to_str()) != Some("sol")
     {
         return Err(format!(
-            "source name `{name}` must be a relative, traversal-free `.solc` path"
+            "source name `{name}` must be a relative, traversal-free `.sol` path"
         ));
     }
     Ok(())
@@ -295,7 +295,7 @@ mod tests {
 
     #[test]
     fn rejects_source_paths_that_escape_the_virtual_workspace() {
-        for source_name in ["../main.solc", "/main.solc", "dir\\main.solc", "main.sol"] {
+        for source_name in ["../main.sol", "/main.sol", "dir\\main.sol", "main.solc"] {
             assert!(validate_source_name(source_name).is_err(), "{source_name}");
         }
     }
@@ -304,11 +304,11 @@ mod tests {
     fn defaults_to_main_entrypoint_and_hull_stage() {
         let request = parse_request(json!({
             "language": "Solcore",
-            "sources": {"main.solc": {"content": "function main() -> word { return 0; }"}},
+            "sources": {"main.sol": {"content": "function main() returns (word) { return 0; }"}},
         }))
         .expect("valid request");
 
-        assert_eq!(request.entrypoint, "main.solc");
+        assert_eq!(request.entrypoint, "main.sol");
         assert_eq!(request.stage, Stage::Hull);
     }
 }

crates/driver/tests/standard_json_cli.rs

@@ -53,9 +53,9 @@ fn standard_json_compiles_checked_hull_without_polluting_stdout() {
     let output = run_standard_json(json!({
         "language": "Solcore",
         "sources": {
-            "main.solc": {"content": "function id(x: word) -> word { return x; }\n"}
+            "main.sol": {"content": "function id(x: word) returns (word) { return x; }\n"}
         },
-        "settings": {"solcore": {"entrypoint": "main.solc", "stage": "hull"}},
+        "settings": {"solcore": {"entrypoint": "main.sol", "stage": "hull"}},
     }));
     let response = response(&output);
 
@@ -68,10 +68,10 @@ fn standard_json_loads_multiple_virtual_source_files() {
     let output = run_standard_json(json!({
         "language": "Solcore",
         "sources": {
-            "main.solc": {"content": "import helper.{id};\nfunction main() -> word { return id(0); }\n"},
-            "helper.solc": {"content": "export { id };\nfunction id(x: word) -> word { return x; }\n"},
+            "main.sol": {"content": "import {id} from helper;\nfunction main() returns (word) { return id(0); }\n"},
+            "helper.sol": {"content": "export { id };\nfunction id(x: word) returns (word) { return x; }\n"},
         },
-        "settings": {"solcore": {"entrypoint": "main.solc", "stage": "frontend"}},
+        "settings": {"solcore": {"entrypoint": "main.sol", "stage": "frontend"}},
     }));
     let response = response(&output);
 
@@ -82,7 +82,7 @@ fn standard_json_loads_multiple_virtual_source_files() {
 fn standard_json_reports_request_errors_in_json() {
     let output = run_standard_json(json!({
         "language": "Solcore",
-        "sources": {"../escape.solc": {"content": "function main() -> word { return 0; }"}},
+        "sources": {"../escape.sol": {"content": "function main() returns (word) { return 0; }"}},
     }));
     let response = response(&output);