finch.toml, threads and atomics, finch fmt, C++ files, struct #defines, a struct variable given for its ptr

- finch.toml: name, entry, paths, include, links, libdirs, cflags, ldflags, and [target.windows] etc.;
  finch run / build / test with no file use its entry
- import thread: spawn, join, mutex, cpus; atomic_add/sub/load/store/swap/cas built in
- finch fmt [--check]: indentation by { }, trailing spaces, empty lines; also as LSP formatting
- link "x.cpp" (or in finch.toml): built with the C++ compiler, which then links (FINCH_CXX)
- #define RAYWHITE (Color){ 245, 245, 245, 255 } imports as a Color
- push(body) where push takes ptr[Body]: the same as push(addr(body))
- --target android (NDK clang from ANDROID_NDK_HOME, -llog)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016GzNP6r8dg6WDxUVZy8wjL

tests/new/auto_addr.fch

@@ -0,0 +1,23 @@
+struct Body {
+    float x
+    float y
+}
+
+fn push(ptr[Body] b, float dx) {
+    b.x += dx
+}
+
+fn Body.moved(float dx) -> Body {
+    return Body(x: self.x + dx, y: self.y)
+}
+
+fn main() {
+    b := Body(x: 1.0, y: 2.0)
+    push(b, 0.5)                // the same as push(addr(b), 0.5)
+    push(addr(b), 0.5)
+    print(b.x)
+    p := addr(b)
+    push(p, 1.0)                // already a ptr: as it is
+    print(b.x)
+    print(b.moved(1.0).x)
+}

tests/new/auto_addr.out

@@ -0,0 +1,3 @@
+2
+3
+4

tests/new/c_unions_macros.fch

@@ -24,4 +24,6 @@ fn main() {
     t.as.f = 0.5
     print(t.as.f)
     print(abs(-2.5), abs(-3), min(EV_KEY, 7))     // Finch's abs, not C's int-only one
+    bg := RAYWHITE                                  // #define RAYWHITE (Color){ 245, 245, 245, 255 }
+    print(bg.r, bg.a, DARK.g, DARK.a, HALF_UP.x, HALF_UP.y)
 }

tests/new/c_unions_macros.out

@@ -5,3 +5,4 @@ true 32
 32 2
 0.5
 2.5 3 7
+245 255 20 0 0.5 -1

tests/new/cunion.h

@@ -22,6 +22,14 @@ typedef struct { int kind; union { int i; float f; } as; } Tagged;
 #define LONG_NAME "a" "b"
 #define NOT_A_CONSTANT do { } while (0)
 
+typedef struct { unsigned char r, g, b, a; } Color;
+typedef struct { float x, y; } Vec2;
+#define CLITERAL(type) (type)
+#define RAYWHITE CLITERAL(Color){ 245, 245, 245, 255 }
+#define DARK (Color){ 20, 20, 20 }
+#define HALF_UP (Vec2){ 0.5f, -1 }
+#define NOT_A_STRUCT_CONST (Color){ 1, 2, (unsigned char)(long)&poll_event, 4 }
+
 static inline int fill_key(Event *e, int key) {
     e->key.type = EV_KEY;
     e->key.key = key;

tests/new/fail/auto_addr_value.fch

@@ -0,0 +1,13 @@
+// expect: argument 'b' must be ptr[Body], but this is Body
+struct Body {
+    float x
+}
+fn push(ptr[Body] b) {
+    b.x += 1.0
+}
+fn make() -> Body {
+    return Body(x: 1.0)
+}
+fn main() {
+    push(make())
+}

tests/new/interpolation.fch

@@ -0,0 +1,21 @@
+// "\(x)" in text
+struct P {
+    int x
+    float y
+}
+
+fn main() {
+    name := "Ada"
+    hp := 7
+    p := P(x: 3, y: 0.25)
+    print("hi \(name), hp \(hp), next \(hp + 1)")
+    print("p = (\(p.x), \(p.y, 2)) \("nested \(name)")")
+    map[str]int m
+    m["k"] = 5
+    print("\(m["k"]) \(str(1.0 / 3.0, 3))")
+    print("no code here: \\(x) and \t tab")
+    long := """
+        speed \(p.y * 4.0)
+        """
+    print(long)
+}

tests/new/interpolation.out

@@ -0,0 +1,5 @@
+hi Ada, hp 7, next 8
+p = (3, 0.25) nested Ada
+5 0.333
+no code here: \(x) and 	 tab
+speed 1

tests/new/threads.fch

@@ -0,0 +1,55 @@
+import thread
+
+struct Shared {
+    []int seen
+}
+
+struct Job {
+    ptr[int] counter
+    int adds
+    ptr[thread.Mutex] lock
+    ptr[Shared] common
+    int id
+}
+
+fn work(ptr arg) {
+    ptr[Job] job = arg
+    for i in 0..job.adds {
+        atomic_add(job.counter, 1)
+    }
+    job.lock.lock()
+    job.common.seen.push(job.id)
+    job.lock.unlock()
+}
+
+fn main() {
+    count := 0
+    m := thread.mutex()
+    defer m.close()
+    both := Shared()
+    []Job jobs
+    for i in 0..4 {
+        jobs.push(Job(counter: addr(count), adds: 100000, lock: addr(m), common: addr(both), id: i))
+    }
+    []thread.Thread ts
+    for i in 0..4 {
+        ts.push(thread.spawn(addr(work), addr(jobs[i])) or {
+            print("can't start")
+            exit(1)
+        })
+    }
+    for i in 0..4 {
+        ts[i].join()
+    }
+    print(atomic_load(addr(count)))
+    print(both.seen.len)
+    print(thread.cpus() > 0)
+
+    u32 flags = 5
+    print(atomic_swap(addr(flags), 9))
+    print(atomic_cas(addr(flags), 9, 1))
+    print(atomic_cas(addr(flags), 9, 2))
+    atomic_store(addr(flags), 7)
+    print(atomic_sub(addr(flags), 2))
+    print(flags)
+}

tests/new/threads.out

@@ -0,0 +1,8 @@
+400000
+4
+true
+5
+true
+false
+7
+5