Update Inline C syntax and documentation/tests

compile.c

@@ -1354,7 +1354,13 @@ CORD compile_statement(env_t *env, ast_t *ast)
         return compile_statement(env, loop);
     }
     case Extern: return CORD_EMPTY;
-    case InlineCCode: return Match(ast, InlineCCode)->code;
+    case InlineCCode: {
+        auto inline_code = Match(ast, InlineCCode);
+        if (inline_code->type)
+            return CORD_all("({ ", inline_code->code, "; })");
+        else
+            return inline_code->code;
+    }
     case Use: {
         auto use = Match(ast, Use);
         if (use->what == USE_LOCAL) {
@@ -3232,7 +3238,7 @@ CORD compile(env_t *env, ast_t *ast)
         if (t->tag == VoidType)
             return CORD_all("{\n", Match(ast, InlineCCode)->code, "\n}");
         else
-            return Match(ast, InlineCCode)->code;
+            return CORD_all("({ ", Match(ast, InlineCCode)->code, "; })");
     }
     case Use: code_err(ast, "Compiling 'use' as expression!");
     case Defer: code_err(ast, "Compiling 'defer' as expression!");

docs/c-interoperability.md

@@ -0,0 +1,37 @@
+# C Interoperability
+
+Tomo is intended to be used as a complete, standalone programming language, but
+it's also meant to be easy to integrate with existing C libraries. In order to
+make this possible, there are a few tools available.
+
+## Using C Libraries 
+
+In order to link against a compiled shared library, you can use `use libfoo.so`
+to cause Tomo to add `-l:libfoo.so` to the linker flags when compiling your
+final executable. You can also use `use <foo.h>` or `use "foo.h"` to cause Tomo
+to insert a corresponding `#include` when compiling your code.
+
+## Inline C Code
+
+As a final escape hatch, you can use `inline C` to add code that will be put,
+verbatim in the transpiled C code generated by Tomo. There are two forms: one
+that creates an expression value and one that creates a block that is executed
+without evaluating to anything:
+
+```tomo
+# Inline C block:
+inline C {
+    printf("This is just a block that is executed without a return value\n");
+}
+
+# Inline C expression (you must specify a type)
+val := inline C : Int32 {
+    int x = 1; x + 1
+}
+```
+
+Inline C expressions must specify a type and they can be [compound statement
+expressions](https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html). In
+other words, if an inline C expression has a type, it will be enclosed
+with `({ ...; })` so that you can put semicolon-terminated statements before
+the final expression in their own scope if you want.

examples/coroutine.tm

@@ -29,16 +29,12 @@ _shared_stack := !@Memory
 
 struct Coroutine(co:@Memory):
     func is_finished(co:Coroutine; inline)->Bool:
-        return inline C (
-            ((aco_t*)$co.$co)->is_finished
-        ):Bool
+        return inline C:Bool {((aco_t*)$co.$co)->is_finished}
 
     func resume(co:Coroutine)->Bool:
         if co:is_finished():
             return no
-        inline C {
-            aco_resume($co.$co);
-        }
+        inline C { aco_resume($co.$co); }
         return yes
 
 func _init():
@@ -46,13 +42,9 @@ func _init():
         aco_set_allocator(GC_malloc, NULL);
         aco_thread_init(aco_exit_fn);
     }
-    _main_co = inline C(
-        aco_create(NULL, NULL, 0, NULL, NULL)
-    ):@Memory
+    _main_co = inline C:@Memory { aco_create(NULL, NULL, 0, NULL, NULL) }
 
-    _shared_stack = inline C(
-        aco_shared_stack_new(0);
-    ):@Memory
+    _shared_stack = inline C:@Memory { aco_shared_stack_new(0) }
 
 func new(co:func())->Coroutine:
     if not _main_co:
@@ -60,9 +52,9 @@ func new(co:func())->Coroutine:
 
     main_co := _main_co
     shared_stack := _shared_stack
-    aco_ptr := inline C (
+    aco_ptr := inline C:@Memory {
         aco_create($main_co, $shared_stack, 0, (void*)$co.fn, $co.userdata)
-    ):@Memory
+    }
     return Coroutine(aco_ptr)
             
 func yield(; inline):

examples/game/player.tm

@@ -13,12 +13,12 @@ struct Player(pos,prev_pos:Vec2):
     SIZE := Vec2(30, 30)
 
     func update(p:&Player):
-        target_x := inline C (
+        target_x := inline C:Num {
             (Num_t)((IsKeyDown(KEY_A) ? -1 : 0) + (IsKeyDown(KEY_D) ? 1 : 0))
-        ) : Num
-        target_y := inline C (
+        }
+        target_y := inline C:Num {
             (Num_t)((IsKeyDown(KEY_W) ? -1 : 0) + (IsKeyDown(KEY_S) ? 1 : 0))
-        ) : Num
+        }
         target_vel := Vec2(target_x, target_y):norm() * WALK_SPEED
 
         vel := (p.pos - p.prev_pos)/World.DT

examples/http.tm

@@ -12,9 +12,9 @@ _curl := !@Memory
 func _send(method:_Method, url:Text, data:Text?, headers=[:Text])->HTTPResponse:
     chunks := @[:Text]
     save_chunk := func(chunk:CString, size:Int64, n:Int64):
-        chunks:insert(inline C (
+        chunks:insert(inline C:Text {
             Text$format("%.*s", $size*$n, $chunk)
-        ) : Text)
+        })
         return n*size
 
     inline C {

examples/log.tm

@@ -6,15 +6,13 @@ timestamp_format := CString("%F %T")
 logfiles := {:Path}
 
 func _timestamp()->Text:
-    c_str := inline C (
-        ({
+    c_str := inline C:CString {
         char *str = GC_MALLOC_ATOMIC(20);
         time_t t; time(&t);
         struct tm *tm_info = localtime(&t);
         strftime(str, 20, "%F %T", tm_info);
-        str;
-        })
-    ) : CString
+        str
+    }
     return c_str:as_text()
 
 func info(text:Text, newline=yes):

parse.c

@@ -366,22 +366,6 @@ size_t match_word(const char **out, const char *word) {
     return strlen(word);
 }
 
-bool match_group(const char **out, char open) {
-    static char mirror_delim[256] = {['(']=')', ['{']='}', ['<']='>', ['[']=']'};
-    const char *pos = *out;
-    if (*pos != open) return 0;
-    char close = mirror_delim[(int)open] ? mirror_delim[(int)open] : open;
-    int depth = 1;
-    for (++pos; *pos && depth > 0; ++pos) {
-        if (*pos == close) --depth;
-        else if (*pos == open) ++depth;
-    }
-    if (depth == 0) {
-        *out = pos;
-        return true;
-    } else return false;
-}
-
 const char *get_word(const char **inout) {
     const char *word = *inout;
     spaces(&word);
@@ -2258,31 +2242,30 @@ PARSER(parse_extern) {
 PARSER(parse_inline_c) {
     const char *start = pos;
     if (!match_word(&pos, "inline")) return NULL;
+
     spaces(&pos);
     if (!match_word(&pos, "C")) return NULL;
-    spaces(&pos);
-    char open = *pos;
-    if (!match(&pos, "(") && !match(&pos, "{"))
-        parser_err(ctx, start, pos, "I expected a '(' or '{' here");
 
-    int64_t indent = get_indent(ctx, pos);
-    whitespace(&pos);
-    // Block:
-    CORD c_code = CORD_EMPTY;
-    while (get_indent(ctx, pos) > indent) {
-        size_t line_len = strcspn(pos, "\r\n");
-        c_code = CORD_all(c_code, GC_strndup(pos, line_len), "\n");
-        pos += line_len;
-        if (whitespace(&pos) == WHITESPACE_NONE) break;
-    }
-    expect_closing(ctx, &pos, open == '(' ? ")" : "}", "I wasn't able to parse the rest of this inline C");
     spaces(&pos);
     type_ast_t *type = NULL;
-    if (open == '(') {
-        if (!match(&pos, ":"))
-            parser_err(ctx, start, pos, "This inline C needs to have a type after it");
-        type = expect(ctx, start, &pos, parse_type, "I couldn't parse the type for this extern");
+    if (match(&pos, ":"))
+        type = expect(ctx, start, &pos, parse_type, "I couldn't parse the type for this inline C code");
+
+    spaces(&pos);
+    if (!match(&pos, "{"))
+        parser_err(ctx, start, pos, "I expected a '{' here");
+
+    int depth = 1;
+    const char *c_code_start = pos;
+    for (; *pos && depth > 0; ++pos) {
+        if (*pos == '}') --depth;
+        else if (*pos == '{') ++depth;
     }
+
+    if (depth != 0)
+        parser_err(ctx, start, start+1, "I couldn't find the closing '}' for this inline C code");
+
+    CORD c_code = GC_strndup(c_code_start, (size_t)((pos-1) - c_code_start));
     return NewAST(ctx->file, start, pos, InlineCCode, .code=c_code, .type_ast=type);
 }
 

test/inline_c.tm

@@ -0,0 +1,8 @@
+
+func main():
+    >> inline C:Int32 { int x = 1 + 2; x }
+    = 3[32]
+
+    >> inline C {
+        say(Text("Inline C code works!"), true);
+    }