Add statement (including block) scope in/inout parameters, and apply that syntax to for (remove : and =), closes #386

Author: hsutter

regression-tests/mixed-bounds-safety-with-assert-2.cpp2

@@ -3,7 +3,7 @@ main: () -> int = {
     v: std::vector<int> = (1, 2, 3, 4, 5);
     add_42_to_subrange(v, 1, 3);
 
-    for v do :(i) =
+    for v do (i)
         std::cout << i << "\n";
 }
 
@@ -15,7 +15,7 @@ add_42_to_subrange: (inout rng:_, start:int, end:int)
     count := 0;
     for  rng
     next count++
-    do   :(inout i) =
+    do   (inout i)
         if start <= count <= end {
             i += 42;
         }

regression-tests/mixed-bounds-safety-with-assert.cpp2

@@ -11,7 +11,7 @@ print_subrange: (rng:_, start:int, end:int) = {
     count := 0;
     for  rng
     next count++
-    do:  (i:_) =
+    do   (i)
         if start <= count && count <= end {
             std::cout << i << "\n";
         }

regression-tests/mixed-fixed-type-aliases.cpp2

@@ -19,6 +19,6 @@ main: (args) -> int = {
     z: u16 = 42;
     test(z);
 
-    for args do :(arg) =
+    for args do (arg)
         std::cout << arg << "\n";
 }

regression-tests/mixed-function-expression-and-std-for-each.cpp2

@@ -24,7 +24,7 @@ main: () -> int = {
         callback
     );
 
-    for view do :(str:_) = {
+    for view do (str) {
         std::cout << str << "\n";
     }
 }

regression-tests/mixed-function-expression-and-std-ranges-for-each-with-capture.cpp2

@@ -6,7 +6,7 @@
 #include <iostream>
 
 main: () -> int = {
-    vec: std::vector<std::string> 
+    vec: std::vector<std::string>
             = ("hello", "2022");
     view: std::span = vec;
 
@@ -17,6 +17,6 @@ main: () -> int = {
     callback := :(inout x:_) = x += "-ish";
     std::ranges::for_each( view, callback );
 
-    for view do :(str:_) =
+    for view do (str)
         std::cout << str << "\n";
 }

regression-tests/mixed-function-expression-and-std-ranges-for-each.cpp2

@@ -6,7 +6,7 @@
 #include <iostream>
 
 main: () -> int = {
-    vec: std::vector<std::string> 
+    vec: std::vector<std::string>
             = ("hello", "2022");
     view: std::span = vec;
 
@@ -16,6 +16,6 @@ main: () -> int = {
     callback := :(inout x:_) = x += "-ish";
     std::ranges::for_each( view, callback );
 
-    for view do :(str:_) =
+    for view do (str)
         std::cout << str << "\n";
 }

regression-tests/mixed-function-expression-with-pointer-capture.cpp2

@@ -6,7 +6,7 @@
 #include <iostream>
 
 main: () -> int = {
-    vec: std::vector<std::string> 
+    vec: std::vector<std::string>
             = ("hello", "2023");
     view: std::span = vec;
 
@@ -18,6 +18,6 @@ main: () -> int = {
     callback := :(inout x:_) = x += "-ish";
     std::ranges::for_each( view, callback );
 
-    for view do :(str:_) =
+    for view do (str)
         std::cout << str << "\n";
 }

regression-tests/mixed-function-expression-with-repeated-capture.cpp2

@@ -6,7 +6,7 @@
 #include <iostream>
 
 main: () -> int = {
-    vec: std::vector<std::string> 
+    vec: std::vector<std::string>
             = ("hello", "2022");
     view: std::span = vec;
 
@@ -17,6 +17,6 @@ main: () -> int = {
     callback := :(inout x:_) = x += "-ish";
     std::ranges::for_each( view, callback );
 
-    for view do :(str:_) =
+    for view do (str)
         std::cout << str << "\n";
 }

regression-tests/mixed-intro-for-with-counter-include-last.cpp2

@@ -3,7 +3,7 @@ main: () -> int
 = {
     v: std::vector<int> = (1, 2, 3, 4, 5);
     counter := 42;
-    for v  next counter *= 2  do: (i:_) = {
+    for v  next counter *= 2  do (i) {
         std::cout << i << " " << counter << "\n";
     }
 }

regression-tests/pure2-break-continue.cpp2

@@ -161,9 +161,9 @@ for_continue_inner: () =
 {
     vi: std::vector = ( 0, 1, 2 );
     counter := 0;
-    for vi next counter++ do :(i) = {
+    for vi next counter++ do (i) {
         vj: std::vector = ( 0, 1, 2 );
-        inner: for vj do :(j) = {
+        inner: for vj do (j) {
             std::cout << i << j << " ";
             if j == 1 {
                 continue inner;
@@ -179,9 +179,9 @@ for_continue_outer: () =
 {
     vi: std::vector = ( 0, 1, 2 );
     counter := 0;
-    outer: for vi next counter++ do :(i) = {
+    outer: for vi next counter++ do (i) {
         vj: std::vector = ( 0, 1, 2 );
-        for vj do :(j) = {
+        for vj do (j) {
             std::cout << i << j << " ";
             if j == 1 {
                 continue outer;
@@ -197,9 +197,9 @@ for_break_inner: () =
 {
     vi: std::vector = ( 0, 1, 2 );
     counter := 0;
-    for vi next counter++ do :(i) = {
+    for vi next counter++ do (i) {
         vj: std::vector = ( 0, 1, 2 );
-        inner: for vj do :(j) = {
+        inner: for vj do (j) {
             std::cout << i << j << " ";
             if j == 1 {
                 break inner;
@@ -215,9 +215,9 @@ for_break_outer: () =
 {
     vi: std::vector = ( 0, 1, 2 );
     counter := 0;
-    outer: for vi next counter++ do :(i) = {
+    outer: for vi next counter++ do (i) {
         vj: std::vector = ( 0, 1, 2 );
-        for vj do :(j) = {
+        for vj do (j) {
             std::cout << i << j << " ";
             if j == 1 {
                 break outer;

regression-tests/pure2-intro-example-hello-2022.cpp2

@@ -1,21 +1,21 @@
 main: () -> int = {
-    vec: std::vector<std::string> 
+    vec: std::vector<std::string>
             = ("hello", "2022");
     view: std::span = vec;
 
-    for view do :(inout str:_) = {
+    for view do (inout str) {
         len := decorate(str);
         println(str, len);
     }
 }
 
-decorate: (inout thing: _ ) -> int = { 
+decorate: (inout thing: _ ) -> int = {
     thing = "[" + thing + "]";
     return thing.ssize();
 }
 
 println: (x: _, len: _) =
     std::cout
-        << ">> " << x 
-        << " - length " 
+        << ">> " << x
+        << " - length "
         << len << "\n";

regression-tests/pure2-intro-example-three-loops.cpp2

@@ -22,7 +22,7 @@ main: () -> int = {
     } while i* > 1 next i*--;
 
     std::cout << "\n";
-    for words do: (inout word:_) =
+    for words do (inout word)
         decorate_and_print(word);
 
     print( : std::string = "end of program" );

regression-tests/pure2-statement-scope-parameters.cpp2

@@ -0,0 +1,15 @@
+
+main: (args) = {
+    local_int := 42;
+
+    //  'in' (read-only) statement scope variable
+    (i := local_int) for args do (arg) {
+        std::cout << i << "\n";     // prints 42
+    }
+
+    //  'inout' (read-write) statement scope variable
+    (inout i := local_int) {
+        i++;
+    }
+    std::cout << local_int << "\n";     // prints 43
+}

regression-tests/pure2-type-and-namespace-aliases.cpp2

@@ -19,7 +19,7 @@ myfunc: () = {
 
     v2 :== v;
 
-    for v2 do :(s) =
+    for v2 do (s)
         std::cout << "(s)$\n";
 }
 

regression-tests/test-results/clang-12/pure2-statement-scope-parameters.cpp.execution

@@ -0,0 +1,2 @@
+42
+43

regression-tests/test-results/clang-12/pure2-statement-scope-parameters.cpp.output

@@ -0,0 +1,2 @@
+42
+43

regression-tests/test-results/gcc-10/pure2-statement-scope-parameters.cpp.execution

@@ -43,7 +43,7 @@ auto add_42_to_subrange(auto& rng, cpp2::in<int> start, cpp2::in<int> end) -> vo
     auto count {0}; 
     for ( auto&& cpp2_range = rng;  
 
-           auto&  i : cpp2_range )  { do 
+          auto&  i : cpp2_range )  { do 
         if ([_0 = start, _1 = count, _2 = end]{ return cpp2::cmp_less_eq(_0,_1) && cpp2::cmp_less_eq(_1,_2); }()) {
             i += 42;
         } while (false); ++count; }

regression-tests/test-results/gcc-10/pure2-statement-scope-parameters.cpp.output

@@ -0,0 +1,2 @@
+42
+43

regression-tests/test-results/mixed-bounds-safety-with-assert-2.cpp

@@ -0,0 +1 @@
+pure2-statement-scope-parameters.cpp

regression-tests/test-results/msvc-2022/pure2-statement-scope-parameters.cpp.execution

@@ -0,0 +1,47 @@
+
+#define CPP2_USE_MODULES         Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+
+#line 2 "pure2-statement-scope-parameters.cpp2"
+auto main(int const argc_, char const* const* const argv_) -> int;
+    
+
+//=== Cpp2 function definitions =================================================
+
+
+#line 2 "pure2-statement-scope-parameters.cpp2"
+auto main(int const argc_, char const* const* const argv_) -> int{
+    auto args = cpp2::make_args(argc_, argv_); 
+#line 3 "pure2-statement-scope-parameters.cpp2"
+    auto local_int {42}; 
+{
+auto const& i = local_int;
+
+    //  'in' (read-only) statement scope variable
+#line 6 "pure2-statement-scope-parameters.cpp2"
+    for ( auto const& cpp2_range = args;  auto const& arg : cpp2_range ) {
+        std::cout << i << "\n";     // prints 42
+    }
+}
+{
+auto& i = local_int;
+
+    //  'inout' (read-write) statement scope variable
+#line 11 "pure2-statement-scope-parameters.cpp2"
+    {
+        ++i;
+    }
+}
+#line 14 "pure2-statement-scope-parameters.cpp2"
+    std::cout << std::move(local_int) << "\n";// prints 43
+}
+

regression-tests/test-results/msvc-2022/pure2-statement-scope-parameters.cpp.output

@@ -0,0 +1,2 @@
+pure2-statement-scope-parameters.cpp2... ok (all Cpp2, passes safety checks)
+