Fix for #141

7 files changed, 72 insertions, 13 deletions

diff --git a/src/codegen/codegen_stmt.c b/src/codegen/codegen_stmt.c
index 70fb297..2f9a2ba 100644
--- a/src/codegen/codegen_stmt.c
+++ b/src/codegen/codegen_stmt.c
@@ -884,8 +884,7 @@ void codegen_node_single(ParserContext *ctx, ASTNode *node, FILE *out)
             }
             else
             {
-                fprintf(out, "    ZC_AUTO %s = _tmp_%d.%s;\n", node->destruct.names[0], id,
-                        check);
+                fprintf(out, "    ZC_AUTO %s = _tmp_%d.%s;\n", node->destruct.names[0], id, check);
             }
         }
         else
@@ -903,8 +902,8 @@ void codegen_node_single(ParserContext *ctx, ASTNode *node, FILE *out)
                     }
                     else
                     {
-                        fprintf(out, "    ZC_AUTO %s = _tmp_%d.%s;\n", node->destruct.names[i],
-                                id, field);
+                        fprintf(out, "    ZC_AUTO %s = _tmp_%d.%s;\n", node->destruct.names[i], id,
+                                field);
                     }
                 }
                 else
@@ -916,8 +915,8 @@ void codegen_node_single(ParserContext *ctx, ASTNode *node, FILE *out)
                     }
                     else
                     {
-                        fprintf(out, "    ZC_AUTO %s = _tmp_%d.v%d;\n", node->destruct.names[i],
-                                id, i);
+                        fprintf(out, "    ZC_AUTO %s = _tmp_%d.v%d;\n", node->destruct.names[i], id,
+                                i);
                     }
                 }
             }
diff --git a/src/lexer/token.c b/src/lexer/token.c
index decabbe..6696a5c 100644
--- a/src/lexer/token.c
+++ b/src/lexer/token.c
@@ -149,6 +149,14 @@ Token lexer_next(Lexer *l)
         {
             return (Token){TOK_DEF, s, 3, start_line, start_col};
         }
+        if (len == 5 && strncmp(s, "trait", 5) == 0)
+        {
+            return (Token){TOK_TRAIT, s, 5, start_line, start_col};
+        }
+        if (len == 4 && strncmp(s, "impl", 4) == 0)
+        {
+            return (Token){TOK_IMPL, s, 4, start_line, start_col};
+        }
         if (len == 8 && strncmp(s, "autofree", 8) == 0)
         {
             return (Token){TOK_AUTOFREE, s, 8, start_line, start_col};
diff --git a/src/parser/parser_core.c b/src/parser/parser_core.c
index e9a418e..ba6f2fe 100644
--- a/src/parser/parser_core.c
+++ b/src/parser/parser_core.c
@@ -700,7 +700,7 @@ static ASTNode *generate_derive_impls(ParserContext *ctx, ASTNode *strct, char *
         {
             // Simplistic Debug for now, I know.
             code = xmalloc(1024);
-            sprintf(code, "impl %s { fn to_string(self) -> char* { return \"%s { ... }\"; } }",
+            sprintf(code, "impl %s { fn to_string(self) -> char* { return \"%s {{ ... }}\"; } }",
                     name, name);
         }
         else if (0 == strcmp(trait, "Copy"))
diff --git a/src/parser/parser_expr.c b/src/parser/parser_expr.c
index df2dcf6..332d9c3 100644
--- a/src/parser/parser_expr.c
+++ b/src/parser/parser_expr.c
@@ -935,6 +935,17 @@ static ASTNode *create_fstring_block(ParserContext *ctx, const char *content)
             free(txt);
         }
 
+        // Handle escape {{
+        if (brace[1] == '{')
+        {
+            ASTNode *cat = ast_create(NODE_RAW_STMT);
+            cat->raw_stmt.content = xstrdup("strcat(_b, \"{\");");
+            tail->next = cat;
+            tail = cat;
+            cur = brace + 2;
+            continue;
+        }
+
         char *end_brace = strchr(brace, '}');
         if (!end_brace)
         {
@@ -1100,8 +1111,30 @@ static ASTNode *parse_float_literal(Token t)
 }
 
 // Parse string literal
-static ASTNode *parse_string_literal(Token t)
+static ASTNode *parse_string_literal(ParserContext *ctx, Token t)
 {
+    // Check for implicit interpolation
+    int has_interpolation = 0;
+    for (int i = 1; i < t.len - 1; i++)
+    {
+        if (t.start[i] == '{')
+        {
+            has_interpolation = 1;
+            break;
+        }
+    }
+
+    if (has_interpolation)
+    {
+
+        char *inner = xmalloc(t.len);
+        strncpy(inner, t.start + 1, t.len - 2);
+        inner[t.len - 2] = 0;
+        ASTNode *node = create_fstring_block(ctx, inner);
+        free(inner);
+        return node;
+    }
+
     ASTNode *node = ast_create(NODE_EXPR_LITERAL);
     node->literal.type_kind = LITERAL_STRING;
     node->literal.string_val = xmalloc(t.len);
@@ -1276,7 +1309,7 @@ ASTNode *parse_primary(ParserContext *ctx, Lexer *l)
     }
     else if (t.type == TOK_STRING)
     {
-        node = parse_string_literal(t);
+        node = parse_string_literal(ctx, t);
     }
     else if (t.type == TOK_FSTRING)
     {
diff --git a/src/parser/parser_stmt.c b/src/parser/parser_stmt.c
index ab5b89c..85e9825 100644
--- a/src/parser/parser_stmt.c
+++ b/src/parser/parser_stmt.c
@@ -1877,7 +1877,7 @@ ASTNode *parse_statement(ParserContext *ctx, Lexer *l)
         lexer_next(&lookahead);
         TokenType next_type = lexer_peek(&lookahead).type;
 
-        if (next_type == TOK_SEMICOLON || next_type == TOK_DOTDOT)
+        if (next_type == TOK_SEMICOLON || next_type == TOK_DOTDOT || next_type == TOK_RBRACE)
         {
             Token t = lexer_next(l); // consume string
 
@@ -1894,8 +1894,7 @@ ASTNode *parse_statement(ParserContext *ctx, Lexer *l)
                 inner[t.len - 2] = 0;
             }
 
-            // ; means println (end of line), .. means print (continuation)
-            int is_ln = (next_type == TOK_SEMICOLON);
+            int is_ln = (next_type == TOK_SEMICOLON || next_type == TOK_RBRACE);
             char **used_syms = NULL;
             int used_count = 0;
             char *code =
@@ -1913,6 +1912,7 @@ ASTNode *parse_statement(ParserContext *ctx, Lexer *l)
                     lexer_next(l); // consume optional ;
                 }
             }
+            // If TOK_RBRACE, do not consume it, so parse_block can see it and terminate loop.
 
             ASTNode *n = ast_create(NODE_RAW_STMT);
             // Append semicolon to Statement Expression to make it a valid statement
diff --git a/tests/features/test_implicit_fstring.zc b/tests/features/test_implicit_fstring.zc
new file mode 100644
index 0000000..85a6c86
--- /dev/null
+++ b/tests/features/test_implicit_fstring.zc
@@ -0,0 +1,19 @@
+
+test "implicit_fstring_interpolation" {
+    let result = 123;
+    let s = "{result}";
+    // Should be "123"
+    assert(strcmp(s, "123") == 0, "Implicit f-string failed");
+}
+
+test "implicit_fstring_complex" {
+    let a = 10;
+    let b = 20;
+    let s = "Sum: {a + b}";
+    assert(strcmp(s, "Sum: 30") == 0, "Complex implicit f-string failed");
+}
+
+test "no_interpolation" {
+    let s = "Hello World";
+    assert(strcmp(s, "Hello World") == 0, "Plain string failed");
+}
diff --git a/tests/features/test_traits_suite.zc b/tests/features/test_traits_suite.zc
index 205bdf6..2ff8378 100644
--- a/tests/features/test_traits_suite.zc
+++ b/tests/features/test_traits_suite.zc
@@ -90,7 +90,7 @@ test "test_derive" {
     
     // Debug
     let s = p1.to_string();
-    assert(strcmp(s, "Point { ... }") == 0, "Debug string matches");
+    assert(strcmp(s, "Point {{ ... }}") == 0, "Debug string matches");
     
     // Clone
     let p2 = p1.clone();