Added subtract-assignment operator

include/ast.h

@@ -14,6 +14,7 @@
 #define AST_NODE_DECLARATION         6
 #define AST_NODE_ARRAY_DECLARATION   2000
 #define AST_NODE_ASSIGNMENT          7
+#define AST_NODE_SUB_ASSIGNMENT      5005
 #define AST_NODE_ARRAY_ASSIGNMENT    2001
 #define AST_NODE_ARRAY_ACCESS        2002
 #define AST_NODE_ARITHMETIC_EXP      8
@@ -59,6 +60,7 @@
 #define AST_OPR_LGL_OR     43 // or
 
 #define AST_OPR_ASSIGNMENT 44 // :=
+#define AST_OPR_SUB_ASSIGNMENT  5006 // -=
 
 #define AST_CONST_INT  45 // INT CONSTANT
 #define AST_CONST_BOOL 46 // BOOL CONSTANT
@@ -100,6 +102,7 @@ struct ast_node_compound_statement;
 struct ast_node_declaration;
 struct ast_node_array_declaration;
 struct ast_node_assignment;
+struct ast_node_sub_assignment;
 struct ast_node_array_assignment;
 struct ast_node_array_access;
 struct ast_node_expression;
@@ -125,6 +128,7 @@ typedef struct ast_node_compound_statement ast_node_compound_statement;
 typedef struct ast_node_declaration ast_node_declaration;
 typedef struct ast_node_array_declaration ast_node_array_declaration;
 typedef struct ast_node_assignment ast_node_assignment;
+typedef struct ast_node_sub_assignment ast_node_sub_assignment;
 typedef struct ast_node_array_assignment ast_node_array_assignment;
 typedef struct ast_node_array_access ast_node_array_access;
 typedef struct ast_node_expression ast_node_expression;
@@ -160,6 +164,7 @@ struct ast_node
         ast_node_declaration *declaration;
         ast_node_array_declaration *array_declaration;
         ast_node_assignment *assignment;
+        ast_node_sub_assignment *sub_assignment;
         ast_node_array_assignment *array_assignment;
         ast_node_conditional_if *if_else;
         ast_node_loop_for *loop_for;
@@ -205,6 +210,14 @@ struct ast_node_array_declaration
     ast_node_expression *expression;
 };
 
+ struct ast_node_sub_assignment
+{
+    int node_type;
+
+    sym_ptr symbol_entry;
+    ast_node_expression *expression;
+};
+
 struct ast_node_array_assignment
 {
     int node_type;
@@ -363,6 +376,7 @@ ast_node_compound_statement *add_compound_statement_node(ast_node_compound_state
 ast_node_declaration *create_declaration_node(sym_ptr symbol, ast_node_expression *exp);
 ast_node_array_declaration *create_array_declaration_node(sym_ptr symbol, ast_node_expression *size, char *initial_string);
 ast_node_assignment *create_assignment_node(sym_ptr symbol, ast_node_expression *exp);
+ast_node_sub_assignment *create_sub_assignment_node(sym_ptr symbol, ast_node_expression *exp);
 ast_node_array_assignment *create_array_assignment_node(sym_ptr symbol, ast_node_expression *index, ast_node_expression *exp);
 ast_node_array_access *create_array_access_node(sym_ptr symbol, ast_node_expression *index);
 ast_node_expression *create_expression_node(int node_type, int opt, int value, ast_node *left, ast_node *right);

include/code_printer.h

@@ -32,6 +32,7 @@
 #define _OPR_LGL_OR  " | " 
 
 #define _OPR_ASSIGNMENT " = " 
+#define _OPR_SUB_ASSIGNMENT " -= " 
 
 #define _DT_INT_ "int"
 #define _DT_VOID_ "void"
@@ -54,6 +55,7 @@ void ast_compound_statement_printer(ast_node_compound_statement *cmpd_stmt, FILE
 void ast_declaration_printer(ast_node_declaration *decl, FILE* handle);
 void ast_array_declaration_printer(ast_node_array_declaration *decl, FILE* handle);
 void ast_assignment_printer(ast_node_assignment *assg, FILE* handle);
+void ast_sub_assignment_printer(ast_node_sub_assignment *sub_assg, FILE* handle);
 void ast_array_assignment_printer(ast_node_array_assignment *assign, FILE *handle);
 void ast_array_access_printer(ast_node_array_access *access, FILE* handle);
 void ast_expression_printer(ast_node_expression *node, FILE* handle);

src/ast.c

@@ -40,6 +40,10 @@ ast_node_statements *create_statement_node(int node_type, void *child)
             stmt->child_nodes.assignment = child;
             break;
 
+        case AST_NODE_SUB_ASSIGNMENT:
+            stmt->child_nodes.sub_assignment = child;
+            break;
+
         case AST_NODE_ARRAY_ASSIGNMENT:
             stmt->child_nodes.array_assignment = child;
             break;
@@ -144,6 +148,17 @@ ast_node_assignment *create_assignment_node(sym_ptr symbol, ast_node_expression
     return assgn;
 }
 
+ast_node_sub_assignment *create_sub_assignment_node(sym_ptr symbol, ast_node_expression *exp)
+{
+    ast_node_sub_assignment *sub_assgn = (ast_node_sub_assignment*)malloc(sizeof(ast_node_sub_assignment));
+
+    sub_assgn->node_type = AST_NODE_ASSIGNMENT;
+    sub_assgn->expression = exp;
+    sub_assgn->symbol_entry = symbol;
+
+    return sub_assgn;
+}
+
 ast_node_array_assignment *create_array_assignment_node(sym_ptr symbol, ast_node_expression *index, ast_node_expression *exp)
 {
     ast_node_array_assignment *assign = (ast_node_array_assignment*)malloc(sizeof(ast_node_array_assignment));

src/code_printer.c

@@ -29,6 +29,10 @@ void ast_compound_statement_printer(ast_node_compound_statement *cmpd_stmt, FILE
                 ast_assignment_printer(((ast_node_statements*)temp)->child_nodes.assignment, handle);
                 break;
 
+            case AST_NODE_SUB_ASSIGNMENT:
+                ast_sub_assignment_printer(((ast_node_statements*)temp)->child_nodes.sub_assignment, handle);
+                break;
+
             case AST_NODE_ARRAY_ASSIGNMENT:
                 ast_array_assignment_printer(((ast_node_statements*)temp)->child_nodes.array_assignment, handle);
                 break;
@@ -174,6 +178,17 @@ void ast_assignment_printer(ast_node_assignment *assg, FILE* handle)
 
 }
 
+void ast_sub_assignment_printer(ast_node_sub_assignment *sub_assg, FILE* handle)
+{
+    if (sub_assg != NULL && handle != NULL)
+    {
+        fprintf(handle, "\t%s -= ", sub_assg->symbol_entry->identifier);
+        ast_expression_printer(sub_assg->expression, handle);
+        fprintf(handle, "%s", ";\n");
+    }
+
+}
+
 void ast_array_assignment_printer(ast_node_array_assignment *assign, FILE* handle)
 {
     if (assign != NULL && handle != NULL)
@@ -696,7 +711,11 @@ int code_printer(ast_node* ast, int pru_id, int test)
             case AST_NODE_ASSIGNMENT:
                 ast_assignment_printer(((ast_node_statements*)temp)->child_nodes.assignment, handle);
                 break;
-
+
+            case AST_NODE_SUB_ASSIGNMENT:
+                ast_sub_assignment_printer(((ast_node_statements*)temp)->child_nodes.sub_assignment, handle);
+                break;
+
             case AST_NODE_ARRAY_ASSIGNMENT:
                 ast_array_assignment_printer(((ast_node_statements*)temp)->child_nodes.array_assignment, handle);
                 break;

src/lexer.l

@@ -35,6 +35,7 @@ bitwise_operators    ("~"|"&"|"|"|">>"|"<<")
 logical_operators    ("not"|"and"|"or")
 function             ("return"|"void"|"def")
 assignment_operator  ([:][=])
+sub_assignment_operator  ([-][=])
 io                   ("digital_read"|"digital_write"|"delay"|"pwm"|"start_counter"|"stop_counter"|"read_counter"|"init_message_channel"|"receive_message"|"send_message"|"send_int"|"send_char"|"send_bool"|"send_ints"|"send_chars"|"send_bools")
 print                ("print"|"println")
 identifier           ([a-zA-Z_][a-zA-Z0-9_]*)
@@ -323,6 +324,10 @@ comma                ([,])
   return OPR_ASSIGNMENT;  
 }
 
+{sub_assignment_operator}   {
+  return OPR_SUB_ASSIGNMENT;  
+}
+
 {io}                    {
   if (!strcmp(yytext, "digital_write"))
   {

src/parser.y

@@ -33,6 +33,7 @@ ast_node *ast = NULL;
     struct ast_node_declaration *declaration;
     struct ast_node_array_declaration *array_declaration;
     struct ast_node_assignment *assignment;
+    struct ast_node_sub_assignment *sub_assignment;
     struct ast_node_array_assignment *array_assignment;
     struct ast_node_array_access *array_access;
     struct ast_node_expression *expression;
@@ -75,6 +76,7 @@ ast_node *ast = NULL;
 %right OPR_BW_NOT OPR_LGL_NOT
 
 %token OPR_ASSIGNMENT
+%token OPR_SUB_ASSIGNMENT
 
 %token SEMICOLON COLON COMMA
 
@@ -106,6 +108,7 @@ ast_node *ast = NULL;
 %type <declaration> declaration declaration_assignment
 %type <array_declaration> array_declaration array_declaration_assignment
 %type <assignment> assignment
+%type <sub_assignment> sub_assignment
 %type <expression> arithmetic_expression boolean_expression relational_expression logical_expression return_statement function_call_datatypes
 %type <range_expression> range_expression
 %type <array_assignment> array_assignment
@@ -183,6 +186,9 @@ statement: compound_statement {
          | assignment {
              $$ = create_statement_node(AST_NODE_ASSIGNMENT, (void*)$1);
          }
+         | sub_assignment {
+             $$ = create_statement_node(AST_NODE_SUB_ASSIGNMENT, (void*)$1);
+         }
          | array_assignment {
              $$ = create_statement_node(AST_NODE_ARRAY_ASSIGNMENT, (void*)$1);
          }
@@ -442,6 +448,74 @@ assignment: INT_IDENTIFIER OPR_ASSIGNMENT arithmetic_expression SEMICOLON {
             }
             ;
 
+sub_assignment: INT_IDENTIFIER OPR_SUB_ASSIGNMENT arithmetic_expression SEMICOLON {
+               if ($1 == NULL)
+               {
+                   yyerror("variable already defined");
+               }
+
+               if ($1->is_function == 1)
+               {
+                   yyerror("identifier is a function, cannot assign value");
+               }
+
+               if ($1->is_constant == 1)
+               {
+                   yyerror("identifer is a pin number constant, cannot assign value");
+               }
+
+               $1->data_type = DT_INTEGER;
+               $1->value = $1->value - $3->value;
+               $$ = create_sub_assignment_node($1, $3);
+
+               printf("%s := %d\n", $1->identifier, $1->value);
+            }
+            | BOOL_IDENTIFIER OPR_SUB_ASSIGNMENT boolean_expression SEMICOLON {
+                if ($1 == NULL)
+                {
+                    yyerror("variable already defined");
+                }
+
+                if ($1->is_function == 1)
+                {
+                    yyerror("identifier is a function, cannot assign value");
+                }
+
+                if ($1->is_constant == 1)
+                {
+                    yyerror("identifer is a pin number constant, cannot assign value");
+                }
+
+                $1->data_type = DT_BOOLEAN;  
+                $1->value = $1->value - $3->value;
+                $$ = create_sub_assignment_node($1, $3);
+
+               printf("%s := %d\n", $1->identifier, $1->value);
+            }
+            | CHAR_IDENTIFIER OPR_SUB_ASSIGNMENT arithmetic_expression SEMICOLON {
+                if ($1 == NULL)
+                {
+                    yyerror("variable already defined");
+                }
+
+                if ($1->is_function == 1)
+                {
+                    yyerror("identifier is a function, cannot assign value");
+                }
+
+                if ($1->is_constant == 1)
+                {
+                    yyerror("identifier is a pin number constant, cannot assign value");
+                }
+
+                $1->data_type = DT_CHAR_;
+                $1->value = $1->value - $3->value;
+                $$ = create_sub_assignment_node($1, $3);
+
+                printf("%s := %c\n", $1->identifier, $1->value);
+            }
+            ;
+
 array_assignment: INT_ARR_IDENTIFIER LSQUARE arithmetic_expression RSQUARE OPR_ASSIGNMENT arithmetic_expression SEMICOLON {
                     if ($1 == NULL)
                     {

tests/run_anywhere/subassign.sim

@@ -0,0 +1,4 @@
+int a := 5;
+int b := 10;
+b-=a;
+print(a);

tests/run_anywhere/subassign.sim.output

@@ -0,0 +1 @@
+5