slices

src/ast/expressions.hpp

@@ -100,6 +100,54 @@ struct Subscript : Expr
     }
 };
 
+struct Slice : Node
+{
+    ptr<Expr> lower;
+    ptr<Expr> upper;
+    ptr<Expr> step;
+    Slice(ptr<Expr> l, ptr<Expr> u, ptr<Expr> s) : upper(std::move(u)), lower(std::move(l)), step(std::move(s)) {}
+    std::string dump(int indent = 0) const override
+    {
+        std::ostringstream oss;
+        oss << indent_str(indent) << "Slice";
+        if (lower)
+        {
+            oss << "\n"
+                << indent_str(indent + 1) << "Lower\n";
+            oss << lower->dump(indent + 2);
+        }
+        if (upper)
+        {
+            oss << "\n"
+                << indent_str(indent + 1) << "Upper\n";
+            oss << upper->dump(indent + 2);
+        }
+        if (step)
+        {
+            oss << "\n"
+                << indent_str(indent + 1) << "Step\n";
+            oss << step->dump(indent + 2);
+        }
+        return oss.str();
+    }
+};
+
+struct SliceSubscript : Expr
+{
+    ptr<Expr> value;
+    ptr<Slice> index;
+    SliceSubscript(ptr<Expr> v, ptr<Slice> i)
+        : value(std::move(v)), index(std::move(i)) {}
+    std::string dump(int indent = 0) const override
+    {
+        std::ostringstream oss;
+        oss << indent_str(indent) << "SliceSubscript\n";
+        oss << value->dump(indent + 1) << '\n';
+        oss << index->dump(indent + 1);
+        return oss.str();
+    }
+};
+
 struct List : Expr
 {
     std::vector<ptr<Expr>> elements;

src/parser.y

@@ -53,6 +53,8 @@
 %right BIT_AND_ASSIGN BIT_OR_ASSIGN BIT_XOR_ASSIGN LSHIFT_ASSIGN RSHIFT_ASSIGN
 
 %type <std::unique_ptr<Expr>> expr
+%type <std::unique_ptr<Expr>> opt_expr
+%type <std::unique_ptr<Slice>> slice
 %type <std::unique_ptr<Stmt>> stmt
 %type <std::vector<std::unique_ptr<Expr>>> args
 %type <std::vector<std::unique_ptr<Stmt>>> stmt_list
@@ -70,8 +72,12 @@ stmt_list:
     ;
 
 stmt:
-      expr NEWLINE        { $$ = std::make_unique<ExprStmt>(std::move($1)); }
-    | expr ASSIGN expr NEWLINE      { $$ = std::make_unique<Assign>(std::move($1), std::move($3));}
+      expr NEWLINE { 
+        $$ = std::make_unique<ExprStmt>(std::move($1));
+    }
+    | expr ASSIGN expr NEWLINE {
+        $$ = std::make_unique<Assign>(std::move($1), std::move($3));
+    }
     | KW_IF expr COLON NEWLINE INDENT stmt_list DEDENT {
         $$ = std::make_unique<If>(std::move($2), std::move($6), std::vector<std::unique_ptr<Stmt>>());
     }
@@ -84,25 +90,40 @@ stmt:
     | KW_DEF IDENTIFIER L_PAREN params R_PAREN COLON NEWLINE INDENT stmt_list DEDENT {
         $$ = std::make_unique<FunctionDef>($2, std::move($4), std::move($9));
     }
-    | KW_RETURN expr NEWLINE { $$ = std::make_unique<Return>(std::move($2));}
+    | KW_RETURN expr NEWLINE { 
+        $$ = std::make_unique<Return>(std::move($2));
+    }
     ;
 
 expr:
       NUMBER              { $$ = std::make_unique<Number>($1); }
     | IDENTIFIER          { $$ = std::make_unique<Identifier>($1); }
     | STRING              { $$ = std::make_unique<String>($1); }
-    | expr PLUS expr      { $$ = std::make_unique<BinOp>(
-                                BinaryOperator(BinaryOperator::ADD),
-                                std::move($1), std::move($3)); }
-    | expr MULTIPLY expr  { $$ = std::make_unique<BinOp>(
-                                BinaryOperator(BinaryOperator::MUL),
-                                std::move($1), std::move($3)); }
-    | L_PAREN expr R_PAREN {$$ = std::move($2); /* #todo: test for precedence*/}
+    | expr PLUS expr      { $$ = std::make_unique<BinOp>( BinaryOperator(BinaryOperator::ADD), std::move($1), std::move($3)); }
+    | expr MULTIPLY expr  { $$ = std::make_unique<BinOp>( BinaryOperator(BinaryOperator::MUL), std::move($1), std::move($3)); }
+    | expr LT expr        { $$ = std::make_unique<BinOp>( BinaryOperator(BinaryOperator::LT) , std::move($1), std::move($3)); }
+    | expr KW_AND expr    { $$ = std::make_unique<BinOp>( BinaryOperator(BinaryOperator::AND) , std::move($1), std::move($3)); }
+    | expr KW_OR expr     { $$ = std::make_unique<BinOp>( BinaryOperator(BinaryOperator::OR) , std::move($1), std::move($3)); }
+    | expr L_BRACKET expr R_BRACKET { $$ = std::make_unique<Subscript>(std::move($1), std::move($3));}
+    | expr L_BRACKET slice R_BRACKET{ $$ = std::make_unique<SliceSubscript>(std::move($1), std::move($3)); }
+    | L_PAREN expr R_PAREN {$$ = std::move($2); }
     | expr L_PAREN args R_PAREN { $$ = std::make_unique<Call>(std::move($1), std::move($3));}
     | expr DOT IDENTIFIER { $$ = std::make_unique<Attribute>(std::move($1), $3);}
     | L_BRACKET args R_BRACKET { $$ = std::make_unique<List>(std::move($2));}
+    | MINUS expr { $$ = std::make_unique<UnaryOpExpr>(UnaryOperator(UnaryOperator::NEG), std::move($2));}
     ;
 
+slice:
+      opt_expr COLON opt_expr
+        { $$ = std::make_unique<Slice>(std::move($1), std::move($3), nullptr); }
+    | opt_expr COLON opt_expr COLON opt_expr
+        { $$ = std::make_unique<Slice>(std::move($1), std::move($3), std::move($5)); }
+    ;
+
+opt_expr:
+                        { $$ = nullptr;}
+    | expr              { $$ = std::move($1);}
+
 args:
       /* empty */         { $$ = std::vector<std::unique_ptr<Expr>>(); }
     | expr                { $$ = std::vector<std::unique_ptr<Expr>>(); 

test/parser/16.out

@@ -2,4 +2,3 @@ Module
   ExprStmt
     UnaryOp(-)
       Number(5)
-

test/parser/17.out

@@ -1,6 +1,5 @@
 Module
   ExprStmt
-    Compare(<)
+    BinOp(<)
       Number(1)
       Number(2)
-

test/parser/18.out

@@ -1,6 +1,5 @@
 Module
   ExprStmt
-    BoolOp(and)
+    BinOp(and)
       Identifier(x)
       Identifier(y)
-

test/parser/19.out

@@ -1,8 +1,7 @@
 Module
   ExprStmt
-    BoolOp(or)
+    BinOp(or)
       Identifier(x)
-      BoolOp(and)
+      BinOp(and)
         Identifier(y)
         Identifier(z)
-

test/parser/20.out

@@ -6,4 +6,3 @@ Module
           Identifier(foo)
         Number(1)
         Number(2)
-

test/parser/21.in

@@ -1,2 +1 @@
 arr[5]
-

test/parser/21.out

@@ -3,4 +3,3 @@ Module
     Subscript
       Identifier(arr)
       Number(5)
-

test/parser/22.in

@@ -1,2 +1 @@
 arr[1:3]
-

test/parser/22.out

@@ -1,7 +1,9 @@
 Module
   ExprStmt
-    Slice
+    SliceSubscript
       Identifier(arr)
+      Slice
+        Lower
           Number(1)
+        Upper
           Number(3)
-