[Parser] Parse lambda expressions

src/lpython/parser/parser.yy

@@ -254,7 +254,12 @@ void yyerror(YYLTYPE *yyloc, LFortran::Parser &p, const std::string &msg)
 %type <comp> comp_for
 %type <vec_comp> comp_for_items
 %type <ast> lambda_expression
-%type <vec_arg> lambda_id_list
+%type <args> lambda_parameter_list_opt
+%type <arg> lambda_parameter
+%type <fn_arg> lambda_parameter_list
+%type <args_> lambda_parameter_list_no_posonly
+%type <var_kw> lambda_parameter_list_starargs
+%type <vec_arg> lambda_defparameter_list
 
 // Precedence
 
@@ -873,16 +878,55 @@ string
     | id TK_STRING { $$ = STRING3($1, $2, @$); }
     ;
 
-lambda_id_list
-    : lambda_id_list "," id { $$ = $1; LIST_ADD($$, ARGS_01($3, @$)); }
-    | id { LIST_NEW($$); LIST_ADD($$, ARGS_01($1, @$)); }
+lambda_parameter
+    : id { $$ = ARGS_01($1, @$); }
+    | id "=" expr { $$ = ARGS_03($1, $3, @$); }
+    ;
+
+lambda_defparameter_list
+    : lambda_defparameter_list "," lambda_parameter { $$ = $1; LIST_ADD($$, $3); }
+    | lambda_parameter { LIST_NEW($$); LIST_ADD($$, $1); }
+    ;
+
+lambda_parameter_list
+    : lambda_defparameter_list "," "/" comma_opt {
+        $$ = PARAMETER_LIST_01($1, nullptr); }
+    | lambda_defparameter_list "," "/" "," lambda_parameter_list_no_posonly {
+        $$ = PARAMETER_LIST_01($1, $5); }
+    | lambda_parameter_list_no_posonly { $$ = PARAMETER_LIST_02($1); }
+    ;
+
+lambda_parameter_list_no_posonly
+    : lambda_defparameter_list comma_opt { $$ = PARAMETER_LIST_03($1, nullptr); }
+    | lambda_defparameter_list "," lambda_parameter_list_starargs {
+        $$ = PARAMETER_LIST_03($1, $3); }
+    | lambda_parameter_list_starargs { $$ = PARAMETER_LIST_04($1); }
+    ;
+
+lambda_parameter_list_starargs
+    : "*" "," lambda_defparameter_list comma_opt { $$ = PARAMETER_LIST_05($3); }
+    | "*" "," "**" lambda_parameter comma_opt { $$ = PARAMETER_LIST_06($4); }
+    | "*" "," lambda_defparameter_list "," "**" lambda_parameter comma_opt {
+        $$ = PARAMETER_LIST_07($3, $6); }
+    | "*" lambda_parameter comma_opt { $$ = PARAMETER_LIST_08($2); }
+    | "*" lambda_parameter "," lambda_defparameter_list comma_opt {
+        $$ = PARAMETER_LIST_09($2, $4); }
+    | "*" lambda_parameter "," "**" lambda_parameter comma_opt {
+        $$ = PARAMETER_LIST_10($2, $5); }
+    | "*" lambda_parameter "," lambda_defparameter_list "," 
+        "**" lambda_parameter comma_opt { $$ = PARAMETER_LIST_11($2, $4, $7); }
+    | "**" lambda_parameter comma_opt { $$ = PARAMETER_LIST_06($2); }
     ;
 
+lambda_parameter_list_opt
+    : lambda_parameter_list { $$ = FUNC_ARGS_01(p.m_a, @$, $1); }
+    | %empty { $$ = PARAMETER_LIST_12(@$); }
+    ;
+
+
 lambda_expression
-    : KW_LAMBDA ":" expr %prec LAMBDA {
-        $$ = LAMBDA_01(PARAMETER_LIST_12(@$), $3, @$); }
-    | KW_LAMBDA lambda_id_list ":" expr %prec LAMBDA {
-        $$ = LAMBDA_01(FUNC_ARG_LIST_01($2, @$), $4, @$); }
+    : KW_LAMBDA lambda_parameter_list_opt ":" expr %prec LAMBDA {
+        $$ = LAMBDA_01($2, $4, @$); }
     ;
 
 expr

src/lpython/parser/semantics.h

@@ -437,42 +437,6 @@ static inline Args *FUNC_ARGS_01(Allocator &al, Location &l, Fn_Arg *parameters)
     return r;
 }
 
-static inline Args *FUNC_ARGS(Allocator &al, Location &l,
-        Arg** m_posonlyargs, size_t n_posonlyargs,
-        Arg** m_args, size_t n_args,
-        Arg** m_vararg, size_t n_vararg,
-        Arg** m_kwonlyargs, size_t n_kwonlyargs,
-        Arg** m_kwarg, size_t n_kwarg) {
-    // TODO: Use parameter_list for LAMBDA instead of lambda_id_list,
-    // after which this function can be removed.
-    Args *r = al.allocate<Args>();
-    Vec<expr_t*> defaults;
-    defaults.reserve(al, 4);
-    Vec<expr_t*> kw_defaults;
-    kw_defaults.reserve(al, 4);
-
-    FUNC_ARGS1_(posonlyargs);
-    FUNC_ARGS1_(args);
-    FUNC_ARGS1_(vararg);
-    FUNC_ARGS1_(kwonlyargs);
-    FUNC_ARGS1_(kwarg);
-
-    r->arguments.loc = l;
-    FUNC_ARGS_(posonlyargs, false);
-    FUNC_ARGS_(args, false);
-    FUNC_ARGS_(vararg, false);
-    FUNC_ARGS_(kwonlyargs, true);
-    FUNC_ARGS_(kwarg, true);
-    r->arguments.m_kw_defaults = kw_defaults.p;
-    r->arguments.n_kw_defaults = kw_defaults.n;
-    r->arguments.m_defaults = defaults.p;
-    r->arguments.n_defaults = defaults.n;
-    return r;
-}
-
-#define FUNC_ARG_LIST_01(args, l) FUNC_ARGS(p.m_a, l, nullptr, 0, \
-        args.p, args.n, nullptr, 0, nullptr, 0, nullptr,0)
-
 #define ARGS_01(arg, l) FUNC_ARG(p.m_a, l, \
         name2char((ast_t *)arg), nullptr, nullptr)
 #define ARGS_02(arg, annotation, l) FUNC_ARG(p.m_a, l, \

tests/parser/lambda2.py

@@ -0,0 +1,70 @@
+# AST tests only
+verify_matching_signatures(lambda x=0: 0, lambda x=0: 0)
+
+input_func = lambda prompt="": next(gen)
+
+cast[key] = lambda x, k=key: array(x, copy=False).astype(k)
+
+x = lambda func=self._try_call,attr=attr : func(attr)
+
+fpos32 = lambda x, **k: np.format_float_positional(np.float32(x), **k)
+
+m = lambda self, *args, **kw: func(self, *args, **kw)
+
+lambda *x, y, z: test
+
+lambda *x, y, z, **args: test
+
+lambda *x, **args: test
+
+lambda **args: test
+
+lambda x, y: test
+
+lambda x, *y: test
+
+lambda x, *y, z: test
+
+lambda x, *y, z, **args: test
+
+lambda x, *y, **args: test
+
+lambda x, **args: test
+
+lambda x, *y, z, **args: test
+
+lambda a, /, b, c: test
+
+lambda a, /, *b: test
+
+lambda a, /, *b, c, d: test
+
+lambda a, /, *b, c, **d: test
+
+lambda a, /, **b: test
+
+lambda a, /, *b, **c: test
+
+lambda a, /, b, c, *d: test
+
+lambda a, /, b, c, **d: test
+
+lambda a, /, b, c, *d, **e: test
+
+lambda a, /, b, c, *d, e, **f: test
+
+lambda *, a: test
+
+lambda *, a, **b: test
+
+lambda a, *, b: test
+
+lambda a, *, b, **c: test
+
+lambda a, /, *, b: test
+
+lambda a, /, b, *, c: test
+
+lambda a, /, *, c, **d: test
+
+lambda a, /, b, *, c, **d: test

tests/reference/ast_new-lambda2-d84336e.json

@@ -0,0 +1,13 @@
+{
+    "basename": "ast_new-lambda2-d84336e",
+    "cmd": "lpython --show-ast --new-parser --no-color {infile} -o {outfile}",
+    "infile": "tests/parser/lambda2.py",
+    "infile_hash": "fd8ff7be24e81b33516b111731ced148b85298a647ee2a0a0b571cfa",
+    "outfile": null,
+    "outfile_hash": null,
+    "stdout": "ast_new-lambda2-d84336e.stdout",
+    "stdout_hash": "02af3cdbd330aef51113ef12f054e2b544b96dc68d58b7b5cbc24423",
+    "stderr": null,
+    "stderr_hash": null,
+    "returncode": 0
+}

tests/reference/ast_new-lambda2-d84336e.stdout

@@ -0,0 +1 @@
+(Module [(Expr (Call (Name verify_matching_signatures Load) [(Lambda ([] [(x () ())] [] [] [] [] [(ConstantInt 0 ())]) (ConstantInt 0 ())) (Lambda ([] [(x () ())] [] [] [] [] [(ConstantInt 0 ())]) (ConstantInt 0 ()))] [])) (Assign [(Name input_func Store)] (Lambda ([] [(prompt () ())] [] [] [] [] [(ConstantStr "" ())]) (Call (Name next Load) [(Name gen Load)] [])) ()) (Assign [(Subscript (Name cast Load) (Name key Load) Store)] (Lambda ([] [(x () ()) (k () ())] [] [] [] [] [(Name key Load)]) (Call (Attribute (Call (Name array Load) [(Name x Load)] [(copy (ConstantBool .false. ()))]) astype Load) [(Name k Load)] [])) ()) (Assign [(Name x Store)] (Lambda ([] [(func () ()) (attr () ())] [] [] [] [] [(Attribute (Name self Load) _try_call Load) (Name attr Load)]) (Call (Name func Load) [(Name attr Load)] [])) ()) (Assign [(Name fpos32 Store)] (Lambda ([] [(x () ())] [] [] [] [(k () ())] []) (Call (Attribute (Name np Load) format_float_positional Load) [(Call (Attribute (Name np Load) float32 Load) [(Name x Load)] [])] [(() (Name k Load))])) ()) (Assign [(Name m Store)] (Lambda ([] [(self () ())] [(args () ())] [] [] [(kw () ())] []) (Call (Name func Load) [(Name self Load) (Starred (Name args Load) Load)] [(() (Name kw Load))])) ()) (Expr (Lambda ([] [] [(x () ())] [(y () ()) (z () ())] [] [] []) (Name test Load))) (Expr (Lambda ([] [] [(x () ())] [(y () ()) (z () ())] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [] [(x () ())] [] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [] [] [] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [(x () ()) (y () ())] [] [] [] [] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [(y () ())] [] [] [] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [(y () ())] [(z () ())] [] [] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [(y () ())] [(z () ())] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [(y () ())] [] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [] [] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([] [(x () ())] [(y () ())] [(z () ())] [] [(args () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ()) (c () ())] [] [] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [(b () ())] [] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [(b () ())] [(c () ()) (d () ())] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [(b () ())] [(c () ())] [] [(d () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [] [] [] [(b () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [(b () ())] [] [] [(c () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ()) (c () ())] [(d () ())] [] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ()) (c () ())] [] [] [] [(d () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ()) (c () ())] [(d () ())] [] [] [(e () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ()) (c () ())] [(d () ())] [(e () ())] [] [(f () ())] []) (Name test Load))) (Expr (Lambda ([] [] [] [(a () ())] [] [] []) (Name test Load))) (Expr (Lambda ([] [] [] [(a () ())] [] [(b () ())] []) (Name test Load))) (Expr (Lambda ([] [(a () ())] [] [(b () ())] [] [] []) (Name test Load))) (Expr (Lambda ([] [(a () ())] [] [(b () ())] [] [(c () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [] [(b () ())] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ())] [] [(c () ())] [] [] []) (Name test Load))) (Expr (Lambda ([(a () ())] [] [] [(c () ())] [] [(d () ())] []) (Name test Load))) (Expr (Lambda ([(a () ())] [(b () ())] [] [(c () ())] [] [(d () ())] []) (Name test Load)))] [])

tests/tests.toml

@@ -516,6 +516,10 @@ ast_new = true
 filename = "parser/lambda1.py"
 ast_new = true
 
+[[test]]
+filename = "parser/lambda2.py"
+ast_new = true
+
 [[test]]
 filename = "parser/tuple1.py"
 ast_new = true