TysonAndre · TysonAndre · Aug 29, 2020
diff --git a/README.md b/README.md
@@ -1,3 +1,28 @@
+# LISP-Imitating Syntax for PHP
+
+Notes:
+
+- This may end up breaking assumptions made by opcache and be unsafe.
+- This is not going to be fully featured
+- This combines the parenthesis of lisp with the behavior of php.
+
+  Writing parsers becomes easier and operator precedence is no longer important
+- This may be a useful reference point for writing DSLs extending PHP
+  or for trying to add new syntax to php.
+
+## Supported features
+
+- `(print expr)`, `(echo expr1 expr2)`
+- Variables `(= $var expr)`
+- Some unary and binary operators
+- Support reading and writing constants as `(const name expr)`
+- Add `(if cond truestmt falsestmt)` statements
+- Support `(while cond stmts)` statements
+- Support `(do stmt1 stmt2)` for statement lists
+- Support function calls `(name_or_var arg1 arg2)`
+
+See [Zend/tests/lisp](Zend/tests/lisp) for examples.
+
 <div align="center">
     <a href="https://php.net">
         <img

diff --git a/Zend/tests/lisp/call.phpt b/Zend/tests/lisp/call.phpt
@@ -0,0 +1,13 @@
+--TEST--
+Function calls
+--FILE--
+(?lisp
+
+(printf "Hello, %s\n" "World")
+(= $printer (. 'pri' 'ntf'))
+($printer "Dynamic %s\n" $printer)
+
+?)
+--EXPECTF--
+Hello, World
+Dynamic printf
diff --git a/Zend/tests/lisp/constants.phpt b/Zend/tests/lisp/constants.phpt
@@ -0,0 +1,13 @@
+--TEST--
+Setting and reading constants
+--FILE--
+(?lisp
+(const MY_CONSTANT "My constant")
+(echo MY_CONSTANT "\n")
+(echo \MY_CONSTANT "\n")
+(echo namespace\MY_CONSTANT "\n")
+?)
+--EXPECTF--
+My constant
+My constant
+My constant
diff --git a/Zend/tests/lisp/if.phpt b/Zend/tests/lisp/if.phpt
@@ -0,0 +1,19 @@
+--TEST--
+If statements
+--FILE--
+(?lisp
+
+(if 1 (= $x "yes") (= $x "no"))
+(echo $x "\n")
+(if 0 (= $x "yes") (= $x "no"))
+(echo $x "\n")
+(if 1 (= $x "!"))
+(echo $x "\n")
+(if 0 (= $x "?"))
+(echo $x "\n")
+?)
+--EXPECTF--
+yes
+no
+!
+!
diff --git a/Zend/tests/lisp/print.phpt b/Zend/tests/lisp/print.phpt
@@ -0,0 +1,13 @@
+--TEST--
+Print basic expressions test
+--FILE--
+(?lisp
+(print "test from lisp\n")
+(print (. (+ 1 2) "\n"))
+(print (* 3 2))
+(print "\n")
+?)
+--EXPECTF--
+test from lisp
+3
+6
diff --git a/Zend/tests/lisp/variables.phpt b/Zend/tests/lisp/variables.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Setting and reading variables
+--FILE--
+(?lisp
+(= $var (- 10 (- 2)))
+(echo $var "\n")
+(= $var (* $var 2))
+(echo (. $var "\n"))
+?)
+--EXPECTF--
+12
+24
diff --git a/Zend/tests/lisp/while.phpt b/Zend/tests/lisp/while.phpt
@@ -0,0 +1,19 @@
+--TEST--
+While statements
+--FILE--
+(?lisp
+
+(= $i 1)
+(while (<= $i 3) (do (echo $i "\n") (++ $i)))
+(while (<= $i 0) (do (echo "unreachable") (= $i (+ $i 1))))
+(echo "After loop $i\n")
+(echo (++$i) "\n")
+(echo (--$i) "\n")
+?)
+--EXPECTF--
+1
+2
+3
+After loop 4
+5
+4
diff --git a/Zend/zend_language_parser.y b/Zend/zend_language_parser.y
@@ -218,6 +218,8 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token T_DOC_COMMENT     "doc comment"
 %token T_OPEN_TAG        "open tag"
 %token T_OPEN_TAG_WITH_ECHO "'<?='"
+%token T_LISP_START      "'(?lisp'"
+%token T_LISP_END        "'?)'"
 %token T_CLOSE_TAG       "'?>'"
 %token T_WHITESPACE      "whitespace"
 %token T_START_HEREDOC   "heredoc start"
@@ -268,6 +270,10 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %type <ast> attributed_statement attributed_class_statement attributed_parameter
 %type <ast> attribute_decl attribute attributes namespace_declaration_name
 %type <ast> match match_arm_list non_empty_match_arm_list match_arm match_arm_cond_list
+%type <ast> lisp_scalar lisp_expr lisp_dereferenceable_expr lisp_top_statement lisp_top_statement_list lisp_statement lisp_statement_list
+%type <ast> lisp_echo_expr lisp_echo_expr_list lisp_const_list lisp_const_decl
+%type <ast> lisp_if_stmt lisp_while_stmt
+%type <ast> lisp_argument_list lisp_non_empty_argument_list lisp_argument lisp_function_call lisp_callable_expr
 
 %type <num> returns_ref function fn is_reference is_variadic variable_modifiers
 %type <num> method_modifiers non_empty_member_modifiers member_modifier optional_visibility_modifier
@@ -487,6 +493,7 @@ statement:
 	|	T_STATIC static_var_list ';'	{ $$ = $2; }
 	|	T_ECHO echo_expr_list ';'		{ $$ = $2; }
 	|	T_INLINE_HTML { $$ = zend_ast_create(ZEND_AST_ECHO, $1); }
+	|   T_LISP_START lisp_top_statement_list T_LISP_END	{ $$ = $2; }
 	|	expr ';' { $$ = $1; }
 	|	T_UNSET '(' unset_variables possible_comma ')' ';' { $$ = $3; }
 	|	T_FOREACH '(' expr T_AS foreach_variable ')' foreach_statement
@@ -1464,6 +1471,169 @@ isset_variable:
 		expr { $$ = zend_ast_create(ZEND_AST_ISSET, $1); }
 ;
 
+lisp_top_statement_list:
+		lisp_top_statement_list lisp_top_statement { $$ = zend_ast_list_add($1, $2); }
+	|	%empty { $$ = zend_ast_create_list(0, ZEND_AST_STMT_LIST); }
+;
+
+lisp_top_statement:
+	lisp_statement { $$ = $1; }
+;
+
+lisp_statement_list:
+		lisp_statement_list lisp_statement { $$ = zend_ast_list_add($1, $2); }
+	|	%empty { $$ = zend_ast_create_list(0, ZEND_AST_STMT_LIST); }
+;
+
+lisp_statement:
+		lisp_expr { $$ = $1; }
+	|	'(' T_ECHO lisp_echo_expr_list ')'  { $$ = $3; }
+	|	'(' T_CONST lisp_const_list ')'  { $$ = $3; }
+	|	'(' T_DO lisp_statement_list ')'  { $$ = $3; }
+	|	lisp_if_stmt { $$ = $1; }
+	|	lisp_while_stmt { $$ = $1; }
+;
+
+lisp_const_list:
+		lisp_const_list lisp_const_decl { $$ = zend_ast_list_add($1, $2); }
+	|	lisp_const_decl { $$ = zend_ast_create_list(1, ZEND_AST_CONST_DECL, $1); }
+;
+
+lisp_const_decl:
+	T_STRING lisp_expr backup_doc_comment { $$ = zend_ast_create(ZEND_AST_CONST_ELEM, $1, $2, ($3 ? zend_ast_create_zval_from_str($3) : NULL)); }
+;
+
+lisp_dereferenceable_expr:
+		T_VARIABLE			{ $$ = zend_ast_create(ZEND_AST_VAR, $1); }
+;
+
+lisp_echo_expr_list:
+		lisp_echo_expr_list lisp_echo_expr { $$ = zend_ast_list_add($1, $2); }
+	|	lisp_echo_expr { $$ = zend_ast_create_list(1, ZEND_AST_STMT_LIST, $1); }
+;
+
+lisp_echo_expr:
+	lisp_expr { $$ = zend_ast_create(ZEND_AST_ECHO, $1); }
+;
+
+lisp_expr:
+	 	'(' T_PRINT lisp_expr ')'  { $$ = zend_ast_create(ZEND_AST_PRINT, $3); }
+	|	lisp_scalar { $$ = $1; }
+	|	lisp_dereferenceable_expr { $$ = $1; }
+	|	lisp_function_call { $$ = $1; }
+	// $ordinaryVar
+
+	// Assignments
+	|	'(' '=' lisp_dereferenceable_expr lisp_expr ')'
+			{ $$ = zend_ast_create(ZEND_AST_ASSIGN, $3, $4); }
+	|	'(' '=' '&' lisp_dereferenceable_expr lisp_expr ')'
+			{ $$ = zend_ast_create(ZEND_AST_ASSIGN_REF, $4, $5); }
+
+	// Unary operators
+	|	'(' '+' lisp_expr ')' { $$ = zend_ast_create(ZEND_AST_UNARY_PLUS, $3); }
+	|	'(' '-' lisp_expr ')' { $$ = zend_ast_create(ZEND_AST_UNARY_MINUS, $3); }
+	|	'(' '!' lisp_expr ')' { $$ = zend_ast_create_ex(ZEND_AST_UNARY_OP, ZEND_BOOL_NOT, $3); }
+	|	'(' '~' lisp_expr ')' { $$ = zend_ast_create_ex(ZEND_AST_UNARY_OP, ZEND_BW_NOT, $3); }
+	|	'(' T_INC lisp_dereferenceable_expr ')' { $$ = zend_ast_create(ZEND_AST_PRE_INC, $3); }
+	|	'(' T_DEC lisp_dereferenceable_expr ')' { $$ = zend_ast_create(ZEND_AST_PRE_DEC, $3); }
+	// Binary operators
+	|	'(' '|' lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_BW_OR, $3, $4); }
+	|	'(' '&' lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_BW_AND, $3, $4); }
+	|	'(' '^' lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_BW_XOR, $3, $4); }
+	|	'(' '.' lisp_expr lisp_expr ')' 	{ $$ = zend_ast_create_binary_op(ZEND_CONCAT, $3, $4); }
+	|	'(' '+' lisp_expr lisp_expr ')' 	{ $$ = zend_ast_create_binary_op(ZEND_ADD, $3, $4); }
+	|	'(' '-' lisp_expr lisp_expr ')' 	{ $$ = zend_ast_create_binary_op(ZEND_SUB, $3, $4); }
+	|	'(' '*' lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_MUL, $3, $4); }
+	|	'(' T_POW lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_POW, $3, $4); }
+	|	'(' '/' lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_DIV, $3, $4); }
+	|	'(' '%' lisp_expr lisp_expr ')' 	{ $$ = zend_ast_create_binary_op(ZEND_MOD, $3, $4); }
+	| 	'(' T_SL lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_SL, $3, $4); }
+	|	'(' T_SR lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_SR, $3, $4); }
+
+	|	'(' T_BOOLEAN_OR lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_AST_OR, $3, $4); }
+	|	'(' T_BOOLEAN_AND lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_AST_AND, $3, $4); }
+	|	'(' T_LOGICAL_OR lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_AST_OR, $3, $4); }
+	|	'(' T_LOGICAL_AND lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_AST_AND, $3, $4); }
+	|	'(' T_LOGICAL_XOR lisp_expr lisp_expr ')'	{ $$ = zend_ast_create_binary_op(ZEND_BOOL_XOR, $3, $4); }
+	|	'(' T_IS_IDENTICAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_IDENTICAL, $3, $4); }
+	|	'(' T_IS_NOT_IDENTICAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_NOT_IDENTICAL, $3, $4); }
+	|	'(' T_IS_EQUAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_EQUAL, $3, $4); }
+	|	'(' T_IS_NOT_EQUAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_NOT_EQUAL, $3, $4); }
+	|	'(' '<' lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_SMALLER, $3, $4); }
+	|	'(' T_IS_SMALLER_OR_EQUAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_IS_SMALLER_OR_EQUAL, $3, $4); }
+	|	'(' '>' lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_AST_GREATER, $3, $4); }
+	|	'(' T_IS_GREATER_OR_EQUAL lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_AST_GREATER_EQUAL, $3, $4); }
+	|	'(' T_SPACESHIP lisp_expr lisp_expr ')'
+			{ $$ = zend_ast_create_binary_op(ZEND_SPACESHIP, $3, $4); }
+;
+
+lisp_scalar:
+		T_LNUMBER 	{ $$ = $1; }
+	|	T_DNUMBER 	{ $$ = $1; }
+	|	T_CONSTANT_ENCAPSED_STRING		{ $$ = $1; }
+	|	'"' encaps_list '"'			 	{ $$ = $2; }
+	|	T_START_HEREDOC T_ENCAPSED_AND_WHITESPACE T_END_HEREDOC { $$ = $2; }
+	|	T_START_HEREDOC T_END_HEREDOC
+			{ $$ = zend_ast_create_zval_from_str(ZSTR_EMPTY_ALLOC()); }
+	|	T_START_HEREDOC encaps_list T_END_HEREDOC { $$ = $2; }
+	|	constant				{ $$ = $1; }
+	// |	class_constant			{ $$ = $1; }
+;
+
+// TODO: (cond (cond1 stmts1) (cond2 stmts2))
+lisp_if_stmt:
+		'(' T_IF lisp_expr lisp_statement ')'
+			{ $$ = zend_ast_create_list(1, ZEND_AST_IF,
+			      zend_ast_create(ZEND_AST_IF_ELEM, $3, $4)); }
+	| 	'(' T_IF lisp_expr lisp_statement lisp_statement ')'
+			{ $$ = zend_ast_create_list(2, ZEND_AST_IF,
+				  zend_ast_create(ZEND_AST_IF_ELEM, $3, $4),
+			      zend_ast_create(ZEND_AST_IF_ELEM, NULL, $5)); }
+;
+
+lisp_while_stmt:
+	'(' T_WHILE lisp_expr lisp_statement ')'
+		{ $$ = zend_ast_create(ZEND_AST_WHILE, $3, $4); }
+;
+
+lisp_argument_list:
+		%empty	{ $$ = zend_ast_create_list(0, ZEND_AST_ARG_LIST); }
+	|	lisp_non_empty_argument_list { $$ = $1; }
+;
+
+lisp_non_empty_argument_list:
+		lisp_argument
+			{ $$ = zend_ast_create_list(1, ZEND_AST_ARG_LIST, $1); }
+	|	lisp_non_empty_argument_list lisp_argument
+			{ $$ = zend_ast_list_add($1, $2); }
+;
+
+lisp_argument:
+		lisp_expr				{ $$ = $1; }
+	|	name ':' lisp_expr
+			{ $$ = zend_ast_create(ZEND_AST_NAMED_ARG, $1, $3); }
+	|	T_ELLIPSIS lisp_expr	{ $$ = zend_ast_create(ZEND_AST_UNPACK, $2); }
+;
+
+lisp_callable_expr:
+		name { $$ = $1; }
+	|	T_VARIABLE { $$ = zend_ast_create(ZEND_AST_VAR, $1); }
+;
+
+
+lisp_function_call:
+		'(' lisp_callable_expr lisp_argument_list ')'
+			{ $$ = zend_ast_create(ZEND_AST_CALL, $2, $3); }
+;
+
 %%
 
 /* Over-ride Bison formatting routine to give better token descriptions.

diff --git a/Zend/zend_language_scanner.l b/Zend/zend_language_scanner.l
@@ -2163,7 +2163,6 @@ string:
 	RETURN_TOKEN(T_OPEN_TAG_WITH_ECHO);
 }
 
-
 <INITIAL>"<?php"([ \t]|{NEWLINE}) {
 	HANDLE_NEWLINE(yytext[yyleng-1]);
 	BEGIN(ST_IN_SCRIPTING);
@@ -2194,6 +2193,17 @@ string:
 	}
 }
 
+<INITIAL>"(?lisp" {
+	HANDLE_NEWLINE(yytext[yyleng-1]);
+	BEGIN(ST_IN_SCRIPTING);
+	RETURN_TOKEN(T_LISP_START);
+}
+
+<ST_IN_SCRIPTING>"?)" {
+	BEGIN(INITIAL);
+	RETURN_TOKEN(T_LISP_END);
+}
+
 <INITIAL>{ANY_CHAR} {
 	if (YYCURSOR > YYLIMIT) {
 		RETURN_END_TOKEN;

diff --git a/ext/tokenizer/tokenizer_data.c b/ext/tokenizer/tokenizer_data.c
@@ -157,6 +157,8 @@ void tokenizer_register_constants(INIT_FUNC_ARGS) {
 	REGISTER_LONG_CONSTANT("T_DOC_COMMENT", T_DOC_COMMENT, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("T_OPEN_TAG", T_OPEN_TAG, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("T_OPEN_TAG_WITH_ECHO", T_OPEN_TAG_WITH_ECHO, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("T_LISP_START", T_LISP_START, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("T_LISP_END", T_LISP_END, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("T_CLOSE_TAG", T_CLOSE_TAG, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("T_WHITESPACE", T_WHITESPACE, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("T_START_HEREDOC", T_START_HEREDOC, CONST_CS | CONST_PERSISTENT);
@@ -307,6 +309,8 @@ char *get_token_type_name(int token_type)
 		case T_OPEN_TAG: return "T_OPEN_TAG";
 		case T_OPEN_TAG_WITH_ECHO: return "T_OPEN_TAG_WITH_ECHO";
 		case T_CLOSE_TAG: return "T_CLOSE_TAG";
+		case T_LISP_START: return "T_LISP_START";
+		case T_LISP_END: return "T_LISP_END";
 		case T_WHITESPACE: return "T_WHITESPACE";
 		case T_START_HEREDOC: return "T_START_HEREDOC";
 		case T_END_HEREDOC: return "T_END_HEREDOC";