qzdoom/src/zscript/zcc-parse.lemon

%token_prefix ZCC_
%token_type { ZCCToken }
%token_destructor {}	// just to avoid a compiler warning
%name ZCCParse
%extra_argument { FScanner *sc }
%syntax_error
{
	FString unexpected, expecting;

	int i;
	int stateno = yypParser->yystack[yypParser->yyidx].stateno;

	unexpected << "Unexpected " << ZCCTokenName(yymajor);

	// Determine all the terminals that the parser would have accepted at this point
	// (see yy_find_shift_action). This list can get quite long. Is it worthwhile to
	// print it when not debugging the grammar, or would that be too confusing to
	// the average user?
	if (stateno < YY_SHIFT_MAX && (i = yy_shift_ofst[stateno])!=YY_SHIFT_USE_DFLT)
	{
		for (int j = 1; j < YYERRORSYMBOL; ++j)
		{
			int k = i + j;
			if (k >= 0 && k < YY_SZ_ACTTAB && yy_lookahead[k] == j)
			{
				expecting << (expecting.IsEmpty() ? "Expecting " : " or ") << ZCCTokenName(j);
			}
		}
	}
	sc->ScriptMessage("%s\n%s\n", unexpected.GetChars(), expecting.GetChars());
}
%parse_accept { sc->ScriptMessage("input accepted\n"); }
%parse_failure { /**failed = true;*/ }

%nonassoc EQ MULEQ DIVEQ MODEQ ADDEQ SUBEQ LSHEQ RSHEQ ANDEQ OREQ XOREQ.
%right QUESTION COLON.
%left OROR.
%left ANDAND.
%left EQEQ NEQ APPROXEQ.
%left LT GT LTEQ GTEQ LTGTEQ IS.
%left DOTDOT.
%left OR.		/* Note that this is like the Ruby precedence for these */
%left XOR.		/* three operators and not the C precedence, since */
%left AND.		/* they are higher priority than the comparisons. */
%left LSH RSH.
%left SUB ADD.
%left MUL DIV MOD CROSSPROD DOTPROD.
%left POW.
%right UNARY ADDADD SUBSUB.
%left DOT LPAREN LBRACKET.
%left SCOPE.


main ::= translation_unit. { sc->ScriptMessage("Parse complete\n"); }

translation_unit ::= .
translation_unit ::= translation_unit external_declaration.
translation_unit ::= translation_unit EOF.
translation_unit ::= error.

external_declaration ::= class_definition.

/* Optional bits. */
opt_semicolon ::= .
opt_semicolon ::= SEMICOLON.

opt_comma ::= .
opt_comma ::= COMMA.

opt_expr ::= .
opt_expr ::= expr.


/* A class definition. Can only occur at global scope. */
class_definition ::= CLASS id_or_string class_ancestry class_flags class_body.

id_or_string ::= IDENTIFIER.
id_or_string ::= string_constant.

class_ancestry ::= .
class_ancestry ::= COLON id_or_string.

class_flags ::= .
class_flags ::= class_flags ABSTRACT.
class_flags ::= class_flags NATIVE.
class_flags ::= class_flags REPLACES id_or_string.


class_body ::= SEMICOLON class_innards EOF.
class_body ::= LBRACE class_innards RBRACE.

class_innards ::= .
class_innards ::= class_innards class_member.

/* Classes can define variables, functions, enums, structs, states, constants, and defaults. */
class_member ::= declarator.
class_member ::= enum_def.
class_member ::= struct_def.
class_member ::= states_def.
class_member ::= default_def.
class_member ::= const_def.

/* Structs can define variables, enums, and structs. */
struct_def ::= STRUCT IDENTIFIER LBRACE struct_body RBRACE opt_semicolon.
struct_member ::= declarator_no_fun.
struct_member ::= enum_def.

/* Enumerators are lists of named integers. */
enum_def ::= ENUM IDENTIFIER enum_type LBRACE enum_list opt_comma RBRACE opt_semicolon.

enum_type ::= .
enum_type ::= COLON int_type.

enum_list ::= enumerator.
enum_list ::= enum_list COMMA enumerator.

enumerator ::= IDENTIFIER.
enumerator ::= IDENTIFIER EQ expr.	/* Expression must be constant. */

/* States */
states_def ::= STATES scanner_mode LBRACE states_body RBRACE.

/* We use a special scanner mode to allow for sprite names and frame characters
 * to not be quoted even if they contain special characters. The scanner_mode
 * nonterminal is used to enter this mode. The scanner automatically leaves it
 * upon pre-defined conditions. See the comments by FScanner::SetStateMode().
 *
 * Note that rules are reduced *after* one token of lookahead has been
 * consumed, so this nonterminal must be placed one token before we want it to
 * take effect. For example, in states_def above, the scanner mode will be
 * set immediately after LBRACE is consumed, rather than immediately after
 * STATES is consumed.
 */
scanner_mode ::= . { sc->SetStateMode(true); }

states_body ::= .
states_body ::= error.
states_body ::= states_body LABELID.
states_body ::= states_body state_line.
states_body ::= states_body state_label.
states_body ::= states_body state_flow.

state_label ::= NWS COLON.

state_flow ::= state_flow_type scanner_mode SEMICOLON.
state_flow_type ::= STOP.
state_flow_type ::= WAIT.
state_flow_type ::= FAIL.
state_flow_type ::= LOOP.
state_flow_type ::= GOTO dotted_identifier state_goto_offset.

state_goto_offset ::= .
state_goto_offset ::= PLUS expr.		/* Must evaluate to an integer constant. */

state_line ::= NWS NWS expr state_opts state_action.

state_opts ::= .
state_opts ::= state_opts BRIGHT.
state_opts ::= state_opts OFFSET LPAREN expr COMMA expr RPAREN.
state_opts ::= state_opts LIGHT LPAREN light_list RPAREN.

light_list ::= STRCONST.
light_list ::= light_list COMMA STRCONST.

/* A state action can be either a compound statement or a single action function call. */
state_action ::= LBRACE statement_list scanner_mode RBRACE.
state_action ::= LBRACE error scanner_mode RBRACE.
state_action ::= state_call scanner_mode SEMICOLON.

state_call ::= .
state_call ::= IDENTIFIER state_call_parms.
state_call_parms ::= .
state_call_parms ::= LPAREN opt_expr_list RPAREN.
state_call_parms ::= LPAREN error RPAREN.

dotted_identifier ::= IDENTIFIER.
dotted_identifier ::= dotted_identifier DOT IDENTIFIER.

/* Definition of a default class instance. */
default_def ::= DEFAULT compound_statement.

/* Type names */
int_type ::= SBYTE.
int_type ::= BYTE.
int_type ::= SHORT.
int_type ::= USHORT.
int_type ::= INT.
int_type ::= UINT.

type_name ::= BOOL.
type_name ::= int_type.
type_name ::= FLOAT.
type_name ::= DOUBLE.
type_name ::= STRING.
type_name ::= VECTOR vector_size.
type_name ::= NAME.
type_name ::= IDENTIFIER.	/* User-defined type (struct, enum, or class) */

vector_size ::= .
vector_size ::= LT INTCONST GT.

/* Type names can also be used as identifiers in contexts where type names
 * are not normally allowed. */
%fallback IDENTIFIER
	SBYTE BYTE SHORT USHORT INT UINT BOOL FLOAT DOUBLE STRING VECTOR NAME.

/* Aggregate types */
aggregate_type ::= MAP LT type array_size COMMA type array_size GT.	/* Hash table */
aggregate_type ::= ARRAY LT type array_size GT.						/* TArray<type> */
aggregate_type ::= CLASS class_restrictor.							/* class<type> */
class_restrictor ::= .
class_restrictor ::= LT IDENTIFIER GT.

type ::= type_name.
type ::= aggregate_type.

type_list ::= type array_size.		/* A comma-separated list of types */
type_list ::= type_list COMMA type array_size.

type_list_or_void ::= VOID.
type_list_or_void ::= type_list.

array_size ::= .
array_size ::= array_size LBRACKET opt_expr RBRACKET.

declarator ::= decl_flags type_list_or_void variables_or_function.	/* Multiple type names are only valid for functions. */
declarator_no_fun ::= decl_flags type variable_list.

variables_or_function ::= IDENTIFIER LPAREN func_params RPAREN func_const opt_func_body.	/* Function */
variables_or_function ::= variable_list SEMICOLON.
variables_or_function ::= error SEMICOLON.

variable_list ::= IDENTIFIER array_size.
variable_list ::= variable_list COMMA IDENTIFIER array_size.

decl_flags ::= .
decl_flags ::= decl_flags NATIVE.
decl_flags ::= decl_flags STATIC.
decl_flags ::= decl_flags PRIVATE.
decl_flags ::= decl_flags PROTECTED.
decl_flags ::= decl_flags LATENT.
decl_flags ::= decl_flags FINAL.
decl_flags ::= decl_flags META.
decl_flags ::= decl_flags ACTION.
decl_flags ::= decl_flags DEPRECATED LPAREN string_constant RPAREN.

func_const ::= .
func_const ::= CONST.

opt_func_body ::= SEMICOLON.
opt_func_body ::= function_body.

func_params ::= .	/* empty */
func_params ::= VOID.
func_params ::= func_param_list.

func_param_list ::= func_param.
func_param_list ::= func_param COMMA func_param_list.

func_param ::= func_param_flags type IDENTIFIER array_size.

func_param_flags ::= .
func_param_flags ::= func_param_flags IN.
func_param_flags ::= func_param_flags OUT.
func_param_flags ::= func_param_flags OPTIONAL.

struct_body ::= struct_member.
struct_body ::= struct_member struct_body.

/* Like UnrealScript, a constant's type is implied by its value's type. */
const_def ::= CONST IDENTIFIER EQ expr SEMICOLON.

/* Expressions */

/* We use default to access a class's default instance. */
%fallback IDENTIFIER
	DEFAULT.

primary ::= IDENTIFIER.
primary ::= SUPER.
primary ::= constant.
primary ::= SELF.
primary ::= LPAREN expr RPAREN.
primary ::= LPAREN error RPAREN.
primary ::= primary LPAREN func_expr_list RPAREN. [DOT]		// Function call
primary ::= primary LBRACKET expr RBRACKET. [DOT]			// Array access
primary ::= primary DOT IDENTIFIER.							// Member access
primary ::= primary ADDADD.		/* postfix++ */
primary ::= primary SUBSUB.		/* postfix-- */
primary ::= SCOPE primary.

unary_expr ::= primary.
unary_expr ::= SUB unary_expr. [UNARY]
unary_expr ::= ADD unary_expr. [UNARY]
unary_expr ::= SUBSUB unary_expr. [UNARY]
unary_expr ::= ADDADD unary_expr. [UNARY]
unary_expr ::= TILDE unary_expr. [UNARY]
unary_expr ::= BANG unary_expr. [UNARY]
unary_expr ::= SIZEOF unary_expr. [UNARY]
unary_expr ::= ALIGNOF unary_expr. [UNARY]

/* Due to parsing conflicts, C-style casting is not supported. You
 * must use C++ function call-style casting instead.
 */

expr ::= unary_expr.
expr ::= expr ADD expr.			/* a + b */
expr ::= expr SUB expr.			/* a - b */
expr ::= expr MUL expr.			/* a * b */
expr ::= expr DIV expr.			/* a / b */
expr ::= expr MOD expr.			/* a % b */
expr ::= expr POW expr.			/* a ** b */
expr ::= expr CROSSPROD expr.	/* a cross b */
expr ::= expr DOTPROD expr.		/* a dot b */
expr ::= expr LSH expr.			/* a << b */
expr ::= expr RSH expr.			/* a >> b */
expr ::= expr DOTDOT expr.		/* a .. b */

expr ::= expr LT expr.			/* a < b */
expr ::= expr GT expr.			/* a > b */
expr ::= expr LTEQ expr.		/* a <= b */
expr ::= expr GTEQ expr.		/* a >= b */
expr ::= expr LTGTEQ expr.		/* a <>= b */
expr ::= expr IS expr.			/* a is b */

expr ::= expr EQEQ expr.		/* a == b */
expr ::= expr NEQ expr.			/* a != b */
expr ::= expr APPROXEQ expr.	/* a ~== b */

expr ::= expr AND expr.			/* a & b */
expr ::= expr XOR expr.			/* a ^ b */
expr ::= expr OR expr.			/* a | b */
expr ::= expr ANDAND expr.		/* a && b */
expr ::= expr OROR expr.		/* a || b */

expr ::= expr SCOPE expr.

expr ::= expr QUESTION expr COLON expr.

opt_expr_list ::= .
opt_expr_list ::= expr_list.

expr_list ::= expr.
expr_list ::= expr_list COMMA expr.

/* A function expression list can also specify a parameter's name,
 * but once you do that, all remaining parameters must also be named. */
func_expr_list ::= .
func_expr_list ::= expr_list.
func_expr_list ::= expr_list COMMA named_expr_list.
func_expr_list ::= named_expr_list.

named_expr_list ::= named_expr.
named_expr_list ::= named_expr_list COMMA named_expr.

named_expr ::= IDENTIFIER COLON expr.

/* Allow C-like concatenation of adjacent string constants. */
string_constant ::= STRCONST.
string_constant ::= string_constant STRCONST.

constant ::= string_constant.
constant ::= INTCONST.
constant ::= FLOATCONST.

function_body ::= compound_statement.

statement ::= labeled_statement.
statement ::= compound_statement.
statement ::= expression_statement.
statement ::= selection_statement.
statement ::= iteration_statement.
statement ::= jump_statement.
statement ::= assign_statement.
statement ::= local_var.
statement ::= error SEMICOLON.

jump_statement ::= CONTINUE SEMICOLON.
jump_statement ::= BREAK SEMICOLON.
jump_statement ::= RETURN SEMICOLON.
jump_statement ::= RETURN expr_list SEMICOLON.

compound_statement ::= LBRACE RBRACE.
compound_statement ::= LBRACE statement_list RBRACE.
compound_statement ::= LBRACE error RBRACE.

statement_list ::= statement.
statement_list ::= statement_list statement.

expression_statement ::= SEMICOLON.
expression_statement ::= expr SEMICOLON.

iteration_statement ::= while_or_until LPAREN expr RPAREN statement.
iteration_statement ::= DO statement while_or_until LPAREN expr RPAREN.
iteration_statement ::= FOR LPAREN for_init_expr SEMICOLON opt_expr SEMICOLON for_bump_expr RPAREN statement.

while_or_until ::= WHILE.
while_or_until ::= UNTIL.

for_init_expr ::= .
for_init_expr ::= expr.
for_init_expr ::= type variable_list EQ expr_list.
for_init_expr ::= assign_expr.

for_bump_expr ::= .
for_bump_expr ::= expr.
for_bump_expr ::= assign_expr.

/* Resolve the shift-reduce conflict here in favor of the shift.
 * This is the default behavior, but using precedence symbols
 * lets us do it without warnings.
 */
%left IF.
%left ELSE.
selection_statement ::= if_front. [IF]
selection_statement ::= if_front ELSE statement. [ELSE]

selection_statement ::= SWITCH LPAREN expr RPAREN statement.

if_front ::= IF LPAREN expr RPAREN statement.

labeled_statement ::= CASE expr COLON.
labeled_statement ::= DEFAULT COLON.

assign_statement ::= assign_expr SEMICOLON. [EQ]

assign_expr ::= expr_list assign_op expr_list.
assign_op ::= EQ.
assign_op ::= MULEQ.
assign_op ::= DIVEQ.
assign_op ::= MODEQ.
assign_op ::= ADDEQ.
assign_op ::= SUBEQ.
assign_op ::= LSHEQ.
assign_op ::= RSHEQ.
assign_op ::= ANDEQ.
assign_op ::= OREQ.
assign_op ::= XOREQ.

local_var ::= type variable_list var_init SEMICOLON.

var_init ::= .
var_init ::= EQ expr_list.