%include
{
// Allocates a new AST node off the parse state's arena.
#define NEW_AST_NODE(type,name) \
	ZCC_##type *name = (ZCC_##type *)stat->SyntaxArena.Alloc(sizeof(ZCC_##type)); \
	name->SiblingNext = name; \
	name->SiblingPrev = name; \
	name->NodeType = AST_##type

// If a is non-null, appends b to a. Otherwise, sets a to b.
#define SAFE_APPEND(a,b) \
	if (a == NULL) a = b; else a->AppendSibling(b);
}

%token_prefix ZCC_
%token_type { ZCCToken }
%token_destructor {}	// just to avoid a compiler warning
%name ZCCParse
%extra_argument { ZCCParseState *stat }
%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);
			}
		}
	}
	stat->sc.ScriptMessage("%s\n%s\n", unexpected.GetChars(), expecting.GetChars());
}
%parse_accept { stat->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. { stat->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.

%type opt_expr{ZCC_Expression *}
opt_expr(X) ::= .
{
	X = NULL;
}
opt_expr(X) ::= expr(A).
{
	X = A;
}


/************ Class Definition ************/
/* Can only occur at global scope. */

%type class_definition{ZCC_Class *}
%type class_head{ZCC_Class *}
%type class_innards{ZCC_Class *}
%type class_body{ZCC_TreeNode *}

class_definition(X) ::= class_head(A) class_body(B).
{
	A->Body = B;
	X = A;
}

class_head(X) ::= CLASS dottable_id(A) class_ancestry(B) class_flags(C).
{
	NEW_AST_NODE(Class,head);
	head->ClassName = A;
	head->ParentName = B;
	head->Flags = C.Flags;
	head->Replaces = C.Replaces;
	X = head;
}

%type class_ancestry{ZCC_Identifier *}
class_ancestry(X) ::= .						{ X = NULL; }
class_ancestry(X) ::= COLON dottable_id(A).	{ X = A; }

%type class_flags{ClassFlagsBlock}
%include{
	struct ClassFlagsBlock {
		VM_UWORD Flags;
		ZCC_Identifier *Replaces;
	};
}
class_flags(X) ::= .										{ X.Flags = 0; X.Replaces = NULL; }
class_flags(X) ::= class_flags(A) ABSTRACT.					{ X.Flags = A.Flags | 0/*FIXME*/; X.Replaces = A.Replaces; }
class_flags(X) ::= class_flags(A) NATIVE.					{ X.Flags = A.Flags | 0/*FIXME*/; X.Replaces = A.Replaces; }
class_flags(X) ::= class_flags(A) REPLACES dottable_id(B).	{ X.Flags = A.Flags; X.Replaces = B; }

/*----- Dottable Identifier -----*/
// This can be either a single identifier or two identifiers connected by a .

%type dottable_id{ZCC_Identifier *}

dottable_id(X) ::= IDENTIFIER(A).
{
	NEW_AST_NODE(Identifier,id);
	id->Id = A.Name();
	X = id;
}
dottable_id(X) ::= dottable_id(A) DOT IDENTIFIER(B).
{
	NEW_AST_NODE(Identifier,id2);
	id2->Id = B.Name();
	A->AppendSibling(id2);
	X = A;
}

/*------ Class Body ------*/
// Body is a list of:
//  * variable definitions
//  * function definitions
//  * enum definitions
//  * struct definitions
//  * state definitions
//  * constants
//  * defaults

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

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

%type struct_def{ZCC_Struct *}
%type enum_def {ZCC_Enum *}
%type states_def {ZCC_States *}

class_member ::= declarator.
class_member ::= enum_def.
class_member ::= struct_def.
class_member ::= states_def.
class_member ::= default_def.
class_member ::= const_def.

/*----- Struct Definition -----*/
/* Structs can define variables, enums<s>, and structs</s>. */

%type struct_body{ZCC_TreeNode *}
%type struct_member{ZCC_TreeNode *}

struct_def(X) ::= STRUCT IDENTIFIER(A) LBRACE struct_body(B) RBRACE opt_semicolon.
{
	NEW_AST_NODE(Struct,def);
	def->StructName = A.Name();
	def->Body = B;
	X = def;
}

struct_body(X) ::= error.								{ X = NULL; }
struct_body(X) ::= struct_member(A).					{ X = A; }
struct_body(X) ::= struct_member(A) struct_body(B).		{ X = A; A->AppendSibling(B); }

struct_member(X) ::= declarator_no_fun(A).				{ X = A; }
struct_member(X) ::= enum_def(A).						{ X = A; }


/*----- Enum Definition -----*/
/* Enumerators are lists of named integers. */

%type enum_type {EZCCIntType}
%type enum_list {ZCC_EnumNode *}
%type enumerator {ZCC_EnumNode *}

enum_def(X) ::= ENUM IDENTIFIER(A) enum_type(B) LBRACE enum_list(C) opt_comma RBRACE opt_semicolon.
{
	NEW_AST_NODE(Enum,def);
	def->EnumName = A.Name();
	def->EnumType = B;
	def->Elements = C;
	X = def;
}

enum_type(X) ::= .										{ X = ZCCINT_Auto; }
enum_type(X) ::= COLON int_type(A).						{ X = A; }

enum_list(X) ::= error.									{ X = NULL; }
enum_list(X) ::= enumerator(A).							{ X = A; }
enum_list(X) ::= enum_list(A) COMMA enumerator(B).		{ X = A; A->AppendSibling(B); }

enumerator(X) ::= IDENTIFIER(A).
{
	NEW_AST_NODE(EnumNode,node);
	node->ElemName = A.Name();
	node->ElemValue = NULL;
	X = node;
}
enumerator(X) ::= IDENTIFIER(A) EQ expr(B).			/* Expression must be constant. */
{
	NEW_AST_NODE(EnumNode,node);
	node->ElemName = A.Name();
	node->ElemValue = B;
	X = node;
}

/************ States ************/

%type states_body {ZCC_StatePart *}
%type state_line {ZCC_StatePart *}
%type state_label {ZCC_StatePart *}
%type state_flow {ZCC_StatePart *}
%type state_flow_type {ZCC_StatePart *}
%type state_goto_offset {ZCC_Expression *}
%type state_action {ZCC_TreeNode *}
%type state_call {ZCC_ExprFuncCall *}

%include
{
	struct StateOpts
	{
		ZCC_Expression *Offset;
		bool Bright;
	};
}
%type state_opts {StateOpts}

states_def(X) ::= STATES scanner_mode LBRACE states_body(A) RBRACE.
{
	NEW_AST_NODE(States,def);
	def->Body = A;
	X = def;
}

/* 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 ::= . { stat->sc.SetStateMode(true); }

states_body(X) ::= .								{ X = NULL; }
states_body(X) ::= error.							{ X = NULL; }
states_body(X) ::= states_body(A) state_line(B).	{ SAFE_APPEND(A,B); X = A; }
states_body(X) ::= states_body(A) state_label(B).	{ SAFE_APPEND(A,B); X = A; }
states_body(X) ::= states_body(A) state_flow(B).	{ SAFE_APPEND(A,B); X = A; }

state_label(X) ::= NWS(A) COLON.
{
	NEW_AST_NODE(StateLabel, label);
	label->Label = A.Name();
	X = label;
}

state_flow(X) ::= state_flow_type(A) scanner_mode SEMICOLON.	{ X = A; }

state_flow_type(X) ::= STOP.			{ NEW_AST_NODE(StateStop, flow); X = flow; }
state_flow_type(X) ::= WAIT.			{ NEW_AST_NODE(StateWait, flow); X = flow; }
state_flow_type(X) ::= FAIL.			{ NEW_AST_NODE(StateFail, flow); X = flow; }
state_flow_type(X) ::= LOOP.			{ NEW_AST_NODE(StateLoop, flow); X = flow; }
state_flow_type(X) ::= GOTO dottable_id(A) state_goto_offset(B).
{
	NEW_AST_NODE(StateGoto, flow);
	flow->Label = A;
	flow->Offset = B;
	X = flow;
}

state_goto_offset(X) ::= .				{ X = NULL; }
state_goto_offset(X) ::= PLUS expr(A).	{ X = A; }	/* Must evaluate to a non-negative integer constant. */

state_line(X) ::= NWS(A) NWS(B) expr state_opts(C) state_action(D).
{
	NEW_AST_NODE(StateLine, line);
	const char *sprite = FName(A.Name()).GetChars();
	memset(line, 0, sizeof(*line));
	if (strlen(sprite) != 4)
	{
		Printf("Sprite name '%s' must be four characters", sprite);
	}
	else
	{
		memcpy(line->Sprite, sprite, 4);
	}
	line->Frames = stat->Strings.Alloc(FName(B.Name()).GetChars());
	line->bBright = C.Bright;
	line->Offset = C.Offset;
	line->Action = D;
	X = line;
}

state_opts(X) ::= .													{ StateOpts opts; opts.Offset = NULL; opts.Bright = false; X = opts; }
state_opts(X) ::= state_opts(A) BRIGHT.								{ A.Bright = true; X = A; }
state_opts(X) ::= state_opts(A) OFFSET LPAREN expr(B) COMMA expr(C) RPAREN.	{ A.Offset = B; B->AppendSibling(C); X = A; }
state_opts(X) ::= state_opts(A) LIGHT LPAREN light_list RPAREN.		{ X = A; }

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(X) ::= LBRACE statement_list(A) scanner_mode RBRACE.	{ X = A; }
state_action(X) ::= LBRACE error scanner_mode RBRACE.				{ X = NULL; }
state_action(X) ::= state_call(A) scanner_mode SEMICOLON.			{ X = A; }

state_call(X) ::= .											{ X = NULL; }
state_call(X) ::= IDENTIFIER(A) func_params(B).
{
	NEW_AST_NODE(ExprFuncCall, expr);
	NEW_AST_NODE(ExprID, func);

	func->Operation = PEX_ID;
	func->Identifier = A.Name();
	expr->Operation = PEX_FuncCall;
	expr->Function = func;
	expr->Parameters = B;
	X = expr;
}

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

/* Type names */
%type int_type {EZCCIntType}
%type type_name {PType *}

int_type(X) ::= SBYTE.						{ X = ZCCINT_SInt8; }
int_type(X) ::= BYTE.						{ X = ZCCINT_UInt8; }
int_type(X) ::= SHORT.						{ X = ZCCINT_SInt16; }
int_type(X) ::= USHORT.						{ X = ZCCINT_UInt16; }
int_type(X) ::= INT.						{ X = ZCCINT_SInt32; }
int_type(X) ::= UINT.						{ X = ZCCINT_UInt32; }

type_name(X) ::= BOOL.						{ /*FIXME*/ X = TypeBool; }
type_name(X) ::= int_type(A).				{ X = A; }
type_name(X) ::= FLOAT.						{ X = TypeFloat32; }
type_name(X) ::= DOUBLE.					{ X = TypeFloat64; }
type_name(X) ::= STRING.					{ X = TypeString; }
type_name(X) ::= VECTOR vector_size(A).		{ X = NewVector(A); }
type_name(X) ::= NAME.						{ X = TypeName; }
type_name(X) ::= IDENTIFIER.	/* User-defined type (struct, enum, or class) */
{
	// FIXME
	X = NULL;
}

%type vector_size {unsigned int}

vector_size ::= .
vector_size(X) ::= LT INTCONST(A) GT.	{ X = A.Int; }

/* 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 */
%type aggregate_type {PType *}
%type type {PType *}
%type type_or_array {PType *}
%type class_restrictor {PClass *}

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

class_restrictor ::= .
class_restrictor ::= LT IDENTIFIER GT.

type(X) ::= type_name(A).					{ X = A; }
type(X) ::= aggregate_type(A).				{ X = A; }

type_or_array ::= type.
type_or_array ::= type array_size.

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

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

%type array_size{ZCC_Expression *}
array_size(X) ::= LBRACKET opt_expr(A) RBRACKET.
{
	if (A == NULL)
	{
		NEW_AST_NODE(Expression,nil);
		X = nil;
	}
	else
	{
		X = A;
	}
}
array_size(X) ::= array_size(A) LBRACKET opt_expr(B) RBRACKET.
{
	if (B == NULL)
	{
		NEW_AST_NODE(Expression,nil);
		A->AppendSibling(nil);
	}
	else
	{
		A->AppendSibling(B);
	}
	X = A;
}

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 Names -----*/
// They get the array size, because that makes it look more like C.
// I might still change my mind and stick array sizes with the rest
// of the type like C#.

%type variable_name{ZCC_VarName *}
%type variable_list{ZCC_VarName *}

variable_name(X) ::= IDENTIFIER(A).
{
	NEW_AST_NODE(VarName,var);
	var->Name = ENamedName(A.Int);
	var->bIsArray = false;
	var->ArraySize = 0;
	X = var;
}
variable_name(X) ::= IDENTIFIER(A) array_size(B).
{
	NEW_AST_NODE(VarName,var);
	var->Name = ENamedName(A.Int);
	var->bIsArray = false;
	var->ArraySize = B;
	X = var;
}
variable_list(X) ::= variable_name(A).
{
	X = A;
}
variable_list(X) ::= variable_list(A) COMMA variable_name(B).
{
	A->AppendSibling(B);
	X = A;
}

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 variable_name.

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

/* 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.

%type expr{ZCC_Expression *}
%type primary{ZCC_Expression *}
%type unary_expr{ZCC_Expression *}
%type constant{ZCC_Expression *}

%include {
#define UNARY_EXPR(X,T) NEW_AST_NODE(ExprUnary, expr); expr->Operation = T; expr->Operand = X
#define BINARY_EXPR(X,Y,T) NEW_AST_NODE(ExprBinary, expr); expr->Operation = T; expr->Left = X; expr->Right = Y
}

/*----- Primary Expressions -----*/

primary(X) ::= IDENTIFIER(A).
{
	NEW_AST_NODE(ExprID, expr);
	expr->Operation = PEX_ID;
	expr->Identifier = A.Name();
	X = expr;
}
primary(X) ::= SUPER.
{
	NEW_AST_NODE(Expression, expr);
	expr->Operation = PEX_Super;
	X = expr;
}
primary(X) ::= constant(A).
{
	X = A;
}
primary(X) ::= SELF.
{
	NEW_AST_NODE(Expression, expr);
	expr->Operation = PEX_Self;
	X = expr;
}
primary(X) ::= LPAREN expr(A) RPAREN.
{
	X = A;
}
primary ::= LPAREN error RPAREN.
primary(X) ::= primary(A) LPAREN func_expr_list(B) RPAREN. [DOT]		// Function call
{
	NEW_AST_NODE(ExprFuncCall, expr);
	expr->Operation = PEX_FuncCall;
	expr->Function = A;
	expr->Parameters = B;
	X = expr;
}
primary(X) ::= primary(A) LBRACKET expr(B) RBRACKET. [DOT]				// Array access
{
	NEW_AST_NODE(ExprBinary, expr);
	expr->Operation = PEX_ArrayAccess;
	expr->Left = A;
	expr->Right = B;
	X = expr;
}
primary(X) ::= primary(A) DOT IDENTIFIER(B).							// Member access
{
	NEW_AST_NODE(ExprMemberAccess, expr);
	expr->Operation = PEX_MemberAccess;
	expr->Left = A;
	expr->Right = ENamedName(B.Int);
	X = expr;
}
primary(X) ::= primary(A) ADDADD.		/* postfix++ */
{
	UNARY_EXPR(A,PEX_PostInc);
	X = expr;
}
primary(X) ::= primary(A) SUBSUB.		/* postfix-- */
{
	UNARY_EXPR(A,PEX_PostDec);
	X = expr;
}
primary(X) ::= SCOPE primary(B).
{
	BINARY_EXPR(NULL,B,PEX_Scope);
	X = expr;
}

/*----- Unary Expressions -----*/

unary_expr(X) ::= primary(A).
{
	X = A;
}
unary_expr(X) ::= SUB unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_Negate);
	X = expr;
}
unary_expr(X) ::= ADD unary_expr(A). [UNARY]
{
	// Even though this is really a no-op, we still need to make a node for
	// it so we can type check that it is being applied to something numeric.
	UNARY_EXPR(A,PEX_AntiNegate);
	X = expr;
}
unary_expr(X) ::= SUBSUB unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_PreDec);
	X = expr;
}
unary_expr(X) ::= ADDADD unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_PreInc);
	X = expr;
}
unary_expr(X) ::= TILDE unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_BitNot);
	X = expr;
}
unary_expr(X) ::= BANG unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_BoolNot);
	X = expr;
}
unary_expr(X) ::= SIZEOF unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_SizeOf);
	X = expr;
}
unary_expr(X) ::= ALIGNOF unary_expr(A). [UNARY]
{
	UNARY_EXPR(A,PEX_AlignOf);
	X = expr;
}

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

/*----- Binary Expressions -----*/

expr(X) ::= unary_expr(A).
{
	A = X;
}
expr(X) ::= expr(A) ADD expr(B).		/* a + b */
{
	BINARY_EXPR(A,B,PEX_Add);
	X = expr;
}
expr(X) ::= expr(A) SUB expr(B).		/* a - b */
{
	BINARY_EXPR(A,B,PEX_Sub);
	X = expr;
}
expr(X) ::= expr(A) MUL expr(B).		/* a * b */
{
	BINARY_EXPR(A,B,PEX_Mul);
	X = expr;
}
expr(X) ::= expr(A) DIV expr(B).		/* a / b */
{
	BINARY_EXPR(A,B,PEX_Div);
	X = expr;
}
expr(X) ::= expr(A) MOD expr(B).		/* a % b */
{
	BINARY_EXPR(A,B,PEX_Mod);
	X = expr;
}
expr(X) ::= expr(A) POW expr(B).		/* a ** b */
{
	BINARY_EXPR(A,B,PEX_Pow);
	X = expr;
}
expr(X) ::= expr(A) CROSSPROD expr(B).	/* a cross b */
{
	BINARY_EXPR(A,B,PEX_CrossProduct);
	X = expr;
}
expr(X) ::= expr(A) DOTPROD expr(B).	/* a dot b */
{
	BINARY_EXPR(A,B,PEX_DotProduct);
	X = expr;
}
expr(X) ::= expr(A) LSH expr(B).		/* a << b */
{
	BINARY_EXPR(A,B,PEX_LeftShift);
	X = expr;
}
expr(X) ::= expr(A) RSH expr(B).		/* a >> b */
{
	BINARY_EXPR(A,B,PEX_RightShift);
	X = expr;
}
expr(X) ::= expr(A) DOTDOT expr(B).		/* a .. b */
{
	BINARY_EXPR(A,B,PEX_Concat);
	X = expr;
}

expr(X) ::= expr(A) LT expr(B).			/* a < b */
{
	BINARY_EXPR(A,B,PEX_LT);
	X = expr;
}
expr(X) ::= expr(A) GT expr(B).			/* a > b */
{
	BINARY_EXPR(A,B,PEX_GT);
	X = expr;
}
expr(X) ::= expr(A) LTEQ expr(B).		/* a <= b */
{
	BINARY_EXPR(A,B,PEX_LTEQ);
	X = expr;
}
expr(X) ::= expr(A) GTEQ expr(B).		/* a >= b */
{
	BINARY_EXPR(A,B,PEX_GTEQ);
	X = expr;
}
expr(X) ::= expr(A) LTGTEQ expr(B).		/* a <>= b */
{
	BINARY_EXPR(A,B,PEX_LTGTEQ);
	X = expr;
}
expr(X) ::= expr(A) IS expr(B).			/* a is b */
{
	BINARY_EXPR(A,B,PEX_Is);
	X = expr;
}

expr(X) ::= expr(A) EQEQ expr(B).		/* a == b */
{
	BINARY_EXPR(A,B,PEX_EQEQ);
	X = expr;
}
expr(X) ::= expr(A) NEQ expr(B).		/* a != b */
{
	BINARY_EXPR(A,B,PEX_NEQ);
	X = expr;
}
expr(X) ::= expr(A) APPROXEQ expr(B).	/* a ~== b */
{
	BINARY_EXPR(A,B,PEX_APREQ);
	X = expr;
}

expr(X) ::= expr(A) AND expr(B).		/* a & b */
{
	BINARY_EXPR(A,B,PEX_BitAnd);
	X = expr;
}
expr(X) ::= expr(A) XOR expr(B).		/* a ^ b */
{
	BINARY_EXPR(A,B,PEX_BitXor);
	X = expr;
}
expr(X) ::= expr(A) OR expr(B).			/* a | b */
{
	BINARY_EXPR(A,B,PEX_BitOr);
	X = expr;
}
expr(X) ::= expr(A) ANDAND expr(B).		/* a && b */
{
	BINARY_EXPR(A,B,PEX_BoolAnd);
	X = expr;
}
expr(X) ::= expr(A) OROR expr(B).		/* a || b */
{
	BINARY_EXPR(A,B,PEX_BoolOr);
	X = expr;
}

expr(X) ::= expr(A) SCOPE expr(B).
{
	BINARY_EXPR(A,B,PEX_Scope);
	X = expr;
}

/*----- Trinary Expression -----*/

expr(X) ::= expr(A) QUESTION expr(B) COLON expr(C).
{
	NEW_AST_NODE(ExprTrinary, expr);
	expr->Operation = PEX_Trinary;
	expr->Test = A;
	expr->Left = B;
	expr->Right = C;
	X = expr;
}

/************ Expression Lists ***********/ 

%type expr_list{ZCC_Expression *}

expr_list(X) ::= expr(A).
{
	X = A;
}
expr_list(X) ::= expr_list(A) COMMA expr(B).
{
	X = A;
	A->AppendSibling(B);
}

/*----- Function argument lists -----*/

/* A function expression list can also specify a parameter's name,
 * but once you do that, all remaining parameters must also be named.
 * We let higher-level code handle this to keep this file simpler. */
%type func_expr_list{ZCC_FuncParm *}
%type named_expr{ZCC_FuncParm *}

func_expr_list(X) ::= .
{
	X = NULL;
}
func_expr_list(X) ::= named_expr(A).
{
	X = A;
}
func_expr_list(X) ::= func_expr_list(A) COMMA named_expr(B).
{
	X = A;
	A->AppendSibling(B);
}

named_expr(X) ::= IDENTIFIER(A) COLON expr(B).
{
	NEW_AST_NODE(FuncParm, parm);
	parm->Value = B;
	parm->Label = ENamedName(A.Int);
	X = parm;
}
named_expr(X) ::= expr(B).
{
	NEW_AST_NODE(FuncParm, parm);
	parm->Value = B;
	parm->Label = NAME_None;
	X = parm;
}

/************ Constants ************/

/* Allow C-like concatenation of adjacent string constants. */
%type string_constant{ZCC_ExprString *}

string_constant(X) ::= STRCONST(A).
{
	NEW_AST_NODE(ExprString, strconst);
	strconst->Operation = PEX_StringConst;
	strconst->Value = A.String;
	X = strconst;
}
string_constant(X) ::= string_constant(A) STRCONST(B).
{
	NEW_AST_NODE(ExprString, strconst);
	strconst->Operation = PEX_StringConst;
	strconst->Value = stat->Strings.Alloc(*(A->Value) + *(B.String));
	X = strconst;
}

constant(X) ::= string_constant(A).
{
	X = A;
}
constant(X) ::= INTCONST(A).
{
	NEW_AST_NODE(ExprInt, intconst);
	intconst->Operation = PEX_IntConst;
	intconst->Value = A.Int;
	X = intconst;
}
constant(X) ::= FLOATCONST(A).
{
	NEW_AST_NODE(ExprFloat, floatconst);
	floatconst->Operation = PEX_FloatConst;
	floatconst->Value = A.Float;
	X = floatconst;
}

/************ Statements ************/

function_body ::= compound_statement.

%type statement{ZCC_Statement *}
statement ::= SEMICOLON.
statement ::= labeled_statement.
statement ::= compound_statement.
statement ::= expression_statement SEMICOLON.
statement ::= selection_statement.
statement ::= iteration_statement.
statement ::= jump_statement.
statement ::= assign_statement SEMICOLON.
statement ::= local_var SEMICOLON.
statement ::= error SEMICOLON.

/*----- Jump Statements -----*/

%type jump_statement{ZCC_Statement *}

jump_statement(A) ::= CONTINUE SEMICOLON.
{
	NEW_AST_NODE(ContinueStmt, stmt);
	A = stmt;
}
jump_statement(A) ::= BREAK SEMICOLON.
{
	NEW_AST_NODE(BreakStmt, stmt);
	A = stmt;
}
jump_statement(A) ::= RETURN SEMICOLON.
{
	NEW_AST_NODE(ReturnStmt, stmt);
	stmt->Values = NULL;
	A = stmt;
}
jump_statement(A) ::= RETURN expr_list(X) SEMICOLON.
{
	NEW_AST_NODE(ReturnStmt, stmt);
	stmt->Values = X;
	A = stmt;
}

/*----- Compound Statements -----*/

%type compound_statement{ZCC_CompoundStmt *}
%type statement_list{ZCC_Statement *}

compound_statement(X) ::= LBRACE RBRACE.
{
	NEW_AST_NODE(CompoundStmt,stmt);
	stmt->Content = NULL;
	X = stmt;
}
compound_statement(X) ::= LBRACE statement_list(A) RBRACE.
{
	NEW_AST_NODE(CompoundStmt,stmt);
	stmt->Content = A;
	X = stmt;
}
compound_statement(X) ::= LBRACE error RBRACE.
{
	NEW_AST_NODE(CompoundStmt,stmt);
	stmt->Content = NULL;
	X = stmt;
}

statement_list(X) ::= statement(A).
{
	X = A;
}
statement_list(X) ::= statement_list(A) statement(B).
{
	X = A;
	A->AppendSibling(B);
}

/*----- Expression Statements -----*/

%type expression_statement{ZCC_ExpressionStmt *}

expression_statement(X) ::= expr(A).
{
	NEW_AST_NODE(ExpressionStmt, stmt);
	stmt->Expression = A;
	X = stmt;
}

/*----- Iteration Statements -----*/

%type iteration_statement{ZCC_Statement *}

// while/until (expr) statement
iteration_statement(X) ::= while_or_until(TY) LPAREN expr(EX) RPAREN statement(ST).
{
	NEW_AST_NODE(IterationStmt, iter);
	if (TY.Int == ZCC_UNTIL)
	{ // Negate the loop condition
		UNARY_EXPR(EX,PEX_BoolNot);
		iter->LoopCondition = expr;
	}
	else
	{
		iter->LoopCondition = EX;
	}
	iter->LoopStatement = ST;
	iter->LoopBumper = NULL;
	iter->CheckAt = ZCC_IterationStmt::Start;
	X = iter;
}
// do statement while/until (expr)
iteration_statement(X) ::= DO statement(ST) while_or_until(TY) LPAREN expr(EX) RPAREN.
{
	NEW_AST_NODE(IterationStmt, iter);
	if (TY.Int == ZCC_UNTIL)
	{ // Negate the loop condition
		UNARY_EXPR(EX,PEX_BoolNot);
		iter->LoopCondition = expr;
	}
	else
	{
		iter->LoopCondition = EX;
	}
	iter->LoopStatement = ST;
	iter->LoopBumper = NULL;
	iter->CheckAt = ZCC_IterationStmt::End;
	X = iter;
}
// for (init; cond; bump) statement
iteration_statement(X) ::= FOR LPAREN for_init(IN) SEMICOLON opt_expr(EX) SEMICOLON for_bump(DO) RPAREN statement(ST).
{
	NEW_AST_NODE(IterationStmt, iter);
	iter->LoopCondition = EX;
	iter->LoopStatement = ST;
	iter->LoopBumper = DO;
	iter->CheckAt = ZCC_IterationStmt::Start;
	// The initialization expression appears outside the loop
	IN->AppendSibling(iter);
	// And the whole thing gets wrapped inside a compound statement in case the loop
	// initializer defined any variables.
	NEW_AST_NODE(CompoundStmt, wrap);
	wrap->Content = IN;
	X = wrap;
}

while_or_until(X) ::= WHILE.
{
	X.Int = ZCC_WHILE;
}
while_or_until(X) ::= UNTIL.
{
	X.Int = ZCC_UNTIL;
}

%type for_init{ZCC_Statement *}
for_init(X) ::= local_var(A).						{ X = A; }
for_init(X) ::= for_bump(A).						{ X = A; }

%type for_bump{ZCC_Statement *}
for_bump(X) ::= .									{ X = NULL; }
for_bump(X) ::= expression_statement(A).			{ X = A; }
for_bump(X) ::= assign_statement(A).				{ X = A; }

/*----- If Statements -----*/

/* 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.
%type selection_statement{ZCC_Statement *}
%type if_front{ZCC_IfStmt *}

selection_statement(X) ::= if_front(A). [IF]
{
	X = A;
}
selection_statement(X) ::= if_front(A) ELSE statement(B). [ELSE]
{
	A->FalsePath = B;
	X = A;
}

if_front(X) ::= IF LPAREN expr(A) RPAREN statement(B).
{
	NEW_AST_NODE(IfStmt,stmt);
	stmt->Condition = A;
	stmt->TruePath = B;
	stmt->FalsePath = NULL;
	X = stmt;
}

/*----- Switch Statements -----*/

selection_statement(X) ::= SWITCH LPAREN expr(A) RPAREN statement(B).
{
	NEW_AST_NODE(SwitchStmt,stmt);
	stmt->Condition = A;
	stmt->Content = B;
	X = stmt;
}

/*----- Case Label "Statements" -----*/

%type labeled_statement{ZCC_CaseStmt *}

labeled_statement(X) ::= CASE expr(A) COLON.
{
	NEW_AST_NODE(CaseStmt,stmt);
	stmt->Condition = A;
	X = stmt;
}
labeled_statement(X) ::= DEFAULT COLON.
{
	NEW_AST_NODE(CaseStmt,stmt);
	stmt->Condition = NULL;
	X = stmt;
}

/*----- Assignment Statements -----*/

%type assign_statement{ZCC_AssignStmt *}

assign_statement(X) ::= expr_list(A) assign_op(OP) expr_list(B). [EQ]
{
	NEW_AST_NODE(AssignStmt,stmt);
	stmt->AssignOp = OP.Int;
	stmt->Dests = A;
	stmt->Sources = B;
	X = stmt;
}

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 Variable Definition "Statements" -----*/

%type local_var{ZCC_LocalVarStmt *}

local_var(X) ::= type(A) variable_list(B) var_init(C).
{
	NEW_AST_NODE(LocalVarStmt,vardef);
	vardef->Type = A;
	vardef->Vars = B;
	vardef->Inits = C;
	X = vardef;
}

%type var_init{ZCC_Expression *}
var_init(X) ::= .						{ X = NULL; }
var_init(X) ::= EQ expr_list(A).		{ X = A; }