existing.at

GNU的词法/语法分析器bison源码

	  DELIMITED
		{ delim_flag = 0; }
	  until
		{
		  if (yychar < 0)
		    do_lookahead();
		  copy_rest_thru($4, $6);
		  a_delete $4;
		  a_delete $6;
		}
	| FOR VARIABLE '=' expr TO expr optional_by DO
		{ delim_flag = 1; }
	  DELIMITED
		{
		  delim_flag = 0;
		  if (yychar < 0)
		    do_lookahead();
		  do_for($2, $4, $6, $7.is_multiplicative, $7.val, $10);
		}
	| simple_if
		{
		  if (yychar < 0)
		    do_lookahead();
		  if ($1.x != 0.0)
		    push_body($1.body);
		  a_delete $1.body;
		}
	| simple_if ELSE
		{ delim_flag = 1; }
	  DELIMITED
		{
		  delim_flag = 0;
		  if (yychar < 0)
		    do_lookahead();
		  if ($1.x != 0.0)
		    push_body($1.body);
		  else
		    push_body($4);
		  a_delete $1.body;
		  a_delete $4;
		}
	| reset_variables
	| RESET
		{ define_variable("scale", 1.0); }
	;

reset_variables:
	RESET VARIABLE
		{
		  reset($2);
		  a_delete $2;
		}
	| reset_variables VARIABLE
		{
		  reset($2);
		  a_delete $2;
		}
	| reset_variables ',' VARIABLE
		{
		  reset($3);
		  a_delete $3;
		}
	;

print_args:
	print_arg
		{ $$ = $1; }
	| print_args print_arg
		{
		  $$.str = new char[strlen($1.str) + strlen($2.str) + 1];
		  strcpy($$.str, $1.str);
		  strcat($$.str, $2.str);
		  a_delete $1.str;
		  a_delete $2.str;
		  if ($1.filename) {
		    $$.filename = $1.filename;
		    $$.lineno = $1.lineno;
		  }
		  else if ($2.filename) {
		    $$.filename = $2.filename;
		    $$.lineno = $2.lineno;
		  }
		}
	;

print_arg:
	expr							%prec ','
		{
		  $$.str = new char[GDIGITS + 1];
		  sprintf($$.str, "%g", $1);
		  $$.filename = 0;
		  $$.lineno = 0;
		}
	| text
		{ $$ = $1; }
	| position						%prec ','
		{
		  $$.str = new char[GDIGITS + 2 + GDIGITS + 1];
		  sprintf($$.str, "%g, %g", $1.x, $1.y);
		  $$.filename = 0;
		  $$.lineno = 0;
		}
	;

simple_if:
	IF any_expr THEN
		{ delim_flag = 1; }
	DELIMITED
		{
		  delim_flag = 0;
		  $$.x = $2;
		  $$.body = $5;
		}
	;

until:
	/* empty */
		{ $$ = 0; }
	| UNTIL TEXT
		{ $$ = $2.str; }
	;

any_expr:
	expr
		{ $$ = $1; }
	| text_expr
		{ $$ = $1; }
	;

text_expr:
	text EQUALEQUAL text
		{
		  $$ = strcmp($1.str, $3.str) == 0;
		  a_delete $1.str;
		  a_delete $3.str;
		}
	| text NOTEQUAL text
		{
		  $$ = strcmp($1.str, $3.str) != 0;
		  a_delete $1.str;
		  a_delete $3.str;
		}
	| text_expr ANDAND text_expr
		{ $$ = ($1 != 0.0 && $3 != 0.0); }
	| text_expr ANDAND expr
		{ $$ = ($1 != 0.0 && $3 != 0.0); }
	| expr ANDAND text_expr
		{ $$ = ($1 != 0.0 && $3 != 0.0); }
	| text_expr OROR text_expr
		{ $$ = ($1 != 0.0 || $3 != 0.0); }
	| text_expr OROR expr
		{ $$ = ($1 != 0.0 || $3 != 0.0); }
	| expr OROR text_expr
		{ $$ = ($1 != 0.0 || $3 != 0.0); }
	| '!' text_expr
		{ $$ = ($2 == 0.0); }
	;


optional_by:
	/* empty */
		{
		  $$.val = 1.0;
		  $$.is_multiplicative = 0;
		}
	| BY expr
		{
		  $$.val = $2;
		  $$.is_multiplicative = 0;
		}
	| BY '*' expr
		{
		  $$.val = $3;
		  $$.is_multiplicative = 1;
		}
	;

element:
	object_spec
		{
		  $$.obj = $1->make_object(&current_position,
					   &current_direction);
		  if ($$.obj == 0)
		    YYABORT;
		  delete $1;
		  if ($$.obj)
		    olist.append($$.obj);
		  else {
		    $$.x = current_position.x;
		    $$.y = current_position.y;
		  }
		}
	| LABEL ':' optional_separator element
		{
		  $$ = $4;
		  define_label($1, & $$);
		  a_delete $1;
		}
	| LABEL ':' optional_separator position_not_place
		{
		  $$.obj = 0;
		  $$.x = $4.x;
		  $$.y = $4.y;
		  define_label($1, & $$);
		  a_delete $1;
		}
	| LABEL ':' optional_separator place
		{
		  $$ = $4;
		  define_label($1, & $$);
		  a_delete $1;
		}
	| '{'
		{
		  $<state>$.x = current_position.x;
		  $<state>$.y = current_position.y;
		  $<state>$.dir = current_direction;
		}
	  element_list '}'
		{
		  current_position.x = $<state>2.x;
		  current_position.y = $<state>2.y;
		  current_direction = $<state>2.dir;
		}
	  optional_element
		{
		  $$ = $3;
		}
	| placeless_element
		{
		  $$.obj = 0;
		  $$.x = current_position.x;
		  $$.y = current_position.y;
		}
	;

optional_element:
	/* empty */
		{}
	| element
		{}
	;

object_spec:
	BOX
		{ $$ = new object_spec(BOX_OBJECT); }
	| CIRCLE
		{ $$ = new object_spec(CIRCLE_OBJECT); }
	| ELLIPSE
		{ $$ = new object_spec(ELLIPSE_OBJECT); }
	| ARC
		{
		  $$ = new object_spec(ARC_OBJECT);
		  $$->dir = current_direction;
		}
	| LINE
		{
		  $$ = new object_spec(LINE_OBJECT);
		  lookup_variable("lineht", & $$->segment_height);
		  lookup_variable("linewid", & $$->segment_width);
		  $$->dir = current_direction;
		}
	| ARROW
		{
		  $$ = new object_spec(ARROW_OBJECT);
		  lookup_variable("lineht", & $$->segment_height);
		  lookup_variable("linewid", & $$->segment_width);
		  $$->dir = current_direction;
		}
	| MOVE
		{
		  $$ = new object_spec(MOVE_OBJECT);
		  lookup_variable("moveht", & $$->segment_height);
		  lookup_variable("movewid", & $$->segment_width);
		  $$->dir = current_direction;
		}
	| SPLINE
		{
		  $$ = new object_spec(SPLINE_OBJECT);
		  lookup_variable("lineht", & $$->segment_height);
		  lookup_variable("linewid", & $$->segment_width);
		  $$->dir = current_direction;
		}
	| text							%prec TEXT
		{
		  $$ = new object_spec(TEXT_OBJECT);
		  $$->text = new text_item($1.str, $1.filename, $1.lineno);
		}
	| PLOT expr
		{
		  $$ = new object_spec(TEXT_OBJECT);
		  $$->text = new text_item(format_number(0, $2), 0, -1);
		}
	| PLOT expr text
		{
		  $$ = new object_spec(TEXT_OBJECT);
		  $$->text = new text_item(format_number($3.str, $2),
					   $3.filename, $3.lineno);
		  a_delete $3.str;
		}
	| '['
		{
		  saved_state *p = new saved_state;
		  $<pstate>$ = p;
		  p->x = current_position.x;
		  p->y = current_position.y;
		  p->dir = current_direction;
		  p->tbl = current_table;
		  p->prev = current_saved_state;
		  current_position.x = 0.0;
		  current_position.y = 0.0;
		  current_table = new PTABLE(place);
		  current_saved_state = p;
		  olist.append(make_mark_object());
		}
	  element_list ']'
		{
		  current_position.x = $<pstate>2->x;
		  current_position.y = $<pstate>2->y;
		  current_direction = $<pstate>2->dir;
		  $$ = new object_spec(BLOCK_OBJECT);
		  olist.wrap_up_block(& $$->oblist);
		  $$->tbl = current_table;
		  current_table = $<pstate>2->tbl;
		  current_saved_state = $<pstate>2->prev;
		  delete $<pstate>2;
		}
	| object_spec HEIGHT expr
		{
		  $$ = $1;
		  $$->height = $3;
		  $$->flags |= HAS_HEIGHT;
		}
	| object_spec RADIUS expr
		{
		  $$ = $1;
		  $$->radius = $3;
		  $$->flags |= HAS_RADIUS;
		}
	| object_spec WIDTH expr
		{
		  $$ = $1;
		  $$->width = $3;
		  $$->flags |= HAS_WIDTH;
		}
	| object_spec DIAMETER expr
		{
		  $$ = $1;
		  $$->radius = $3/2.0;
		  $$->flags |= HAS_RADIUS;
		}
	| object_spec expr					%prec HEIGHT
		{
		  $$ = $1;
		  $$->flags |= HAS_SEGMENT;
		  switch ($$->dir) {
		  case UP_DIRECTION:
		    $$->segment_pos.y += $2;
		    break;
		  case DOWN_DIRECTION:
		    $$->segment_pos.y -= $2;
		    break;
		  case RIGHT_DIRECTION:
		    $$->segment_pos.x += $2;
		    break;
		  case LEFT_DIRECTION:
		    $$->segment_pos.x -= $2;
		    break;
		  }
		}
	| object_spec UP
		{
		  $$ = $1;
		  $$->dir = UP_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.y += $$->segment_height;
		}
	| object_spec UP expr
		{
		  $$ = $1;
		  $$->dir = UP_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.y += $3;
		}
	| object_spec DOWN
		{
		  $$ = $1;
		  $$->dir = DOWN_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.y -= $$->segment_height;
		}
	| object_spec DOWN expr
		{
		  $$ = $1;
		  $$->dir = DOWN_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.y -= $3;
		}
	| object_spec RIGHT
		{
		  $$ = $1;
		  $$->dir = RIGHT_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x += $$->segment_width;
		}
	| object_spec RIGHT expr
		{
		  $$ = $1;
		  $$->dir = RIGHT_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x += $3;
		}
	| object_spec LEFT
		{
		  $$ = $1;
		  $$->dir = LEFT_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x -= $$->segment_width;
		}
	| object_spec LEFT expr
		{
		  $$ = $1;
		  $$->dir = LEFT_DIRECTION;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x -= $3;
		}
	| object_spec FROM position
		{
		  $$ = $1;
		  $$->flags |= HAS_FROM;
		  $$->from.x = $3.x;
		  $$->from.y = $3.y;
		}
	| object_spec TO position
		{
		  $$ = $1;
		  if ($$->flags & HAS_SEGMENT)
		    $$->segment_list = new segment($$->segment_pos,
						   $$->segment_is_absolute,
						   $$->segment_list);
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x = $3.x;
		  $$->segment_pos.y = $3.y;
		  $$->segment_is_absolute = 1;
		  $$->flags |= HAS_TO;
		  $$->to.x = $3.x;
		  $$->to.y = $3.y;
		}
	| object_spec AT position
		{
		  $$ = $1;
		  $$->flags |= HAS_AT;
		  $$->at.x = $3.x;
		  $$->at.y = $3.y;
		  if ($$->type != ARC_OBJECT) {
		    $$->flags |= HAS_FROM;
		    $$->from.x = $3.x;
		    $$->from.y = $3.y;
		  }
		}
	| object_spec WITH path
		{
		  $$ = $1;
		  $$->flags |= HAS_WITH;
		  $$->with = $3;
		}
	| object_spec WITH position				%prec ','
		{
		  $$ = $1;
		  $$->flags |= HAS_WITH;
		  position pos;
		  pos.x = $3.x;
		  pos.y = $3.y;
		  $$->with = new path(pos);
		}
	| object_spec BY expr_pair
		{
		  $$ = $1;
		  $$->flags |= HAS_SEGMENT;
		  $$->segment_pos.x += $3.x;
		  $$->segment_pos.y += $3.y;
		}
	| object_spec THEN
		{
		  $$ = $1;
		  if ($$->flags & HAS_SEGMENT) {
		    $$->segment_list = new segment($$->segment_pos,
						   $$->segment_is_absolute,
						   $$->segment_list);
		    $$->flags &= ~HAS_SEGMENT;
		    $$->segment_pos.x = $$->segment_pos.y = 0.0;
		    $$->segment_is_absolute = 0;
		  }
		}
	| object_spec SOLID
		{
		  $$ = $1;	// nothing
		}
	| object_spec DOTTED
		{
		  $$ = $1;
		  $$->flags |= IS_DOTTED;
		  lookup_variable("dashwid", & $$->dash_width);
		}
	| object_spec DOTTED expr
		{
		  $$ = $1;
		  $$->flags |= IS_DOTTED;
		  $$->dash_width = $3;
		}
	| object_spec DASHED