SVG路径数据的EBNF语法指定为：
svg-path:
wsp* moveto-drawto-command-groups? wsp*
moveto-drawto-command-groups:
moveto-drawto-command-group
| moveto-drawto-command-group wsp* moveto-drawto-command-groups
moveto-drawto-command-group:
moveto wsp* drawto-commands?
drawto-commands:
drawto-command
| drawto-command wsp* drawto-commands
drawto-command:
closepath
| lineto
| horizontal-lineto
| vertical-lineto
| curveto
| smooth-curveto
| quadratic-bezier-curveto
| smooth-quadratic-bezier-curveto
| elliptical-arc
moveto:
( "M" | "m" ) wsp* moveto-argument-sequence
moveto-argument-sequence:
coordinate-pair
| coordinate-pair comma-wsp? lineto-argument-sequence
closepath:
("Z" | "z")
lineto:
( "L" | "l" ) wsp* lineto-argument-sequence
lineto-argument-sequence:
coordinate-pair
| coordinate-pair comma-wsp? lineto-argument-sequence
horizontal-lineto:
( "H" | "h" ) wsp* horizontal-lineto-argument-sequence
horizontal-lineto-argument-sequence:
coordinate
| coordinate comma-wsp? horizontal-lineto-argument-sequence
vertical-lineto:
( "V" | "v" ) wsp* vertical-lineto-argument-sequence
vertical-lineto-argument-sequence:
coordinate
| coordinate comma-wsp? vertical-lineto-argument-sequence
curveto:
( "C" | "c" ) wsp* curveto-argument-sequence
curveto-argument-sequence:
curveto-argument
| curveto-argument comma-wsp? curveto-argument-sequence
curveto-argument:
coordinate-pair comma-wsp? coordinate-pair comma-wsp? coordinate-pair
smooth-curveto:
( "S" | "s" ) wsp* smooth-curveto-argument-sequence
smooth-curveto-argument-sequence:
smooth-curveto-argument
| smooth-curveto-argument comma-wsp? smooth-curveto-argument-sequence
smooth-curveto-argument:
coordinate-pair comma-wsp? coordinate-pair
quadratic-bezier-curveto:
( "Q" | "q" ) wsp* quadratic-bezier-curveto-argument-sequence
quadratic-bezier-curveto-argument-sequence:
quadratic-bezier-curveto-argument
| quadratic-bezier-curveto-argument comma-wsp?
quadratic-bezier-curveto-argument-sequence
quadratic-bezier-curveto-argument:
coordinate-pair comma-wsp? coordinate-pair
smooth-quadratic-bezier-curveto:
( "T" | "t" ) wsp* smooth-quadratic-bezier-curveto-argument-sequence
smooth-quadratic-bezier-curveto-argument-sequence:
coordinate-pair
| coordinate-pair comma-wsp? smooth-quadratic-bezier-curveto-argument-sequence
elliptical-arc:
( "A" | "a" ) wsp* elliptical-arc-argument-sequence
elliptical-arc-argument-sequence:
elliptical-arc-argument
| elliptical-arc-argument comma-wsp? elliptical-arc-argument-sequence
elliptical-arc-argument:
nonnegative-number comma-wsp? nonnegative-number comma-wsp?
number comma-wsp flag comma-wsp? flag comma-wsp? coordinate-pair
coordinate-pair:
coordinate comma-wsp? coordinate
coordinate:
number
nonnegative-number:
integer-constant
| floating-point-constant
number:
sign? integer-constant
| sign? floating-point-constant
flag:
"0" | "1"
comma-wsp:
(wsp+ comma? wsp*) | (comma wsp*)
comma:
","
integer-constant:
digit-sequence
floating-point-constant:
fractional-constant exponent?
| digit-sequence exponent
fractional-constant:
digit-sequence? "." digit-sequence
| digit-sequence "."
exponent:
( "e" | "E" ) sign? digit-sequence
sign:
"+" | "-"
digit-sequence:
digit
| digit digit-sequence
digit:
"0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
wsp:
(#x20 | #x9 | #xD | #xA)
为了能够使用antlr3：
，我稍微修改了一下grammar Paths;
eval : svg_path;
svg_path:
wsp* moveto_drawto_command_groups? wsp*;
moveto_drawto_command_groups:
moveto_drawto_command_group
| moveto_drawto_command_group wsp* moveto_drawto_command_groups;
moveto_drawto_command_group:
moveto wsp* drawto_commands?;
drawto_commands:
drawto_command
| drawto_command wsp* drawto_commands;
drawto_command:
closepath
| lineto
| horizontal_lineto
| vertical_lineto
| curveto
| smooth_curveto
| quadratic_bezier_curveto
| smooth_quadratic_bezier_curveto
| elliptical_arc;
moveto:
( 'M' | 'm' ) wsp* moveto_argument_sequence;
moveto_argument_sequence:
coordinate_pair
| coordinate_pair comma_wsp? lineto_argument_sequence;
closepath:
('Z' | 'z');
lineto:
( 'L' | 'l' ) wsp* lineto_argument_sequence;
lineto_argument_sequence:
coordinate_pair
| coordinate_pair comma_wsp? lineto_argument_sequence;
horizontal_lineto:
( 'H' | 'h' ) wsp* horizontal_lineto_argument_sequence;
horizontal_lineto_argument_sequence:
coordinate
| coordinate comma_wsp? horizontal_lineto_argument_sequence;
vertical_lineto:
( 'V' | 'v' ) wsp* vertical_lineto_argument_sequence;
vertical_lineto_argument_sequence:
coordinate
| coordinate comma_wsp? vertical_lineto_argument_sequence;
curveto:
( 'C' | 'c' ) wsp* curveto_argument_sequence;
curveto_argument_sequence:
curveto_argument
| curveto_argument comma_wsp? curveto_argument_sequence;
curveto_argument:
coordinate_pair comma_wsp? coordinate_pair comma_wsp? coordinate_pair;
smooth_curveto:
( 'S' | 's' ) wsp* smooth_curveto_argument_sequence;
smooth_curveto_argument_sequence:
smooth_curveto_argument
| smooth_curveto_argument comma_wsp? smooth_curveto_argument_sequence;
smooth_curveto_argument:
coordinate_pair comma_wsp? coordinate_pair;
quadratic_bezier_curveto:
( 'Q' | 'q' ) wsp* quadratic_bezier_curveto_argument_sequence;
quadratic_bezier_curveto_argument_sequence:
quadratic_bezier_curveto_argument
| quadratic_bezier_curveto_argument comma_wsp?
quadratic_bezier_curveto_argument_sequence;
quadratic_bezier_curveto_argument:
coordinate_pair comma_wsp? coordinate_pair;
smooth_quadratic_bezier_curveto:
( 'T' | 't' ) wsp* smooth_quadratic_bezier_curveto_argument_sequence;
smooth_quadratic_bezier_curveto_argument_sequence:
coordinate_pair
| coordinate_pair comma_wsp? smooth_quadratic_bezier_curveto_argument_sequence;
elliptical_arc:
( 'A' | 'a' ) wsp* elliptical_arc_argument_sequence;
elliptical_arc_argument_sequence:
elliptical_arc_argument
| elliptical_arc_argument comma_wsp? elliptical_arc_argument_sequence;
elliptical_arc_argument:
nonnegative_number comma_wsp? nonnegative_number comma_wsp?
number comma_wsp flag comma_wsp? flag comma_wsp? coordinate_pair;
coordinate_pair:
coordinate comma_wsp? coordinate;
coordinate:
number;
nonnegative_number:
integer_constant
| floating_point_constant;
number:
sign? integer_constant
| sign? floating_point_constant;
flag:
'0' | '1';
comma_wsp:
(wsp+ comma? wsp*) | (comma wsp*);
comma:
',';
integer_constant:
digit_sequence;
floating_point_constant:
fractional_constant exponent?
| digit_sequence exponent;
fractional_constant:
digit_sequence? '.' digit_sequence
| digit_sequence '.';
exponent:
( 'e' | 'E' ) sign? digit_sequence;
sign:
'+' | '-';
digit_sequence:
digit
| digit digit_sequence;
digit:
('0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9');
wsp:
(' ' | '\t' | '\r'| '\n');
但是当我尝试生成解析器时，我收到以下警告和错误：
warning(200): Paths.g:6:5: Decision can match input such as "' '..'\n'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(211): Paths.g:7:29: [fatal] rule moveto_drawto_command_groups has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): Paths.g:11:12: Decision can match input such as "' '..'\n'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(211): Paths.g:12:16: [fatal] rule drawto_commands has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:27:25: [fatal] rule moveto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:34:25: [fatal] rule lineto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:39:36: [fatal] rule horizontal_lineto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): Paths.g:39:36: Decision can match input such as "'+'..'-' {'0'..'1', '2'..'9'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(211): Paths.g:44:34: [fatal] rule vertical_lineto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): Paths.g:44:34: Decision can match input such as "'+'..'-' {'0'..'1', '2'..'9'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(211): Paths.g:49:26: [fatal] rule curveto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:56:33: [fatal] rule smooth_curveto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:63:43: [fatal] rule quadratic_bezier_curveto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:71:50: [fatal] rule smooth_quadratic_bezier_curveto_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:76:33: [fatal] rule elliptical_arc_argument_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
warning(200): Paths.g:86:19: Decision can match input such as "{'0'..'1', '2'..'9'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): Paths.g:89:7: Decision can match input such as "'+'..'-' {'0'..'1', '2'..'9'}" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): Paths.g:95:6: Decision can match input such as "' '..'\n'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(211): Paths.g:100:24: [fatal] rule floating_point_constant has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:103:20: [fatal] rule fractional_constant has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
error(211): Paths.g:110:15: [fatal] rule digit_sequence has non-LL(*) decision due to recursive rule invocations reachable from alts 1,2. Resolve by left-factoring or using syntactic predicates or using backtrack=true option.
我使用antlr的方式是错误的，我对原始语法的修改是不正确的，还是原始语法不正确？