GrammarWML - Revision history

Bssarkar: /* Help Markup */ typofix: XMl -> XML

2026-04-25T13:12:13Z

‎Help Markup: typofix: XMl -> XML

Celtic Minstrel: /* Progressive Values */ Add new section covering AnimationWML's progressive values

2026-03-19T07:45:09Z

‎Progressive Values: Add new section covering AnimationWML's progressive values

Celtic Minstrel: Simplify a few very basic productions with special symbols

2026-03-19T07:26:04Z

Simplify a few very basic productions with special symbols

Celtic Minstrel: Summarize EBNF syntax at the top of the page, including the special extended syntax I'm using.

2026-03-19T07:19:56Z

Summarize EBNF syntax at the top of the page, including the special extended syntax I'm using.

Celtic Minstrel: /* Help Markup */ Add a new section describing Help markup

2026-03-19T07:11:29Z

‎Help Markup: Add a new section describing Help markup

Celtic Minstrel: /* Context-free Grammars */ Add new section covering Context-free grammar

2026-03-19T06:57:33Z

‎Context-free Grammars: Add new section covering Context-free grammar

Celtic Minstrel: Remove "Under Construction" note

2026-03-19T06:38:12Z

Remove "Under Construction" note

Celtic Minstrel: /* Wesnoth Formula Language */ Rewrite in EBNF

2026-03-19T06:37:52Z

‎Wesnoth Formula Language: Rewrite in EBNF

Celtic Minstrel: Update opening blurb

2026-03-19T06:17:19Z

Update opening blurb

Celtic Minstrel: /* WML Substitutions */ Rewrite in EBNF

2026-03-19T06:10:30Z

‎WML Substitutions: Rewrite in EBNF

@@ Line 158: / Line 158: @@
 == Help Markup ==
-This grammar defines the [[help markup]] used in Wesnoth help topics and GUI2 rich labels. It's ''almost'' HTML and ''almost'' XMl but not quite either.
+This grammar defines the [[help markup]] used in Wesnoth help topics and GUI2 rich labels. It's ''almost'' HTML and ''almost'' XML but not quite either.
 <syntaxhighlight lang=ebnf>

@@ Line 180: / Line 180: @@
 name = name_char , {name_char} ;
 name_char = ?letter? | ?digit? | '_'
 </syntaxhighlight>
 [[Category:WML Reference]]

@@ Line 15: / Line 15: @@
 ** <tt>?newline?</tt>, <tt>?tab?</tt>, and <tt>?space?</tt> represent the named non-printable characters.
 ** <tt>?unicode?</tt> represents any valid Unicode character.
 == WML Preprocessor ==
@@ Line 55: / Line 58: @@
 comparison_op = '<' | '<=' | '==' | '!=' | '>=' | '>' ;
 version_string = integer , ['.' , integer] ;
-integer = digit , {digit} ;
+integer = ?digit? , {?digit?} ;
 </syntaxhighlight>
@@ Line 75: / Line 77: @@
 raw_string = '<<' , {?unicode? - '>' | '>' , ?unicode? - '>'} , '>>' ;
 textdomain = '#textdomain' domain_char , {domain_char} , ?newline? ;
-wml_id_char = lowercase | uppercase | digit | '_' ;
+wml_id_char = ?letter? | ?digit? | '_' ;
 domain_char = wml_id_char | '-' ;
 </syntaxhighlight>
@@ Line 93: / Line 90: @@
 wml_var_path = {wml_var_name , [wml_var_index] , '.'} , wml_var_name ;
 wml_var_name = wml_id_char, {wml_id_char} ; (* wml_id_char is defined in the WML grammar, above *)
-wml_var_index = '[' , digit , {digit} , ']' ; (* as is digit *)
+wml_var_index = '[' , ?digit? , {?digit?} , ']' ;
 wml_var_default = '?' , default_char, {default_char} , '|' ;
 default_char = ?unicode? - '|' ;
@@ Line 107: / Line 104: @@
 production = symbol , '=' , alternative , {'|' , alternative} , ?newline? ;
 symbol = symbol_char , {symbol_char} ;
-symbol_char = lowercase | uppercase | digit | '_' ; (* Unsure on this, need to check it *)
+symbol_char = ?letter? | ?digit? | '_' ; (* Unsure on this, need to check it *)
 alternative = {terminal} ;
 terminal = '{' , symbol , '}' | '{!}' | '{(}' | '{)}' | (?unicode? - '}') ;
@@ Line 146: / Line 143: @@
 wfl_value = 'functions' | wfl_name | wfl_number | wfl_string | wfl_container | wfl_function_call ;
 wfl_name = wfl_id_char , {wfl_id_char} ;
-wfl_id_char = lowercase | uppercase | '_' ; (* Note: digits are NOT allowed! *)
+wfl_id_char = ?letter? | '_' ; (* Note: digits are NOT allowed! *)
-wfl_number = digit , {digit} , ['.' , digit , {digit}] ;
+wfl_number = ?digit? , {?digit?} , ['.' , ?digit? , {?digit?}] ;
 wfl_string = "'" , {wfl_string_char | wfl_string_subst | wfl_string_escape} , "'" ;
 wfl_string_char = ?unicode? - ("'" | "[") ;
@@ Line 168: / Line 165: @@
 literal = ?unicode? - ('<' , '&' , '\') ;
 escape = '\' , ?unicode? ;
-entity = '&#' , digit , {digit} , ';'
+entity = '&#' , ?digit? , {?digit?} , ';'
-        | '&#x' , hexdigit , {hexdigit} , ';'
+        | '&#x' , ?hexdigit? , {?hexdigit?} , ';'
         | '&' , name , ';'
+        ;
@@ Line 182: / Line 179: @@
+                 ;
 name = name_char , {name_char} ;
-digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' ;
+name_char = ?letter? | ?digit? | '_'
 </syntaxhighlight>
 [[Category:WML Reference]]

@@ Line 1: / Line 1: @@
 {{WML Tags}}
-This page contains a formal grammar of the Wesnoth domain-specific languages, including WML and its preprocessor. It does not attempt to capture any of the ways that the Wesnoth engine may interpret a string, such as WML variable substitution. It also doesn't fully capture the potential consequences of macros, for example the use of unbalanced WML tags. The syntax used is [https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form Extended Backus-Naur form].
+This page contains a formal grammar of the Wesnoth domain-specific languages, including WML and its preprocessor. It does not attempt to capture any of the ways that the Wesnoth engine may interpret a string, such as WML variable substitution. It also doesn't fully capture the potential consequences of macros, for example the use of unbalanced WML tags. The syntax used is [https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form Extended Backus-Naur form]:
 == WML Preprocessor ==
@@ Line 43: / Line 57: @@
 integer = digit , {digit} ;
 digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' ;
 </syntaxhighlight>
@@ Line 58: / Line 71: @@
 wml_value = wml_value_component , {'+' , [?newline? , [textdomain]] , wml_value_component} ;
 wml_value_component = text | ['_'] , (string | raw_string) ;
-text = {char - '+' | '"' | ?newline?} ;
+text = {?unicode? - '+' | '"' | ?newline?} ;
-string = '"' . {char - '"' | '""'} , '"' ;
+string = '"' . {?unicode? - '"' | '""'} , '"' ;
-raw_string = '<<' , {char - '>' | '>' , char - '>'} , '>>' ;
+raw_string = '<<' , {?unicode? - '>' | '>' , ?unicode? - '>'} , '>>' ;
 textdomain = '#textdomain' domain_char , {domain_char} , ?newline? ;
 wml_id_char = lowercase | uppercase | digit | '_' ;
@@ Line 69: / Line 82: @@
 digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' ;
 domain_char = wml_id_char | '-' ;
 </syntaxhighlight>
@@ Line 83: / Line 95: @@
 wml_var_index = '[' , digit , {digit} , ']' ; (* as is digit *)
 wml_var_default = '?' , default_char, {default_char} , '|' ;
-default_char = char - '|' ;
+default_char = ?unicode? - '|' ;
 wml_formula = '$' , '(' , wfl_document , ')' ;
 </syntaxhighlight>
@@ Line 97: / Line 109: @@
 symbol_char = lowercase | uppercase | digit | '_' ; (* Unsure on this, need to check it *)
 alternative = {terminal} ;
-terminal = '{' , symbol , '}' | '{!}' | '{(}' | '{)}' | (?any unicode character? - '}') ;
+terminal = '{' , symbol , '}' | '{!}' | '{(}' | '{)}' | (?unicode? - '}') ;
 </syntaxhighlight>
@@ Line 106: / Line 118: @@
 <syntaxhighlight lang=ebnf>
 wfl_comment = '#' , {wfl_comment_char} , '#' ;
-wfl_comment_char = char - '#' ;
+wfl_comment_char = ?unicode? - '#' ;
 wfl_file_run = 'wfl' , wfl_string , wfl_file_content , 'wflend' ;
 wfl_file_content = {?any token? - 'wflend'} ;
@@ Line 137: / Line 149: @@
 wfl_number = digit , {digit} , ['.' , digit , {digit}] ;
 wfl_string = "'" , {wfl_string_char | wfl_string_subst | wfl_string_escape} , "'" ;
-wfl_string_char = char - ("'" | "[") ;
+wfl_string_char = ?unicode? - ("'" | "[") ;
 wfl_string_subst = '[' , wfl_formula , ']' ;
 wfl_string_escape = "[']" | '[(]' | '[)]' ;
@@ Line 154: / Line 166: @@
 document = {text | tag} ;
 text = {literal | entity | escape} ;
-literal = ?any unicode character? - ('<' , '&' , '\') ;
+literal = ?unicode? - ('<' , '&' , '\') ;
-escape = '\' , ?any unicode character? ;
+escape = '\' , ?unicode? ;
 entity = '&#' , digit , {digit} , ';'
         | '&#x' , hexdigit , {hexdigit} , ';'
@@ Line 165: / Line 177: @@
+     ;
 attribute = name , ['=' , attribute_value] ;
-attribute_value = {?any unicode character? - ("'" | '"' | ?space?)} (* Unquoted value *)
+attribute_value = {?unicode? - ("'" | '"' | ?space?)} (* Unquoted value *)
                  | "'" , text - "'" , "'"
                  | '"' , text - '"' , '"'

@@ Line 145: / Line 145: @@
 wml_key_value = wfl_formula , '->' , wfl_formula ;
 wfl_function_call = wfl_name , '(' , [wfl_expression_list] , ')' ;
 </syntaxhighlight>
 [[Category:WML Reference]]

← Older revision		Revision as of 06:38, 19 March 2026
Line 1:		Line 1:
−	~~----~~
−
−	~~'''Note:''' This page is currently undergoing reconstruction. Information on the page may become misleading or occasionally wrong for brief periods of time.~~
−
−	~~----~~
−
	{{WML Tags}}		{{WML Tags}}
	This page contains a formal grammar of the Wesnoth domain-specific languages, including WML and its preprocessor. It does not attempt to capture any of the ways that the Wesnoth engine may interpret a string, such as WML variable substitution. It also doesn't fully capture the potential consequences of macros, for example the use of unbalanced WML tags. The syntax used is [https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form Extended Backus-Naur form].		This page contains a formal grammar of the Wesnoth domain-specific languages, including WML and its preprocessor. It does not attempt to capture any of the ways that the Wesnoth engine may interpret a string, such as WML variable substitution. It also doesn't fully capture the potential consequences of macros, for example the use of unbalanced WML tags. The syntax used is [https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form Extended Backus-Naur form].

@@ Line 97: / Line 97: @@
 This grammar describes the syntax of the [[Wesnoth Formula Language]]. Though it specifies the format of comments and file markers, they are not integrated into the main grammar since it treats the equivalently to whitespace. The grammar may not be completely accurate to the actual in-game parser.
- wfl_comment := '#' [^#]* '#'
+<syntaxhighlight lang=ebnf>
- wfl_file_run := 'wfl' wfl_string «any token»* 'wflend'
+wfl_comment = '#' , {wfl_comment_char} , '#' ;
- wfl_document := wfl_function_definition* wfl_formula
+wfl_comment_char = char - '#' ;
- wfl_function_definition := 'def' wfl_name '(' wfl_function_args ')' wfl_formula ';'
+wfl_file_run = 'wfl' , wfl_string , wfl_file_content , 'wflend' ;
- wfl_function_args := (wfl_function_arg (',' wfl_function_arg)*)?
+wfl_file_content = {?any token? - 'wflend'} ;
- wfl_function_arg := wfl_name '*'?
+wfl_document = {wfl_function_definition} , wfl_formula ;
- wfl_formula := 'not'? where_expression
+wfl_function_definition = 'def' , wfl_name , '(' , [wfl_function_args] , ')' , wfl_formula , ';' ;
- wfl_formula := bracketed_expression
+wfl_function_args = wfl_function_arg , {',' , wfl_function_arg} ;
- bracketed_expression := '(' wfl_formula ')'
+wfl_function_arg = wfl_name , ['*'] ;
- where_expression := (boolean_or_expression | bracketed_expression) ('where' wfl_variables)*
+wfl_formula = ['not'] , where_expression | bracketed_expression ;
- wfl_variables := wfl_variable (',' wfl_variable)*
+bracketed_expression = '(' , wfl_formula , ')' ;
- wfl_variable := wfl_name '=' wfl_formula
+where_expression = (boolean_or_expression | bracketed_expression) , {'where' , wfl_variables} ;
- boolean_or_expression := (boolean_and_expression | bracketed_expression) ('or' wfl_formula)*
+wfl_variables = wfl_variable , {',' , wfl_variable} ;
- boolean_and_expression := (comparison_expression | bracketed_expression) ('and' wfl_formula)*
+wfl_variable = wfl_name , '=' , wfl_formula ;
- comparison_expression := (containment_expression | bracketed_expression) (comparison_op wfl_formula)*
+boolean_or_expression = (boolean_and_expression | bracketed_expression) , {'or' , wfl_formula} ;
- comparison_op := '=' | '!=' | '<' | '>' | '<=' | '>='
+boolean_and_expression = (comparison_expression | bracketed_expression) , {'and' , wfl_formula} ;
- containment_expression := (range_expression | bracketed_expression) ('in' wfl_formula)*
+comparison_expression = (containment_expression | bracketed_expression) , {comparison_op , wfl_formula} ;
- range_expression := (additive_expression | bracketed_expression) ('~' wfl_formula)*
+comparison_op = '=' | '!=' | '<' | '>' | '<=' | '>=' ;
- additive_expression := negation_opt? (multiplicative_expression | bracketed_expression) (additive_op wfl_formula)*
+containment_expression = (range_expression | bracketed_expression) , {'in' , wfl_formula} ;
- negation_op := '-' | '+'
+range_expression = (additive_expression | bracketed_expression) , {'~' , wfl_formula} ;
- additive_op := '-' | '+' | '..'
+additive_expression = [negation_op] , (multiplicative_expression | bracketed_expression) , {additive_op , wfl_formula} ;
- multiplicative_expression := (exponent_expression | bracketed_expression) (multiplicative_op wfl_formula)*
+negation_op = '-' | '+' ;
- muliplicative_op := '*' | '/' | '%'
+additive_op = '-' | '+' | '..' ;
- exponent_expression := (wfl_formula '^')* (dice_expression | bracketed_expression)
+multiplicative_expression := (exponent_expression | bracketed_expression) , {multiplicative_op , wfl_formula} ;
- dice_expression := (dot_expression | bracketed_expression) ('d' wfl_formula)*
+muliplicative_op = '*' | '/' | '%' ;
- dot_expression := (wfl_value | bracketed_expression) ('.' wfl_formula)*
+exponent_expression = {wfl_formula , '^'} , (dice_expression | bracketed_expression) ;
- wfl_value := 'functions' | wfl_name | wfl_number | wfl_string | wfl_container | wfl_function_call
+dice_expression = (dot_expression | bracketed_expression) , {'d' , wfl_formula} ;
- wfl_name := [a-zA-Z_]+
+dot_expression = (wfl_value | bracketed_expression) , {'.' , wfl_formula} ;
- wfl_number := [0-9]+ ('.' [0-9]+)?
+wfl_value = 'functions' | wfl_name | wfl_number | wfl_string | wfl_container | wfl_function_call ;
- wfl_string := "'" ([^'[]+ | wfl_string_subst | wfl_string_escape)* "'"
+wfl_name = wfl_id_char , {wfl_id_char} ;
- wfl_string_subst := '[' wfl_formula ']'
+wfl_id_char = lowercase | uppercase | '_' ; (* Note: digits are NOT allowed! *)
- wfl_string_escape := "[']" | '[(]' | '[)]'
+wfl_number = digit , {digit} , ['.' , digit , {digit}] ;
- wfl_container := '[' ('->' | wfl_expression_list | wfl_key_value_list)? ']'
+wfl_string = "'" , {wfl_string_char | wfl_string_subst | wfl_string_escape} , "'" ;
- wfl_expression_list := wfl_formula (',' wfl_formula)*
+wfl_string_char = char - ("'" | "[") ;
- wfl_key_value_list := wfl_formula '->' wfl_formula (',' wfl_formula '->' wfl_formula)*
+wfl_string_subst = '[' , wfl_formula , ']' ;
- wfl_function_call := wfl_name '(' wfl_expression_list? ')'
+wfl_string_escape = "[']" | '[(]' | '[)]' ;
 [[Category:WML Reference]]

@@ Line 89: / Line 89: @@
 This grammar describes the syntax of WML substitutions, the syntax used to specify that variables should be substituted into the value of a WML attribute. The grammar here describes a single placeholder, without regard to the fact that they can be nested. Thus, parsing a string using this grammar would only succeed if done from right to left ''while'' performing the substitutions.
- wml_substitution := wml_var | wml_formula | '$|'
+<syntaxhighlight lang=ebnf>
- wml_var := '$' wml_var_path (wml_var_default | '|')?
+wml_substitution = wml_var | wml_formula | '$|' ;
- wml_var_path := (wml_var_name wml_var_index? '.')* wml_var_name
+wml_var = '$' , wml_var_path , [wml_var_default | '|'] ;
- wml_var_name := [a-zA-Z0-9_]+
+wml_var_path = {wml_var_name , [wml_var_index] , '.'} , wml_var_name ;
- wml_var_index := '[' [0-9]+ ']'
+wml_var_name = wml_id_char, {wml_id_char} ; (* wml_id_char is defined in the WML grammar, above *)
- wml_var_default := '?' [^|]+ '|'
+wml_var_index = '[' , digit , {digit} , ']' ; (* as is digit *)
- wml_formula := '$' '(' wfl_document ')'
+wml_var_default = '?' , default_char, {default_char} , '|' ;
 == Wesnoth Formula Language ==