L-rule

Revision as of 13:30, 21 March 2010

Ph-rule (phonetic rule) is the formalism used for generating spelling changes in the UNL^arium framework.

When to use Ph-rules

Ph-rules are used for generating sound changes that produce spelling changes (such as "a">"an", "I am">"I'm", etc). They are also used to generate spelling conventions, such as the use of capital letters and punctuation marks.

When not to use Ph-rules

Ph-rules are not to be used for sound changes that do not affect spelling.

Syntax

The general syntax for Ph-rules is the following:

CONDITION := ACTION;

Where:

• CONDITION is a single form or a sequence of forms over which actions will take place; and
• ACTION is the action to be performed over each form or sequence of forms of the CONDITION.

CONDITION and ACTION may be expressed as:

• a character or string of characters, between quotes: ("a");
• a tag or list of tags, extracted from the UNDL Foundation tagset: (VOW);
• a combination of characters and tags: ("a",PRE);

Context-sensitiveness

Ph-rules are normally sensitive to the context and apply over a set of conditions. In this case, each form must be isolated between parentheses, which are automatically co-indexed between the CONDITION and the ACTION field, so that the action described inside the first parentheses of the ACTION field applies over the form inside the first parentheses of the CONDITION field, and so on.

• Simple Ph-rule
  • ("I am"):=("I'm"); (replace "I am" by "I'm")
• Complex Ph-rule
  • ("a",ART)(BLK)(VOW):=("an")()(); (replace "a" by "an" in front of a blank space and a vowel)

Types of Ph-rules

There are basically three types of Ph-rules:

• REPLACEMENT, when the number of parentheses on the CONDITION field is equal to the number of parentheses in the ACTION field:

(1)(2)(...)(N):=(1)(2)(...)(N);

• ADDITION, when the number of parentheses on the CONDITION field is lower than the number of parentheses in the ACTION field;

(1)(2)(...)(N):=(1)(2)(...)(N)(N+1)(...);

• DELETION, when the number of parentheses on the CONDITION field is greater than the number of parentheses in the ACTION field.

(1)(2)(...)(N):=(1)(2)(...)(N-1);

Examples

Observations

Rules will only be applied if all conditions are true

X:=”y”<”z”; ( “zabc” changes to “yabc”, but “abc” remains “abc” since there is no "z" to be replaced)

String fields are necessarily continuous

X:=”aaa”<”xyz”; ( “xyzbbb” changes to “aaabbb”, but “bxbybz” remains “bxbybz” since there is no continuous string "xyz" to be replaced)

Each action is applied only once (i.e, rules are not exhaustive)

PLR:=0>”s”; ("X" becomes "Xs", and not "Xssssss...")

The replacement rule applies only once to the same string

X:=”a”:”b”; ( “aaa” becomes “baa” and not “bbb”)

In prefixation and suffixation rules, the part to be deleted may be represented by the number of characters (without quotes)

In infixation rules, the position of the addition may be made with reference to the end of string by using "-".

In replacement rules, the part to be deleted may be omitted if the whole string is to be replaced

In replacement rules, the part to be deleted may be represented by an interval of characters in the format [beginning-end]

The symbol “^” is used for negation (“^MCL” means “not MCL”)

NOU&^MCL:=”x”:”y”; (If NOU and not MCL then replace “x” by “y”)

“<<” and “>>” add blank spaces^[1]

X:=”a”<<”b” (“bc” becomes “a bc” and not “abc”)

Common mistakes

• nou:= ”y”<”z”; (WRONG: Tags are case sensitive)
• NNN:= ”y”<”z”; (WRONG: NNN is not defined in the tagset)
• NOUFEM:=”y”<”z”; (WRONG: Tags must be separated by “&”)
• NOU,FEM:=”y”<”z”; (WRONG: Tags must be separated by “&”)
• NOU & FEM:=”y”<”z”; (WRONG: There can be no blank spaces between tags)
• X:=1<1; (WRONG: The left side must always be a string in a prefixation rule)
• X:=1>1; (WRONG: The right side must always be a string in a suffixation rule)
• X:=1; (WRONG: Replacement rules do not allow for numbers)
• X:=1:1; (WRONG: Replacement rules do not allow for numbers)

Complex a-rules

Complex a-rules are formed from the combination of simple a-rules:

• circumfixation (prefixation + suffixation), to add a prefix and a suffix at the same time
• prefixation + infixation, to add a prefix and a suffix at the same time
• infixation + suffixation, to add an infix and a suffix at the same time
• prefixation + infixation + suffixation, to add a prefix, an infix and a suffix at the same time

Syntax

Complex a-rules are formed by concatenating simple a-rules with ",":

circumfixation

CONDITION := “ADDED” < DELETED , DELETED > "ADDED";

prefixation + infixation

CONDITION := “ADDED” < DELETED , DELETED > "ADDED";

infixation + suffixation

CONDITION := DELETED > "ADDED" , "DELETED" > "ADDED";

etc.

Examples

Observations

Complex a-rules are also used to integrate different simple a-rules

Actions are applied from left to right (i.e., order is important)

PLR := "s" > "ses", "y" > "ies"; (kiss > kisses, city > cities)

PLR := "y" > "ies", "s" > "ses"; (kiss > kisses, city>cities>citieses)

Formal syntax

A-rules comply with the following syntax:

<A-RULE>           ::= <CONDITION> “:=” <ACTION> ("," <ACTION>)* “;”
<CONDITION>        ::= <ATAG>(“&”(“^”)?<ATAG>)*
<ATAG>             ::= {one of the tags defined in the UNDLF Tagset}
<ACTION>           ::= <PREFIXATION> | <SUFFIXATION> | <INFIXATION> | <REPLACEMENT>
<PREFIXATION>      ::= <ADDED>	 {“<” | “<<”} 	(<DELETED>)?
<SUFFIXATION>      ::= (<DELETED>)? {“>” | “>>”} 	<ADDED>
<INFIXATION>       ::= "["<DELETED"]" ">" <ADDED> | <ADDED> "<" "["<DELETED"]"
<REPLACEMENT>      ::= ( <STRING> ":" )? <ADDED> | "[" <INTEGER> "-" <INTEGER> "]" ":"  <ADDED>
<ADDED>            ::= <STRING> 
<DELETED>          ::= <STRING> | <INTEGER>  
<STRING>           ::= “ “ “ [a..Z]+ “ “ “
<INTEGER>          ::= [0..9]+

where

<a> = a is a non-terminal symbol
“a“ = a is a constant
a | b = a or b
{ a | b } = either a or b
(a)? = a can occur 0 or 1 time
(a)* = a can be repeated 0 or more times
(a)+ = a can be repeated 1 or more times

Notes

1. ↑ This feature is not supported by the UNL^dev and it is automatically replaced, in the UNL^arium, by a blank space.