Class Extractor
BaseClass for an extractor strategy.
This class follows the pattern with inheritance from Lua classes.
Metamethods
| Extractor:__index (key) | Lookup of missing class members. |
Methods
| Extractor:create (...) | Create a new instance. |
| Extractor:_init (...) | Initialize a new instance. |
| Extractor:setType (str) | Set type |
| Extractor:hasType () | Has type |
| Extractor:getType () | Get the type of the strategy. |
| Extractor:addPattern (str, initial, final) | Add pattern Register a single pattern. |
| Extractor:addKeyword (str) | Add keyword Transform a single keyword to a registered set of patterns. |
| Extractor:addDelimiters (first, second[, exclude=false]) | Add delimiters Transform a pair of delimiters to a registered set of patterns. |
| Extractor:numPatterns () | Num patterns |
| Extractor:find (str, pos) | Try to find the string for this strategy. |
| Extractor:onCast (func) | Set the on-cast method. |
| Extractor:cast (str) | Cast the string into the correct type for this strategy. |
| Extractor:placeholder () | Get the placeholder for this strategy. |
Metamethods
- Extractor:__index (key)
-
Lookup of missing class members.
Parameters:
- key string lookup of member
Returns:
anyRaises:
on wrong arguments
Methods
- Extractor:create (...)
-
Create a new instance.
Parameters:
- ... vararg forwarded to Extractor:_init
Returns:
self - Extractor:_init (...)
-
Initialize a new instance.
Parameters:
- ... vararg list of patterns
Returns:
self - Extractor:setType (str)
-
Set type
Parameters:
- str string to be used as type
Returns:
self - Extractor:hasType ()
-
Has type
Returns:
boolean - Extractor:getType ()
-
Get the type of the strategy.
All extractor strategies have an explicit type name.
Returns:
string - Extractor:addPattern (str, initial, final)
-
Add pattern
Register a single pattern.
Parameters:
- str string to be used for pattern
- initial number offset
- final number offset
Returns:
self - Extractor:addKeyword (str)
-
Add keyword
Transform a single keyword to a registered set of patterns.
Parameters:
- str string to be used for keywords
Returns:
self - Extractor:addDelimiters (first, second[, exclude=false])
-
Add delimiters
Transform a pair of delimiters to a registered set of patterns.
Parameters:
Returns:
self - Extractor:numPatterns ()
-
Num patterns
Returns:
number - Extractor:find (str, pos)
-
Try to find the string for this strategy.
The goodness of the match is given by the returned position.
If found it should return a position and the found string.
Parameters:
- str string used as the extraction source
- pos number for an inclusive index where extraction starts
Returns:
nil or number,numberRaises:
on wrong arguments - Extractor:onCast (func)
-
Set the on-cast method.
Parameters:
- func function
Returns:
self - Extractor:cast (str)
-
Cast the string into the correct type for this strategy.
Parameters:
- str string used as the extraction source (unused)
Returns:
anyRaises:
Unconditional error unless handler exist - Extractor:placeholder ()
-
Get the placeholder for this strategy.
Returns:
string