Axaprj.LexFeatExtr

Text Feature Extraction Formal Grammar Engine

• Takenet.Textc involved, uses own Takenet.Textc .Net Core port
• common info Formal Grammar
• common info Backus–Naur form

code

VS 2017, VS 2019, .NET Core v2.1

terms and naming

• Terminal Symbol - A Symbol that presented a particular input token or token sequence. The base element of Expressions.
• Non-Terminal Symbol - A Symbol that presented a particular Rule. The base element of Expressions and Rules.
• Rule - Matching non-terminal symbol to Expressions(joined by OR, ordered).
• Expression - Boolean expression (joined by AND Symbols, a Terminal Symbol is true when it conforms to corresponding by order input token, Non-Terminal Symbol is true when its Rule is true).
• Grammar - Set of Rules with a start Symbol.
• Product - Objects created when an input token is matching to Symbol. Non-terminal Products are collections of Products.
• Product - The whole text-processing result. Is a root node of tree with non-terminal Product nodes and terminal Product leaves.
• Production - Production Produces Product.
• Symbol Attribute - Specification of a Symbol. Implements token matching and Product creation.

example

Trivial grammar

Sum calculator

Lists parsing

Consumption info analyzer demo

Sample of specialized texts parsing. Randomly selected parts of specialized texts are used. Easy spacing preprocessing required. See the grammar in source Axaprj.LexFeatExtr.Tests.ConsumptionDemo. Texts and processing results are following:

• "its combined fuel consumption is reduced to up to 2.4 liters per 100 kilometers ( 98 mpg US ) , with CO 2 emissions of up to 56 grams per kilometer ."

Consumption[combined consumption 
	Vals[Val[val:2.4 l100km] ( Val[val:98 mpg] )]
]
CO2Val[val:56 gkm]

• "The lowest combined fuel consumption for the range is 7.9 L / 100 km for LS-U and LS-T 4 x 4 autos ( 209 CO 2 emissions ) , and peaks at 8.1 L / 100 km ( for all LS-T and LS-U 4 x 2 and LS-M 4 x 4 ) ."

Consumption[combined consumption 
    Vals[Val[val:7.9 l100km]]
]
// 8.1 value omitted -  bug of the current demo grammar

• "Its combined fuel consumption is 141.2 - 122.8 mpg , while CO 2 emissions are at least 49 g / km ."

Consumption[combined consumption 
	Vals[Val[[vfrom: 141.2, vto: 122.8] mpg]]
] 
CO2Val[val:49 gkm]

• "NEDC combined fuel consumption is 4.2 - 4.1 l / 100 km ( preliminary fuel consumption NEDC 1 : urban 4.9 - 4.8 l / 100 km ; extra - urban 3.8 - 3.6 l / 100 km ; combined 4.2 - 4.1 l / 100 km , 95 - 93 g / km CO 2 ;"

Consumption[combined consumption 
	Vals[Val[[vfrom: 4.2, vto: 4.1] l100km]]
] 
Consumption[consumption 
	Vals[
		Val[urban [vfrom: 4.9, vto: 4.8] l100km] ; 
		Val[exurban [vfrom: 3.8, vto: 3.6] l100km] ; 
		Val[combined [vfrom: 4.2, vto: 4.1] l100km] ,
	]
] 
CO2Val[[vfrom: 95, vto: 93] gkm]

authors

Axaprj, Igor Alexeev

You are welcome to Property Indicators Lab! We know how to use it in real projects. For any questions, please contact us at email [email protected].