C# Class Loyc.LLParserGenerator.CodeGenHelperBase

See IPGCodeGenHelper.CreateTryWrapperForRecognizer for more information.

Generates code for the default error branch of prediction (called when there is no explicit error branch).

Generate code to check an and-predicate during or after prediction, e.g. &!{foo} becomes !(foo) during prediction and Check(!(foo)); afterward.

LLLPG substitutes $LI and $LA before it calls this method. This method can return null to suppress the Check statement.

Generate code to match a set, e.g. @{ MatchRange('a', 'z'); or @{ MatchExcept('\n', '\r'); }. If the set is too complex, a declaration for it is created in classBody.

Returns (Skip()), or (MatchAny()) if the result is to be saved.

Generates code to read LA(k).

Returns the data type of LA(k)

Sets ListType and/or ListInitializer based on an expression. A statement like Type x = expr sets ListType = Type and ListInitializer = expr; A statement like Type x just sets ListType = Type; and any other expression expr sets ListInitializer = expr.

Decides whether to use a switch() and for which cases, using BaseCostForSwitch and GetRelativeCostForSwitch.

Returns an LNode representing a call to the specified LLLPG API. For example, if the user used a "inputSource=input" option, then ApiCall(_Match, F.Literal('7')) would generate a node that represents input.Match('7').

Returns an LNode representing a call to the specified LLLPG API. For example, if the user used a "inputSource=input" option, then ApiCall(_Match, F.Literal('7')) would generate a node that represents input.Match('7').

Generates a declaration for a variable that holds the set.

For example, if setName is foo, a set such as [aeiouy] might use an external declaration such as HashSet<int> foo = NewSet('a', 'e', 'i', 'o', 'u', 'y');

Generates code to test whether a terminal is in the set.

At first, LLParserGenerator calls this method with setName == null. If it returns null, it calls the method a second time, giving the name of an external variable in which the set is held (see GenerateSetDecl(IPGTerminalSet)). For example, if the subject is @la0, the test for a simple set like [a-z?] might be something like (la0 >= 'a' && 'z' >= la0) || la0 == '?'. When the setName is foo, the test might be foo.Contains(la0) instead.

Gets the literals or symbols to use for switch cases of a set (just the values, not including the case labels.)

Used to help decide whether a "switch" or an if statement will be used to handle a prediction tree, and if so which branches. This method should calculate the "cost of switch" (which generally represents a code size penalty, as there is a separate case for every element of the set) and the "cost of if" (which generally represents a speed penalty) and return the difference (so that positive numbers favor "switch" and negative numbers favor "if".)

If the set is inverted, return a something like -1000000 to ensure 'switch' is not used for that set.