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/*
* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.automata;
import org.antlr.v4.runtime.atn.ATN;
import org.antlr.v4.runtime.atn.ATNState;
import org.antlr.v4.tool.ast.ActionAST;
import org.antlr.v4.tool.ast.BlockAST;
import org.antlr.v4.tool.ast.GrammarAST;
import org.antlr.v4.tool.ast.PredAST;
import org.antlr.v4.tool.ast.TerminalAST;
import java.util.List;
public interface ATNFactory {
/** A pair of states pointing to the left/right (start and end) states of a
* state submachine. Used to build ATNs.
*/
public static class Handle {
public ATNState left;
public ATNState right;
public Handle(ATNState left, ATNState right) {
this.left = left;
this.right = right;
}
@Override
public String toString() {
return "("+left+","+right+")";
}
}
ATN createATN();
void setCurrentRuleName(String name);
void setCurrentOuterAlt(int alt);
Handle rule(GrammarAST ruleAST, String name, Handle blk);
ATNState newState();
Handle label(Handle t);
Handle listLabel(Handle t);
Handle tokenRef(TerminalAST node);
Handle set(GrammarAST associatedAST, List<GrammarAST> alts, boolean invert);
Handle charSetLiteral(GrammarAST charSetAST);
Handle range(GrammarAST a, GrammarAST b);
/** For a non-lexer, just build a simple token reference atom.
* For a lexer, a string is a sequence of char to match. That is,
* "fog" is treated as 'f' 'o' 'g' not as a single transition in
* the DFA. Machine== o-'f'->o-'o'->o-'g'->o and has n+1 states
* for n characters.
*/
Handle stringLiteral(TerminalAST stringLiteralAST);
/** For reference to rule r, build
*
* o-e->(r) o
*
* where (r) is the start of rule r and the trailing o is not linked
* to from rule ref state directly (it's done thru the transition(0)
* RuleClosureTransition.
*
* If the rule r is just a list of tokens, it's block will be just
* a set on an edge o->o->o-set->o->o->o, could inline it rather than doing
* the rule reference, but i'm not doing this yet as I'm not sure
* it would help much in the ATN->DFA construction.
*
* TODO add to codegen: collapse alt blks that are sets into single matchSet
* @param node
*/
Handle ruleRef(GrammarAST node);
/** From an empty alternative build Grip o-e->o */
Handle epsilon(GrammarAST node);
/** Build what amounts to an epsilon transition with a semantic
* predicate action. The pred is a pointer into the AST of
* the SEMPRED token.
*/
Handle sempred(PredAST pred);
/** Build what amounts to an epsilon transition with an action.
* The action goes into ATN though it is ignored during analysis.
*/
Handle action(ActionAST action);
Handle action(String action);
Handle alt(List<Handle> els);
/** From A|B|..|Z alternative block build
*
* o->o-A->o->o (last ATNState is blockEndATNState pointed to by all alts)
* | ^
* o->o-B->o--|
* | |
* ... |
* | |
* o->o-Z->o--|
*
* So every alternative gets begin ATNState connected by epsilon
* and every alt right side points at a block end ATNState. There is a
* new ATNState in the ATNState in the Grip for each alt plus one for the
* end ATNState.
*
* Special case: only one alternative: don't make a block with alt
* begin/end.
*
* Special case: if just a list of tokens/chars/sets, then collapse
* to a single edge'd o-set->o graph.
*
* Set alt number (1..n) in the left-Transition ATNState.
*/
Handle block(BlockAST blockAST, GrammarAST ebnfRoot, List<Handle> alternativeGrips);
// Handle notBlock(GrammarAST blockAST, Handle set);
/** From (A)? build either:
*
* o--A->o
* | ^
* o---->|
*
* or, if A is a block, just add an empty alt to the end of the block
*/
Handle optional(GrammarAST optAST, Handle blk);
/** From (A)+ build
*
* |---| (Transition 2 from A.right points at alt 1)
* v | (follow of loop is Transition 1)
* o->o-A-o->o
*
* Meaning that the last ATNState in A points back to A's left Transition ATNState
* and we add a new begin/end ATNState. A can be single alternative or
* multiple.
*
* During analysis we'll call the follow link (transition 1) alt n+1 for
* an n-alt A block.
*/
Handle plus(GrammarAST plusAST, Handle blk);
/** From (A)* build
*
* |---|
* v |
* o->o-A-o--o (Transition 2 from block end points at alt 1; follow is Transition 1)
* | ^
* o---------| (optional branch is 2nd alt of optional block containing A+)
*
* Meaning that the last (end) ATNState in A points back to A's
* left side ATNState and we add 3 new ATNStates (the
* optional branch is built just like an optional subrule).
* See the Aplus() method for more on the loop back Transition.
* The new node on right edge is set to RIGHT_EDGE_OF_CLOSURE so we
* can detect nested (A*)* loops and insert an extra node. Previously,
* two blocks shared same EOB node.
*
* There are 2 or 3 decision points in a A*. If A is not a block (i.e.,
* it only has one alt), then there are two decisions: the optional bypass
* and then loopback. If A is a block of alts, then there are three
* decisions: bypass, loopback, and A's decision point.
*
* Note that the optional bypass must be outside the loop as (A|B)* is
* not the same thing as (A|B|)+.
*
* This is an accurate ATN representation of the meaning of (A)*, but
* for generating code, I don't need a DFA for the optional branch by
* virtue of how I generate code. The exit-loopback-branch decision
* is sufficient to let me make an appropriate enter, exit, loop
* determination. See codegen.g
*/
Handle star(GrammarAST starAST, Handle blk);
/** Build an atom with all possible values in its label */
Handle wildcard(GrammarAST associatedAST);
Handle lexerAltCommands(Handle alt, Handle cmds);
Handle lexerCallCommand(GrammarAST ID, GrammarAST arg);
Handle lexerCommand(GrammarAST ID);
}
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