diff options
Diffstat (limited to 'tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java')
-rw-r--r-- | tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java new file mode 100644 index 0000000..eacfd5a --- /dev/null +++ b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java @@ -0,0 +1,65 @@ +/* + * [The "BSD license"] + * Copyright (c) 2012 Terence Parr + * Copyright (c) 2012 Sam Harwell + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package org.antlr.v4.codegen.model; + +import org.antlr.v4.codegen.OutputModelFactory; +import org.antlr.v4.runtime.atn.DecisionState; +import org.antlr.v4.runtime.misc.IntervalSet; +import org.antlr.v4.tool.ast.GrammarAST; + +import java.util.List; + +/** (A B C)? */ +public class LL1OptionalBlockSingleAlt extends LL1Choice { + @ModelElement public SrcOp expr; + @ModelElement public List<SrcOp> followExpr; // might not work in template if size>1 + + public LL1OptionalBlockSingleAlt(OutputModelFactory factory, + GrammarAST blkAST, + List<CodeBlockForAlt> alts) + { + super(factory, blkAST, alts); + this.decision = ((DecisionState)blkAST.atnState).decision; + + /** Lookahead for each alt 1..n */ +// IntervalSet[] altLookSets = LinearApproximator.getLL1LookaheadSets(dfa); + IntervalSet[] altLookSets = factory.getGrammar().decisionLOOK.get(decision); + altLook = getAltLookaheadAsStringLists(altLookSets); + IntervalSet look = altLookSets[0]; + IntervalSet followLook = altLookSets[1]; + + IntervalSet expecting = look.or(followLook); + this.error = getThrowNoViableAlt(factory, blkAST, expecting); + + expr = addCodeForLookaheadTempVar(look); + followExpr = factory.getLL1Test(followLook, blkAST); + } +} |