Examples with LeftRecursiveRuleAltInfo org.antlr.v4.analysis.LeftRecursiveRuleAltInfo used on opensource projects

Example 11 with LeftRecursiveRuleAltInfo

use of org.antlr.v4.analysis.LeftRecursiveRuleAltInfo in project antlr4 by antlr.

the class OutputModelController method buildLeftRecursiveRuleFunction.

public void buildLeftRecursiveRuleFunction(LeftRecursiveRule r, LeftRecursiveRuleFunction function) {
    buildNormalRuleFunction(r, function);
    // now inject code to start alts
    CodeGenerator gen = delegate.getGenerator();
    STGroup codegenTemplates = gen.getTemplates();
    // pick out alt(s) for primaries
    CodeBlockForOuterMostAlt outerAlt = (CodeBlockForOuterMostAlt) function.code.get(0);
    List<CodeBlockForAlt> primaryAltsCode = new ArrayList<CodeBlockForAlt>();
    SrcOp primaryStuff = outerAlt.ops.get(0);
    if (primaryStuff instanceof Choice) {
        Choice primaryAltBlock = (Choice) primaryStuff;
        primaryAltsCode.addAll(primaryAltBlock.alts);
    } else {
        // just a single alt I guess; no block
        primaryAltsCode.add((CodeBlockForAlt) primaryStuff);
    }
    // pick out alt(s) for op alts
    StarBlock opAltStarBlock = (StarBlock) outerAlt.ops.get(1);
    CodeBlockForAlt altForOpAltBlock = opAltStarBlock.alts.get(0);
    List<CodeBlockForAlt> opAltsCode = new ArrayList<CodeBlockForAlt>();
    SrcOp opStuff = altForOpAltBlock.ops.get(0);
    if (opStuff instanceof AltBlock) {
        AltBlock opAltBlock = (AltBlock) opStuff;
        opAltsCode.addAll(opAltBlock.alts);
    } else {
        // just a single alt I guess; no block
        opAltsCode.add((CodeBlockForAlt) opStuff);
    }
    // Insert code in front of each primary alt to create specialized ctx if there was a label
    for (int i = 0; i < primaryAltsCode.size(); i++) {
        LeftRecursiveRuleAltInfo altInfo = r.recPrimaryAlts.get(i);
        if (altInfo.altLabel == null)
            continue;
        ST altActionST = codegenTemplates.getInstanceOf("recRuleReplaceContext");
        altActionST.add("ctxName", Utils.capitalize(altInfo.altLabel));
        Action altAction = new Action(delegate, function.altLabelCtxs.get(altInfo.altLabel), altActionST);
        CodeBlockForAlt alt = primaryAltsCode.get(i);
        alt.insertOp(0, altAction);
    }
    // Insert code to set ctx.stop after primary block and before op * loop
    ST setStopTokenAST = codegenTemplates.getInstanceOf("recRuleSetStopToken");
    Action setStopTokenAction = new Action(delegate, function.ruleCtx, setStopTokenAST);
    outerAlt.insertOp(1, setStopTokenAction);
    // Insert code to set _prevctx at start of * loop
    ST setPrevCtx = codegenTemplates.getInstanceOf("recRuleSetPrevCtx");
    Action setPrevCtxAction = new Action(delegate, function.ruleCtx, setPrevCtx);
    opAltStarBlock.addIterationOp(setPrevCtxAction);
    // Insert code in front of each op alt to create specialized ctx if there was an alt label
    for (int i = 0; i < opAltsCode.size(); i++) {
        ST altActionST;
        LeftRecursiveRuleAltInfo altInfo = r.recOpAlts.getElement(i);
        String templateName;
        if (altInfo.altLabel != null) {
            templateName = "recRuleLabeledAltStartAction";
            altActionST = codegenTemplates.getInstanceOf(templateName);
            altActionST.add("currentAltLabel", altInfo.altLabel);
        } else {
            templateName = "recRuleAltStartAction";
            altActionST = codegenTemplates.getInstanceOf(templateName);
            altActionST.add("ctxName", Utils.capitalize(r.name));
        }
        altActionST.add("ruleName", r.name);
        // add label of any lr ref we deleted
        altActionST.add("label", altInfo.leftRecursiveRuleRefLabel);
        if (altActionST.impl.formalArguments.containsKey("isListLabel")) {
            altActionST.add("isListLabel", altInfo.isListLabel);
        } else if (altInfo.isListLabel) {
            delegate.getGenerator().tool.errMgr.toolError(ErrorType.CODE_TEMPLATE_ARG_ISSUE, templateName, "isListLabel");
        }
        Action altAction = new Action(delegate, function.altLabelCtxs.get(altInfo.altLabel), altActionST);
        CodeBlockForAlt alt = opAltsCode.get(i);
        alt.insertOp(0, altAction);
    }
}