Examples with AltBlock org.antlr.v4.codegen.model.AltBlock used on opensource projects

Example 1 with AltBlock

use of org.antlr.v4.codegen.model.AltBlock 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);
    }
}