Support older R versions

.github/workflows/full-test.yaml

@@ -18,7 +18,7 @@ jobs:
       fail-fast: false
       matrix:
         # currently we offer no official support for 3.x
-        r-version: [ '4.4.0', '4.3.2', '4.2.3', '4.0.0' ]
+        r-version: [ '4.4.0', '4.3.2', '4.2.3', '4.0.0', '3.6.3', '3.0.0', '2.15.3', '2.0.0', '1.9.1', '1.6.2' ]
         os: [ ubuntu-latest ]
         include:
            - os: macos-latest

src/r-bridge/lang-4.x/ast/model/type.ts

@@ -138,6 +138,10 @@ export const enum RawRType {
 	 * https://github.com/REditorSupport/languageserver/pull/328
 	 */
 	ExprOfAssignOrHelp = 'expr_or_assign_or_help',
+	/**
+	 * Pre-4.0 version of expr_or_assign_or_help, see {@link RawRType.ExprOfAssignOrHelp} documentation
+	 */
+	LegacyEqualAssign = 'equal_assign',
 	/** T65 */
 	ExpressionList = 'exprlist',
 }

src/r-bridge/lang-4.x/ast/parser/xml/internal/functions/normalize-call.ts

@@ -29,7 +29,7 @@ import { tryNormalizeSymbol } from '../values/normalize-symbol'
  */
 export function tryNormalizeFunctionCall(data: NormalizerData, mappedWithName: NamedXmlBasedJson[]): RFunctionCall | RNext | RBreak | undefined {
 	const fnBase = mappedWithName[0]
-	if(fnBase.name !== RawRType.Expression && fnBase.name !== RawRType.ExprOfAssignOrHelp) {
+	if(fnBase.name !== RawRType.Expression && fnBase.name !== RawRType.ExprOfAssignOrHelp && fnBase.name !== RawRType.LegacyEqualAssign) {
 		parseLog.trace(`expected function call name to be wrapped an expression, yet received ${fnBase.name}`)
 		return undefined
 	}

src/r-bridge/lang-4.x/ast/parser/xml/internal/loops/normalize-for.ts

@@ -25,7 +25,7 @@ export function tryNormalizeFor(
 		return undefined
 	} else if(head.name !== RawRType.ForCondition) {
 		throw new XmlParseError(`expected condition for for-loop but found ${JSON.stringify(head)}`)
-	} else if(body.name !== RawRType.Expression && body.name !== RawRType.ExprOfAssignOrHelp) {
+	} else if(body.name !== RawRType.Expression && body.name !== RawRType.ExprOfAssignOrHelp && body.name !== RawRType.LegacyEqualAssign) {
 		throw new XmlParseError(`expected expr body for for-loop but found ${JSON.stringify(body)}`)
 	}
 

src/r-bridge/lang-4.x/ast/parser/xml/internal/normalize-access.ts

@@ -80,7 +80,7 @@ export function tryNormalizeAccess(data: NormalizerData, mappedWithName: NamedXm
 	}
 
 	const accessed = mappedWithName[0]
-	if(accessed.name !== RawRType.Expression && accessed.name !== RawRType.ExprOfAssignOrHelp) {
+	if(accessed.name !== RawRType.Expression && accessed.name !== RawRType.ExprOfAssignOrHelp && accessed.name !== RawRType.LegacyEqualAssign) {
 		parseLog.trace(`expected accessed element to be wrapped an expression, yet received ${accessed.name}`)
 		return undefined
 	}

src/r-bridge/lang-4.x/ast/parser/xml/internal/structure/normalize-expressions.ts

@@ -79,7 +79,7 @@ function splitExprs(tokens: readonly NamedXmlBasedJson[]) {
 			lastExpr = false
 			last = i + 1
 		} else {
-			const thisExpr = token.name === RawRType.Expression || token.name === RawRType.ExprOfAssignOrHelp
+			const thisExpr = token.name === RawRType.Expression || token.name === RawRType.ExprOfAssignOrHelp || token.name === RawRType.LegacyEqualAssign
 			if(thisExpr && lastExpr) {
 				if(i > last) {
 					segments.push(tokens.slice(last, i))

src/r-bridge/lang-4.x/ast/parser/xml/internal/structure/normalize-single-node.ts

@@ -38,6 +38,7 @@ export function normalizeSingleNode(data: NormalizerData, elem: NamedXmlBasedJso
 		case RawRType.ExpressionList:
 		case RawRType.Expression:
 		case RawRType.ExprOfAssignOrHelp:
+		case RawRType.LegacyEqualAssign:
 			return normalizeExpression(data, elem.content)
 		case RawRType.NumericConst:
 			return normalizeNumber(data, elem.content)