From 3a5ccdfc13436e823976fb30e1a73c6581aeb199 Mon Sep 17 00:00:00 2001
From: Riccardo Azzolini <riccardo4096@gmail.com>
Date: Wed, 30 Jan 2019 19:58:47 +0100
Subject: [PATCH] Keep track of sub-function identifier tokens for error
 reporting

---
 .../math/rules/dsl/frontend/Parser.java       | 25 ++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/it/cavallium/warppi/math/rules/dsl/frontend/Parser.java b/core/src/main/java/it/cavallium/warppi/math/rules/dsl/frontend/Parser.java
index c7f50e73..8349f453 100644
--- a/core/src/main/java/it/cavallium/warppi/math/rules/dsl/frontend/Parser.java
+++ b/core/src/main/java/it/cavallium/warppi/math/rules/dsl/frontend/Parser.java
@@ -30,6 +30,10 @@ public class Parser {
 	private final Consumer<? super DslException> errorReporter;
 	private int current = 0;
 
+	// For error reporting
+	private String currentRuleName;
+	private final Map<String, Map<SubFunctionPattern, List<Token>>> subFunctionIdentifiers = new HashMap<>();
+
 	public Parser(final List<Token> tokens, final Consumer<? super DslException> errorReporter) {
 		this.tokens = tokens;
 		this.errorReporter = errorReporter;
@@ -39,6 +43,10 @@ public class Parser {
 		return rules();
 	}
 
+	public List<Token> getSubFunctionIdentifiers(final String ruleName, final SubFunctionPattern subFunction) {
+		return subFunctionIdentifiers.get(ruleName).get(subFunction);
+	}
+
 	// rules = { rule } , EOF ;
 	private List<PatternRule> rules() {
 		final List<PatternRule> rules = new ArrayList<>();
@@ -59,6 +67,7 @@ public class Parser {
 	private PatternRule rule() throws UnexpectedTokenException {
 		final RuleType type = ruleType();
 		final String name = matchOrFail(IDENTIFIER).lexeme;
+		currentRuleName = name; // This field must be set before calling pattern() and replacements()
 		matchOrFail(COLON);
 		final Pattern target = pattern();
 		matchOrFail(ARROW);
@@ -212,7 +221,9 @@ public class Parser {
 			case NUMBER:
 				return new NumberPattern(new BigDecimal(curToken.lexeme));
 			case IDENTIFIER:
-				return new SubFunctionPattern(curToken.lexeme);
+				final SubFunctionPattern subFunction = new SubFunctionPattern(curToken.lexeme);
+				saveSubFunctionIdentifier(subFunction, curToken);
+				return subFunction;
 			case LEFT_PAREN:
 				final Pattern grouped = sum();
 				matchOrFail(RIGHT_PAREN);
@@ -221,6 +232,18 @@ public class Parser {
 		throw new UnexpectedTokenException(curToken);
 	}
 
+	private void saveSubFunctionIdentifier(final SubFunctionPattern subFunction, final Token curToken) {
+		final Map<SubFunctionPattern, List<Token>> ruleMap = subFunctionIdentifiers.computeIfAbsent(
+				currentRuleName,
+				key -> new HashMap<>()
+		);
+		final List<Token> subFunctionList = ruleMap.computeIfAbsent(
+				subFunction,
+				key -> new ArrayList<>()
+		);
+		subFunctionList.add(curToken);
+	}
+
 	private Pattern matchLeftAssoc(
 			final PatternParser operandParser,
 			final Map<TokenType, BiFunction<Pattern, Pattern, Pattern>> operators