CF Grammar improvements

Parser/private/CfGrammar.cpp

@@ -0,0 +1,62 @@
+
+#include "NewPlacement.hpp"
+#include "CfGrammar.hpp"
+
+using namespace tp;
+
+bool CfGrammar::compile() {
+
+	if (!rules.length()) {
+		printf("Grammar must have at leas one rule\n");
+		return false;
+	}
+
+	if (startTerminal == String()) {
+		printf("Using first rule's non-terminal as grammar's root. Define explicitly - 'Start : id'\n");
+		startTerminal = rules.first()->data.id;
+	}
+
+	// find all rules
+	for (auto rule : rules) {
+
+		if (!rule->args.length()) {
+			printf("Rule must have at leas one terminal or non-terminal. See rule '%s'\n", rule->id.read());
+			return false;
+		}
+
+		if (!mNonTerminals.presents(rule->id)) {
+			mNonTerminals.put(rule->id, {});
+		}
+		auto nonTerminal = &mNonTerminals.get(rule->id);
+
+		nonTerminal->rules.pushBack(&rule.data());
+	}
+
+	for (auto nonTerminal : mNonTerminals) {
+		for (auto rule : nonTerminal->val.rules) {
+			for (auto arg : rule->args) {
+
+				if (arg->isTerminal) {
+					mTerminals.put(rule->id, {});
+				} else {
+					auto idx = mNonTerminals.presents(arg->id);
+					if (!idx) {
+						printf("Referenced non-terminal '%s' is not defined\n", arg->id.read());
+						return false;
+					}
+					auto reference = &mNonTerminals.getSlotVal(idx);
+					reference->references.put(nonTerminal->key, &nonTerminal->val);
+					nonTerminal->val.referencing.put(arg->id, reference);
+				}
+			}
+		}
+	}
+
+	for (auto nonTerminal : mNonTerminals) {
+		if (!nonTerminal->val.references.size() && nonTerminal->key != startTerminal) {
+			printf("Non-terminal '%s' is defined but not used\n", nonTerminal->key.read());
+		}
+	}
+
+	return true;
+}