1 files changed, 101 insertions, 0 deletions
diff --git a/Parser.cpp b/Parser.cpp
new file mode 100644
index 0000000..84c3217
--- /dev/null
+++ b/Parser.cpp
@@ -0,0 +1,101 @@
+#include <cstring>
+#include <sstream>
+#include <cstdarg>
+
+#include "Parser.h"
+
+using std::getline;
+
+ParserException::ParserException(const char * fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	size_t sz = vsnprintf(NULL, 0, fmt, args) + 1;
+	if (error != NULL) free(error);
+	error = (char *) malloc(sz);
+	vsnprintf(error, sz, fmt, args);
+	va_end(args);
+}
+
+ParserException::~ParserException() {
+	if (error != NULL)
+		free(error);
+}
+
+const char * ParserException::what() {
+	return error;
+}
+
+size_t Parser::filter(char * input) {
+	size_t
+		len = strlen(input),
+		offset = 0,
+		i = 0;
+
+	while (i < len) {
+		if(input[i] == '#') {
+			offset += len - i;
+			break;
+		}
+
+		size_t skip = strspn(input + i, " \t\n");
+		if (skip > 0) {
+			offset += skip;
+			i += skip;
+			continue;
+		}
+
+		input[i - offset] = input[i];
+		i++;
+	}
+
+	input[len - offset] = '\0';
+	return len - offset;
+}
+
+void Parser::set_circuit(Circuit & circuit) {
+	this->circuit = &circuit;
+}
+
+void Parser::parse(istream & input) {
+	unsigned linenum = 0;
+	string line_str;
+	while (getline(input, line_str)) {
+		linenum++;
+		char* line = line_str.data();
+		size_t len = Parser::filter(line);
+
+		if (len == 0) continue; // ignore empty lines
+
+		char* label = strtok(line, ":");
+		if (label == NULL) throw ParserException("syntax error on line %u", linenum);
+
+		char* content = strtok(NULL, ";");
+		if (content == NULL) throw ParserException("syntax error on line %u", linenum);
+
+		vector<string> nodes;
+		while ((content = strtok(content, ",")) != NULL) {
+			nodes.push_back(content);
+			content = NULL;
+		}
+		
+		if (circuit == nullptr) throw ParserException("circuit is not initialized!");
+		circuit->create(label, nodes);
+	}
+}
+
+
+istream & operator >> (istream & s, Parser & parser) {
+	parser.parse(s);
+	return s;
+}
+
+istream & operator << (Parser & parser, istream & s) {
+	parser.parse(s);
+	return s;
+}
+
+void Parser::parse(string input) {
+	std::istringstream s(input);
+	parse(s);
+}
+