WIP parser

4 files changed, 124 insertions, 17 deletions

diff --git a/Parser.cpp b/Parser.cpp
index d76f11a..5774a0e 100644
--- a/Parser.cpp
+++ b/Parser.cpp
@@ -1,20 +1,105 @@
+#include <cstring>
+#include <sstream>
+#include <cstdarg>
+
 #include "Parser.h"
 
-void Parser::parse(string input) const {
-	std::cout << input << std::endl;
+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);
 }
 
-istream & Parser::parse(const Parser & parser, istream & s) const {
-	string temp(std::istreambuf_iterator<char>(s), {});
-	parse(temp);
-	return s;
+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::parse(istream & input) const {
+	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;
+		}
+		
+		handle_line(label, nodes);
+	}
+}
+
+void Parser::handle_line(string label, vector<string> nodes) const {
+	if (nodes.size() == 1) {
+		printf("node or net ");
+	} else {
+		printf("net ");
+	}
+
+	printf("[%s]\n", label.c_str());
 }
 
 istream & operator >> (istream & s, const Parser & parser) {
-	return parser.parse(parser, s);
+	parser.parse(s);
+	return s;
 }
 
 istream & operator << (const Parser & parser, istream & s) {
-	return parser.parse(parser, s);
+	parser.parse(s);
+	return s;
+}
+
+void Parser::parse(string input) const {
+	std::istringstream s(input);
+	parse(s);
 }
 
diff --git a/Parser.h b/Parser.h
index 58d062f..2124eab 100644
--- a/Parser.h
+++ b/Parser.h
@@ -2,16 +2,38 @@
 
 #include <iostream>
 #include <istream>
+#include <exception>
+#include <vector>
 
 using std::istream;
 using std::string;
+using std::vector;
+
+class ParserException : public std::exception {
+public:
+	ParserException(const char * fmt, ...);
+	~ParserException();
+	const char * what();
+
+private:
+	char * error = NULL;
+};
 
 class Parser {
 public:
 	void parse(string input) const;
+	void parse(istream & input) const;
+
+	/**
+	 * \brief preprocess (filter) line of input
+	 *
+	 * normalize whitespace and remove comments
+	 */
+	static size_t filter(char * input);
+
+	void handle_line(string label, vector<string> nodes) const;
 
 private:
-	istream & parse(const Parser & parser, istream & s) const;
 	friend istream & operator << (const Parser & parser, istream & s);
 	friend istream & operator >> (istream & s, const Parser & parser);
 };
diff --git a/circuits/full-adder.txt b/circuits/full-adder.txt
index d0c3854..9b85bc7 100644
--- a/circuits/full-adder.txt
+++ b/circuits/full-adder.txt
@@ -17,14 +17,14 @@ NODE9: AND;
 NODE10: AND;
 NODE11: OR;
 
-Cin: NODE3,NODE7,NODE10;
-A: NODE1,NODE2;
-B: NODE1,NODE2;
-NODE1: NODE3,NODE5;
-NODE2: NODE4,NODE6;
+Cin: NODE3, NODE7, NODE10;
+A: NODE1, NODE2;
+B: NODE1, NODE2;
+NODE1: NODE3, NODE5;
+NODE2: NODE4, NODE6;
 NODE3: NODE6;
 NODE4: NODE5;
-NODE5: NODE8,NODE9;
+NODE5: NODE8, NODE9;
 NODE6: Cout;
 NODE7: NODE9;
 NODE8: NODE10;
diff --git a/main.cpp b/main.cpp
index cca0636..2a15a39 100644
--- a/main.cpp
+++ b/main.cpp
@@ -22,14 +22,14 @@ int main(int argc, char** argv) {
 
 	try {
 		file >> main_parser;
-	} catch (exception e) {
+	} catch (ParserException & e) {
 		cout << "Parser error: " << e.what() << endl;
 		return EXIT_FAILURE;
 	}
 
 	// try {
 	//   circuit.run();
-	// } catch (exception e) {
+	// } catch (exception& e) {
 	//   cout << "Circuit error: " << e.what() << endl;
 	//   return EXIT_FAILURE;
 	// }