From 29d8eda23886eedcde3fefafdfc7d74d6acaddcd Mon Sep 17 00:00:00 2001
From: VaclavT <vaclavt@gmail.com>
Date: Wed, 17 Mar 2021 23:58:33 +0100
Subject: [PATCH] fix parsing of negative numbers, less memory, faster

---
 clib/csvparser.cpp | 90 +++++++++++++++++++++++-----------------------
 clib/csvparser.h   |  9 ++---
 debug.lsp          |  3 ++
 3 files changed, 53 insertions(+), 49 deletions(-)

diff --git a/clib/csvparser.cpp b/clib/csvparser.cpp
index 0a491d6..f999d5d 100644
--- a/clib/csvparser.cpp
+++ b/clib/csvparser.cpp
@@ -17,9 +17,12 @@ MlValue CsvParser::parseCSV(const std::string &csvSource) {
 	bool newLine(false);
 	std::string field;
 
-	// PERF optimize it for memory usage and performance
-	std::vector<std::vector<std::string>> parsed_data;        // TODO some default size here
-	std::vector<std::string> line;
+	std::vector<MlValue> parsed_data;
+	// TODO when csvSource is really big use some bigger nr to prevent reallocations
+	parsed_data.reserve(128);
+
+	std::vector<MlValue> line;
+	line.reserve(32);
 
 	std::string::const_iterator aChar = csvSource.begin();
 	while (aChar != csvSource.end()) {
@@ -31,7 +34,7 @@ MlValue CsvParser::parseCSV(const std::string &csvSource) {
 			if (inQuote == true) {
 				field += *aChar;
 			} else {
-				line.push_back(field);
+				line.push_back(ivalualize(field));
 				field.clear();
 			}
 		} else if (*aChar == line_separator || *aChar == line_separator2) {
@@ -39,8 +42,8 @@ MlValue CsvParser::parseCSV(const std::string &csvSource) {
 				field += *aChar;
 			} else {
 				if (newLine == false) {
-					line.push_back(field);
-					addLine(line, parsed_data);
+					line.push_back(ivalualize(field));
+					add_line(line, parsed_data);
 					field.clear();
 					line.clear();
 					newLine = true;
@@ -55,41 +58,15 @@ MlValue CsvParser::parseCSV(const std::string &csvSource) {
 	}
 
 	if (field.size())
-		line.push_back(field);
+		line.push_back(ivalualize(field));
 
-	addLine(line, parsed_data);
+	add_line(line, parsed_data);
 
-	return ivalualize(parsed_data);
+	return parsed_data;
 }
 
-MlValue CsvParser::ivalualize(std::vector<std::vector<std::string> > &parsed_data) const {
-	int rows = parsed_data.size();
-	int cols = rows > 0 ? parsed_data[0].size() : 0;
 
-	std::vector<MlValue> result;
-
-	if (rows > 0 && cols > 0) {
-		for (int r = 0; r < rows; r++) {
-			std::vector<MlValue> row;
-			for (int c = 0; c < cols; c++) {
-				std::string value = parsed_data[r][c];
-				if (is_string_int(value)) {
-					row.push_back(MlValue(stoi(value)));
-				}
-				if (is_string_float(value)) {
-					row.push_back(MlValue(std::stod(value)));
-				} else {
-					row.push_back(MlValue::string(value));
-				}
-			}
-			result.push_back(row);
-		}
-	}
-
-	return result;
-}
-
-void CsvParser::addLine(const std::vector<std::string> &line, std::vector<std::vector<std::string> > &lines) {
+void CsvParser::add_line(const std::vector<MlValue> &line, std::vector<MlValue>  &lines) {
 	if (skip_header && !header_skiped) {
 		header_skiped = true;
 	} else {
@@ -98,17 +75,40 @@ void CsvParser::addLine(const std::vector<std::string> &line, std::vector<std::v
 	}
 }
 
-
-// std::regex int_underscored_regex("[0-9][0-9_]+[0-9]");
-std::regex int_regex("[0-9]+");
-std::regex double_regex("[0-9]+\\.[0-9]+");
+MlValue CsvParser::ivalualize(const std::string &value) const {
+	long int_val;
+	double float_val;
+	if (value.empty() || ((!isdigit(value[0])) && (value[0] != '-') && (value[0] != '+'))) {
+		return MlValue::string(value);
+	} else if (is_string_int(value, int_val)) {
+		return MlValue(int_val);
+	} else if (is_string_float(value, float_val)) {
+		return MlValue(float_val);
+	} else {
+		return MlValue::string(value);
+	}
+}
 
 // Is string representing int value
-bool CsvParser::is_string_int(const std::string &str) const {
-	return std::regex_match(str, int_regex);
+bool CsvParser::is_string_int(const std::string &s, long &val) const {
+    char *end_ptr;
+    errno = 0;
+	if(s.empty() || ((!isdigit(s[0])) && (s[0] != '-') && (s[0] != '+'))) return false;
+    val = strtol(s.c_str(), &end_ptr, 10);
+	if ( *end_ptr != '\0' ) return false;
+    if (errno == ERANGE && (val == LONG_MIN || val == LONG_MAX)) return false;
+    if (val == 0 && errno != 0) return false;
+    return true;
 }
 
 // Is string representing float value
-bool CsvParser::is_string_float(const std::string &str) const {
-	return std::regex_match(str, double_regex);
-}
+bool CsvParser::is_string_float(const std::string &s, double &val) const {
+    char *end_ptr;
+    errno = 0;
+	if(s.empty() || ((!isdigit(s[0])) && (s[0] != '-') && (s[0] != '+'))) return false;
+    val = strtod(s.c_str(), &end_ptr);
+    if ( *end_ptr != '\0' ) return false;
+    if (errno == ERANGE && (val == HUGE_VAL || val == -HUGE_VAL)) return false;
+    if (val == 0 && errno != 0) return false;
+    return true;
+}
\ No newline at end of file
diff --git a/clib/csvparser.h b/clib/csvparser.h
index 2559920..d1f780f 100644
--- a/clib/csvparser.h
+++ b/clib/csvparser.h
@@ -3,6 +3,7 @@
 
 #include "../ml.h"
 
+#include <math.h>
 #include <string>
 #include <vector>
 #include <regex>
@@ -25,11 +26,11 @@ public:
     MlValue parseCSV(const std::string &csvSource);
 
 private:
-    void addLine(const std::vector<std::string> &line, std::vector<std::vector<std::string> > &lines);
+    void add_line(const std::vector<MlValue> &line, std::vector<MlValue>  &lines);
 
-    MlValue ivalualize(std::vector<std::vector<std::string> > &parsed_data) const;
+    MlValue ivalualize(const std::string &value) const;
 
-    bool is_string_int(const std::string &str) const;
+    bool is_string_int(const std::string &s, long &val) const;
 
-    bool is_string_float(const std::string &str) const;
+    bool is_string_float(const std::string &s, double &val) const;
 };
diff --git a/debug.lsp b/debug.lsp
index aa767d1..89b8c0a 100644
--- a/debug.lsp
+++ b/debug.lsp
@@ -26,5 +26,8 @@
 (benchmark "benchmark range 1000 : " (range 1 1000))
 
 
+(define fdx_list (parse-csv (read-file "tests/csv_data.csv")))
+(print fdx_list)
+
 
 (sleep 1.5)
\ No newline at end of file