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/*******************************************************************************
* Copyright 2014 uniVocity Software Pty Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.univocity.parsers.common.input;
import com.univocity.parsers.common.*;
import java.io.*;
/**
* The definition of a character input reader used by all uniVocity-parsers that extend {@link AbstractParser}.
*
* This interface declares basic functionalities to provide a common input manipulation structure for all parser classes.
*
Implementations of this interface MUST convert the sequence of newline characters defined by {@link Format#getLineSeparator()} into the normalized newline character provided in {@link Format#getNormalizedNewline()}.
*
* @author uniVocity Software Pty Ltd - [email protected]
* @see com.univocity.parsers.common.Format
*/
public interface CharInputReader extends CharInput {
/**
* Initializes the CharInputReader implementation with a {@link java.io.Reader} which provides access to the input.
*
* @param reader A {@link java.io.Reader} that provides access to the input.
*/
void start(Reader reader);
/**
* Stops the CharInputReader from reading characters from the {@link java.io.Reader} provided in {@link CharInputReader#start(Reader)} and closes it.
*/
void stop();
/**
* Returns the next character in the input provided by the active {@link java.io.Reader}.
*
If the input contains a sequence of newline characters (defined by {@link Format#getLineSeparator()}), this method will automatically converted them to the newline character specified in {@link Format#getNormalizedNewline()}.
*
A subsequent call to this method will return the character after the newline sequence.
*
* @return the next character in the input. '\0' if there are no more characters in the input or if the CharInputReader was stopped.
*/
char nextChar();
/**
* Returns the last character returned by the {@link #nextChar()} method.
*
* @return the last character returned by the {@link #nextChar()} method.'\0' if there are no more characters in the input or if the CharInputReader was stopped.
*/
char getChar();
/**
* Returns the number of characters returned by {@link CharInputReader#nextChar()} at any given time.
*
* @return the number of characters returned by {@link CharInputReader#nextChar()}
*/
long charCount();
/**
* Returns the number of newlines read so far.
*
* @return the number of newlines read so far.
*/
long lineCount();
/**
* Skips characters in the input until the given number of lines is discarded.
*
* @param lineCount the number of lines to skip from the current location in the input
*/
void skipLines(long lineCount);
/**
* Collects the comment line found on the input.
*
* @return the text found in the comment from the current position.
*/
String readComment();
/**
* Indicates to the input reader that the parser is running in "escape" mode and
* new lines should be returned as-is to prevent modifying the content of the parsed value.
*
* @param escaping flag indicating that the parser is escaping values and line separators are to be returned as-is.
*/
void enableNormalizeLineEndings(boolean escaping);
/**
* Returns the line separator by this character input reader. This could be the line separator defined
* in the {@link Format#getLineSeparator()} configuration, or the line separator sequence identified automatically
* when {@link CommonParserSettings#isLineSeparatorDetectionEnabled()} evaluates to {@code true}.
*
* @return the line separator in use.
*/
char[] getLineSeparator();
/**
* Skips characters from the current input position, until a non-whitespace character, or a stop character is found
*
* @param current the current character of the input
* @param stopChar1 the first stop character (which can be a whitespace)
* @param stopChar2 the second character (which can be a whitespace)
*
* @return the first non-whitespace character (or delimiter) found in the input.
*/
char skipWhitespace(char current, char stopChar1, char stopChar2);
/**
* Returns a String with the input character sequence parsed to produce the current record.
*
* @return the text content parsed for the current input record.
*/
String currentParsedContent();
/**
* Marks the start of a new record in the input, used internally to calculate the result of {@link #currentParsedContent()}
*/
void markRecordStart();
/**
* Attempts to collect a {@code String} from the current position until a stop character is found on the input,
* or a line ending is reached. If the {@code String} can be obtained, the current position of the parser will be updated to
* the last consumed character. If the internal buffer needs to be reloaded, this method will return {@code null}
* and the current position of the buffer will remain unchanged.
*
* @param ch the current character to be considered. If equal to the stop character the {@code nullValue} will be returned
* @param stop the stop character that identifies the end of the content to be collected
* @param trim flag indicating whether or not trailing whitespaces should be discarded
* @param nullValue value to return when the length of the content to be returned is {@code 0}.
* @param maxLength the maximum length of the {@code String} to be returned. If the length exceeds this limit, {@code null} will be returned
*
* @return the {@code String} found on the input, or {@code null} if the buffer needs to reloaded or the maximum length has been exceeded.
*/
String getString(char ch, char stop, boolean trim, String nullValue, int maxLength);
/**
* Attempts to collect a quoted {@code String} from the current position until a closing quote or stop character is found on the input,
* or a line ending is reached. If the {@code String} can be obtained, the current position of the parser will be updated to
* the last consumed character. If the internal buffer needs to be reloaded, this method will return {@code null}
* and the current position of the buffer will remain unchanged.
*
* @param quote the quote character
* @param escape the quote escape character
* @param escapeEscape the escape of the quote escape character
* @param maxLength the maximum length of the {@code String} to be returned. If the length exceeds this limit, {@code null} will be returned
* @param stop1 the first stop character that identifies the end of the content to be collected
* @param stop2 the second stop character that identifies the end of the content to be collected
* @param keepQuotes flag to indicate the quotes that wrap the resulting {@code String} should be kept.
* @param keepEscape flag to indicate that escape sequences should be kept
* @param trimLeading flag to indicate leading whitespaces should be trimmed
* @param trimTrailing flag to indicate that trailing whitespaces should be trimmed
* @return the {@code String} found on the input, or {@code null} if the buffer needs to reloaded or the maximum length has been exceeded.
*/
String getQuotedString(char quote, char escape, char escapeEscape, int maxLength, char stop1, char stop2, boolean keepQuotes, boolean keepEscape, boolean trimLeading, boolean trimTrailing);
}