import { IRawDiff } from '../model/diff';
/**
 * A parser for the GNU unified diff format
 *
 * See https://www.gnu.org/software/diffutils/manual/html_node/Detailed-Unified.html
 */
export declare class DiffParser {
    /**
     * Line start pointer.
     *
     * The offset into the text property where the current line starts (ie either zero
     * or one character ahead of the last newline character).
     */
    private ls;
    /**
     * Line end pointer.
     *
     * The offset into the text property where the current line ends (ie it points to
     * the newline character) or -1 if the line boundary hasn't been determined yet
     */
    private le;
    /**
     * The text buffer containing the raw, unified diff output to be parsed
     */
    private text;
    constructor();
    /**
     * Resets the internal parser state so that it can be reused.
     *
     * This is done automatically at the end of each parse run.
     */
    private reset;
    /**
     * Aligns the internal character pointers at the boundaries of
     * the next line.
     *
     * Returns true if successful or false if the end of the diff
     * has been reached.
     */
    private nextLine;
    /**
     * Advances to the next line and returns it as a substring
     * of the raw diff text. Returns null if end of diff was
     * reached.
     */
    private readLine;
    /** Tests if the current line starts with the given search text */
    private lineStartsWith;
    /** Tests if the current line ends with the given search text */
    private lineEndsWith;
    /**
     * Returns the starting character of the next line without
     * advancing the internal state. Returns null if advancing
     * would mean reaching the end of the diff.
     */
    private peek;
    /**
     * Parse the diff header, meaning everything from the
     * start of the diff output to the end of the line beginning
     * with +++
     *
     * Example diff header:
     *
     *   diff --git a/app/src/lib/diff-parser.ts b/app/src/lib/diff-parser.ts
     *   index e1d4871..3bd3ee0 100644
     *   --- a/app/src/lib/diff-parser.ts
     *   +++ b/app/src/lib/diff-parser.ts
     *
     * Returns an object with information extracted from the diff
     * header (currently whether it's a binary patch) or null if
     * the end of the diff was reached before the +++ line could be
     * found (which is a valid state).
     */
    private parseDiffHeader;
    /**
     * Attempts to convert a RegExp capture group into a number.
     * If the group doesn't exist or wasn't captured the function
     * will return the value of the defaultValue parameter or throw
     * an error if no default value was provided. If the captured
     * string can't be converted to a number an error will be thrown.
     */
    private numberFromGroup;
    /**
     * Parses a hunk header or throws an error if the given line isn't
     * a well-formed hunk header.
     *
     * We currently only extract the line number information and
     * ignore any hunk headings.
     *
     * Example hunk header:
     *
     * @@ -84,10 +82,8 @@ export function parseRawDiff(lines: ReadonlyArray<string>): Diff {
     *
     * Where everything after the last @@ is what's known as the hunk, or section, heading
     */
    private parseHunkHeader;
    /**
     * Convenience function which lets us leverage the type system to
     * prove exhaustive checks in parseHunk.
     *
     * Takes an arbitrary string and checks to see if the first character
     * of that string is one of the allowed prefix characters for diff
     * lines (ie lines in between hunk headers).
     */
    private parseLinePrefix;
    /**
     * Parses a hunk, including its header or throws an error if the diff doesn't
     * contain a well-formed diff hunk at the current position.
     *
     * Expects that the position has been advanced to the beginning of a presumed
     * diff hunk header.
     *
     * @param linesConsumed The number of unified diff lines consumed up until
     *                      this point by the diff parser. Used to give the
     *                      position and length (in lines) of the parsed hunk
     *                      relative to the overall parsed diff. These numbers
     *                      have no real meaning in the context of a diff and
     *                      are only used to aid the app in line-selections.
     */
    private parseHunk;
    /**
     * Parse a well-formed unified diff into hunks and lines.
     *
     * @param text A unified diff produced by git diff, git log --patch
     *             or any other git plumbing command that produces unified
     *             diffs.
     */
    parse(text: string): IRawDiff;
}