Merge branch 'master' into iwyu

1 files changed, 988 insertions, 0 deletions

diff --git a/src/tokenizer.cpp b/src/tokenizer.cpp
new file mode 100644
index 00000000..319eb2d9
--- /dev/null
+++ b/src/tokenizer.cpp
@@ -0,0 +1,988 @@
+/** \file tokenizer.c
+
+A specialized tokenizer for tokenizing the fish language. In the
+future, the tokenizer should be extended to support marks,
+tokenizing multiple strings and disposing of unused string
+segments.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#include <wchar.h>
+#include <wctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <string>
+
+#include "fallback.h" // IWYU pragma: keep
+#include "common.h"
+#include "wutil.h" // IWYU pragma: keep - needed for wgettext
+#include "tokenizer.h"
+
+/* Wow what a hack */
+#define TOK_CALL_ERROR(t, e, x) do { tok_call_error((t), (e), (t)->squash_errors ? L"" : (x)); } while (0)
+
+/**
+   Error string for unexpected end of string
+*/
+#define QUOTE_ERROR _( L"Unexpected end of string, quotes are not balanced" )
+
+/**
+   Error string for mismatched parenthesis
+*/
+#define PARAN_ERROR _( L"Unexpected end of string, parenthesis do not match" )
+
+/**
+   Error string for mismatched square brackets
+*/
+#define SQUARE_BRACKET_ERROR _( L"Unexpected end of string, square brackets do not match" )
+
+
+/**
+   Error string for invalid redirections
+*/
+#define REDIRECT_ERROR _( L"Invalid input/output redirection" )
+
+/**
+   Error string for when trying to pipe from fd 0
+*/
+#define PIPE_ERROR _( L"Cannot use stdin (fd 0) as pipe output" )
+
+/**
+   Characters that separate tokens. They are ordered by frequency of occurrence to increase parsing speed.
+*/
+#define SEP L" \n|\t;#\r<>^&"
+
+/**
+   Descriptions of all tokenizer errors
+*/
+static const wchar_t *tok_desc[] =
+{
+    N_(L"Tokenizer not yet initialized"),
+    N_(L"Tokenizer error"),
+    N_(L"String"),
+    N_(L"Pipe"),
+    N_(L"End of command"),
+    N_(L"Redirect output to file"),
+    N_(L"Append output to file"),
+    N_(L"Redirect input to file"),
+    N_(L"Redirect to file descriptor"),
+    N_(L"Redirect output to file if file does not exist"),
+    N_(L"Run job in background"),
+    N_(L"Comment")
+};
+
+
+
+/**
+   Set the latest tokens string to be the specified error message
+*/
+static void tok_call_error(tokenizer_t *tok, int error_type, const wchar_t *error_message)
+{
+    tok->last_type = TOK_ERROR;
+    tok->error = error_type;
+    tok->last_token = error_message;
+}
+
+int tok_get_error(tokenizer_t *tok)
+{
+    return tok->error;
+}
+
+
+tokenizer_t::tokenizer_t(const wchar_t *b, tok_flags_t flags) : buff(NULL), orig_buff(NULL), last_type(TOK_NONE), last_pos(0), has_next(false), accept_unfinished(false), show_comments(false), show_blank_lines(false), last_quote(0), error(0), squash_errors(false), cached_lineno_offset(0), cached_lineno_count(0), continue_line_after_comment(false)
+{
+    CHECK(b,);
+
+    this->accept_unfinished = !!(flags & TOK_ACCEPT_UNFINISHED);
+    this->show_comments = !!(flags & TOK_SHOW_COMMENTS);
+    this->squash_errors = !!(flags & TOK_SQUASH_ERRORS);
+    this->show_blank_lines = !!(flags & TOK_SHOW_BLANK_LINES);
+
+    this->has_next = (*b != L'\0');
+    this->orig_buff = this->buff = b;
+    this->cached_lineno_offset = 0;
+    this->cached_lineno_count = 0;
+    tok_next(this);
+}
+
+enum token_type tok_last_type(tokenizer_t *tok)
+{
+    CHECK(tok, TOK_ERROR);
+    CHECK(tok->buff, TOK_ERROR);
+
+    return tok->last_type;
+}
+
+const wchar_t *tok_last(tokenizer_t *tok)
+{
+    CHECK(tok, 0);
+
+    return tok->last_token.c_str();
+}
+
+int tok_has_next(tokenizer_t *tok)
+{
+    /*
+      Return 1 on broken tokenizer
+    */
+    CHECK(tok, 1);
+    CHECK(tok->buff, 1);
+
+    /*  fwprintf( stderr, L"has_next is %ls \n", tok->has_next?L"true":L"false" );*/
+    return   tok->has_next;
+}
+
+/**
+   Tests if this character can be a part of a string. The redirect ^ is allowed unless it's the first character.
+   Hash (#) starts a comment if it's the first character in a token; otherwise it is considered a string character.
+   See #953.
+*/
+bool tok_is_string_character(wchar_t c, bool is_first)
+{
+    switch (c)
+    {
+            /* Unconditional separators */
+        case L'\0':
+        case L' ':
+        case L'\n':
+        case L'|':
+        case L'\t':
+        case L';':
+        case L'\r':
+        case L'<':
+        case L'>':
+        case L'&':
+            return false;
+
+            /* Conditional separator */
+        case L'^':
+            return ! is_first;
+
+        default:
+            return true;
+    }
+}
+
+/**
+   Quick test to catch the most common 'non-magical' characters, makes
+   read_string slightly faster by adding a fast path for the most
+   common characters. This is obviously not a suitable replacement for
+   iswalpha.
+*/
+static int myal(wchar_t c)
+{
+    return (c>=L'a' && c<=L'z') || (c>=L'A'&&c<=L'Z');
+}
+
+/**
+   Read the next token as a string
+*/
+static void read_string(tokenizer_t *tok)
+{
+    const wchar_t *start;
+    long len;
+    int do_loop=1;
+    int paran_count=0;
+
+    start = tok->buff;
+    bool is_first = true;
+
+    enum tok_mode_t
+    {
+        mode_regular_text = 0, // regular text
+        mode_subshell = 1, // inside of subshell
+        mode_array_brackets = 2, // inside of array brackets
+        mode_array_brackets_and_subshell = 3 // inside of array brackets and subshell, like in '$foo[(ech'
+    } mode = mode_regular_text;
+
+    while (1)
+    {
+        if (!myal(*tok->buff))
+        {
+            if (*tok->buff == L'\\')
+            {
+                tok->buff++;
+                if (*tok->buff == L'\0')
+                {
+                    if ((!tok->accept_unfinished))
+                    {
+                        TOK_CALL_ERROR(tok, TOK_UNTERMINATED_ESCAPE, QUOTE_ERROR);
+                        return;
+                    }
+                    else
+                    {
+                        /* Since we are about to increment tok->buff, decrement it first so the increment doesn't go past the end of the buffer. https://github.com/fish-shell/fish-shell/issues/389 */
+                        tok->buff--;
+                        do_loop = 0;
+                    }
+                }
+
+                tok->buff++;
+                continue;
+            }
+
+            switch (mode)
+            {
+                case mode_regular_text:
+                {
+                    switch (*tok->buff)
+                    {
+                        case L'(':
+                        {
+                            paran_count=1;
+                            mode = mode_subshell;
+                            break;
+                        }
+
+                        case L'[':
+                        {
+                            if (tok->buff != start)
+                                mode = mode_array_brackets;
+                            break;
+                        }
+
+                        case L'\'':
+                        case L'"':
+                        {
+
+                            const wchar_t *end = quote_end(tok->buff);
+                            tok->last_quote = *tok->buff;
+                            if (end)
+                            {
+                                tok->buff=(wchar_t *)end;
+                            }
+                            else
+                            {
+                                tok->buff += wcslen(tok->buff);
+
+                                if (! tok->accept_unfinished)
+                                {
+                                    TOK_CALL_ERROR(tok, TOK_UNTERMINATED_QUOTE, QUOTE_ERROR);
+                                    return;
+                                }
+                                do_loop = 0;
+
+                            }
+                            break;
+                        }
+
+                        default:
+                        {
+                            if (! tok_is_string_character(*(tok->buff), is_first))
+                            {
+                                do_loop=0;
+                            }
+                        }
+                    }
+                    break;
+                }
+
+                case mode_array_brackets_and_subshell:
+                case mode_subshell:
+                    switch (*tok->buff)
+                    {
+                        case L'\'':
+                        case L'\"':
+                        {
+                            const wchar_t *end = quote_end(tok->buff);
+                            if (end)
+                            {
+                                tok->buff=(wchar_t *)end;
+                            }
+                            else
+                            {
+                                tok->buff += wcslen(tok->buff);
+                                if ((!tok->accept_unfinished))
+                                {
+                                    TOK_CALL_ERROR(tok, TOK_UNTERMINATED_QUOTE, QUOTE_ERROR);
+                                    return;
+                                }
+                                do_loop = 0;
+                            }
+
+                            break;
+                        }
+
+                        case L'(':
+                            paran_count++;
+                            break;
+                        case L')':
+                            paran_count--;
+                            if (paran_count == 0)
+                            {
+                                mode = (mode == mode_array_brackets_and_subshell ? mode_array_brackets : mode_regular_text);
+                            }
+                            break;
+                        case L'\0':
+                            do_loop = 0;
+                            break;
+                    }
+                    break;
+
+                case mode_array_brackets:
+                    switch (*tok->buff)
+                    {
+                        case L'(':
+                            paran_count=1;
+                            mode = mode_array_brackets_and_subshell;
+                            break;
+
+                        case L']':
+                            mode = mode_regular_text;
+                            break;
+
+                        case L'\0':
+                            do_loop = 0;
+                            break;
+                    }
+                    break;
+            }
+        }
+
+
+        if (!do_loop)
+            break;
+
+        tok->buff++;
+        is_first = false;
+    }
+
+    if ((!tok->accept_unfinished) && (mode != mode_regular_text))
+    {
+        switch (mode)
+        {
+            case mode_subshell:
+                TOK_CALL_ERROR(tok, TOK_UNTERMINATED_SUBSHELL, PARAN_ERROR);
+                break;
+            case mode_array_brackets:
+            case mode_array_brackets_and_subshell:
+                TOK_CALL_ERROR(tok, TOK_UNTERMINATED_SUBSHELL, SQUARE_BRACKET_ERROR); // TOK_UNTERMINATED_SUBSHELL is a lie but nobody actually looks at it
+                break;
+            default:
+                assert(0 && "Unexpected mode in read_string");
+                break;
+        }
+        return;
+    }
+
+
+    len = tok->buff - start;
+
+    tok->last_token.assign(start, len);
+    tok->last_type = TOK_STRING;
+}
+
+/**
+   Read the next token as a comment.
+*/
+static void read_comment(tokenizer_t *tok)
+{
+    const wchar_t *start;
+
+    start = tok->buff;
+    while (*(tok->buff)!= L'\n' && *(tok->buff)!= L'\0')
+        tok->buff++;
+
+
+    size_t len = tok->buff - start;
+    tok->last_token.assign(start, len);
+    tok->last_type = TOK_COMMENT;
+}
+
+
+
+/* Reads a redirection or an "fd pipe" (like 2>|) from a string. Returns how many characters were consumed. If zero, then this string was not a redirection.
+
+   Also returns by reference the redirection mode, and the fd to redirection. If there is overflow, *out_fd is set to -1.
+*/
+static size_t read_redirection_or_fd_pipe(const wchar_t *buff, enum token_type *out_redirection_mode, int *out_fd)
+{
+    bool errored = false;
+    int fd = 0;
+    enum token_type redirection_mode = TOK_NONE;
+
+    size_t idx = 0;
+
+    /* Determine the fd. This may be specified as a prefix like '2>...' or it may be implicit like '>' or '^'. Try parsing out a number; if we did not get any digits then infer it from the first character. Watch out for overflow. */
+    long long big_fd = 0;
+    for (; iswdigit(buff[idx]); idx++)
+    {
+        /* Note that it's important we consume all the digits here, even if it overflows. */
+        if (big_fd <= INT_MAX)
+            big_fd = big_fd * 10 + (buff[idx] - L'0');
+    }
+
+    fd = (big_fd > INT_MAX ? -1 : static_cast<int>(big_fd));
+
+    if (idx == 0)
+    {
+        /* We did not find a leading digit, so there's no explicit fd. Infer it from the type */
+        switch (buff[idx])
+        {
+            case L'>':
+                fd = STDOUT_FILENO;
+                break;
+            case L'<':
+                fd = STDIN_FILENO;
+                break;
+            case L'^':
+                fd = STDERR_FILENO;
+                break;
+            default:
+                errored = true;
+                break;
+        }
+    }
+
+    /* Either way we should have ended on the redirection character itself like '>' */
+    wchar_t redirect_char = buff[idx++]; //note increment of idx
+    if (redirect_char == L'>' || redirect_char == L'^')
+    {
+        redirection_mode = TOK_REDIRECT_OUT;
+        if (buff[idx] == redirect_char)
+        {
+            /* Doubled up like ^^ or >>. That means append */
+            redirection_mode = TOK_REDIRECT_APPEND;
+            idx++;
+        }
+    }
+    else if (redirect_char == L'<')
+    {
+        redirection_mode = TOK_REDIRECT_IN;
+    }
+    else
+    {
+        /* Something else */
+        errored = true;
+    }
+
+    /* Optional characters like & or ?, or the pipe char | */
+    wchar_t opt_char = buff[idx];
+    if (opt_char == L'&')
+    {
+        redirection_mode = TOK_REDIRECT_FD;
+        idx++;
+    }
+    else if (opt_char == L'?')
+    {
+        redirection_mode = TOK_REDIRECT_NOCLOB;
+        idx++;
+    }
+    else if (opt_char == L'|')
+    {
+        /* So the string looked like '2>|'. This is not a redirection - it's a pipe! That gets handled elsewhere. */
+        redirection_mode = TOK_PIPE;
+        idx++;
+    }
+
+    /* Don't return valid-looking stuff on error */
+    if (errored)
+    {
+        idx = 0;
+        redirection_mode = TOK_NONE;
+    }
+
+    /* Return stuff */
+    if (out_redirection_mode != NULL)
+        *out_redirection_mode = redirection_mode;
+    if (out_fd != NULL)
+        *out_fd = fd;
+
+    return idx;
+}
+
+enum token_type redirection_type_for_string(const wcstring &str, int *out_fd)
+{
+    enum token_type mode = TOK_NONE;
+    int fd = 0;
+    read_redirection_or_fd_pipe(str.c_str(), &mode, &fd);
+    /* Redirections only, no pipes */
+    if (mode == TOK_PIPE || fd < 0)
+        mode = TOK_NONE;
+    if (out_fd != NULL)
+        *out_fd = fd;
+    return mode;
+}
+
+int fd_redirected_by_pipe(const wcstring &str)
+{
+    /* Hack for the common case */
+    if (str == L"|")
+    {
+        return STDOUT_FILENO;
+    }
+
+    enum token_type mode = TOK_NONE;
+    int fd = 0;
+    read_redirection_or_fd_pipe(str.c_str(), &mode, &fd);
+    /* Pipes only */
+    if (mode != TOK_PIPE || fd < 0)
+        fd = -1;
+    return fd;
+}
+
+int oflags_for_redirection_type(enum token_type type)
+{
+    switch (type)
+    {
+        case TOK_REDIRECT_APPEND:
+            return O_CREAT | O_APPEND | O_WRONLY;
+        case TOK_REDIRECT_OUT:
+            return O_CREAT | O_WRONLY | O_TRUNC;
+        case TOK_REDIRECT_NOCLOB:
+            return O_CREAT | O_EXCL | O_WRONLY;
+        case TOK_REDIRECT_IN:
+            return O_RDONLY;
+
+        default:
+            return -1;
+    }
+}
+
+/**
+   Test if a character is whitespace. Differs from iswspace in that it
+   does not consider a newline to be whitespace.
+*/
+static bool my_iswspace(wchar_t c)
+{
+    return c != L'\n' && iswspace(c);
+}
+
+
+const wchar_t *tok_get_desc(int type)
+{
+    if (type < 0 || (size_t)type >= (sizeof tok_desc / sizeof *tok_desc))
+    {
+        return _(L"Invalid token type");
+    }
+    return _(tok_desc[type]);
+}
+
+void tok_next(tokenizer_t *tok)
+{
+
+    CHECK(tok,);
+    CHECK(tok->buff,);
+
+    if (tok_last_type(tok) == TOK_ERROR)
+    {
+        tok->has_next=false;
+        return;
+    }
+
+    if (!tok->has_next)
+    {
+        /*    wprintf( L"EOL\n" );*/
+        tok->last_type = TOK_END;
+        return;
+    }
+
+    while (1)
+    {
+        if (tok->buff[0] == L'\\' && tok->buff[1] == L'\n')
+        {
+            tok->buff += 2;
+            tok->continue_line_after_comment = true;
+        }
+        else if (my_iswspace(tok->buff[0]))
+        {
+            tok->buff++;
+        }
+        else
+        {
+            break;
+        }
+    }
+
+
+    while (*tok->buff == L'#')
+    {
+        if (tok->show_comments)
+        {
+            tok->last_pos = tok->buff - tok->orig_buff;
+            read_comment(tok);
+
+            if (tok->buff[0] == L'\n' && tok->continue_line_after_comment)
+                tok->buff++;
+
+            return;
+        }
+        else
+        {
+            while (*(tok->buff)!= L'\n' && *(tok->buff)!= L'\0')
+                tok->buff++;
+
+            if (tok->buff[0] == L'\n' && tok->continue_line_after_comment)
+                tok->buff++;
+        }
+
+        while (my_iswspace(*(tok->buff))) {
+            tok->buff++;
+        }
+    }
+
+    tok->continue_line_after_comment = false;
+
+    tok->last_pos = tok->buff - tok->orig_buff;
+
+    switch (*tok->buff)
+    {
+        case L'\0':
+            tok->last_type = TOK_END;
+            /*fwprintf( stderr, L"End of string\n" );*/
+            tok->has_next = false;
+            break;
+        case 13: // carriage return
+        case L'\n':
+        case L';':
+            tok->last_type = TOK_END;
+            tok->buff++;
+            // Hack: when we get a newline, swallow as many as we can
+            // This compresses multiple subsequent newlines into a single one
+            if (! tok->show_blank_lines)
+            {
+                while (*tok->buff == L'\n' || *tok->buff == 13 /* CR */ || *tok->buff == ' ' || *tok->buff == '\t')
+                {
+                    tok->buff++;
+                }
+            }
+            tok->last_token.clear();
+            break;
+        case L'&':
+            tok->last_type = TOK_BACKGROUND;
+            tok->buff++;
+            break;
+
+        case L'|':
+            tok->last_token = L"1";
+            tok->last_type = TOK_PIPE;
+            tok->buff++;
+            break;
+
+        case L'>':
+        case L'<':
+        case L'^':
+        {
+            /* There's some duplication with the code in the default case below. The key difference here is that we must never parse these as a string; a failed redirection is an error! */
+            enum token_type mode = TOK_NONE;
+            int fd = -1;
+            size_t consumed = read_redirection_or_fd_pipe(tok->buff, &mode, &fd);
+            if (consumed == 0 || fd < 0)
+            {
+                TOK_CALL_ERROR(tok, TOK_OTHER, REDIRECT_ERROR);
+            }
+            else
+            {
+                tok->buff += consumed;
+                tok->last_type = mode;
+                tok->last_token = to_string(fd);
+            }
+        }
+        break;
+
+        default:
+        {
+            /* Maybe a redirection like '2>&1', maybe a pipe like 2>|, maybe just a string */
+            size_t consumed = 0;
+            enum token_type mode = TOK_NONE;
+            int fd = -1;
+            if (iswdigit(*tok->buff))
+                consumed = read_redirection_or_fd_pipe(tok->buff, &mode, &fd);
+
+            if (consumed > 0)
+            {
+                /* It looks like a redirection or a pipe. But we don't support piping fd 0. Note that fd 0 may be -1, indicating overflow; but we don't treat that as a tokenizer error. */
+                if (mode == TOK_PIPE && fd == 0)
+                {
+                    TOK_CALL_ERROR(tok, TOK_OTHER, PIPE_ERROR);
+                }
+                else
+                {
+                    tok->buff += consumed;
+                    tok->last_type = mode;
+                    tok->last_token = to_string(fd);
+                }
+            }
+            else
+            {
+                /* Not a redirection or pipe, so just a string */
+                read_string(tok);
+            }
+        }
+        break;
+
+    }
+
+}
+
+wcstring tok_first(const wchar_t *str)
+{
+    wcstring result;
+    if (str)
+    {
+        tokenizer_t t(str, TOK_SQUASH_ERRORS);
+        switch (tok_last_type(&t))
+        {
+            case TOK_STRING:
+            {
+                const wchar_t *tmp = tok_last(&t);
+                if (tmp != NULL)
+                    result = tmp;
+                break;
+            }
+            default:
+                break;
+        }
+    }
+    return result;
+}
+
+int tok_get_pos(const tokenizer_t *tok)
+{
+    CHECK(tok, 0);
+    return (int)tok->last_pos;
+}
+
+size_t tok_get_extent(const tokenizer_t *tok)
+{
+    CHECK(tok, 0);
+    size_t current_pos = tok->buff - tok->orig_buff;
+    return current_pos > tok->last_pos ? current_pos - tok->last_pos : 0;
+}
+
+
+void tok_set_pos(tokenizer_t *tok, int pos)
+{
+    CHECK(tok,);
+
+    tok->buff = tok->orig_buff + pos;
+    tok->has_next = true;
+    tok_next(tok);
+}
+
+bool move_word_state_machine_t::consume_char_punctuation(wchar_t c)
+{
+    enum
+    {
+        s_always_one = 0,
+        s_whitespace,
+        s_alphanumeric,
+        s_end
+    };
+
+    bool consumed = false;
+    while (state != s_end && ! consumed)
+    {
+        switch (state)
+        {
+            case s_always_one:
+                /* Always consume the first character */
+                consumed = true;
+                state = s_whitespace;
+                break;
+
+            case s_whitespace:
+                if (iswspace(c))
+                {
+                    /* Consumed whitespace */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_alphanumeric;
+                }
+                break;
+
+            case s_alphanumeric:
+                if (iswalnum(c))
+                {
+                    /* Consumed alphanumeric */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_end;
+                }
+                break;
+
+            case s_end:
+            default:
+                break;
+        }
+    }
+    return consumed;
+}
+
+bool move_word_state_machine_t::is_path_component_character(wchar_t c)
+{
+    /* Always treat separators as first. All this does is ensure that we treat ^ as a string character instead of as stderr redirection, which I hypothesize is usually what is desired. */
+    return tok_is_string_character(c, true) && ! wcschr(L"/={,}'\"", c);
+}
+
+bool move_word_state_machine_t::consume_char_path_components(wchar_t c)
+{
+    enum
+    {
+        s_initial_punctuation,
+        s_whitespace,
+        s_separator,
+        s_slash,
+        s_path_component_characters,
+        s_end
+    };
+
+    //printf("state %d, consume '%lc'\n", state, c);
+    bool consumed = false;
+    while (state != s_end && ! consumed)
+    {
+        switch (state)
+        {
+            case s_initial_punctuation:
+                if (! is_path_component_character(c))
+                {
+                    consumed = true;
+                }
+                state = s_whitespace;
+                break;
+
+            case s_whitespace:
+                if (iswspace(c))
+                {
+                    /* Consumed whitespace */
+                    consumed = true;
+                }
+                else if (c == L'/' || is_path_component_character(c))
+                {
+                    /* Path component */
+                    state = s_slash;
+                }
+                else
+                {
+                    /* Path separator */
+                    state = s_separator;
+                }
+                break;
+
+            case s_separator:
+                if (! iswspace(c) && ! is_path_component_character(c))
+                {
+                    /* Consumed separator */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_end;
+                }
+                break;
+
+            case s_slash:
+                if (c == L'/')
+                {
+                    /* Consumed slash */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_path_component_characters;
+                }
+                break;
+
+            case s_path_component_characters:
+                if (is_path_component_character(c))
+                {
+                    /* Consumed string character except slash */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_end;
+                }
+                break;
+
+                /* We won't get here, but keep the compiler happy */
+            case s_end:
+            default:
+                break;
+        }
+    }
+    return consumed;
+}
+
+bool move_word_state_machine_t::consume_char_whitespace(wchar_t c)
+{
+    enum
+    {
+        s_always_one = 0,
+        s_blank,
+        s_graph,
+        s_end
+    };
+
+    bool consumed = false;
+    while (state != s_end && ! consumed)
+    {
+        switch (state)
+        {
+            case s_always_one:
+                /* Always consume the first character */
+                consumed = true;
+                state = s_blank;
+                break;
+
+            case s_blank:
+                if (iswblank(c))
+                {
+                    /* Consumed whitespace */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_graph;
+                }
+                break;
+
+            case s_graph:
+                if (iswgraph(c))
+                {
+                    /* Consumed printable non-space */
+                    consumed = true;
+                }
+                else
+                {
+                    state = s_end;
+                }
+                break;
+
+            case s_end:
+            default:
+                break;
+        }
+    }
+    return consumed;
+}
+
+bool move_word_state_machine_t::consume_char(wchar_t c)
+{
+    switch (style)
+    {
+        case move_word_style_punctuation:
+            return consume_char_punctuation(c);
+        case move_word_style_path_components:
+            return consume_char_path_components(c);
+        case move_word_style_whitespace:
+            return consume_char_whitespace(c);
+        default:
+            return false;
+    }
+}
+
+move_word_state_machine_t::move_word_state_machine_t(move_word_style_t syl) : state(0), style(syl)
+{
+}
+
+void move_word_state_machine_t::reset()
+{
+    state = 0;
+}