X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flanguage%2Flexer%2Flexer.c;h=9a27d867b98cb87e15420671819ab24ccd1ca1fa;hb=993af59a283dbad8b26a390535f76cdeb00a9108;hp=9101245176035a0e9bb3ba5cc514caf944b6f25a;hpb=43b1296aafe7582e7dbe6c2b6a8b478d7d9b0fcf;p=pspp
diff --git a/src/language/lexer/lexer.c b/src/language/lexer/lexer.c
index 9101245176..9a27d867b9 100644
--- a/src/language/lexer/lexer.c
+++ b/src/language/lexer/lexer.c
@@ -1,5 +1,5 @@
/* PSPP - a program for statistical analysis.
- Copyright (C) 1997-9, 2000, 2006 Free Software Foundation, Inc.
+ Copyright (C) 1997-9, 2000, 2006, 2009, 2010, 2011 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -15,392 +15,257 @@
along with this program. If not, see . */
#include
-#include "lexer.h"
-#include
-#include
+
+#include "language/lexer/lexer.h"
+
#include
+#include
#include
#include
#include
#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-#include "size_max.h"
+#include
+#include
+#include
+#include
+#include
+
+#include "data/file-name.h"
+#include "language/command.h"
+#include "language/lexer/scan.h"
+#include "language/lexer/segment.h"
+#include "language/lexer/token.h"
+#include "libpspp/assertion.h"
+#include "libpspp/cast.h"
+#include "libpspp/deque.h"
+#include "libpspp/i18n.h"
+#include "libpspp/ll.h"
+#include "libpspp/message.h"
+#include "libpspp/misc.h"
+#include "libpspp/str.h"
+#include "libpspp/u8-istream.h"
+#include "output/journal.h"
+#include "output/text-item.h"
+
+#include "gl/c-ctype.h"
+#include "gl/minmax.h"
+#include "gl/xalloc.h"
+#include "gl/xmemdup0.h"
#include "gettext.h"
#define _(msgid) gettext (msgid)
#define N_(msgid) msgid
+/* A token within a lex_source. */
+struct lex_token
+ {
+ /* The regular token information. */
+ struct token token;
+
+ /* Location of token in terms of the lex_source's buffer.
+ src->tail <= line_pos <= token_pos <= src->head. */
+ size_t token_pos; /* Start of token. */
+ size_t token_len; /* Length of source for token in bytes. */
+ size_t line_pos; /* Start of line containing token_pos. */
+ int first_line; /* Line number at token_pos. */
+ };
-#define DUMP_TOKENS 0
-
-
-struct lexer
-{
- struct string line_buffer;
-
- struct source_stream *ss;
-
- int token; /* Current token. */
- double tokval; /* T_POS_NUM, T_NEG_NUM: the token's value. */
-
- char tokid [LONG_NAME_LEN + 1]; /* T_ID: the identifier. */
-
- struct string tokstr; /* T_ID, T_STRING: token string value.
- For T_ID, this is not truncated as is
- tokid. */
-
- char *prog; /* Pointer to next token in line_buffer. */
- bool dot; /* True only if this line ends with a terminal dot. */
-
- int put_token ; /* If nonzero, next token returned by lex_get().
- Used only in exceptional circumstances. */
-
- struct string put_tokstr;
- double put_tokval;
-};
+/* A source of tokens, corresponding to a syntax file.
+ This is conceptually a lex_reader wrapped with everything needed to convert
+ its UTF-8 bytes into tokens. */
+struct lex_source
+ {
+ struct ll ll; /* In lexer's list of sources. */
+ struct lex_reader *reader;
+ struct segmenter segmenter;
+ bool eof; /* True if T_STOP was read from 'reader'. */
+
+ /* Buffer of UTF-8 bytes. */
+ char *buffer;
+ size_t allocated; /* Number of bytes allocated. */
+ size_t tail; /* &buffer[0] offset into UTF-8 source. */
+ size_t head; /* &buffer[head - tail] offset into source. */
+
+ /* Positions in source file, tail <= pos <= head for each member here. */
+ size_t journal_pos; /* First byte not yet output to journal. */
+ size_t seg_pos; /* First byte not yet scanned as token. */
+ size_t line_pos; /* First byte of line containing seg_pos. */
+
+ int n_newlines; /* Number of new-lines up to seg_pos. */
+ bool suppress_next_newline;
+
+ /* Tokens. */
+ struct deque deque; /* Indexes into 'tokens'. */
+ struct lex_token *tokens; /* Lookahead tokens for parser. */
+ };
-static int parse_id (struct lexer *);
+static struct lex_source *lex_source_create (struct lex_reader *);
+static void lex_source_destroy (struct lex_source *);
-/* How a string represents its contents. */
-enum string_type
+/* Lexer. */
+struct lexer
{
- CHARACTER_STRING, /* Characters. */
- BINARY_STRING, /* Binary digits. */
- OCTAL_STRING, /* Octal digits. */
- HEX_STRING /* Hexadecimal digits. */
+ struct ll_list sources; /* Contains "struct lex_source"s. */
};
-static int parse_string (struct lexer *, enum string_type);
-
-#if DUMP_TOKENS
-static void dump_token (struct lexer *);
-#endif
+static struct lex_source *lex_source__ (const struct lexer *);
+static const struct lex_token *lex_next__ (const struct lexer *, int n);
+static void lex_source_push_endcmd__ (struct lex_source *);
+
+static void lex_source_pop__ (struct lex_source *);
+static bool lex_source_get__ (const struct lex_source *);
+static void lex_source_error_valist (struct lex_source *, int n0, int n1,
+ const char *format, va_list)
+ PRINTF_FORMAT (4, 0);
+static const struct lex_token *lex_source_next__ (const struct lex_source *,
+ int n);
-/* Initialization. */
-
-/* Initializes the lexer. */
-struct lexer *
-lex_create (struct source_stream *ss)
+/* Initializes READER with the specified CLASS and otherwise some reasonable
+ defaults. The caller should fill in the others members as desired. */
+void
+lex_reader_init (struct lex_reader *reader,
+ const struct lex_reader_class *class)
{
- struct lexer *lexer = xzalloc (sizeof (*lexer));
-
- ds_init_empty (&lexer->tokstr);
- ds_init_empty (&lexer->put_tokstr);
- ds_init_empty (&lexer->line_buffer);
- lexer->ss = ss;
-
- return lexer;
+ reader->class = class;
+ reader->syntax = LEX_SYNTAX_AUTO;
+ reader->error = LEX_ERROR_INTERACTIVE;
+ reader->file_name = NULL;
+ reader->line_number = 0;
}
-struct source_stream *
-lex_get_source_stream (const struct lexer *lex)
+/* Frees any file name already in READER and replaces it by a copy of
+ FILE_NAME, or if FILE_NAME is null then clears any existing name. */
+void
+lex_reader_set_file_name (struct lex_reader *reader, const char *file_name)
{
- return lex->ss;
+ free (reader->file_name);
+ reader->file_name = file_name != NULL ? xstrdup (file_name) : NULL;
+}
+
+/* Creates and returns a new lexer. */
+struct lexer *
+lex_create (void)
+{
+ struct lexer *lexer = xzalloc (sizeof *lexer);
+ ll_init (&lexer->sources);
+ return lexer;
}
-
+/* Destroys LEXER. */
void
lex_destroy (struct lexer *lexer)
{
- if ( NULL != lexer )
+ if (lexer != NULL)
{
- ds_destroy (&lexer->put_tokstr);
- ds_destroy (&lexer->tokstr);
- ds_destroy (&lexer->line_buffer);
+ struct lex_source *source, *next;
+ ll_for_each_safe (source, next, struct lex_source, ll, &lexer->sources)
+ lex_source_destroy (source);
free (lexer);
}
}
+/* Inserts READER into LEXER so that the next token read by LEXER comes from
+ READER. Before the caller, LEXER must either be empty or at a T_ENDCMD
+ token. */
+void
+lex_include (struct lexer *lexer, struct lex_reader *reader)
+{
+ assert (ll_is_empty (&lexer->sources) || lex_token (lexer) == T_ENDCMD);
+ ll_push_head (&lexer->sources, &lex_source_create (reader)->ll);
+}
+
+/* Appends READER to LEXER, so that it will be read after all other current
+ readers have already been read. */
+void
+lex_append (struct lexer *lexer, struct lex_reader *reader)
+{
+ ll_push_tail (&lexer->sources, &lex_source_create (reader)->ll);
+}
-/* Common functions. */
+/* Advacning. */
+
+static struct lex_token *
+lex_push_token__ (struct lex_source *src)
+{
+ struct lex_token *token;
+
+ if (deque_is_full (&src->deque))
+ src->tokens = deque_expand (&src->deque, src->tokens, sizeof *src->tokens);
+
+ token = &src->tokens[deque_push_front (&src->deque)];
+ token_init (&token->token);
+ return token;
+}
-/* Copies put_token, lexer->put_tokstr, put_tokval into token, tokstr,
- tokval, respectively, and sets tokid appropriately. */
static void
-restore_token (struct lexer *lexer)
+lex_source_pop__ (struct lex_source *src)
{
- assert (lexer->put_token != 0);
- lexer->token = lexer->put_token;
- ds_assign_string (&lexer->tokstr, &lexer->put_tokstr);
- str_copy_trunc (lexer->tokid, sizeof lexer->tokid, ds_cstr (&lexer->tokstr));
- lexer->tokval = lexer->put_tokval;
- lexer->put_token = 0;
+ token_destroy (&src->tokens[deque_pop_back (&src->deque)].token);
}
-/* Copies token, tokstr, lexer->tokval into lexer->put_token, put_tokstr,
- put_lexer->tokval respectively. */
static void
-save_token (struct lexer *lexer)
+lex_source_pop_front (struct lex_source *src)
{
- lexer->put_token = lexer->token;
- ds_assign_string (&lexer->put_tokstr, &lexer->tokstr);
- lexer->put_tokval = lexer->tokval;
+ token_destroy (&src->tokens[deque_pop_front (&src->deque)].token);
}
-/* Parses a single token, setting appropriate global variables to
- indicate the token's attributes. */
+/* Advances LEXER to the next token, consuming the current token. */
void
lex_get (struct lexer *lexer)
{
- /* Find a token. */
- for (;;)
- {
- if (NULL == lexer->prog && ! lex_get_line (lexer) )
- {
- lexer->token = T_STOP;
- return;
- }
-
- /* If a token was pushed ahead, return it. */
- if (lexer->put_token)
- {
- restore_token (lexer);
-#if DUMP_TOKENS
- dump_token (lexer);
-#endif
- return;
- }
+ struct lex_source *src;
- for (;;)
- {
- /* Skip whitespace. */
- while (isspace ((unsigned char) *lexer->prog))
- lexer->prog++;
-
- if (*lexer->prog)
- break;
-
- if (lexer->dot)
- {
- lexer->dot = 0;
- lexer->token = '.';
-#if DUMP_TOKENS
- dump_token (lexer);
-#endif
- return;
- }
- else if (!lex_get_line (lexer))
- {
- lexer->prog = NULL;
- lexer->token = T_STOP;
-#if DUMP_TOKENS
- dump_token (lexer);
-#endif
- return;
- }
-
- if (lexer->put_token)
- {
- restore_token (lexer);
-#if DUMP_TOKENS
- dump_token (lexer);
-#endif
- return;
- }
- }
-
-
- /* Actually parse the token. */
- ds_clear (&lexer->tokstr);
-
- switch (*lexer->prog)
- {
- case '-': case '.':
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9':
- {
- char *tail;
-
- /* `-' can introduce a negative number, or it can be a
- token by itself. If it is not followed by a digit or a
- decimal point, it is definitely not a number.
- Otherwise, it might be either, but most of the time we
- want it as a number. When the syntax calls for a `-'
- token, lex_negative_to_dash() must be used to break
- negative numbers into two tokens. */
- if (*lexer->prog == '-')
- {
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- while (isspace ((unsigned char) *lexer->prog))
- lexer->prog++;
-
- if (!isdigit ((unsigned char) *lexer->prog) && *lexer->prog != '.')
- {
- lexer->token = '-';
- break;
- }
- lexer->token = T_NEG_NUM;
- }
- else
- lexer->token = T_POS_NUM;
-
- /* Parse the number, copying it into tokstr. */
- while (isdigit ((unsigned char) *lexer->prog))
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- if (*lexer->prog == '.')
- {
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- while (isdigit ((unsigned char) *lexer->prog))
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- }
- if (*lexer->prog == 'e' || *lexer->prog == 'E')
- {
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- if (*lexer->prog == '+' || *lexer->prog == '-')
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- while (isdigit ((unsigned char) *lexer->prog))
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- }
-
- /* Parse as floating point. */
- lexer->tokval = strtod (ds_cstr (&lexer->tokstr), &tail);
- if (*tail)
- {
- msg (SE, _("%s does not form a valid number."),
- ds_cstr (&lexer->tokstr));
- lexer->tokval = 0.0;
-
- ds_clear (&lexer->tokstr);
- ds_put_char (&lexer->tokstr, '0');
- }
-
- break;
- }
-
- case '\'': case '"':
- lexer->token = parse_string (lexer, CHARACTER_STRING);
- break;
-
- case '(': case ')': case ',': case '=': case '+': case '/':
- lexer->token = *lexer->prog++;
- break;
-
- case '*':
- if (*++lexer->prog == '*')
- {
- lexer->prog++;
- lexer->token = T_EXP;
- }
- else
- lexer->token = '*';
- break;
-
- case '<':
- if (*++lexer->prog == '=')
- {
- lexer->prog++;
- lexer->token = T_LE;
- }
- else if (*lexer->prog == '>')
- {
- lexer->prog++;
- lexer->token = T_NE;
- }
- else
- lexer->token = T_LT;
- break;
-
- case '>':
- if (*++lexer->prog == '=')
- {
- lexer->prog++;
- lexer->token = T_GE;
- }
- else
- lexer->token = T_GT;
- break;
-
- case '~':
- if (*++lexer->prog == '=')
- {
- lexer->prog++;
- lexer->token = T_NE;
- }
- else
- lexer->token = T_NOT;
- break;
-
- case '&':
- lexer->prog++;
- lexer->token = T_AND;
- break;
-
- case '|':
- lexer->prog++;
- lexer->token = T_OR;
- break;
-
- case 'b': case 'B':
- if (lexer->prog[1] == '\'' || lexer->prog[1] == '"')
- lexer->token = parse_string (lexer, BINARY_STRING);
- else
- lexer->token = parse_id (lexer);
- break;
+ src = lex_source__ (lexer);
+ if (src == NULL)
+ return;
- case 'o': case 'O':
- if (lexer->prog[1] == '\'' || lexer->prog[1] == '"')
- lexer->token = parse_string (lexer, OCTAL_STRING);
- else
- lexer->token = parse_id (lexer);
- break;
+ if (!deque_is_empty (&src->deque))
+ lex_source_pop__ (src);
- case 'x': case 'X':
- if (lexer->prog[1] == '\'' || lexer->prog[1] == '"')
- lexer->token = parse_string (lexer, HEX_STRING);
- else
- lexer->token = parse_id (lexer);
- break;
+ while (deque_is_empty (&src->deque))
+ if (!lex_source_get__ (src))
+ {
+ lex_source_destroy (src);
+ src = lex_source__ (lexer);
+ if (src == NULL)
+ return;
+ }
+}
+
+/* Issuing errors. */
- default:
- if (lex_is_id1 (*lexer->prog))
- {
- lexer->token = parse_id (lexer);
- break;
- }
- else
- {
- if (isgraph ((unsigned char) *lexer->prog))
- msg (SE, _("Bad character in input: `%c'."), *lexer->prog++);
- else
- msg (SE, _("Bad character in input: `\\%o'."), *lexer->prog++);
- continue;
- }
- }
- break;
- }
+/* Prints a syntax error message containing the current token and
+ given message MESSAGE (if non-null). */
+void
+lex_error (struct lexer *lexer, const char *format, ...)
+{
+ va_list args;
-#if DUMP_TOKENS
- dump_token (lexer);
-#endif
+ va_start (args, format);
+ lex_next_error_valist (lexer, 0, 0, format, args);
+ va_end (args);
}
-/* Parses an identifier at the current position into tokid and
- tokstr.
- Returns the correct token type. */
-static int
-parse_id (struct lexer *lexer)
+/* Prints a syntax error message containing the current token and
+ given message MESSAGE (if non-null). */
+void
+lex_error_valist (struct lexer *lexer, const char *format, va_list args)
+{
+ lex_next_error_valist (lexer, 0, 0, format, args);
+}
+
+/* Prints a syntax error message containing the current token and
+ given message MESSAGE (if non-null). */
+void
+lex_next_error (struct lexer *lexer, int n0, int n1, const char *format, ...)
{
- struct substring rest_of_line
- = ss_substr (ds_ss (&lexer->line_buffer),
- ds_pointer_to_position (&lexer->line_buffer, lexer->prog),
- SIZE_MAX);
- struct substring id = ss_head (rest_of_line,
- lex_id_get_length (rest_of_line));
- lexer->prog += ss_length (id);
+ va_list args;
- ds_assign_substring (&lexer->tokstr, id);
- str_copy_trunc (lexer->tokid, sizeof lexer->tokid, ds_cstr (&lexer->tokstr));
- return lex_id_to_token (id);
+ va_start (args, format);
+ lex_next_error_valist (lexer, n0, n1, format, args);
+ va_end (args);
}
/* Reports an error to the effect that subcommand SBC may only be
@@ -422,33 +287,28 @@ lex_sbc_missing (struct lexer *lexer, const char *sbc)
/* Prints a syntax error message containing the current token and
given message MESSAGE (if non-null). */
void
-lex_error (struct lexer *lexer, const char *message, ...)
+lex_next_error_valist (struct lexer *lexer, int n0, int n1,
+ const char *format, va_list args)
{
- char *token_rep;
- char where[128];
+ struct lex_source *src = lex_source__ (lexer);
- token_rep = lex_token_representation (lexer);
- if (lexer->token == T_STOP)
- strcpy (where, "end of file");
- else if (lexer->token == '.')
- strcpy (where, "end of command");
+ if (src != NULL)
+ lex_source_error_valist (src, n0, n1, format, args);
else
- snprintf (where, sizeof where, "`%s'", token_rep);
- free (token_rep);
-
- if (message)
{
- char buf[1024];
- va_list args;
-
- va_start (args, message);
- vsnprintf (buf, 1024, message, args);
- va_end (args);
+ struct string s;
- msg (SE, _("Syntax error %s at %s."), buf, where);
+ ds_init_empty (&s);
+ ds_put_format (&s, _("Syntax error at end of input"));
+ if (format != NULL)
+ {
+ ds_put_cstr (&s, ": ");
+ ds_put_vformat (&s, format, args);
+ }
+ ds_put_byte (&s, '.');
+ msg (SE, "%s", ds_cstr (&s));
+ ds_destroy (&s);
}
- else
- msg (SE, _("Syntax error at %s."), where);
}
/* Checks that we're at end of command.
@@ -458,7 +318,7 @@ lex_error (struct lexer *lexer, const char *message, ...)
int
lex_end_of_command (struct lexer *lexer)
{
- if (lexer->token != '.')
+ if (lex_token (lexer) != T_ENDCMD && lex_token (lexer) != T_STOP)
{
lex_error (lexer, _("expecting end of command"));
return CMD_FAILURE;
@@ -473,36 +333,29 @@ lex_end_of_command (struct lexer *lexer)
bool
lex_is_number (struct lexer *lexer)
{
- return lexer->token == T_POS_NUM || lexer->token == T_NEG_NUM;
+ return lex_next_is_number (lexer, 0);
}
-
/* Returns true if the current token is a string. */
bool
lex_is_string (struct lexer *lexer)
{
- return lexer->token == T_STRING;
+ return lex_next_is_string (lexer, 0);
}
-
/* Returns the value of the current token, which must be a
floating point number. */
double
lex_number (struct lexer *lexer)
{
- assert (lex_is_number (lexer));
- return lexer->tokval;
+ return lex_next_number (lexer, 0);
}
/* Returns true iff the current token is an integer. */
bool
lex_is_integer (struct lexer *lexer)
{
- return (lex_is_number (lexer)
- && lexer->tokval != NOT_LONG
- && lexer->tokval >= LONG_MIN
- && lexer->tokval <= LONG_MAX
- && floor (lexer->tokval) == lexer->tokval);
+ return lex_next_is_integer (lexer, 0);
}
/* Returns the value of the current token, which must be an
@@ -510,18 +363,70 @@ lex_is_integer (struct lexer *lexer)
long
lex_integer (struct lexer *lexer)
{
- assert (lex_is_integer (lexer));
- return lexer->tokval;
+ return lex_next_integer (lexer, 0);
+}
+
+/* Token testing functions with lookahead.
+
+ A value of 0 for N as an argument to any of these functions refers to the
+ current token. Lookahead is limited to the current command. Any N greater
+ than the number of tokens remaining in the current command will be treated
+ as referring to a T_ENDCMD token. */
+
+/* Returns true if the token N ahead of the current token is a number. */
+bool
+lex_next_is_number (struct lexer *lexer, int n)
+{
+ enum token_type next_token = lex_next_token (lexer, n);
+ return next_token == T_POS_NUM || next_token == T_NEG_NUM;
+}
+
+/* Returns true if the token N ahead of the current token is a string. */
+bool
+lex_next_is_string (struct lexer *lexer, int n)
+{
+ return lex_next_token (lexer, n) == T_STRING;
+}
+
+/* Returns the value of the token N ahead of the current token, which must be a
+ floating point number. */
+double
+lex_next_number (struct lexer *lexer, int n)
+{
+ assert (lex_next_is_number (lexer, n));
+ return lex_next_tokval (lexer, n);
+}
+
+/* Returns true if the token N ahead of the current token is an integer. */
+bool
+lex_next_is_integer (struct lexer *lexer, int n)
+{
+ double value;
+
+ if (!lex_next_is_number (lexer, n))
+ return false;
+
+ value = lex_next_tokval (lexer, n);
+ return value > LONG_MIN && value <= LONG_MAX && floor (value) == value;
+}
+
+/* Returns the value of the token N ahead of the current token, which must be
+ an integer. */
+long
+lex_next_integer (struct lexer *lexer, int n)
+{
+ assert (lex_next_is_integer (lexer, n));
+ return lex_next_tokval (lexer, n);
}
/* Token matching functions. */
-/* If TOK is the current token, skips it and returns true
+/* If the current token has the specified TYPE, skips it and returns true.
Otherwise, returns false. */
bool
-lex_match (struct lexer *lexer, int t)
+lex_match (struct lexer *lexer, enum token_type type)
{
- if (lexer->token == t)
+ if (lex_token (lexer) == type)
{
lex_get (lexer);
return true;
@@ -530,15 +435,26 @@ lex_match (struct lexer *lexer, int t)
return false;
}
-/* If the current token is the identifier S, skips it and returns
- true. The identifier may be abbreviated to its first three
- letters.
- Otherwise, returns false. */
+/* If the current token matches IDENTIFIER, skips it and returns true.
+ IDENTIFIER may be abbreviated to its first three letters. Otherwise,
+ returns false.
+
+ IDENTIFIER must be an ASCII string. */
bool
-lex_match_id (struct lexer *lexer, const char *s)
+lex_match_id (struct lexer *lexer, const char *identifier)
{
- if (lexer->token == T_ID
- && lex_id_match (ss_cstr (s), ss_cstr (lexer->tokid)))
+ return lex_match_id_n (lexer, identifier, 3);
+}
+
+/* If the current token is IDENTIFIER, skips it and returns true. IDENTIFIER
+ may be abbreviated to its first N letters. Otherwise, returns false.
+
+ IDENTIFIER must be an ASCII string. */
+bool
+lex_match_id_n (struct lexer *lexer, const char *identifier, size_t n)
+{
+ if (lex_token (lexer) == T_ID
+ && lex_id_match_n (ss_cstr (identifier), lex_tokss (lexer), n))
{
lex_get (lexer);
return true;
@@ -547,8 +463,8 @@ lex_match_id (struct lexer *lexer, const char *s)
return false;
}
-/* If the current token is integer N, skips it and returns true.
- Otherwise, returns false. */
+/* If the current token is integer X, skips it and returns true. Otherwise,
+ returns false. */
bool
lex_match_int (struct lexer *lexer, int x)
{
@@ -563,44 +479,46 @@ lex_match_int (struct lexer *lexer, int x)
/* Forced matches. */
-/* If this token is identifier S, fetches the next token and returns
- nonzero.
- Otherwise, reports an error and returns zero. */
+/* If this token is IDENTIFIER, skips it and returns true. IDENTIFIER may be
+ abbreviated to its first 3 letters. Otherwise, reports an error and returns
+ false.
+
+ IDENTIFIER must be an ASCII string. */
bool
-lex_force_match_id (struct lexer *lexer, const char *s)
+lex_force_match_id (struct lexer *lexer, const char *identifier)
{
- if (lex_match_id (lexer, s))
+ if (lex_match_id (lexer, identifier))
return true;
else
{
- lex_error (lexer, _("expecting `%s'"), s);
+ lex_error (lexer, _("expecting `%s'"), identifier);
return false;
}
}
-/* If the current token is T, skips the token. Otherwise, reports an
- error and returns from the current function with return value false. */
+/* If the current token has the specified TYPE, skips it and returns true.
+ Otherwise, reports an error and returns false. */
bool
-lex_force_match (struct lexer *lexer, int t)
+lex_force_match (struct lexer *lexer, enum token_type type)
{
- if (lexer->token == t)
+ if (lex_token (lexer) == type)
{
lex_get (lexer);
return true;
}
else
{
- lex_error (lexer, _("expecting `%s'"), lex_token_name (t));
+ lex_error (lexer, _("expecting `%s'"), token_type_to_string (type));
return false;
}
}
-/* If this token is a string, does nothing and returns true.
+/* If the current token is a string, does nothing and returns true.
Otherwise, reports an error and returns false. */
bool
lex_force_string (struct lexer *lexer)
{
- if (lexer->token == T_STRING)
+ if (lex_is_string (lexer))
return true;
else
{
@@ -609,7 +527,7 @@ lex_force_string (struct lexer *lexer)
}
}
-/* If this token is an integer, does nothing and returns true.
+/* If the current token is an integer, does nothing and returns true.
Otherwise, reports an error and returns false. */
bool
lex_force_int (struct lexer *lexer)
@@ -623,7 +541,7 @@ lex_force_int (struct lexer *lexer)
}
}
-/* If this token is a number, does nothing and returns true.
+/* If the current token is a number, does nothing and returns true.
Otherwise, reports an error and returns false. */
bool
lex_force_num (struct lexer *lexer)
@@ -635,649 +553,1081 @@ lex_force_num (struct lexer *lexer)
return false;
}
-/* If this token is an identifier, does nothing and returns true.
+/* If the current token is an identifier, does nothing and returns true.
Otherwise, reports an error and returns false. */
bool
lex_force_id (struct lexer *lexer)
{
- if (lexer->token == T_ID)
+ if (lex_token (lexer) == T_ID)
return true;
lex_error (lexer, _("expecting identifier"));
return false;
}
+
+/* Token accessors. */
-/* Weird token functions. */
-
-/* Returns the first character of the next token, except that if the
- next token is not an identifier, the character returned will not be
- a character that can begin an identifier. Specifically, the
- hexstring lead-in X' causes lookahead() to return '. Note that an
- alphanumeric return value doesn't guarantee an ID token, it could
- also be a reserved-word token. */
-int
-lex_look_ahead (struct lexer *lexer)
+/* Returns the type of LEXER's current token. */
+enum token_type
+lex_token (const struct lexer *lexer)
{
- if (lexer->put_token)
- return lexer->put_token;
+ return lex_next_token (lexer, 0);
+}
- for (;;)
- {
- if (NULL == lexer->prog && ! lex_get_line (lexer) )
- return 0;
-
- for (;;)
- {
- while (isspace ((unsigned char) *lexer->prog))
- lexer->prog++;
- if (*lexer->prog)
- break;
-
- if (lexer->dot)
- return '.';
- else if (!lex_get_line (lexer))
- return 0;
-
- if (lexer->put_token)
- return lexer->put_token;
- }
-
- if ((toupper ((unsigned char) *lexer->prog) == 'X'
- || toupper ((unsigned char) *lexer->prog) == 'B'
- || toupper ((unsigned char) *lexer->prog) == 'O')
- && (lexer->prog[1] == '\'' || lexer->prog[1] == '"'))
- return '\'';
-
- return *lexer->prog;
- }
+/* Returns the number in LEXER's current token.
+
+ Only T_NEG_NUM and T_POS_NUM tokens have meaningful values. For other
+ tokens this function will always return zero. */
+double
+lex_tokval (const struct lexer *lexer)
+{
+ return lex_next_tokval (lexer, 0);
}
-/* Makes the current token become the next token to be read; the
- current token is set to T. */
-void
-lex_put_back (struct lexer *lexer, int t)
+/* Returns the null-terminated string in LEXER's current token, UTF-8 encoded.
+
+ Only T_ID and T_STRING tokens have meaningful strings. For other tokens
+ this functions this function will always return NULL.
+
+ The UTF-8 encoding of the returned string is correct for variable names and
+ other identifiers. Use filename_to_utf8() to use it as a filename. Use
+ data_in() to use it in a "union value". */
+const char *
+lex_tokcstr (const struct lexer *lexer)
{
- save_token (lexer);
- lexer->token = t;
+ return lex_next_tokcstr (lexer, 0);
}
-/* Makes the current token become the next token to be read; the
- current token is set to the identifier ID. */
-void
-lex_put_back_id (struct lexer *lexer, const char *id)
+/* Returns the string in LEXER's current token, UTF-8 encoded. The string is
+ null-terminated (but the null terminator is not included in the returned
+ substring's 'length').
+
+ Only T_ID and T_STRING tokens have meaningful strings. For other tokens
+ this functions this function will always return NULL.
+
+ The UTF-8 encoding of the returned string is correct for variable names and
+ other identifiers. Use filename_to_utf8() to use it as a filename. Use
+ data_in() to use it in a "union value". */
+struct substring
+lex_tokss (const struct lexer *lexer)
{
- assert (lex_id_to_token (ss_cstr (id)) == T_ID);
- save_token (lexer);
- lexer->token = T_ID;
- ds_assign_cstr (&lexer->tokstr, id);
- str_copy_trunc (lexer->tokid, sizeof lexer->tokid, ds_cstr (&lexer->tokstr));
+ return lex_next_tokss (lexer, 0);
}
-/* Weird line processing functions. */
+/* Looking ahead.
-/* Returns the entire contents of the current line. */
-const char *
-lex_entire_line (const struct lexer *lexer)
+ A value of 0 for N as an argument to any of these functions refers to the
+ current token. Lookahead is limited to the current command. Any N greater
+ than the number of tokens remaining in the current command will be treated
+ as referring to a T_ENDCMD token. */
+
+static const struct lex_token *
+lex_next__ (const struct lexer *lexer_, int n)
{
- return ds_cstr (&lexer->line_buffer);
+ struct lexer *lexer = CONST_CAST (struct lexer *, lexer_);
+ struct lex_source *src = lex_source__ (lexer);
+
+ if (src != NULL)
+ return lex_source_next__ (src, n);
+ else
+ {
+ static const struct lex_token stop_token =
+ { TOKEN_INITIALIZER (T_STOP, 0.0, ""), 0, 0, 0, 0 };
+
+ return &stop_token;
+ }
}
-const struct string *
-lex_entire_line_ds (const struct lexer *lexer)
+static const struct lex_token *
+lex_source_next__ (const struct lex_source *src, int n)
{
- return &lexer->line_buffer;
+ while (deque_count (&src->deque) <= n)
+ {
+ if (!deque_is_empty (&src->deque))
+ {
+ struct lex_token *front;
+
+ front = &src->tokens[deque_front (&src->deque, 0)];
+ if (front->token.type == T_STOP || front->token.type == T_ENDCMD)
+ return front;
+ }
+
+ lex_source_get__ (src);
+ }
+
+ return &src->tokens[deque_back (&src->deque, n)];
}
-/* As lex_entire_line(), but only returns the part of the current line
- that hasn't already been tokenized. */
-const char *
-lex_rest_of_line (const struct lexer *lexer)
+/* Returns the "struct token" of the token N after the current one in LEXER.
+ The returned pointer can be invalidated by pretty much any succeeding call
+ into the lexer, although the string pointer within the returned token is
+ only invalidated by consuming the token (e.g. with lex_get()). */
+const struct token *
+lex_next (const struct lexer *lexer, int n)
{
- return lexer->prog;
+ return &lex_next__ (lexer, n)->token;
}
-/* Returns true if the current line ends in a terminal dot,
- false otherwise. */
-bool
-lex_end_dot (const struct lexer *lexer)
+/* Returns the type of the token N after the current one in LEXER. */
+enum token_type
+lex_next_token (const struct lexer *lexer, int n)
{
- return lexer->dot;
+ return lex_next (lexer, n)->type;
}
-/* Causes the rest of the current input line to be ignored for
- tokenization purposes. */
-void
-lex_discard_line (struct lexer *lexer)
+/* Returns the number in the tokn N after the current one in LEXER.
+
+ Only T_NEG_NUM and T_POS_NUM tokens have meaningful values. For other
+ tokens this function will always return zero. */
+double
+lex_next_tokval (const struct lexer *lexer, int n)
{
- ds_cstr (&lexer->line_buffer); /* Ensures ds_end points to something valid */
- lexer->prog = ds_end (&lexer->line_buffer);
- lexer->dot = false;
- lexer->put_token = 0;
+ const struct token *token = lex_next (lexer, n);
+ return token->number;
}
+/* Returns the null-terminated string in the token N after the current one, in
+ UTF-8 encoding.
-/* Discards the rest of the current command.
- When we're reading commands from a file, we skip tokens until
- a terminal dot or EOF.
- When we're reading commands interactively from the user,
- that's just discarding the current line, because presumably
- the user doesn't want to finish typing a command that will be
- ignored anyway. */
-void
-lex_discard_rest_of_command (struct lexer *lexer)
+ Only T_ID and T_STRING tokens have meaningful strings. For other tokens
+ this functions this function will always return NULL.
+
+ The UTF-8 encoding of the returned string is correct for variable names and
+ other identifiers. Use filename_to_utf8() to use it as a filename. Use
+ data_in() to use it in a "union value". */
+const char *
+lex_next_tokcstr (const struct lexer *lexer, int n)
{
- if (!getl_is_interactive (lexer->ss))
- {
- while (lexer->token != T_STOP && lexer->token != '.')
- lex_get (lexer);
- }
- else
- lex_discard_line (lexer);
+ return lex_next_tokss (lexer, n).string;
}
-
-/* Weird line reading functions. */
-/* Remove C-style comments in STRING, begun by slash-star and
- terminated by star-slash or newline. */
-static void
-strip_comments (struct string *string)
+/* Returns the string in the token N after the current one, in UTF-8 encoding.
+ The string is null-terminated (but the null terminator is not included in
+ the returned substring's 'length').
+
+ Only T_ID and T_STRING tokens have meaningful strings. For other tokens
+ this functions this function will always return NULL.
+
+ The UTF-8 encoding of the returned string is correct for variable names and
+ other identifiers. Use filename_to_utf8() to use it as a filename. Use
+ data_in() to use it in a "union value". */
+struct substring
+lex_next_tokss (const struct lexer *lexer, int n)
{
- char *cp;
- int quote;
- bool in_comment;
+ return lex_next (lexer, n)->string;
+}
+
+/* If LEXER is positioned at the (pseudo)identifier S, skips it and returns
+ true. Otherwise, returns false.
+
+ S may consist of an arbitrary number of identifiers, integers, and
+ punctuation e.g. "KRUSKAL-WALLIS", "2SLS", or "END INPUT PROGRAM".
+ Identifiers may be abbreviated to their first three letters. Currently only
+ hyphens, slashes, and equals signs are supported as punctuation (but it
+ would be easy to add more).
- in_comment = false;
- quote = EOF;
- for (cp = ds_cstr (string); *cp; )
+ S must be an ASCII string. */
+bool
+lex_match_phrase (struct lexer *lexer, const char *s)
+{
+ int tok_idx;
+
+ for (tok_idx = 0; ; tok_idx++)
{
- /* If we're not in a comment, check for quote marks. */
- if (!in_comment)
+ enum token_type token;
+ unsigned char c;
+
+ while (c_isspace (*s))
+ s++;
+
+ c = *s;
+ if (c == '\0')
{
- if (*cp == quote)
- quote = EOF;
- else if (*cp == '\'' || *cp == '"')
- quote = *cp;
+ int i;
+
+ for (i = 0; i < tok_idx; i++)
+ lex_get (lexer);
+ return true;
}
- /* If we're not inside a quotation, check for comment. */
- if (quote == EOF)
+ token = lex_next_token (lexer, tok_idx);
+ switch (c)
{
- if (cp[0] == '/' && cp[1] == '*')
- {
- in_comment = true;
- *cp++ = ' ';
- *cp++ = ' ';
- continue;
- }
- else if (in_comment && cp[0] == '*' && cp[1] == '/')
+ case '-':
+ if (token != T_DASH)
+ return false;
+ s++;
+ break;
+
+ case '/':
+ if (token != T_SLASH)
+ return false;
+ s++;
+ break;
+
+ case '=':
+ if (token != T_EQUALS)
+ return false;
+ s++;
+ break;
+
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ {
+ unsigned int value;
+
+ if (token != T_POS_NUM)
+ return false;
+
+ value = 0;
+ do
+ {
+ value = value * 10 + (*s++ - '0');
+ }
+ while (c_isdigit (*s));
+
+ if (lex_next_tokval (lexer, tok_idx) != value)
+ return false;
+ }
+ break;
+
+ default:
+ if (lex_is_id1 (c))
{
- in_comment = false;
- *cp++ = ' ';
- *cp++ = ' ';
- continue;
+ int len;
+
+ if (token != T_ID)
+ return false;
+
+ len = lex_id_get_length (ss_cstr (s));
+ if (!lex_id_match (ss_buffer (s, len),
+ lex_next_tokss (lexer, tok_idx)))
+ return false;
+
+ s += len;
}
+ else
+ NOT_REACHED ();
}
-
- /* Check commenting. */
- if (in_comment)
- *cp = ' ';
- cp++;
}
}
-/* Prepares LINE, which is subject to the given SYNTAX rules, for
- tokenization by stripping comments and determining whether it
- is the beginning or end of a command and storing into
- *LINE_STARTS_COMMAND and *LINE_ENDS_COMMAND appropriately. */
-void
-lex_preprocess_line (struct string *line,
- enum getl_syntax syntax,
- bool *line_starts_command,
- bool *line_ends_command)
-{
- strip_comments (line);
- ds_rtrim (line, ss_cstr (CC_SPACES));
- *line_ends_command = (ds_chomp (line, get_endcmd ())
- || (ds_is_empty (line) && get_nulline ()));
- *line_starts_command = false;
- if (syntax == GETL_BATCH)
+static int
+lex_source_get_first_line_number (const struct lex_source *src, int n)
+{
+ return lex_source_next__ (src, n)->first_line;
+}
+
+static int
+count_newlines (char *s, size_t length)
+{
+ int n_newlines = 0;
+ char *newline;
+
+ while ((newline = memchr (s, '\n', length)) != NULL)
{
- int first = ds_first (line);
- *line_starts_command = !isspace (first);
- if (first == '+' || first == '-')
- *ds_data (line) = ' ';
+ n_newlines++;
+ length -= (newline + 1) - s;
+ s = newline + 1;
}
+
+ return n_newlines;
}
-/* Reads a line, without performing any preprocessing.
- Sets *SYNTAX, if SYNTAX is non-null, to the line's syntax
- mode. */
-bool
-lex_get_line_raw (struct lexer *lexer, enum getl_syntax *syntax)
+static int
+lex_source_get_last_line_number (const struct lex_source *src, int n)
{
- enum getl_syntax dummy;
- bool ok = getl_read_line (lexer->ss, &lexer->line_buffer,
- syntax != NULL ? syntax : &dummy);
- return ok;
+ const struct lex_token *token = lex_source_next__ (src, n);
+
+ if (token->first_line == 0)
+ return 0;
+ else
+ {
+ char *token_str = &src->buffer[token->token_pos - src->tail];
+ return token->first_line + count_newlines (token_str, token->token_len) + 1;
+ }
}
-/* Reads a line for use by the tokenizer, and preprocesses it by
- removing comments, stripping trailing whitespace and the
- terminal dot, and removing leading indentors. */
-bool
-lex_get_line (struct lexer *lexer)
+static int
+count_columns (const char *s_, size_t length)
{
- bool line_starts_command;
- enum getl_syntax syntax;
+ const uint8_t *s = CHAR_CAST (const uint8_t *, s_);
+ int columns;
+ size_t ofs;
+ int mblen;
- if (!lex_get_line_raw (lexer, &syntax))
+ columns = 0;
+ for (ofs = 0; ofs < length; ofs += mblen)
{
- lexer->prog = NULL;
- return false;
+ ucs4_t uc;
+
+ mblen = u8_mbtouc (&uc, s + ofs, length - ofs);
+ if (uc != '\t')
+ {
+ int width = uc_width (uc, "UTF-8");
+ if (width > 0)
+ columns += width;
+ }
+ else
+ columns = ROUND_UP (columns + 1, 8);
}
- lex_preprocess_line (&lexer->line_buffer, syntax,
- &line_starts_command, &lexer->dot);
+ return columns + 1;
+}
+
+static int
+lex_source_get_first_column (const struct lex_source *src, int n)
+{
+ const struct lex_token *token = lex_source_next__ (src, n);
+ return count_columns (&src->buffer[token->line_pos - src->tail],
+ token->token_pos - token->line_pos);
+}
+
+static int
+lex_source_get_last_column (const struct lex_source *src, int n)
+{
+ const struct lex_token *token = lex_source_next__ (src, n);
+ char *start, *end, *newline;
+
+ start = &src->buffer[token->line_pos - src->tail];
+ end = &src->buffer[(token->token_pos + token->token_len) - src->tail];
+ newline = memrchr (start, '\n', end - start);
+ if (newline != NULL)
+ start = newline + 1;
+ return count_columns (start, end - start);
+}
- if (line_starts_command)
- lexer->put_token = '.';
+/* Returns the 1-based line number of the start of the syntax that represents
+ the token N after the current one in LEXER. Returns 0 for a T_STOP token or
+ if the token is drawn from a source that does not have line numbers. */
+int
+lex_get_first_line_number (const struct lexer *lexer, int n)
+{
+ const struct lex_source *src = lex_source__ (lexer);
+ return src != NULL ? lex_source_get_first_line_number (src, n) : 0;
+}
- lexer->prog = ds_cstr (&lexer->line_buffer);
- return true;
+/* Returns the 1-based line number of the end of the syntax that represents the
+ token N after the current one in LEXER, plus 1. Returns 0 for a T_STOP
+ token or if the token is drawn from a source that does not have line
+ numbers.
+
+ Most of the time, a single token is wholly within a single line of syntax,
+ but there are two exceptions: a T_STRING token can be made up of multiple
+ segments on adjacent lines connected with "+" punctuators, and a T_NEG_NUM
+ token can consist of a "-" on one line followed by the number on the next.
+ */
+int
+lex_get_last_line_number (const struct lexer *lexer, int n)
+{
+ const struct lex_source *src = lex_source__ (lexer);
+ return src != NULL ? lex_source_get_last_line_number (src, n) : 0;
}
-
-/* Token names. */
-/* Returns the name of a token. */
+/* Returns the 1-based column number of the start of the syntax that represents
+ the token N after the current one in LEXER. Returns 0 for a T_STOP
+ token.
+
+ Column numbers are measured according to the width of characters as shown in
+ a typical fixed-width font, in which CJK characters have width 2 and
+ combining characters have width 0. */
+int
+lex_get_first_column (const struct lexer *lexer, int n)
+{
+ const struct lex_source *src = lex_source__ (lexer);
+ return src != NULL ? lex_source_get_first_column (src, n) : 0;
+}
+
+/* Returns the 1-based column number of the end of the syntax that represents
+ the token N after the current one in LEXER, plus 1. Returns 0 for a T_STOP
+ token.
+
+ Column numbers are measured according to the width of characters as shown in
+ a typical fixed-width font, in which CJK characters have width 2 and
+ combining characters have width 0. */
+int
+lex_get_last_column (const struct lexer *lexer, int n)
+{
+ const struct lex_source *src = lex_source__ (lexer);
+ return src != NULL ? lex_source_get_last_column (src, n) : 0;
+}
+
+/* Returns the name of the syntax file from which the current command is drawn.
+ Returns NULL for a T_STOP token or if the command's source does not have
+ line numbers.
+
+ There is no version of this function that takes an N argument because
+ lookahead only works to the end of a command and any given command is always
+ within a single syntax file. */
const char *
-lex_token_name (int token)
+lex_get_file_name (const struct lexer *lexer)
{
- if (lex_is_keyword (token))
- return lex_id_name (token);
- else if (token < 256)
- {
- static char t[256][2];
- char *s = t[token];
- s[0] = token;
- s[1] = '\0';
- return s;
- }
- else
- NOT_REACHED ();
+ struct lex_source *src = lex_source__ (lexer);
+ return src == NULL ? NULL : src->reader->file_name;
}
-/* Returns an ASCII representation of the current token as a
- malloc()'d string. */
-char *
-lex_token_representation (struct lexer *lexer)
+/* Returns the syntax mode for the syntax file from which the current drawn is
+ drawn. Returns LEX_SYNTAX_AUTO for a T_STOP token or if the command's
+ source does not have line numbers.
+
+ There is no version of this function that takes an N argument because
+ lookahead only works to the end of a command and any given command is always
+ within a single syntax file. */
+enum lex_syntax_mode
+lex_get_syntax_mode (const struct lexer *lexer)
{
- char *token_rep;
+ struct lex_source *src = lex_source__ (lexer);
+ return src == NULL ? LEX_SYNTAX_AUTO : src->reader->syntax;
+}
+
+/* Returns the error mode for the syntax file from which the current drawn is
+ drawn. Returns LEX_ERROR_INTERACTIVE for a T_STOP token or if the command's
+ source does not have line numbers.
+
+ There is no version of this function that takes an N argument because
+ lookahead only works to the end of a command and any given command is always
+ within a single syntax file. */
+enum lex_error_mode
+lex_get_error_mode (const struct lexer *lexer)
+{
+ struct lex_source *src = lex_source__ (lexer);
+ return src == NULL ? LEX_ERROR_INTERACTIVE : src->reader->error;
+}
+
+/* If the source that LEXER is currently reading has error mode
+ LEX_ERROR_INTERACTIVE, discards all buffered input and tokens, so that the
+ next token to be read comes directly from whatever is next read from the
+ stream.
- switch (lexer->token)
+ It makes sense to call this function after encountering an error in a
+ command entered on the console, because usually the user would prefer not to
+ have cascading errors. */
+void
+lex_interactive_reset (struct lexer *lexer)
+{
+ struct lex_source *src = lex_source__ (lexer);
+ if (src != NULL && src->reader->error == LEX_ERROR_INTERACTIVE)
{
- case T_ID:
- case T_POS_NUM:
- case T_NEG_NUM:
- return ds_xstrdup (&lexer->tokstr);
- break;
+ src->head = src->tail = 0;
+ src->journal_pos = src->seg_pos = src->line_pos = 0;
+ src->n_newlines = 0;
+ src->suppress_next_newline = false;
+ segmenter_init (&src->segmenter, segmenter_get_mode (&src->segmenter));
+ while (!deque_is_empty (&src->deque))
+ lex_source_pop__ (src);
+ lex_source_push_endcmd__ (src);
+ }
+}
- case T_STRING:
- {
- int hexstring = 0;
- char *sp, *dp;
-
- for (sp = ds_cstr (&lexer->tokstr); sp < ds_end (&lexer->tokstr); sp++)
- if (!isprint ((unsigned char) *sp))
- {
- hexstring = 1;
- break;
- }
-
- token_rep = xmalloc (2 + ds_length (&lexer->tokstr) * 2 + 1 + 1);
-
- dp = token_rep;
- if (hexstring)
- *dp++ = 'X';
- *dp++ = '\'';
-
- if (!hexstring)
- for (sp = ds_cstr (&lexer->tokstr); *sp; )
- {
- if (*sp == '\'')
- *dp++ = '\'';
- *dp++ = (unsigned char) *sp++;
- }
- else
- for (sp = ds_cstr (&lexer->tokstr); sp < ds_end (&lexer->tokstr); sp++)
- {
- *dp++ = (((unsigned char) *sp) >> 4)["0123456789ABCDEF"];
- *dp++ = (((unsigned char) *sp) & 15)["0123456789ABCDEF"];
- }
- *dp++ = '\'';
- *dp = '\0';
-
- return token_rep;
- }
- break;
+/* Advances past any tokens in LEXER up to a T_ENDCMD or T_STOP. */
+void
+lex_discard_rest_of_command (struct lexer *lexer)
+{
+ while (lex_token (lexer) != T_STOP && lex_token (lexer) != T_ENDCMD)
+ lex_get (lexer);
+}
- case T_STOP:
- token_rep = xmalloc (1);
- *token_rep = '\0';
- return token_rep;
+/* Discards all lookahead tokens in LEXER, then discards all input sources
+ until it encounters one with error mode LEX_ERROR_INTERACTIVE or until it
+ runs out of input sources. */
+void
+lex_discard_noninteractive (struct lexer *lexer)
+{
+ struct lex_source *src = lex_source__ (lexer);
- case T_EXP:
- return xstrdup ("**");
+ if (src != NULL)
+ {
+ while (!deque_is_empty (&src->deque))
+ lex_source_pop__ (src);
- default:
- return xstrdup (lex_token_name (lexer->token));
+ for (; src != NULL && src->reader->error != LEX_ERROR_INTERACTIVE;
+ src = lex_source__ (lexer))
+ lex_source_destroy (src);
}
-
- NOT_REACHED ();
}
-/* Really weird functions. */
+static size_t
+lex_source_max_tail__ (const struct lex_source *src)
+{
+ const struct lex_token *token;
+ size_t max_tail;
-/* Most of the time, a `-' is a lead-in to a negative number. But
- sometimes it's actually part of the syntax. If a dash can be part
- of syntax then this function is called to rip it off of a
- number. */
-void
-lex_negative_to_dash (struct lexer *lexer)
+ assert (src->seg_pos >= src->line_pos);
+ max_tail = MIN (src->journal_pos, src->line_pos);
+
+ /* Use the oldest token also. (We know that src->deque cannot be empty
+ because we are in the process of adding a new token, which is already
+ initialized enough to use here.) */
+ token = &src->tokens[deque_back (&src->deque, 0)];
+ assert (token->token_pos >= token->line_pos);
+ max_tail = MIN (max_tail, token->line_pos);
+
+ return max_tail;
+}
+
+static void
+lex_source_expand__ (struct lex_source *src)
{
- if (lexer->token == T_NEG_NUM)
+ if (src->head - src->tail >= src->allocated)
{
- lexer->token = T_POS_NUM;
- lexer->tokval = -lexer->tokval;
- ds_assign_substring (&lexer->tokstr, ds_substr (&lexer->tokstr, 1, SIZE_MAX));
- save_token (lexer);
- lexer->token = '-';
+ size_t max_tail = lex_source_max_tail__ (src);
+ if (max_tail > src->tail)
+ {
+ /* Advance the tail, freeing up room at the head. */
+ memmove (src->buffer, src->buffer + (max_tail - src->tail),
+ src->head - max_tail);
+ src->tail = max_tail;
+ }
+ else
+ {
+ /* Buffer is completely full. Expand it. */
+ src->buffer = x2realloc (src->buffer, &src->allocated);
+ }
+ }
+ else
+ {
+ /* There's space available at the head of the buffer. Nothing to do. */
}
}
-/* Skip a COMMENT command. */
-void
-lex_skip_comment (struct lexer *lexer)
+static void
+lex_source_read__ (struct lex_source *src)
{
- for (;;)
+ do
{
- if (!lex_get_line (lexer))
+ size_t head_ofs;
+ size_t n;
+
+ lex_source_expand__ (src);
+
+ head_ofs = src->head - src->tail;
+ n = src->reader->class->read (src->reader, &src->buffer[head_ofs],
+ src->allocated - head_ofs,
+ segmenter_get_prompt (&src->segmenter));
+ if (n == 0)
{
- lexer->put_token = T_STOP;
- lexer->prog = NULL;
+ /* End of input.
+
+ Ensure that the input always ends in a new-line followed by a null
+ byte, as required by the segmenter library. */
+
+ if (src->head == src->tail
+ || src->buffer[src->head - src->tail - 1] != '\n')
+ src->buffer[src->head++ - src->tail] = '\n';
+
+ lex_source_expand__ (src);
+ src->buffer[src->head++ - src->tail] = '\0';
+
return;
}
- if (lexer->put_token == '.')
- break;
-
- ds_cstr (&lexer->line_buffer); /* Ensures ds_end will point to a valid char */
- lexer->prog = ds_end (&lexer->line_buffer);
- if (lexer->dot)
- break;
+ src->head += n;
}
+ while (!memchr (&src->buffer[src->seg_pos - src->tail], '\n',
+ src->head - src->seg_pos));
+}
+
+static struct lex_source *
+lex_source__ (const struct lexer *lexer)
+{
+ return (ll_is_empty (&lexer->sources) ? NULL
+ : ll_data (ll_head (&lexer->sources), struct lex_source, ll));
+}
+
+static struct substring
+lex_source_get_syntax__ (const struct lex_source *src, int n0, int n1)
+{
+ const struct lex_token *token0 = lex_source_next__ (src, n0);
+ const struct lex_token *token1 = lex_source_next__ (src, MAX (n0, n1));
+ size_t start = token0->token_pos;
+ size_t end = token1->token_pos + token1->token_len;
+
+ return ss_buffer (&src->buffer[start - src->tail], end - start);
}
-
-/* Private functions. */
-/* When invoked, tokstr contains a string of binary, octal, or
- hex digits, according to TYPE. The string is converted to
- characters having the specified values. */
static void
-convert_numeric_string_to_char_string (struct lexer *lexer,
- enum string_type type)
+lex_ellipsize__ (struct substring in, char *out, size_t out_size)
{
- const char *base_name;
- int base;
- int chars_per_byte;
- size_t byte_cnt;
- size_t i;
- char *p;
+ size_t out_maxlen;
+ size_t out_len;
+ int mblen;
- switch (type)
+ assert (out_size >= 16);
+ out_maxlen = out_size - (in.length >= out_size ? 3 : 0) - 1;
+ for (out_len = 0; out_len < in.length; out_len += mblen)
{
- case BINARY_STRING:
- base_name = _("binary");
- base = 2;
- chars_per_byte = 8;
- break;
- case OCTAL_STRING:
- base_name = _("octal");
- base = 8;
- chars_per_byte = 3;
- break;
- case HEX_STRING:
- base_name = _("hex");
- base = 16;
- chars_per_byte = 2;
- break;
- default:
- NOT_REACHED ();
+ if (in.string[out_len] == '\n'
+ || (in.string[out_len] == '\r'
+ && out_len + 1 < in.length
+ && in.string[out_len + 1] == '\n'))
+ break;
+
+ mblen = u8_mblen (CHAR_CAST (const uint8_t *, in.string + out_len),
+ in.length - out_len);
+ if (out_len + mblen > out_maxlen)
+ break;
}
- byte_cnt = ds_length (&lexer->tokstr) / chars_per_byte;
- if (ds_length (&lexer->tokstr) % chars_per_byte)
- msg (SE, _("String of %s digits has %d characters, which is not a "
- "multiple of %d."),
- base_name, (int) ds_length (&lexer->tokstr), chars_per_byte);
+ memcpy (out, in.string, out_len);
+ strcpy (&out[out_len], out_len < in.length ? "..." : "");
+}
+
+static void
+lex_source_error_valist (struct lex_source *src, int n0, int n1,
+ const char *format, va_list args)
+{
+ const struct lex_token *token;
+ struct string s;
+ struct msg m;
+
+ ds_init_empty (&s);
+
+ token = lex_source_next__ (src, n0);
+ if (token->token.type == T_ENDCMD)
+ ds_put_cstr (&s, _("Syntax error at end of command"));
+ else
+ {
+ struct substring syntax = lex_source_get_syntax__ (src, n0, n1);
+ if (!ss_is_empty (syntax))
+ {
+ char syntax_cstr[64];
+
+ lex_ellipsize__ (syntax, syntax_cstr, sizeof syntax_cstr);
+ ds_put_format (&s, _("Syntax error at `%s'"), syntax_cstr);
+ }
+ else
+ ds_put_cstr (&s, _("Syntax error"));
+ }
- p = ds_cstr (&lexer->tokstr);
- for (i = 0; i < byte_cnt; i++)
+ if (format)
{
- int value;
- int j;
-
- value = 0;
- for (j = 0; j < chars_per_byte; j++, p++)
- {
- int v;
-
- if (*p >= '0' && *p <= '9')
- v = *p - '0';
- else
- {
- static const char alpha[] = "abcdef";
- const char *q = strchr (alpha, tolower ((unsigned char) *p));
-
- if (q)
- v = q - alpha + 10;
- else
- v = base;
- }
-
- if (v >= base)
- msg (SE, _("`%c' is not a valid %s digit."), *p, base_name);
-
- value = value * base + v;
- }
-
- ds_cstr (&lexer->tokstr)[i] = (unsigned char) value;
+ ds_put_cstr (&s, ": ");
+ ds_put_vformat (&s, format, args);
}
+ ds_put_byte (&s, '.');
+
+ m.category = MSG_C_SYNTAX;
+ m.severity = MSG_S_ERROR;
+ m.file_name = src->reader->file_name;
+ m.first_line = lex_source_get_first_line_number (src, n0);
+ m.last_line = lex_source_get_last_line_number (src, n1);
+ m.first_column = lex_source_get_first_column (src, n0);
+ m.last_column = lex_source_get_last_column (src, n1);
+ m.text = ds_steal_cstr (&s);
+ msg_emit (&m);
+}
+
+static void PRINTF_FORMAT (2, 3)
+lex_get_error (struct lex_source *src, const char *format, ...)
+{
+ va_list args;
+ int n;
+
+ va_start (args, format);
- ds_truncate (&lexer->tokstr, byte_cnt);
+ n = deque_count (&src->deque) - 1;
+ lex_source_error_valist (src, n, n, format, args);
+ lex_source_pop_front (src);
+
+ va_end (args);
}
-/* Parses a string from the input buffer into tokstr. The input
- buffer pointer lexer->prog must point to the initial single or double
- quote. TYPE indicates the type of string to be parsed.
- Returns token type. */
-static int
-parse_string (struct lexer *lexer, enum string_type type)
+static bool
+lex_source_get__ (const struct lex_source *src_)
{
- if (type != CHARACTER_STRING)
- lexer->prog++;
+ struct lex_source *src = CONST_CAST (struct lex_source *, src_);
+
+ struct state
+ {
+ struct segmenter segmenter;
+ enum segment_type last_segment;
+ int newlines;
+ size_t line_pos;
+ size_t seg_pos;
+ };
+
+ struct state state, saved;
+ enum scan_result result;
+ struct scanner scanner;
+ struct lex_token *token;
+ int n_lines;
+ int i;
+
+ if (src->eof)
+ return false;
+
+ state.segmenter = src->segmenter;
+ state.newlines = 0;
+ state.seg_pos = src->seg_pos;
+ state.line_pos = src->line_pos;
+ saved = state;
+
+ token = lex_push_token__ (src);
+ scanner_init (&scanner, &token->token);
+ token->line_pos = src->line_pos;
+ token->token_pos = src->seg_pos;
+ if (src->reader->line_number > 0)
+ token->first_line = src->reader->line_number + src->n_newlines;
+ else
+ token->first_line = 0;
- /* Accumulate the entire string, joining sections indicated by +
- signs. */
for (;;)
{
- /* Single or double quote. */
- int c = *lexer->prog++;
-
- /* Accumulate section. */
- for (;;)
- {
- /* Check end of line. */
- if (*lexer->prog == '\0')
- {
- msg (SE, _("Unterminated string constant."));
- goto finish;
- }
-
- /* Double quote characters to embed them in strings. */
- if (*lexer->prog == c)
- {
- if (lexer->prog[1] == c)
- lexer->prog++;
- else
- break;
- }
-
- ds_put_char (&lexer->tokstr, *lexer->prog++);
- }
- lexer->prog++;
-
- /* Skip whitespace after final quote mark. */
- if (lexer->prog == NULL)
- break;
- for (;;)
- {
- while (isspace ((unsigned char) *lexer->prog))
- lexer->prog++;
- if (*lexer->prog)
- break;
-
- if (lexer->dot)
- goto finish;
-
- if (!lex_get_line (lexer))
- goto finish;
- }
-
- /* Skip plus sign. */
- if (*lexer->prog != '+')
- break;
- lexer->prog++;
-
- /* Skip whitespace after plus sign. */
- if (lexer->prog == NULL)
- break;
- for (;;)
- {
- while (isspace ((unsigned char) *lexer->prog))
- lexer->prog++;
- if (*lexer->prog)
- break;
-
- if (lexer->dot)
- goto finish;
-
- if (!lex_get_line (lexer))
- {
- msg (SE, _("Unexpected end of file in string concatenation."));
- goto finish;
- }
- }
-
- /* Ensure that a valid string follows. */
- if (*lexer->prog != '\'' && *lexer->prog != '"')
- {
- msg (SE, _("String expected following `+'."));
- goto finish;
- }
- }
+ enum segment_type type;
+ const char *segment;
+ size_t seg_maxlen;
+ int seg_len;
+
+ segment = &src->buffer[state.seg_pos - src->tail];
+ seg_maxlen = src->head - state.seg_pos;
+ seg_len = segmenter_push (&state.segmenter, segment, seg_maxlen, &type);
+ if (seg_len < 0)
+ {
+ lex_source_read__ (src);
+ continue;
+ }
- /* We come here when we've finished concatenating all the string sections
- into one large string. */
-finish:
- if (type != CHARACTER_STRING)
- convert_numeric_string_to_char_string (lexer, type);
+ state.last_segment = type;
+ state.seg_pos += seg_len;
+ if (type == SEG_NEWLINE)
+ {
+ state.newlines++;
+ state.line_pos = state.seg_pos;
+ }
- if (ds_length (&lexer->tokstr) > 255)
+ result = scanner_push (&scanner, type, ss_buffer (segment, seg_len),
+ &token->token);
+ if (result == SCAN_SAVE)
+ saved = state;
+ else if (result == SCAN_BACK)
+ {
+ state = saved;
+ break;
+ }
+ else if (result == SCAN_DONE)
+ break;
+ }
+
+ n_lines = state.newlines;
+ if (state.last_segment == SEG_END_COMMAND && !src->suppress_next_newline)
{
- msg (SE, _("String exceeds 255 characters in length (%d characters)."),
- (int) ds_length (&lexer->tokstr));
- ds_truncate (&lexer->tokstr, 255);
+ n_lines++;
+ src->suppress_next_newline = true;
}
+ else if (n_lines > 0 && src->suppress_next_newline)
+ {
+ n_lines--;
+ src->suppress_next_newline = false;
+ }
+ for (i = 0; i < n_lines; i++)
+ {
+ const char *newline;
+ const char *line;
+ size_t line_len;
- return T_STRING;
-}
-
-#if DUMP_TOKENS
-/* Reads one token from the lexer and writes a textual representation
- on stdout for debugging purposes. */
-static void
-dump_token (struct lexer *lexer)
-{
- {
- const char *curfn;
- int curln;
+ line = &src->buffer[src->journal_pos - src->tail];
+ newline = rawmemchr (line, '\n');
+ line_len = newline - line;
+ if (line_len > 0 && line[line_len - 1] == '\r')
+ line_len--;
+
+ text_item_submit (text_item_create_nocopy (TEXT_ITEM_SYNTAX,
+ xmemdup0 (line, line_len)));
+
+ src->journal_pos += newline - line + 1;
+ }
+
+ token->token_len = state.seg_pos - src->seg_pos;
- curln = getl_source_location (lexer->ss);
- curfn = getl_source_name (lexer->ss);
- if (curfn)
- fprintf (stderr, "%s:%d\t", curfn, curln);
- }
+ src->segmenter = state.segmenter;
+ src->seg_pos = state.seg_pos;
+ src->line_pos = state.line_pos;
+ src->n_newlines += state.newlines;
- switch (lexer->token)
+ switch (token->token.type)
{
- case T_ID:
- fprintf (stderr, "ID\t%s\n", lexer->tokid);
+ default:
break;
- case T_POS_NUM:
- case T_NEG_NUM:
- fprintf (stderr, "NUM\t%f\n", lexer->tokval);
+ case T_STOP:
+ token->token.type = T_ENDCMD;
+ src->eof = true;
break;
- case T_STRING:
- fprintf (stderr, "STRING\t\"%s\"\n", ds_cstr (&lexer->tokstr));
+ case SCAN_BAD_HEX_LENGTH:
+ lex_get_error (src, _("String of hex digits has %d characters, which "
+ "is not a multiple of 2"),
+ (int) token->token.number);
break;
- case T_STOP:
- fprintf (stderr, "STOP\n");
+ case SCAN_BAD_HEX_DIGIT:
+ case SCAN_BAD_UNICODE_DIGIT:
+ lex_get_error (src, _("`%c' is not a valid hex digit"),
+ (int) token->token.number);
break;
- case T_EXP:
- fprintf (stderr, "MISC\tEXP\"");
+ case SCAN_BAD_UNICODE_LENGTH:
+ lex_get_error (src, _("Unicode string contains %d bytes, which is "
+ "not in the valid range of 1 to 8 bytes"),
+ (int) token->token.number);
break;
- case 0:
- fprintf (stderr, "MISC\tEOF\n");
+ case SCAN_BAD_UNICODE_CODE_POINT:
+ lex_get_error (src, _("U+%04X is not a valid Unicode code point"),
+ (int) token->token.number);
break;
- default:
- if (lex_is_keyword (lexer->token))
- fprintf (stderr, "KEYWORD\t%s\n", lex_token_name (lexer->token));
- else
- fprintf (stderr, "PUNCT\t%c\n", lexer->token);
+ case SCAN_EXPECTED_QUOTE:
+ lex_get_error (src, _("Unterminated string constant"));
+ break;
+
+ case SCAN_EXPECTED_EXPONENT:
+ lex_get_error (src, _("Missing exponent following `%s'"),
+ token->token.string.string);
+ break;
+
+ case SCAN_UNEXPECTED_DOT:
+ lex_get_error (src, _("Unexpected `.' in middle of command"));
+ break;
+
+ case SCAN_UNEXPECTED_CHAR:
+ {
+ char c_name[16];
+ lex_get_error (src, _("Bad character %s in input"),
+ uc_name (token->token.number, c_name));
+ }
+ break;
+
+ case SCAN_SKIP:
+ lex_source_pop_front (src);
break;
}
+
+ return true;
+}
+
+static void
+lex_source_push_endcmd__ (struct lex_source *src)
+{
+ struct lex_token *token = lex_push_token__ (src);
+ token->token.type = T_ENDCMD;
+ token->token_pos = 0;
+ token->token_len = 0;
+ token->line_pos = 0;
+ token->first_line = 0;
}
-#endif /* DUMP_TOKENS */
+static struct lex_source *
+lex_source_create (struct lex_reader *reader)
+{
+ struct lex_source *src;
+ enum segmenter_mode mode;
+
+ src = xzalloc (sizeof *src);
+ src->reader = reader;
+
+ if (reader->syntax == LEX_SYNTAX_AUTO)
+ mode = SEG_MODE_AUTO;
+ else if (reader->syntax == LEX_SYNTAX_INTERACTIVE)
+ mode = SEG_MODE_INTERACTIVE;
+ else if (reader->syntax == LEX_SYNTAX_BATCH)
+ mode = SEG_MODE_BATCH;
+ else
+ NOT_REACHED ();
+ segmenter_init (&src->segmenter, mode);
-/* Token Accessor Functions */
+ src->tokens = deque_init (&src->deque, 4, sizeof *src->tokens);
-int
-lex_token (const struct lexer *lexer)
+ lex_source_push_endcmd__ (src);
+
+ return src;
+}
+
+static void
+lex_source_destroy (struct lex_source *src)
+{
+ char *file_name = src->reader->file_name;
+ if (src->reader->class->close != NULL)
+ src->reader->class->close (src->reader);
+ free (file_name);
+ free (src->buffer);
+ while (!deque_is_empty (&src->deque))
+ lex_source_pop__ (src);
+ free (src->tokens);
+ ll_remove (&src->ll);
+ free (src);
+}
+
+struct lex_file_reader
+ {
+ struct lex_reader reader;
+ struct u8_istream *istream;
+ char *file_name;
+ };
+
+static struct lex_reader_class lex_file_reader_class;
+
+/* Creates and returns a new lex_reader that will read from file FILE_NAME (or
+ from stdin if FILE_NAME is "-"). The file is expected to be encoded with
+ ENCODING, which should take one of the forms accepted by
+ u8_istream_for_file(). SYNTAX and ERROR become the syntax mode and error
+ mode of the new reader, respectively.
+
+ Returns a null pointer if FILE_NAME cannot be opened. */
+struct lex_reader *
+lex_reader_for_file (const char *file_name, const char *encoding,
+ enum lex_syntax_mode syntax,
+ enum lex_error_mode error)
{
- return lexer->token;
+ struct lex_file_reader *r;
+ struct u8_istream *istream;
+
+ istream = (!strcmp(file_name, "-")
+ ? u8_istream_for_fd (encoding, STDIN_FILENO)
+ : u8_istream_for_file (encoding, file_name, O_RDONLY));
+ if (istream == NULL)
+ {
+ msg (ME, _("Opening `%s': %s."), file_name, strerror (errno));
+ return NULL;
+ }
+
+ r = xmalloc (sizeof *r);
+ lex_reader_init (&r->reader, &lex_file_reader_class);
+ r->reader.syntax = syntax;
+ r->reader.error = error;
+ r->reader.file_name = xstrdup (file_name);
+ r->reader.line_number = 1;
+ r->istream = istream;
+ r->file_name = xstrdup (file_name);
+
+ return &r->reader;
}
-double
-lex_tokval (const struct lexer *lexer)
+static struct lex_file_reader *
+lex_file_reader_cast (struct lex_reader *r)
{
- return lexer->tokval;
+ return UP_CAST (r, struct lex_file_reader, reader);
}
-const char *
-lex_tokid (const struct lexer *lexer)
+static size_t
+lex_file_read (struct lex_reader *r_, char *buf, size_t n,
+ enum prompt_style prompt_style UNUSED)
{
- return lexer->tokid;
+ struct lex_file_reader *r = lex_file_reader_cast (r_);
+ ssize_t n_read = u8_istream_read (r->istream, buf, n);
+ if (n_read < 0)
+ {
+ msg (ME, _("Error reading `%s': %s."), r->file_name, strerror (errno));
+ return 0;
+ }
+ return n_read;
}
-const struct string *
-lex_tokstr (const struct lexer *lexer)
+static void
+lex_file_close (struct lex_reader *r_)
{
- return &lexer->tokstr;
+ struct lex_file_reader *r = lex_file_reader_cast (r_);
+
+ if (u8_istream_fileno (r->istream) != STDIN_FILENO)
+ {
+ if (u8_istream_close (r->istream) != 0)
+ msg (ME, _("Error closing `%s': %s."), r->file_name, strerror (errno));
+ }
+ else
+ u8_istream_free (r->istream);
+
+ free (r->file_name);
+ free (r);
}
+
+static struct lex_reader_class lex_file_reader_class =
+ {
+ lex_file_read,
+ lex_file_close
+ };
+
+struct lex_string_reader
+ {
+ struct lex_reader reader;
+ struct substring s;
+ size_t offset;
+ };
+
+static struct lex_reader_class lex_string_reader_class;
+
+/* Creates and returns a new lex_reader for the contents of S, which must be
+ encoded in UTF-8. The new reader takes ownership of S and will free it
+ with ss_dealloc() when it is closed. */
+struct lex_reader *
+lex_reader_for_substring_nocopy (struct substring s)
+{
+ struct lex_string_reader *r;
+
+ r = xmalloc (sizeof *r);
+ lex_reader_init (&r->reader, &lex_string_reader_class);
+ r->reader.syntax = LEX_SYNTAX_INTERACTIVE;
+ r->s = s;
+ r->offset = 0;
+
+ return &r->reader;
+}
+
+/* Creates and returns a new lex_reader for a copy of null-terminated string S,
+ which must be encoded in UTF-8. The caller retains ownership of S. */
+struct lex_reader *
+lex_reader_for_string (const char *s)
+{
+ struct substring ss;
+ ss_alloc_substring (&ss, ss_cstr (s));
+ return lex_reader_for_substring_nocopy (ss);
+}
+
+/* Formats FORMAT as a printf()-like format string and creates and returns a
+ new lex_reader for the formatted result. */
+struct lex_reader *
+lex_reader_for_format (const char *format, ...)
+{
+ struct lex_reader *r;
+ va_list args;
+
+ va_start (args, format);
+ r = lex_reader_for_substring_nocopy (ss_cstr (xvasprintf (format, args)));
+ va_end (args);
+
+ return r;
+}
+
+static struct lex_string_reader *
+lex_string_reader_cast (struct lex_reader *r)
+{
+ return UP_CAST (r, struct lex_string_reader, reader);
+}
+
+static size_t
+lex_string_read (struct lex_reader *r_, char *buf, size_t n,
+ enum prompt_style prompt_style UNUSED)
+{
+ struct lex_string_reader *r = lex_string_reader_cast (r_);
+ size_t chunk;
+
+ chunk = MIN (n, r->s.length - r->offset);
+ memcpy (buf, r->s.string + r->offset, chunk);
+ r->offset += chunk;
+
+ return chunk;
+}
+
+static void
+lex_string_close (struct lex_reader *r_)
+{
+ struct lex_string_reader *r = lex_string_reader_cast (r_);
+
+ ss_dealloc (&r->s);
+ free (r);
+}
+
+static struct lex_reader_class lex_string_reader_class =
+ {
+ lex_string_read,
+ lex_string_close
+ };