Initial commit.

1 files changed, 253 insertions, 0 deletions

diff --git a/src/lexer.c b/src/lexer.c
new file mode 100644
index 0000000..41d6784
--- /dev/null
+++ b/src/lexer.c
@@ -0,0 +1,253 @@
+/*
+Copyright (C) 2016  Paweł Redman
+
+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 the Free Software Foundation; either version 3
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software Foundation,
+Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
+*/
+
+#include "common.h"
+#include <ctype.h>
+
+int lexer_open(lexer_state_t *ls, const char *path, vstr_t *token)
+{
+	ls->error = 0;
+	ls->path = path;
+
+	ls->fp = fopen(path, "r");
+	if (!ls->fp)
+		return -errno;
+
+	ls->eof = false;
+
+	ls->token = token;
+	ls->buf_e = ls->buf_c = ls->buf;
+	ls->cc = ls->lc = ls->Cc = 0;
+
+	ls->in_token = false;
+	ls->in_quote = false;
+	ls->in_comment = false;
+
+	return 0;
+}
+
+//RETURN VALUES
+//	<0 on error
+//	0 on success
+//	note: sets ls->eof to true if there's no more data left
+static int fill_buffer(lexer_state_t *ls)
+{
+	size_t read;
+
+	read = fread(ls->buf, 1, sizeof(ls->buf), ls->fp);
+	debug("read = %zu\n", read);
+	if (read < sizeof(ls->buf)) {
+		if (ferror(ls->fp)) {
+			fclose(ls->fp);
+			return -errno;
+		}
+
+		ls->eof = true;
+		fclose(ls->fp);
+		debug("no data left, ls->fp closed\n");
+	}
+
+	ls->buf_c = ls->buf;
+	ls->buf_e = ls->buf + read;
+	return 0;
+}
+
+//RETURN VALUES
+//	-ENOMEM
+//	-EAGAIN when the buffer runs out
+//	0 on success
+//	1 when no data is left
+static int read_buffer(lexer_state_t *ls)
+{
+	while (ls->buf_c < ls->buf_e) {
+		bool ret_token = false;
+
+		debug("*ls->buf_c = %c, ls->last = %c\n", *ls->buf_c, ls->last);
+
+		if (*ls->buf_c == '\n') {
+			ls->lc++;
+			ls->Cc = 0;
+		}
+
+		if (ls->in_comment) {
+			if (*ls->buf_c == '\n')
+				ls->in_comment = false;
+		} else if (isspace(*ls->buf_c) && !ls->in_quote) {
+			if (ls->in_token) {
+				ls->in_token = false;
+				ret_token = true;
+			}
+		} else if (*ls->buf_c == '/' && ls->last == '/') {
+			ls->in_comment = true;
+			ls->in_token = false;
+
+			ls->token->size--; // remove the first slash
+			if (ls->token->size)
+				ret_token = true;
+		} else if (*ls->buf_c == '\"' &&
+		           (ls->cc && ls->last != '\\')) {
+			ls->in_quote = !ls->in_quote;
+
+			if (!ls->in_quote) {
+				ls->in_token = false;
+				ret_token = true;
+			}
+		} else {
+			if (!ls->in_token) {
+				ls->in_token = true;
+			}
+		}
+
+		if (ls->in_token)
+			if (vstr_putc(ls->token, *ls->buf_c)) {
+				ls->error = ENOMEM;
+				return -ENOMEM;
+			}
+
+		ls->last = *ls->buf_c;
+		ls->buf_c++;
+		ls->cc++;
+		ls->Cc++;
+
+		if (ret_token)
+			return 0;
+	}
+
+	if (ls->eof) {
+		if (ls->token->size > 0)
+			return 0;
+		return 1;
+	}
+
+	return -EAGAIN;
+}
+
+//RETURN VALUES
+//	<0 on error
+//	0 on success
+//	1 when no data is left
+int lexer_get_token(lexer_state_t *ls)
+{
+	int ret;
+
+	vstr_clear(ls->token);
+
+	while (1) {
+		ret = read_buffer(ls);
+		debug("read_buffer = %i\n", ret);
+		if (ret != -EAGAIN)
+			return ret;
+
+		ret = fill_buffer(ls);
+		debug("fill_buffer = %i\n", ret);
+		if (ret < 0)
+			return ret;
+	}
+}
+
+void lexer_perror(lexer_state_t *ls, const char *fmt, ...)
+{
+	va_list vl;
+
+	fprintf(stderr, "%s:%zu:%zu: ", ls->path, ls->lc + 1, ls->Cc + 1);
+
+	if (ls->error) {
+		perror(NULL);
+	} else {
+		va_start(vl, fmt);
+		vfprintf(stderr, fmt, vl);
+		va_end(vl);
+	}
+}
+
+void lexer_perror_eg(lexer_state_t *ls, const char *expected)
+{
+	if (ls->eof && ls->buf_c == ls->buf_e)
+		lexer_perror(ls, "expected %s, got EOF\n", expected);
+	else {
+		vstr_termz(ls->token);
+		lexer_perror(ls, "expected %s, got \"%s\"\n", expected,
+		             ls->token->data);
+	}
+}
+
+int lexer_assert(lexer_state_t *ls, const char *match, const char *desc)
+{
+	int ret;
+
+	ret = lexer_get_token(ls);
+	if (ret) {
+		lexer_perror(ls, "expected %s%s\"%s\", got EOF\n",
+		             (desc ? desc : ""), (desc ? " " : ""), match);
+		return 1;
+	}
+
+	if (vstr_cmp(ls->token, match)) {
+		vstr_termz(ls->token);
+		lexer_perror(ls, "expected %s%s\"%s\", got \"%s\"\n",
+		             (desc ? desc : ""), (desc ? " " : ""), match,
+		             ls->token->data);
+		return 1;
+	}
+
+	return 0;
+} 
+
+//RETURN VALUE
+//	-1 on eof (also success)
+//	0 on success
+//	1 on error
+int lexer_assert_or_eof(lexer_state_t *ls, const char *match, const char *desc)
+{
+	int ret;
+
+	ret = lexer_get_token(ls);
+	if (ret < 0) {
+		perror("lexer");
+		return 1;
+	}
+
+	if (ret == 1) {
+		return -1;
+	}
+
+	if (vstr_cmp(ls->token, match)) {
+		lexer_perror(ls, "expected %s%s\"%s\" or EOF, got \"%.*s\"\n",
+		             (desc ? desc : ""), (desc ? " " : ""), match,
+		             (int)ls->token->size, ls->token->data);
+		return 1;
+	}
+
+	return 0;
+} 
+
+int lexer_get_floats(lexer_state_t *ls, float *out, size_t count)
+{
+	size_t i;
+
+	for (i = 0; i < count; i++) {
+		if (lexer_get_token(ls)) {
+			lexer_perror_eg(ls, "a number");
+			return 1;
+		}
+
+		out[i] = vstr_atof(ls->token);
+	}
+
+	return 0;
+}