commit 69bdd906cbdaaab353fb7f2d20fd70c31c19d31d
from: Omar Polo <op@omarpolo.com>
date: Tue Jun 15 13:54:32 2021 UTC

first revision of a parser for the configuration file

There is only the code to do the parsing, not actually applying them.
The accepted syntax is as follows:

	# `set' to, hum, set options
	set max-redirect = 5
	set new-tab-url  = "about:blank"

	# change the styling
	style tabline foreground white
	style tabline background black
	style line.title2 {
		prefix "## "
		cont   "   "
		attr   bold
	}

	# keybindings management

	bind global-map "1 G" beginning-of-buffer

	bind minibuffer-map "C-c" minibuffer-abort
	unbind minibuffer-map "C-g"

commit - 89fd2bea5a51ccb48581f8c7acf5788e35ead60a
commit + 69bdd906cbdaaab353fb7f2d20fd70c31c19d31d
blob - 7fd8be6ca2455868777513733d2496ac021f1e17
blob + 197094d148d98d5113efad3d6bd01f9a877d85fc
--- configure.ac
+++ configure.ac
@@ -3,6 +3,7 @@ AC_CONFIG_LIBOBJ_DIR(compat)
 AM_INIT_AUTOMAKE([-Wall foreign subdir-objects])
 AC_PROG_CC_C99
 AC_USE_SYSTEM_EXTENSIONS
+AC_PROG_YACC
 
 PKG_PROG_PKG_CONFIG
 
blob - /dev/null
blob + e03c44868486748ab561d70e313109cd0f80d495 (mode 644)
--- /dev/null
+++ parse.y
@@ -0,0 +1,279 @@
+/*
+ * Much of the design is taken from doas (parse.y rev 1.29)
+ *
+ * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
+ * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+%{
+
+#include "telescope.h"
+
+#include <ctype.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+	union {
+		char	*str;
+		int	 num;
+	};
+	int lineno;
+	int colno;
+} yystype;
+#define YYSTYPE yystype
+
+static const char *path;
+
+FILE *yyfp;
+
+int parse_errors = 0;
+
+static void yyerror(const char *, ...);
+static int yylex(void);
+
+%}
+
+%token TSET
+%token TSTYLE TPRFX TCONT TBG TFG TATTR TBOLD TUNDERLINE
+%token TBIND TUNBIND
+
+%token <str> TSTRING
+%token <num> TNUMBER
+
+%%
+
+grammar		: /* empty */
+		| grammar '\n'
+		| grammar rule '\n'
+		| error '\n'
+		;
+
+rule		: set | style | bind | unbind ;
+
+set		: TSET TSTRING '=' TSTRING	{ printf("set %s = \"%s\"\n", $2, $4); }
+		| TSET TSTRING '=' TNUMBER	{ printf("set %s = %d\n", $2, $4); }
+		;
+
+style		: TSTYLE TSTRING { printf("(%s) ", $2); }	styleopt
+		| TSTYLE TSTRING { printf("[%s]\n", $2); }	'{' styleopts '}'
+		;
+
+styleopts	: /* empty */
+		| styleopts '\n'
+		| styleopts styleopt '\n'
+		;
+
+styleopt	: TPRFX TSTRING			{ printf("style prefix setted to \"%s\"\n", $2); }
+		| TCONT TSTRING			{ printf("style cont setted to \"%s\"\n", $2); }
+		| TBG TSTRING			{ printf("style background setted to \"%s\"\n", $2); }
+		| TFG TSTRING			{ printf("style foreground setted to \"%s\"\n", $2); }
+		| TATTR TBOLD			{ printf("style attr setted to bold\n"); }
+		| TATTR TUNDERLINE		{ printf("style attr setted to underline\n"); }
+		;
+
+bind		: TBIND TSTRING TSTRING TSTRING	{ printf("TODO: bind %s %s %s\n", $2, $3, $4); }
+		;
+
+unbind		: TUNBIND TSTRING TSTRING	{ printf("TODO: unbind %s %s\n", $2, $3); }
+		;
+
+%%
+
+void
+yyerror(const char *fmt, ...)
+{
+	va_list va;
+
+	fprintf(stderr, "%s:%d ", path, yylval.lineno+1);
+	va_start(va, fmt);
+	vfprintf(stderr, fmt, va);
+	va_end(va);
+	fprintf(stderr, "\n");
+	parse_errors++;
+}
+
+static struct keyword {
+	const char *word;
+	int token;
+} keywords[] = {
+	{ "set", TSET },
+	{ "style", TSTYLE },
+	{ "prefix", TPRFX },
+	{ "cont", TCONT },
+	{ "background", TBG },
+	{ "foreground", TFG },
+	{ "attr", TATTR },
+	{ "bold", TBOLD },
+	{ "underline", TUNDERLINE },
+	{ "bind", TBIND },
+	{ "unbind", TUNBIND },
+};
+
+int
+yylex(void)
+{
+	char buf[1024], *ebuf, *p, *str;
+	const char *errstr;
+	int c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
+	size_t i;
+
+	p = buf;
+	ebuf = buf + sizeof(buf);
+
+repeat:
+	/* skip whitespace first */
+	for (c = getc(yyfp); c == ' ' || c == '\t' || c == '\f'; c = getc(yyfp))
+		yylval.colno++;
+
+	/* check for special one-character constructions */
+	switch (c) {
+	case '\n':
+		yylval.colno = 0;
+		yylval.lineno++;
+		/* fallthrough */
+	case '{':
+	case '}':
+	case '=':
+		return c;
+	case '#':
+		/* skip comments; NUL is allowed; no continuation */
+		while ((c = getc(yyfp)) != '\n')
+			if (c == EOF)
+				goto eof;
+		yylval.colno = 0;
+		yylval.lineno++;
+		return c;
+	case EOF:
+		goto eof;
+	}
+
+	/* parsing next word */
+	for (;; c = getc(yyfp), yylval.colno++) {
+		switch (c) {
+		case '\0':
+			yyerror("unallowed character NULL in column %d",
+			    yylval.colno+1);
+			escape = 0;
+			continue;
+		case '\\':
+			escape = !escape;
+			if (escape)
+				continue;
+			break;
+		case '\n':
+			if (quotes)
+				yyerror("unterminated quotes in column %d",
+				    yylval.colno+1);
+			if (escape) {
+				nonkw = 1;
+				escape = 0;
+				yylval.colno = 0;
+				yylval.lineno++;
+			}
+			goto eow;
+		case EOF:
+			if (escape)
+				yyerror("unterminated escape in column %d",
+				    yylval.colno);
+			if (quotes)
+				yyerror("unterminated quotes in column %d",
+				    qpos + 1);
+			goto eow;
+		case '{':
+		case '}':
+		case '=':
+		case '#':
+		case ' ':
+		case '\t':
+			if (!escape && !quotes)
+				goto eow;
+			break;
+		case '"':
+			if (!escape) {
+				quotes = !quotes;
+				if (quotes) {
+					nonkw = 1;
+					qpos = yylval.colno;
+				}
+				continue;
+			}
+		}
+		*p++ = c;
+		if (p == ebuf) {
+			yyerror("line too long");
+			p = buf;
+		}
+		escape = 0;
+	}
+
+eow:
+	*p = 0;
+	if (c != EOF)
+		ungetc(c, yyfp);
+	if (p == buf) {
+		/*
+		 * There could be a number of reason for empty buffer,
+		 * and we handle all of them here, to avoid cluttering
+		 * the main loop.
+		 */
+		if (c == EOF)
+			goto eof;
+		else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
+			goto repeat;
+	}
+	if (!nonkw) {
+		for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
+			if (strcmp(buf, keywords[i].word) == 0)
+				return keywords[i].token;
+		}
+	}
+	c = *buf;
+	if (!nonkw && (c == '-' || isdigit(c))) {
+		yylval.num = strtonum(buf, INT_MIN, INT_MAX, &errstr);
+		if (errstr != NULL)
+			yyerror("number is %s: %s", errstr, buf);
+		return TNUMBER;
+	}
+	if ((str = strdup(buf)) == NULL)
+		err(1, "%s", __func__);
+	yylval.str = str;
+	return TSTRING;
+
+eof:
+	if (ferror(yyfp))
+		yyerror("input error reading config");
+	return 0;
+}
+
+void
+parseconfig(const char *filename, int fonf)
+{
+	if ((yyfp = fopen(filename, "r")) == NULL) {
+		if (fonf)
+			err(1, "%s", filename);
+		return;
+	}
+
+	path = filename;
+	yyparse();
+	fclose(yyfp);
+	if (parse_errors)
+		exit(1);
+}