From bee6d0881334d4d043ace36428b7aa3cdd73f23c Mon Sep 17 00:00:00 2001
From: Thomas Voss <mail@thomasvoss.com>
Date: Wed, 4 Sep 2024 02:09:26 +0200
Subject: Improve interactive usage

---
 src/lexer.l     | 13 ++++++++++---
 src/main.c      | 48 +++++++++++++++++++++++++++++++++++++++++++-----
 src/parser.y    |  5 +++--
 src/pinocchio.h |  5 +++++
 4 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/src/lexer.l b/src/lexer.l
index 3bbfd12..ed8d599 100644
--- a/src/lexer.l
+++ b/src/lexer.l
@@ -1,13 +1,18 @@
 %option noinput
 %option nounput
 %option noyywrap
+%option yylineno
 
 %{
 #include <err.h>
+#include <stdlib.h>
 
 #include "parser.h"
+#include "pinocchio.h"
 
 #define YY_USER_ACTION yylloc.first_line = yylloc.last_line = yylineno;
+
+extern const char *current_file;
 %}
 
 %%
@@ -20,7 +25,7 @@
 \<=>|⇔  { return EQUIV; }
 \(      { return OPAR;  }
 \)      { return CPAR;  }
-\n      { return EOL;   } /* Only eat one NL for better interactive usage */
+\n      { return EOL;   }
 [a-zA-Z] {
 	yylval.ch = *yytext;
 	return IDENT;
@@ -28,7 +33,9 @@
 
 [ \t]+ ;
 
-	/* TODO: Swap ‘-’ for name of the input file */
-. { errx(1, "%s:%d: Unrecognized character ‘%c’", "-", yylineno, *yytext); }
+. {
+	user_error("%s:%d: Unrecognized character ‘%c’",
+		current_file, yylineno, *yytext);
+}
 
 %%
diff --git a/src/main.c b/src/main.c
index 1457c75..8cd8468 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,11 +2,13 @@
 #include <err.h>
 #include <langinfo.h>
 #include <locale.h>
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include "lexer.h"
 #include "parser.h"
@@ -17,7 +19,10 @@
 #	define __has_builtin(x) (0)
 #endif
 
-static bool utf8;
+static int rv;
+static bool interactive, utf8;
+
+const char *current_file;
 
 static bool eqnsolve(eqn_t *, uint64_t, uint64_t);
 static int  eqnprint(eqn_t *);
@@ -41,11 +46,31 @@ main(int argc, char **argv)
 {
 	setlocale(LC_ALL, "");
 	utf8 = strcmp(nl_langinfo(CODESET), "UTF-8") == 0;
-	if (argc > 1) {
-		if ((yyin = fopen(argv[1], "r")) == NULL)
-			err(1, "fopen: %s", argv[1]);
+	interactive = isatty(STDIN_FILENO);
+
+	if (argc == 1) {
+		current_file = "-";
+		for (;;) {
+			int ret = yyparse();
+			if (ret == 0)
+				break;
+			rv = EXIT_FAILURE;
+		}
+	} else for (int i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "-") == 0)
+			yyin = stdin;
+		else if ((yyin = fopen(argv[i], "r")) == NULL) {
+			warn("fopen: %s", argv[1]);
+			rv = EXIT_FAILURE;
+			continue;
+		}
+
+		current_file = argv[1];
+		yyparse();
+		fclose(yyin);
 	}
-	return yyparse();
+
+	return rv;
 }
 
 void
@@ -204,3 +229,16 @@ eqnfree(eqn_t *e)
 	}
 	free(e);
 }
+
+void
+user_error(const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vwarnx(fmt, ap);
+	va_end(ap);
+	if (interactive)
+		rv = EXIT_FAILURE;
+	else
+		exit(EXIT_FAILURE);
+}
diff --git a/src/parser.y b/src/parser.y
index ae31d16..503c2e4 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -10,6 +10,8 @@
 static ast_t astmerge(int, ast_t, ast_t);
 static void *xmalloc(size_t);
 static void yyerror(const char *);
+
+extern const char *current_file;
 %}
 
 %code requires {
@@ -105,6 +107,5 @@ xmalloc(size_t n)
 void
 yyerror(const char *s)
 {
-	/* TODO: Get filename */
-	errx(1, "-:%d: %s\n", yylloc.first_line, s);
+	user_error("%s:%d: %s", current_file, yylloc.first_line, s);
 }
diff --git a/src/pinocchio.h b/src/pinocchio.h
index 0c19def..fb74f3c 100644
--- a/src/pinocchio.h
+++ b/src/pinocchio.h
@@ -20,5 +20,10 @@ typedef struct {
 } ast_t;
 
 void astprocess(ast_t);
+void user_error(const char *, ...)
+#if __GNUC__
+	__attribute__((format(printf, 1, 2)))
+#endif
+	;
 
 #endif /* !PINOCCIO_H */
-- 
cgit v1.2.3