whole bunch of graph stuff, fixing up, basic arithmetic peepholes...

1 files changed, 15 insertions, 7 deletions

diff --git a/lex.c b/lex.c
index 12cd284..a254e7b 100644
--- a/lex.c
+++ b/lex.c
@@ -6,6 +6,7 @@
 #include "strio.h"
 
 void lex_start(Lexer *l, const char *path) {
+	l->ofs = 0;
 	l->filename = str_dup(str_from_cstr(path), &l->arena);
 	FILE *f = fopen(path, "r/o");
 	if (!f) {
@@ -57,9 +58,11 @@ void lex_expected_not(Lexer *l, TokMask t) {
 	}
 }
 
-void lex_pos(Lexer *l, int *line, int *col) {
+/* should only be called in the event of errors, so probably not
+ * much of an issue that this has to scan the whole file */
+void lex_pos(Lexer *l, int ofs, int *line, int *col) {
 	int ln = 0, c = 0;
-	for (int i = 0; i < l->ofs; i++) {
+	for (int i = 0; i < ofs; i++) {
 		if (l->buf.s[i] == '\n') {
 			ln++;
 			c = 0;
@@ -75,9 +78,12 @@ void lex_pos(Lexer *l, int *line, int *col) {
 }
 
 void lex_error(Lexer *l, LexErr e, Str msg) {
+	lex_error_at(l, l->pos, e, msg);
+}
+
+void lex_error_at(Lexer *l, LexSpan pos, LexErr e, Str msg) {
 	int line, col;
-	l->ofs -= l->ident.n;
-	lex_pos(l, &line, &col);
+	lex_pos(l, pos.ofs, &line, &col);
 
 	fprintf(stderr, "%s", e == LE_ERROR ? "\x1b[1;31m" : "\x1b[1;33m");
 
@@ -85,14 +91,14 @@ void lex_error(Lexer *l, LexErr e, Str msg) {
 		(int)l->filename.n, l->filename.s, line + 1, col + 1, (int)msg.n, msg.s);
 
 	{
-		int ofs = l->ofs;
+		int ofs = pos.ofs;
 		int line_start = ofs;
 		while (line_start > 0 && l->buf.s[line_start - 1] != '\n') line_start--;
 		int line_end = line_start;
 		while (line_end < l->buf.n && l->buf.s[line_end] != '\n') line_end++;
 		fprintf(stderr, "%.*s\n", line_end - line_start, &l->buf.s[line_start]);
-		for (int i = 0; i < col; i++) putchar(' ');
-		for (int i = ofs; i < ofs + l->ident.n && i < line_end; i++) putchar('^');
+		for (int i = 0; i < col; i++) fputc(' ', stderr);
+		for (int i = ofs; i < ofs + pos.n && i < line_end; i++) fputc('^', stderr);
 		putchar('\n');
 	}
 
@@ -142,6 +148,7 @@ recurse:
 
 	int start_ofs = i;
 	l->ident = (Str) { &l->buf.s[start_ofs], 0 };
+	l->pos = (LexSpan) { start_ofs, 0 };
 	if (i >= l->buf.n) {
 		l->tok = TOK_EOF;
 		return;
@@ -186,6 +193,7 @@ recurse:
 		lex_error(l, LE_ERROR, S("Invalid token"));
 	}
 	l->ident.n = i - start_ofs;
+	l->pos.n = i - start_ofs;
 	l->ofs = i;
 	if (l->tok == TOK_IDENT) {
 		l->tok = ident_to_keyword(l->ident);