From 8f9c0b621e97e02560841ab3a2f72d5c39e3f59a Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Fri, 27 Sep 2019 05:27:57 +0300
Subject: [PATCH] parser: fix columns in errors

---
 compiler/parser.v  | 58 +++++++---------------------------------------
 compiler/scanner.v | 12 +++++++---
 2 files changed, 18 insertions(+), 52 deletions(-)

diff --git a/compiler/parser.v b/compiler/parser.v
index cf9547097d..2501acac52 100644
--- a/compiler/parser.v
+++ b/compiler/parser.v
@@ -20,7 +20,7 @@ struct Tok {
 	lit      string
 	line_nr  int
 	name_idx int // name table index for O(1) lookup
-//       col int
+	col      int
 }
 
 struct Parser {
@@ -131,35 +131,24 @@ fn (v mut V) new_parser(path string) Parser {
 	$if js {
 		p.is_js = true
 	}
-
 	if p.pref.is_repl {
 		p.scanner.should_print_line_on_error = false
 	}
-	
 	v.cgen.line_directives = v.pref.is_debuggable
 	v.cgen.file = path
-
 	for {
 	       res := p.scanner.scan()
 	       p.tokens << Tok {
 	               tok: res.tok
 	               lit: res.lit
 	               line_nr: p.scanner.line_nr
+	              col: p.scanner.pos - p.scanner.last_nl_pos
 	       }
 	        if res.tok == .eof {
 	                break
 	        }
 	}
-	
 	v.add_parser(p)
-	/*
-	if !(p in v.parsers) {
-		v.parsers << p
-		
-	}	
-	*/
-	
-	//p.next()
 	//p.scanner.debug_tokens()
 	return p
 }
@@ -184,8 +173,7 @@ fn (p mut Parser) next() {
 	 p.tok = res.tok
 	 p.lit = res.lit
 	 p.scanner.line_nr = res.line_nr
- }
-
+}
 
 fn (p & Parser) peek() Token {
 	if p.token_idx >= p.tokens.len - 2 {
@@ -193,40 +181,8 @@ fn (p & Parser) peek() Token {
 	}
 	tok := p.tokens[p.token_idx]
 	return tok.tok
-/*
-	// save scanner state
-	pos := s.pos
-	line := s.line_nr
-	inside_string := s.inside_string
-	inter_start := s.inter_start
-	inter_end := s.inter_end
-
-	res := s.scan()
-	tok := res.tok
-
-	// restore scanner state
-	s.pos = pos
-	s.line_nr = line
-	s.inside_string = inside_string
-	s.inter_start = inter_start
-	s.inter_end = inter_end
-	return tok
-	*/
 }
 
-
-
-/*
-fn (p mut Parser) next_old() {
-	p.prev_tok2 = p.prev_tok
-	p.prev_tok = p.tok
-	p.scanner.prev_tok = p.tok
-	res := p.scanner.scan()
-	p.tok = res.tok
-	p.lit = res.lit
-}
-*/
-
 fn (p &Parser) log(s string) {
 /*
 	if !p.pref.is_verbose {
@@ -911,7 +867,7 @@ fn (p mut Parser) error(s string) {
 		println('pass=$p.pass fn=`$p.cur_fn.name`\n')
 	}
 	p.cgen.save()
-	// V git pull hint
+	// V up hint
 	cur_path := os.getwd()
 	if !p.pref.is_repl && !p.pref.is_test && ( p.file_path.contains('v/compiler') || cur_path.contains('v/compiler') ){
 		println('\n=========================')
@@ -928,7 +884,11 @@ fn (p mut Parser) error(s string) {
 	}
 	// p.scanner.debug_tokens()
 	// Print `[]int` instead of `array_int` in errors
-	p.scanner.error(s.replace('array_', '[]').replace('__', '.').replace('Option_', '?'))
+	e := s.replace('array_', '[]')
+		.replace('__', '.')
+		.replace('Option_', '?')
+		.replace('main.', '')
+	p.scanner.error_with_col(e, p.tokens[p.token_idx-1].col)
 }
 
 fn (p &Parser) first_pass() bool {
diff --git a/compiler/scanner.v b/compiler/scanner.v
index dae1b67b5b..7bc2b3ed1f 100644
--- a/compiler/scanner.v
+++ b/compiler/scanner.v
@@ -20,6 +20,7 @@ mut:
 	text           string
 	pos            int
 	line_nr        int
+	last_nl_pos    int // for calculating column
 	inside_string  bool
 	inter_start   bool // for hacky string interpolation TODO simplify
 	inter_end     bool
@@ -238,6 +239,7 @@ fn (s mut Scanner) skip_whitespace() {
 	for s.pos < s.text.len && s.text[s.pos].is_white() {
 		// Count \r\n as one line
 		if is_nl(s.text[s.pos]) && !s.expect('\r\n', s.pos-1) {
+			s.last_nl_pos = s.pos
 			s.line_nr++
 		}
 		s.pos++
@@ -640,9 +642,13 @@ fn (s &Scanner) current_column() int {
 }
 
 fn (s &Scanner) error(msg string) {
+	s.error_with_col(msg, 0)
+}
+
+fn (s &Scanner) error_with_col(msg string, col int) {
+	column := col-1
 	linestart := s.find_current_line_start_position()
 	lineend := s.find_current_line_end_position()
-	column := s.pos - linestart
 	if s.should_print_line_on_error && lineend > linestart {
 		line := s.text.substr( linestart, lineend )
 		// The pointerline should have the same spaces/tabs as the offending
@@ -667,8 +673,8 @@ fn (s &Scanner) error(msg string) {
 	// and jump to their source with a keyboard shortcut.
 	// Using only the filename leads to inability of IDE/editors
 	// to find the source file, when it is in another folder.
-	println('${s.file_path}:${s.line_nr + 1}:${column+1}: $msg')
-	//println('${fullpath}:${s.line_nr + 1}:${column+1}: $msg')
+	//println('${s.file_path}:${s.line_nr + 1}:${column+1}: $msg')
+	println('${fullpath}:${s.line_nr + 1}:${column+1}: $msg')
 	exit(1)
 }