From 72e74acb5168310e80195c4cc3219822131df9a9 Mon Sep 17 00:00:00 2001
From: jaortega <jaortega>
Date: Sun, 3 Dec 2000 10:35:52 +0000
Subject: (mix_eval_expr) now keeps track of error position

---
 mixlib/mix_eval_scanner.l | 42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/mixlib/mix_eval_scanner.l b/mixlib/mix_eval_scanner.l
index 443654d..af7fd67 100644
--- a/mixlib/mix_eval_scanner.l
+++ b/mixlib/mix_eval_scanner.l
@@ -1,7 +1,7 @@
 /* -*-c-*- ------------------ mix_eval_scanner.l :
  * scanner used by mix_eval_t
  * ------------------------------------------------------------------
- *  Last change: Time-stamp: <00/12/02 22:48:00 jose>
+ *  Last change: Time-stamp: <00/12/03 11:33:21 jose>
  * ------------------------------------------------------------------
  * Copyright (C) 2000 jose antonio ortega ruiz <jaortega@acm.org>
  *  
@@ -28,6 +28,9 @@
 #define YY_DECL							\
   mix_eval_result_t  mix_eval_expr (mix_eval_data_ *data)
 
+  /* keep track of current position in buffer */
+#define YY_USER_ACTION yypos += yyleng;
+
 #define RETURN_STATE(err)			\
   do {						\
     done = TRUE;                                \
@@ -44,7 +47,7 @@
 static mix_word_t
   eval_binop_ (const gchar *op, mix_word_t x, mix_word_t y);
  
-static void
+static int
   unput_word_ (mix_word_t word);
  
 %}
@@ -85,11 +88,13 @@ wexpr   {expr}({fpart})?(,{expr}({fpart})?)*
   mix_word_t wexpr_val_tmp = MIX_WORD_ZERO;
   mix_eval_result_t state = MIX_EVAL_OK;
   gchar *expr_cp;
+  gint yypos = -22; /* to account for padding */
   gboolean is_fp = FALSE, done = FALSE;
   g_assert (data != NULL && data->expr != NULL);
   /* make room enough to unput computed values */
-  expr_cp = g_strdup_printf ("                              %s", data->expr);
+  expr_cp = g_strdup_printf ("%-20s%s"," ", data->expr);
   buffer = yy_scan_string (expr_cp);
+  data->errpos = -1;
 %}
   
 
@@ -102,18 +107,21 @@ wexpr   {expr}({fpart})?(,{expr}({fpart})?)*
   {ws} /* eat whitespace */
   . {
     if (!done && state == MIX_EVAL_OK) {
-      yyless (0);
+       yypos -= yyleng; yyless (0);
       yy_push_state (WEVAL);
     } else {
       CLEAN_UP ();
       if (state == MIX_EVAL_OK) return (MIX_EVAL_SYNTAX);
+      data->errpos = yypos;
       return state;
     }
   }
   "\n" {
     CLEAN_UP();
     if (state == MIX_EVAL_OK)
-      data->value = wexpr_val;
+	data->value = wexpr_val;
+    else
+	data->errpos = yypos;
     return state;
   }
 }			
@@ -140,13 +148,13 @@ wexpr   {expr}({fpart})?(,{expr}({fpart})?)*
   {number} {
     wexpr_val = mix_word_new (atol (yytext));
   }
-  {expr}  yyless (0); yy_push_state (EVAL);
+  {expr}  yypos -= yyleng; yyless (0); yy_push_state (EVAL);
   ,/{expr} /* eat comma if followed by expression */
   [\t\n ] { /* ok if not inside an f-part */
     if ( is_fp ) {
       RETURN_STATE (MIX_EVAL_MIS_PAREN);
     }
-    unput (yytext[yyleng-1]);
+    unput (yytext[yyleng-1]); --yypos;
     done = TRUE;
     yy_pop_state ();
   }
@@ -170,13 +178,13 @@ wexpr   {expr}({fpart})?(,{expr}({fpart})?)*
   "***" {
     mix_word_t loc = mix_short_to_word_fast (data->loc);
     (void)mix_word_mul (loc, loc, NULL, &loc);
-    unput_word_ (loc);
+    yypos -= unput_word_ (loc);
   }
   {binop}"*" {
     expr_val = eval_binop_ (yytext, expr_val, 
 			    mix_short_to_word_fast (data->loc));
   }
-  "*"         unput_word_ (mix_short_to_word_fast (data->loc));
+  "*"    yypos -= unput_word_ (mix_short_to_word_fast (data->loc));
   {number}    expr_val = mix_word_new (atol (yytext));
   {symbol} {
     if ( !mix_symbol_table_is_defined (data->table, yytext) ) {
@@ -185,8 +193,8 @@ wexpr   {expr}({fpart})?(,{expr}({fpart})?)*
     expr_val = mix_symbol_table_value (data->table, yytext);
   }
   [,)(\n\t ]   {
-    unput (yytext[0]);
-    unput_word_ (expr_val);
+    unput (yytext[0]); --yypos;
+    yypos -= unput_word_ (expr_val);
     yy_pop_state ();
   }
   
@@ -232,15 +240,17 @@ eval_binop_ (const gchar *op, mix_word_t x, mix_word_t y)
 }
 
 
-static void
+static int
 unput_word_ (mix_word_t word)					
 {								
   gchar *value;						
-  gint k;							
+  gint k, result;							
   value = g_strdup_printf ("%s%ld",				
 			   mix_word_is_negative (word)? "-":"+",
-			   mix_word_magnitude (word));		
-  for (k = strlen (value) - 1; k >= 0; --k)			
+			   mix_word_magnitude (word));
+  result = strlen (value);
+  for (k = result - 1; k >= 0; --k)			
     unput (value[k]);						
-  g_free (value);						
+  g_free (value);
+  return result;
 }
-- 
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