From 9ec5e89c859b70b03a65ff773f8f85eddc277f71 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Thu, 24 Jun 2021 07:47:48 -0700
Subject: parser: no string allocation when scanning floats.

Each time the scanner processes a floating-point token,
it allocates a string object, just so it can call flo_str.
The object is then garbage. Let's stop doing that.

* lib.c (flo_str_utf8): New function, closely based on flo_str.
Takes a char * string.

* lib.h (flo_str_utf8): Declared.

* parser.l (out_of_range_float): Take the token as a const
char * string instead of a Lisp string, so we can just pass
yytext to this function.
(grammar): Use flo_str_utf8 instead flo_str, and pass yytext
to out_of_range_float.

* lex.yy.c.shipped: Updated.
---
 parser.l | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

(limited to 'parser.l')

diff --git a/parser.l b/parser.l
index ce3a5573..02465e26 100644
--- a/parser.l
+++ b/parser.l
@@ -130,10 +130,10 @@ static void yyerrprepf(scanner_t *scanner, val fmt, ...)
   }
 }
 
-static void out_of_range_float(scanner_t *scanner, val tok)
+static void out_of_range_float(scanner_t *scanner, const char *tok)
 {
     yyerrorf(scanner, lit("out-of-range floating-point literal: ~a"),
-             tok, nao);
+             string_utf8(tok), nao);
 }
 
 static wchar_t char_esc(int letter)
@@ -343,15 +343,13 @@ NJPUNC  [^(){},:\[\]"~*^ \t\n]
 }
 
 <SPECIAL,NESTED,BRACED>{WS}{FLO} {
-  val str = string_own(utf8_dup_from(yytext));
-
   if (yy_top_state(yyscanner) == INITIAL
       || yy_top_state(yyscanner) == QSILIT
       || yy_top_state(yyscanner) == QWLIT)
     yy_pop_state(yyscanner);
 
-  if ((yylval->val = flo_str(str)) == nil)
-    out_of_range_float(yyg, str);
+  if ((yylval->val = flo_str_utf8(yytext)) == nil)
+    out_of_range_float(yyg, yytext);
 
   return NUMBER;
 }
@@ -368,22 +366,20 @@ NJPUNC  [^(){},:\[\]"~*^ \t\n]
       || yy_top_state(yyscanner) == QWLIT)
     yy_pop_state(yyscanner);
 
-  if ((yylval->val = flo_str(str)) == nil)
-    out_of_range_float(yyg, str);
+  if ((yylval->val = flo_str_utf8(yytext)) == nil)
+    out_of_range_float(yyg, yytext);
 
   return NUMBER;
 }
 
 <SPECIAL,QSPECIAL,NESTED,BRACED>{FLODOT}/[^.] {
-  val str = string_own(utf8_dup_from(yytext));
-
   if (yy_top_state(yyscanner) == INITIAL
       || yy_top_state(yyscanner) == QSILIT
       || yy_top_state(yyscanner) == QWLIT)
     yy_pop_state(yyscanner);
 
-  if ((yylval->val = flo_str(str)) == nil)
-    out_of_range_float(yyg, str);
+  if ((yylval->val = flo_str_utf8(yytext)) == nil)
+    out_of_range_float(yyg, yytext);
 
   return NUMBER;
 }
@@ -1178,9 +1174,8 @@ NJPUNC  [^(){},:\[\]"~*^ \t\n]
 }
 
 <JSON>{JNUM} {
-  val str = string_own(utf8_dup_from(yytext));
-  if ((yylval->val = flo_str(str)) == nil)
-    out_of_range_float(yyg, str);
+  if ((yylval->val = flo_str_utf8(yytext)) == nil)
+    out_of_range_float(yyg, yytext);
   return NUMBER;
 }
 
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