From 770132ff37f7b14da4e1a8f7d53e86b8fdaaf7e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kr=C3=BCger?=
 <45282134+UweKrueger@users.noreply.github.com>
Date: Thu, 18 Jun 2020 22:33:41 +0200
Subject: [PATCH] float: make default string representations for floats become
 alike

---
 vlib/builtin/float.v                    | 36 ++++++++++++++-----------
 vlib/v/tests/num_lit_call_method_test.v | 11 +++++++-
 2 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/vlib/builtin/float.v b/vlib/builtin/float.v
index e52e0ffa19..2726b14e50 100644
--- a/vlib/builtin/float.v
+++ b/vlib/builtin/float.v
@@ -7,23 +7,22 @@ import strconv.ftoa
 
 #include <float.h>
 // ----- f64 to string functions -----
-// str return a f64 as string in scientific notation, auto display digits limit
+// str return a f64 as string in suitable notation
 [inline]
-pub fn (d f64) str() string {
-	return ftoa.ftoa_64(d)
-}
-
-[inline]
-pub fn (d any_float) str() string {
-	x := f64(d)
+pub fn (x f64) str() string {
 	abs_x := f64_abs(x)
-	if abs_x >= 0.01 && abs_x < 1.0e16 {
+	if abs_x >= 0.0001 && abs_x < 1.0e6 {
 		return ftoa.f64_to_str_l(x)
 	} else {
 		return ftoa.ftoa_64(x)
 	}
 }
 
+[inline]
+pub fn (d any_float) str() string {
+	return f64(d).str()
+}
+
 // return a string of the input f64 in scientific notation with digit_num deciamals displayed, max 17 digits
 [inline]
 pub fn (x f64) strsci(digit_num int) string {
@@ -43,10 +42,15 @@ pub fn (x f64) strlong() string {
 }
 
 // ----- f32 to string functions -----
-// str return a f32 as string in scientific notation, auto display digits limit
+// str return a f32 as string in suitable notation
 [inline]
-pub fn (d f32) str() string {
-	return ftoa.ftoa_32(d)
+pub fn (x f32) str() string {
+	abs_x := f32_abs(x)
+	if abs_x >= 0.0001 && abs_x < 1.0e6 {
+		return ftoa.f32_to_str_l(x)
+	} else {
+		return ftoa.ftoa_32(x)
+	}
 }
 
 // return a string of the input f32 in scientific notation with digit_num deciamals displayed, max 8 digits
@@ -69,7 +73,7 @@ pub fn (x f32) strlong() string {
 
 // ----- C functions -----
 [inline]
-fn f32_abs(a f32) f32 {
+pub fn f32_abs(a f32) f32 {
 	return if a < 0 {
 		-a
 	} else {
@@ -88,7 +92,7 @@ fn f64_abs(a f64) f64 {
 
 
 [inline]
-fn f32_max(a, b f32) f32 {
+pub fn f32_max(a, b f32) f32 {
 	return if a > b {
 		a
 	} else {
@@ -97,7 +101,7 @@ fn f32_max(a, b f32) f32 {
 }
 
 [inline]
-fn f32_min(a, b f32) f32 {
+pub fn f32_min(a, b f32) f32 {
 	return if a < b {
 		a
 	} else {
@@ -106,7 +110,7 @@ fn f32_min(a, b f32) f32 {
 }
 
 [inline]
-fn f64_max(a, b f64) f64 {
+pub fn f64_max(a, b f64) f64 {
 	return if a > b {
 		a
 	} else {
diff --git a/vlib/v/tests/num_lit_call_method_test.v b/vlib/v/tests/num_lit_call_method_test.v
index 3346d3acb8..448911295b 100644
--- a/vlib/v/tests/num_lit_call_method_test.v
+++ b/vlib/v/tests/num_lit_call_method_test.v
@@ -21,8 +21,17 @@ fn test_float_lit_call_method() {
 	x4 := .003e2.str()
 	assert x4 == '0.3'
 	x5 := 2.e-3.str()
-	assert x5 == '2.e-03'
+	assert x5 == '0.002'
 	x6 := 5.0.str()
 	assert x6 == '5.'
 	// x7 := 5..str()    Syntax `5.` is allowed, but do not call method on it (`5..str()` is parsed as a range). Use `5.0.str()` instead.
+	x8 := 7.345e-7.str()
+	assert x8 == '7.345e-07'
+	x9 := 5.725e6.str()
+	assert x9 == '5.725e+06'
+
+	a := f32(12.3).str()
+	assert a[0..4] == '12.3' // there is still trailing garbage
+	assert f32(7.345e-7).str() == '7.345e-07'
+	assert f32(5.725e6).str() == '5.725e+06'
 }