From 243af92ed77b7673e36f4e40da7036a42e610ae2 Mon Sep 17 00:00:00 2001
From: Mirek Fidler <mirek.fidler@gmail.com>
Date: Wed, 14 Jun 2023 16:49:08 +0200
Subject: [PATCH] Core: CParser::ReadDoubleNoE (to ignore E part of double)

---
 uppsrc/Core/CvFlt.cpp                 | 17 +++++++++++++++--
 uppsrc/Core/Parser.h                  |  1 +
 uppsrc/Core/src.tpp/CParser_en-us.tpp |  6 ++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/uppsrc/Core/CvFlt.cpp b/uppsrc/Core/CvFlt.cpp
index 188411d9b..aee6b28ba 100644
--- a/uppsrc/Core/CvFlt.cpp
+++ b/uppsrc/Core/CvFlt.cpp
@@ -510,7 +510,7 @@ String FormatF(double x, int precision, dword flags)
 }
 
 template <typename CHAR, typename BYTE>
-const CHAR *ScanDbl(double& result, const CHAR *s, int alt_dp)
+const CHAR *ScanDbl(double& result, const CHAR *s, int alt_dp, bool E = true)
 {
 	SkipSpaces__<CHAR, BYTE>(s);
 
@@ -571,7 +571,7 @@ const CHAR *ScanDbl(double& result, const CHAR *s, int alt_dp)
 		ReadNumber();
 		exp += int(s0 - s) + ignored;
 	}
-	if(*s == 'e' || *s == 'E') {
+	if(E && (*s == 'e' || *s == 'E')) {
 		dword e = 0;
 		bool overflow = false;
 		s++;
@@ -676,4 +676,17 @@ double CParser::ReadDouble()
 	return n;
 }
 
+double CParser::ReadDoubleNoE()
+{
+	LTIMING("ReadDouble No E");
+	double n;
+	const char *t = ScanDbl<char, byte>(n, term, '.', false);
+	if(!t) ThrowError("missing number");
+	if(!IsFin(n))
+		ThrowError("invalid number");
+	term = t;
+	DoSpaces();
+	return n;
+}
+
 };
\ No newline at end of file
diff --git a/uppsrc/Core/Parser.h b/uppsrc/Core/Parser.h
index 3f98b6fba..7add18770 100644
--- a/uppsrc/Core/Parser.h
+++ b/uppsrc/Core/Parser.h
@@ -64,6 +64,7 @@ public:
 	bool   IsDouble() const                   { return IsInt(); }
 	bool   IsDouble2() const;
 	double ReadDouble();
+	double ReadDoubleNoE();
 	bool   IsString() const                   { return IsChar('\"'); };
 	String ReadOneString(bool chkend = true);
 	String ReadString(bool chkend = true);
diff --git a/uppsrc/Core/src.tpp/CParser_en-us.tpp b/uppsrc/Core/src.tpp/CParser_en-us.tpp
index e738193c1..6ff2c0c28 100644
--- a/uppsrc/Core/src.tpp/CParser_en-us.tpp
+++ b/uppsrc/Core/src.tpp/CParser_en-us.tpp
@@ -312,6 +312,12 @@ As an exception to C lexical rules, ReadDouble also recognizes
 form starting with decimal point, like `".21`".&]
 [s3; &]
 [s4; &]
+[s5;:Upp`:`:CParser`:`:ReadDoubleNoE`(`): [@(0.0.255) double] [* ReadDoubleNoE]()&]
+[s2;%% Speacial variant of ReadDouble that ignores exponential part 
+of number. E.g. CParser(`"1.2em`").ReadDoubleNoE() returns 1.2 
+(and does not throw error for invalid double).&]
+[s3; &]
+[s4; &]
 [s5;:CParser`:`:IsString`(`)const: [@(0.0.255) bool]_[* IsString]()_[@(0.0.255) const]&]
 [s2;%% Tests for C`-like string literal at the current position. 
 Same as [* IsChar](`'`\`"`');&]