From a08e64f37fb03200dfb24fc6bfe291da26a62cc6 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 8 Apr 2020 22:12:42 +0200
Subject: [PATCH] cgen: operator overloading

---
 vlib/math/bits/bits.v            |  4 +-
 vlib/math/bits/bits_test.v       | 36 +++++++++---------
 vlib/math/complex/complex.v      |  8 ++--
 vlib/math/complex/complex_test.v |  2 +
 vlib/v/gen/cgen.v                | 17 +++++++--
 vlib/v/util/util.v               | 63 +++++++++++++++++++++++---------
 6 files changed, 85 insertions(+), 45 deletions(-)

diff --git a/vlib/math/bits/bits.v b/vlib/math/bits/bits.v
index 88d999465c..66d89b30dc 100644
--- a/vlib/math/bits/bits.v
+++ b/vlib/math/bits/bits.v
@@ -271,11 +271,11 @@ pub fn len_16(x u16) int {
 pub fn len_32(x u32) int {
 	mut y := x
 	mut n := 0
-	if y >= 1<<16 {
+	if y >= (1<<16) {
 		y >>= 16
 		n = 16
 	}
-	if y >= 1<<8 {
+	if y >= (1<<8) {
 		y >>= 8
 		n += 8
 	}
diff --git a/vlib/math/bits/bits_test.v b/vlib/math/bits/bits_test.v
index e2b59007ec..9b74d9d9f7 100644
--- a/vlib/math/bits/bits_test.v
+++ b/vlib/math/bits/bits_test.v
@@ -6,32 +6,32 @@ module bits
 fn test_bits(){
 	mut i := 0
 	mut i1:= u64(0)
-	
+
 	//
 	// --- LeadingZeros ---
 	//
-	
+
 	// 8 bit
 	i = 1
 	for x in 0..8 {
 		//C.printf("x:%02x lz: %d cmp: %d\n", i << x, leading_zeros_8(i << x), 7-x)
 		assert leading_zeros_8(byte(i << x)) == 7 - x
 	}
-	
+
 	// 16 bit
 	i = 1
 	for x in 0..16 {
 		//C.printf("x:%04x lz: %d cmp: %d\n", u16(i) << x, leading_zeros_16(u16(i) << x), 15-x)
 		assert leading_zeros_16(u16(i) << x) == 15 - x
 	}
-	
+
 	// 32 bit
 	i = 1
 	for x in 0..32 {
 		//C.printf("x:%08x lz: %d cmp: %d\n", u32(i) << x, leading_zeros_32(u32(i) << x), 31-x)
 		assert leading_zeros_32(u32(i) << x) == 31 - x
 	}
-	
+
 	// 64 bit
 	i = 1
 	for x in 0..64 {
@@ -50,7 +50,7 @@ fn test_bits(){
 		assert ones_count_8(byte(i)) == x
 		i = (i << 1) + 1
 	}
-	
+
 	// 16 bit
 	i = 0
 	for x in 0..17 {
@@ -58,7 +58,7 @@ fn test_bits(){
 		assert ones_count_16(u16(i)) == x
 		i = (i << 1) + 1
 	}
-	
+
 	// 32 bit
 	i = 0
 	for x in 0..33 {
@@ -66,7 +66,7 @@ fn test_bits(){
 		assert ones_count_32(u32(i)) == x
 		i = (i << 1) + 1
 	}
-	
+
 	// 64 bit
 	i1 = 0
 	for x in 0..65 {
@@ -76,7 +76,7 @@ fn test_bits(){
 	}
 
 	//
-	// --- rotate_left/right --- 
+	// --- rotate_left/right ---
 	//
 	assert rotate_left_8( 0x12 , 4) == 0x21
 	assert rotate_left_16( 0x1234 , 8) == 0x3412
@@ -86,7 +86,7 @@ fn test_bits(){
 	//
 	// --- reverse ---
 	//
-	
+
 	// 8 bit
 	i = 0
 	for x in 0..9 {
@@ -102,7 +102,7 @@ fn test_bits(){
 		assert reverse_8(byte(i)) == rv
 		i = (i << 1) + 1
 	}
-	
+
 	// 16 bit
 	i = 0
 	for x in 0..17 {
@@ -118,7 +118,7 @@ fn test_bits(){
 		assert reverse_16(u16(i)) == rv
 		i = (i << 1) + 1
 	}
-	
+
 	// 32 bit
 	i = 0
 	for x in 0..33 {
@@ -134,7 +134,7 @@ fn test_bits(){
 		assert reverse_32(u32(i)) == rv
 		i = (i << 1) + 1
 	}
-	
+
 	// 64 bit
 	i1 = 0
 	for x in 0..64 {
@@ -190,7 +190,7 @@ fn test_bits(){
 	//
 	// --- sub ---
 	//
-	
+
 	// 32 bit
 	i = 1
 	for x in 1..32 {
@@ -202,7 +202,7 @@ fn test_bits(){
 
 		diff, borrow_out = sub_32(v0, v1, u32(1))
 		//C.printf("x:%08x [%llu,%llu] %08x\n", u32(i) << x, diff, borrow_out, v0 - v1)
-		assert diff == (v1 - 1) 
+		assert diff == (v1 - 1)
 		assert borrow_out == u32(0)
 
 		diff, borrow_out = sub_32(v1, v0, u32(1))
@@ -221,7 +221,7 @@ fn test_bits(){
 
 		diff, borrow_out = sub_64(v0, v1, u64(1))
 		//C.printf("x:%08x [%llu,%llu] %08x\n", u64(i) << x, diff, borrow_out, v0 - v1)
-		assert diff == (v1 - 1) 
+		assert diff == (v1 - 1)
 		assert borrow_out == u64(0)
 
 		diff, borrow_out = sub_64(v1, v0, u64(1))
@@ -236,7 +236,7 @@ fn test_bits(){
 	// 32 bit
 	i = 1
 	for x in 0..32 {
-		v0 := u32(i) << x
+		v0 := (u32(i) << x)
 		v1 := v0 - 1
 		hi, lo := mul_32(v0, v1)
 		//C.printf("x:%08x [%llu,%llu] %llu\n", v0, hi, lo, u64(v0 * v1))
@@ -285,5 +285,5 @@ fn test_bits(){
 		assert rem == rem1
 		assert rem == rem_64(hi, lo, y)
 	}
-	
+
 }
diff --git a/vlib/math/complex/complex.v b/vlib/math/complex/complex.v
index 3dd52ed6bc..c4602a014c 100644
--- a/vlib/math/complex/complex.v
+++ b/vlib/math/complex/complex.v
@@ -366,7 +366,7 @@ pub fn (c Complex) asinh() Complex {
 // Based on
 // http://www.suitcaseofdreams.net/Inverse__Hyperbolic_Functions.htm
 pub fn (c Complex) acosh() Complex {
-	if(c.re > 1) {
+	if c.re > 1 {
 		return c.add(
 			c.pow(2)
 			.subtract(complex(1,0))
@@ -391,7 +391,7 @@ pub fn (c Complex) acosh() Complex {
 // http://www.suitcaseofdreams.net/Inverse__Hyperbolic_Functions.htm
 pub fn (c Complex) atanh() Complex {
 	one := complex(1,0)
-	if(c.re < 1) {
+	if c.re < 1 {
 		return complex(1.0/2,0).multiply(
 			one
 			.add(c)
@@ -421,7 +421,7 @@ pub fn (c Complex) atanh() Complex {
 // http://www.suitcaseofdreams.net/Inverse__Hyperbolic_Functions.htm
 pub fn (c Complex) acoth() Complex {
 	one := complex(1,0)
-	if(c.re < 0 || c.re > 1) {
+	if c.re < 0 || c.re > 1 {
 		return complex(1.0/2,0).multiply(
 			c
 			.add(one)
@@ -479,7 +479,7 @@ pub fn (c Complex) acoth() Complex {
 // http://www.suitcaseofdreams.net/Inverse__Hyperbolic_Functions.htm
 pub fn (c Complex) acsch() Complex {
 	one := complex(1,0)
-	if(c.re < 0) {
+	if c.re < 0 {
 		return one.subtract(
 			one.add(
 				c.pow(2)
diff --git a/vlib/math/complex/complex_test.v b/vlib/math/complex/complex_test.v
index 4e91083daf..b74c66998e 100644
--- a/vlib/math/complex/complex_test.v
+++ b/vlib/math/complex/complex_test.v
@@ -168,6 +168,8 @@ fn test_complex_mulinv() {
 	mut c2 := cmplx.complex(0.067568,-0.094595)
 	mut result := c1.mulinv()
 	// Some issue with precision comparison in f64 using == operator hence serializing to string
+	println(c2.str())
+	println(result.str())
 	assert result.str().eq(c2.str())
 	c1 = cmplx.complex(-3,4)
 	c2 = cmplx.complex(-0.12,-0.16)
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 94ddcdcb47..0a700337a1 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -788,6 +788,10 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 		}
 	} else {
 		mut name := it.name
+		c := name[0]
+		if c in [`+`, `-`, `*`, `/`] {
+			name = util.replace_op(name)
+		}
 		if it.is_method {
 			name = g.table.get_type_symbol(it.receiver.typ).name + '_' + name
 		}
@@ -796,9 +800,6 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 		} else {
 			name = c_name(name)
 		}
-		if name.starts_with('_op_') {
-			name = op_to_fn_name(name)
-		}
 		// type_name := g.table.Type_to_str(it.return_type)
 		type_name := g.typ(it.return_type)
 		g.write('$type_name ${name}(')
@@ -1295,6 +1296,7 @@ fn (g mut Gen) assign_expr(node ast.AssignExpr) {
 }
 
 fn (g mut Gen) infix_expr(node ast.InfixExpr) {
+	left_sym := g.table.get_type_symbol(node.left_type)
 	// println('infix_expr() op="$node.op.str()" line_nr=$node.pos.line_nr')
 	// g.write('/*infix*/')
 	// if it.left_type == table.string_type_idx {
@@ -1412,6 +1414,15 @@ fn (g mut Gen) infix_expr(node ast.InfixExpr) {
 		g.write(',')
 		g.expr(node.right)
 		g.write(')')
+	} else if node.op in [.plus, .minus, .mul, .div] && (left_sym.name[0].is_capital() || left_sym.name.contains('.')) {
+		g.write(g.typ(node.left_type))
+		g.write('_')
+		g.write(util.replace_op(node.op.str()))
+		g.write('(')
+		g.expr(node.left)
+		g.write(', ')
+		g.expr(node.right)
+		g.write(')')
 	} else {
 		need_par := node.op in [.amp, .pipe, .xor]		// `x & y == 0` => `(x & y) == 0` in C
 		if need_par {
diff --git a/vlib/v/util/util.v b/vlib/v/util/util.v
index b142757899..fef61901a3 100644
--- a/vlib/v/util/util.v
+++ b/vlib/v/util/util.v
@@ -3,8 +3,10 @@
 // that can be found in the LICENSE file.
 module util
 
-import os
-import v.pref
+import (
+	os
+	v.pref
+)
 
 pub const (
 	v_version = '0.1.26'
@@ -22,7 +24,7 @@ pub fn full_hash() string {
 	build_hash := vhash()
 	current_hash := githash(false)
 	if build_hash == current_hash {
-	   return build_hash
+		return build_hash
 	}
 	return '${build_hash}.${current_hash}'
 }
@@ -41,7 +43,7 @@ pub fn full_v_version() string {
 // NB: githash(true) must be called only when v detects that it builds itself.
 // For all other programs, githash(false) should be used.
 pub fn githash(should_get_from_filesystem bool) string {
-	for {
+	for  {
 		// The `for` construct here is used as a goto substitute.
 		// The code in this function will break out of the `for`
 		// if it detects an error and can not continue.
@@ -50,7 +52,7 @@ pub fn githash(should_get_from_filesystem bool) string {
 			vroot := os.dir(vexe)
 			// .git/HEAD
 			git_head_file := os.join_path(vroot, '.git', 'HEAD')
-			if !os.exists( git_head_file ) {
+			if !os.exists(git_head_file) {
 				break
 			}
 			// 'ref: refs/heads/master' ... the current branch name
@@ -60,11 +62,11 @@ pub fn githash(should_get_from_filesystem bool) string {
 			gcbranch_rel_path := head_content.replace('ref: ', '').trim_space()
 			gcbranch_file := os.join_path(vroot, '.git', gcbranch_rel_path)
 			// .git/refs/heads/master
-			if !os.exists( gcbranch_file ) {
+			if !os.exists(gcbranch_file) {
 				break
 			}
 			// get the full commit hash contained in the ref heads file
-			current_branch_hash := os.read_file( gcbranch_file ) or {
+			current_branch_hash := os.read_file(gcbranch_file) or {
 				break
 			}
 			desired_hash_length := 7
@@ -81,20 +83,18 @@ pub fn githash(should_get_from_filesystem bool) string {
 }
 
 //
-
 fn set_vroot_folder(vroot_path string) {
 	// Preparation for the compiler module:
 	// VEXE env variable is needed so that compiler.vexe_path()
 	// can return it later to whoever needs it:
 	vname := if os.user_os() == 'windows' { 'v.exe' } else { 'v' }
-	os.setenv('VEXE', os.real_path(os.join_path( vroot_path, vname)), true)
+	os.setenv('VEXE', os.real_path(os.join_path(vroot_path, vname)), true)
 }
 
 pub fn launch_tool(is_verbose bool, tool_name string) {
 	vexe := pref.vexe_path()
 	vroot := os.dir(vexe)
 	set_vroot_folder(vroot)
-
 	tool_args := os.args[1..].join(' ')
 	tool_exe := path_of_executable(os.real_path('$vroot/cmd/tools/$tool_name'))
 	tool_source := os.real_path('$vroot/cmd/tools/${tool_name}.v')
@@ -105,7 +105,6 @@ pub fn launch_tool(is_verbose bool, tool_name string) {
 		println('launch_tool tool_args   : $tool_args')
 		println('launch_tool tool_command: $tool_command')
 	}
-
 	// TODO Caching should be done on the `vlib/v` level.
 	mut should_compile := false
 	if !os.exists(tool_exe) {
@@ -115,7 +114,6 @@ pub fn launch_tool(is_verbose bool, tool_name string) {
 			// v was recompiled, maybe after v up ...
 			// rebuild the tool too just in case
 			should_compile = true
-
 			if tool_name == 'vself' || tool_name == 'vup' {
 				// The purpose of vself/up is to update and recompile v itself.
 				// After the first 'v self' execution, v will be modified, so
@@ -133,14 +131,15 @@ pub fn launch_tool(is_verbose bool, tool_name string) {
 	if is_verbose {
 		println('launch_tool should_compile: $should_compile')
 	}
-
 	if should_compile {
 		mut compilation_command := '"$vexe" '
 		compilation_command += '"$tool_source"'
 		if is_verbose {
 			println('Compiling $tool_name with: "$compilation_command"')
 		}
-		tool_compilation := os.exec(compilation_command) or { panic(err) }
+		tool_compilation := os.exec(compilation_command) or {
+			panic(err)
+		}
 		if tool_compilation.exit_code != 0 {
 			mut err := 'Permission denied'
 			if !tool_compilation.output.contains('Permission denied') {
@@ -153,7 +152,6 @@ pub fn launch_tool(is_verbose bool, tool_name string) {
 	if is_verbose {
 		println('launch_tool running tool command: $tool_command ...')
 	}
-
 	exit(os.system(tool_command))
 }
 
@@ -180,13 +178,42 @@ pub fn read_file(file_path string) ?string {
 	return raw_text
 }
 
-
 [inline]
 fn imin(a, b int) int {
-    return if a < b { a } else { b }
+	return if a < b {
+		a
+	} else {
+		b
+	}
 }
 
 [inline]
 fn imax(a, b int) int {
-    return if a > b { a } else { b }
+	return if a > b {
+		a
+	} else {
+		b
+	}
+}
+
+fn replace_op(s string) string {
+	last_char := s[s.len - 1]
+	suffix := match last_char {
+		`+` {
+			'_plus'
+		}
+		`-` {
+			'_minus'
+		}
+		`*` {
+			'_mult'
+		}
+		`/` {
+			'_div'
+		}
+		else {
+			''
+		}
+	}
+	return s[..s.len - 1] + suffix
 }