Improve toNumber, fix protect

Author: fbogsany

base.go

@@ -256,7 +256,7 @@ var baseLibrary = []RegistryFunction{
 	}},
 	{"type", func(l *State) int {
 		CheckAny(l, 1)
-		PushString(l, TypeName(l, 1))
+		PushString(l, TypeNameOf(l, 1))
 		return 1
 	}},
 	{"xpcall", func(l *State) int {

debug.go

@@ -53,7 +53,7 @@ func (l *State) orderError(left, right value) {
 }
 
 func (l *State) arithError(v1, v2 value) {
-	if _, ok := toNumber(v1); !ok {
+	if _, ok := l.toNumber(v1); !ok {
 		v2 = v1
 	}
 	l.typeError(v2, "perform arithmetic on")

libs.go

@@ -5,6 +5,7 @@ func OpenLibraries(l *State) {
 		{"_G", BaseOpen},
 		{"package", PackageOpen},
 		{"math", MathOpen},
+		{"string", StringOpen},
 	}
 	for _, lib := range libs {
 		Require(l, lib.Name, lib.Function, true)

lua.go

@@ -568,7 +568,7 @@ func IsGoFunction(l *State, index int) bool {
 //
 // http://www.lua.org/manual/5.2/manual.html#lua_isnumber
 func IsNumber(l *State, index int) bool {
-	_, ok := toNumber(l.indexToValue(index))
+	_, ok := l.toNumber(l.indexToValue(index))
 	return ok
 }
 
@@ -654,7 +654,7 @@ func Compare(l *State, index1, index2 int, op ComparisonOperator) bool {
 //
 // http://www.lua.org/manual/5.2/manual.html#lua_tointegerx
 func ToInteger(l *State, index int) (int, bool) {
-	if n, ok := toNumber(l.indexToValue(index)); ok {
+	if n, ok := l.toNumber(l.indexToValue(index)); ok {
 		return int(n), true
 	}
 	return 0, false
@@ -672,7 +672,7 @@ func ToInteger(l *State, index int) (int, bool) {
 //
 // http://www.lua.org/manual/5.2/manual.html#lua_tounsignedx
 func ToUnsigned(l *State, index int) (uint, bool) {
-	if n, ok := toNumber(l.indexToValue(index)); ok {
+	if n, ok := l.toNumber(l.indexToValue(index)); ok {
 		const supUnsigned = float64(^uint(0)) + 1
 		return uint(n - math.Floor(n/supUnsigned)*supUnsigned), true
 	}
@@ -1256,7 +1256,7 @@ func TypeName(l *State, t Type) string { return typeNames[t+1] }
 // If the operation failed, the second return value will be false.
 //
 // http://www.lua.org/manual/5.2/manual.html#lua_tonumberx
-func ToNumber(l *State, index int) (float64, bool) { return toNumber(l.indexToValue(index)) }
+func ToNumber(l *State, index int) (float64, bool) { return l.toNumber(l.indexToValue(index)) }
 
 // ToBoolean converts the Lua value at `index` to a Go boolean.  Like all
 // tests in Lua, the only true values are `true` booleans and `nil`.

math_test.go

@@ -3,8 +3,17 @@ package lua
 import "testing"
 
 func TestMath(t *testing.T) {
+	t.Skip()
 	l := NewState()
 	OpenLibraries(l)
-	LoadString(l, "print(math.abs(-math.pi))")
+	// SetHooker(l, func(state *State, ar *Debug) {
+	// 	ci := state.callInfo.(*luaCallInfo)
+	// 	printStack(state.stack[ci.base():state.top])
+	// 	println(ci.code[ci.savedPC].String())
+	// 	p := state.stack[ci.function()].(*luaClosure).prototype
+	// 	println(p.source, p.lineInfo[ci.savedPC])
+	// }, MaskCount, 1)
+	// LoadString(l, "print(math.abs(-math.pi))")
+	LoadFile(l, "fixtures/math.lua", "text")
 	Call(l, 0, 0)
 }

parser_test.go

@@ -18,7 +18,7 @@ func load(l *State, t *testing.T, fileName string) *luaClosure {
 func TestParser(t *testing.T) {
 	l := NewState()
 	OpenLibraries(l)
-	// SetHook(l, func(state *State, ar *Debug) {
+	// SetHooker(l, func(state *State, ar *Debug) {
 	// 	printStack(state.stack[state.callInfo.(*luaCallInfo).base():state.top])
 	// 	println(state.callInfo.(*luaCallInfo).code[state.callInfo.(*luaCallInfo).savedPC].String())
 	// }, MaskCount, 1)

scanner_test.go

@@ -35,6 +35,7 @@ func TestScanner(t *testing.T) {
 		{"0x0.1E", []token{{t: tkNumber, n: 0.1171875}}},
 		{"0xA23p-4", []token{{t: tkNumber, n: 162.1875}}},
 		{"0X1.921FB54442D18P+1", []token{{t: tkNumber, n: 3.141592653589793}}},
+		{"  -0xa  ", []token{{t: '-'}, {t: tkNumber, n: 10.0}}},
 	}
 	for i, v := range tests {
 		testScanner(t, i, v.source, v.tokens)

stack.go

@@ -409,9 +409,8 @@ func (l *State) throw(errorCode error) {
 	}
 }
 
-func (l *State) protect(f func()) error {
+func (l *State) protect(f func()) (err error) {
 	nestedGoCallCount, protectFunction := l.nestedGoCallCount, l.protectFunction
-	var err error
 	l.protectFunction = func() {
 		if e := recover(); e != nil {
 			err = e.(error)

types.go

@@ -6,6 +6,7 @@ import (
 	"reflect"
 	"runtime"
 	"strconv"
+	"strings"
 )
 
 type value interface{}
@@ -132,16 +133,37 @@ func arith(op Operator, v1, v2 float64) float64 {
 	panic(fmt.Sprintf("not an arithmetic op code (%d)", op))
 }
 
-func toNumber(r value) (float64, bool) {
-	if v, ok := r.(float64); ok {
-		return v, true
+func (l *State) parseNumber(s string) (float64, bool) {
+	scanner := scanner{l: l, r: strings.NewReader(s)}
+	t := scanner.scan()
+	if t.t == '-' {
+		if t := scanner.scan(); t.t == tkNumber {
+			return -t.n, true
+		}
+	} else if t.t == tkNumber {
+		return t.n, true
 	}
-	if s, ok := r.(string); ok {
-		if v, err := strconv.ParseFloat(s, 64); err == nil { // TODO handle hexadecimal floats
+	return 0.0, false
+}
+
+func (l *State) toNumber(r value) (v float64, ok bool) {
+	if v, ok = r.(float64); ok {
+		return
+	}
+	var s string
+	if s, ok = r.(string); ok {
+		s = strings.TrimSpace(s)
+		if v, err := strconv.ParseFloat(s, 64); err == nil {
 			return v, true
 		}
+		if err := l.protectedCall(func() { v, ok = l.parseNumber(s) }, l.top, l.errorFunction); err == nil {
+			return
+		} else {
+			l.pop() // Remove error message from the stack.
+			ok = false
+		}
 	}
-	return 0.0, false
+	return
 }
 
 func numberToString(f float64) string {

vm.go

@@ -7,8 +7,8 @@ import (
 )
 
 func (l *State) arith(rb, rc value, op tm) value {
-	b, bok := toNumber(rb)
-	c, cok := toNumber(rc)
+	b, bok := l.toNumber(rb)
+	c, cok := l.toNumber(rc)
 	if bok && cok {
 		return arith(Operator(op-tmAdd)+OpAdd, b, c)
 	} else if result, ok := l.callBinaryTagMethod(rb, rc, op); ok {
@@ -485,11 +485,11 @@ func (l *State) execute() {
 			}
 		case opForPrep:
 			a := i.a()
-			if init, ok := toNumber(frame[a+0]); !ok {
+			if init, ok := l.toNumber(frame[a+0]); !ok {
 				l.runtimeError("'for' initial value must be a number")
-			} else if limit, ok := toNumber(frame[a+1]); !ok {
+			} else if limit, ok := l.toNumber(frame[a+1]); !ok {
 				l.runtimeError("'for' limit must be a number")
-			} else if step, ok := toNumber(frame[a+2]); !ok {
+			} else if step, ok := l.toNumber(frame[a+2]); !ok {
 				l.runtimeError("'for' step must be a number")
 			} else {
 				frame[a+0], frame[a+1], frame[a+2] = init-step, limit, step
@@ -518,7 +518,7 @@ func (l *State) execute() {
 				c = expectNext(opExtraArg).ax()
 			}
 			h := frame[a].(*table)
-			start := c - 1*listItemsPerFlush
+			start := (c - 1) * listItemsPerFlush
 			last := start + n
 			if last > cap(h.array) {
 				h.extendArray(last)