py, parse: float - fix parsing of out of range floats and floats with spaces

Author: ncw

parser/lexer.go

@@ -695,24 +695,22 @@ isNumber:
 			imaginary = true
 			toParse = s[:len(s)-1]
 		}
-		f, err := strconv.ParseFloat(toParse, 64)
+		value, err = py.FloatFromString(toParse)
 		if err != nil {
-			panic(py.ExceptionNewf(py.ValueError, "invalid literal for float: '%s' (%v)", toParse, err))
+			panic(err)
 		}
 		if imaginary {
-			value = py.Complex(complex(0, f))
-		} else {
-			value = py.Float(f)
+			value = py.Complex(complex(0, value.(py.Float)))
 		}
 	} else if s = decimalInteger.FindString(x.line); s != "" {
 		last := s[len(s)-1]
 		if last == 'j' || last == 'J' {
 			toParse := s[:len(s)-1]
-			f, err := strconv.ParseFloat(toParse, 64)
+			value, err = py.FloatFromString(toParse)
 			if err != nil {
-				panic(py.ExceptionNewf(py.ValueError, "invalid literal for imaginary number: '%s' (%v)", toParse, err))
+				panic(err)
 			}
-			value = py.Complex(complex(0, f))
+			value = py.Complex(complex(0, value.(py.Float)))
 		} else {
 			// Discard numbers with leading 0 except all 0s
 			if illegalDecimalInteger.FindString(s) != "" {

py/float.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"math/big"
 	"strconv"
+	"strings"
 )
 
 var FloatType = ObjectType.NewType("float", "float(x) -> floating point number\n\nConvert a string or number to a floating point number, if possible.", FloatNew, nil)
@@ -52,9 +53,19 @@ func (a Float) M__repr__() (Object, error) {
 
 // FloatFromString turns a string into a Float
 func FloatFromString(str string) (Object, error) {
+	str = strings.TrimSpace(str)
 	f, err := strconv.ParseFloat(str, 64)
 	if err != nil {
-		return nil, ExceptionNewf(ValueError, "could not convert string to float: '%s'", str)
+		if numErr, ok := err.(*strconv.NumError); ok {
+			if numErr.Err == strconv.ErrRange {
+				if str[0] == '-' {
+					return Float(math.Inf(-1)), nil
+				} else {
+					return Float(math.Inf(1)), nil
+				}
+			}
+		}
+		return nil, ExceptionNewf(ValueError, "invalid literal for float: '%s'", str)
 	}
 	return Float(f), nil
 }

py/tests/float.py

@@ -0,0 +1,13 @@
+from libtest import assertRaises
+
+doc="float"
+assert float("1.5") == 1.5
+assert float(" 1.5") == 1.5
+assert float(" 1.5 ") == 1.5
+assert float("1.5 ") == 1.5
+assert float("-1E9") == -1E9
+assert float("1E400") == float("inf")
+assert float(" -1E400") == float("-inf")
+assertRaises(ValueError, float, "1 E200")
+
+doc="finished"