Skip to content

S
StdEnv-doc
Commit 5928340c authored by John van Groningen's avatar John van Groningen
Browse files
Options

improve accuracy of toReal for strings, fix conversion of denormalized numbers

parent 9c652777
Hide whitespace changes
Inline Side-by-side
Showing with 115 additions and 55 deletions
StdEnv 64 Changed Files/StdReal.icl
View file @ 5928340c
......@@ -7,7 +7,7 @@ implementation module StdReal
import StdClass
import StdOverloaded,StdInt,StdArray
from StdBool import &&,||,not
from StdChar import instance == Char, class ==(..)
from StdChar import instance == Char, instance < Char, class ==(..)
instance + Real
where
......@@ -243,7 +243,7 @@ where
instance toReal {#Char}
where
toReal::!{#Char} -> Real
toReal :: !{#Char} -> Real
toReal s
| len == 0
= 0.0
......@@ -254,41 +254,71 @@ where
// otherwise
= val
where
len
= size s
signedval
= toReal2 s 1 0.0 False 1.0 False 0 0
val
= toReal2 s 0 0.0 False 1.0 False 0 0
first
= s.[0]
toReal2 s posn val dec_new dval exp eneg eval
len = size s
first = s.[0]
signedval = toReal1 s 1 0.0
val = toReal1 s 0 0.0
toReal1 :: !{#Char} !Int !Real -> Real
toReal1 s posn val
| posn == len
= val
| digit
= toReal1 s (posn+1) (toReal n + 10.0*val)
| c == '.'
= toRealWithDot s (posn+1) val 0
| c== 'e' || c== 'E'
| posn<len-2 && s.[posn+1] == '-'
= toRealWithExp s (posn+2) val 0 (-1) 0
| posn<len-2 && s.[posn+1] == '+'
= toRealWithExp s (posn+2) val 0 (+1) 0
| posn<len-1
= toRealWithExp s (posn+1) val 0 1 0
= 0.0
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = c>='0' && c<='9'
toRealWithDot :: !{#Char} !Int !Real !Int -> Real
toRealWithDot s posn val dn
| posn == len
= val*dval*10.0 ^ toReal (eneg*eval)
| digit && not dec_new && not exp
= toReal2 s (posn+1) (toReal n + 10.0*val) dec_new dval exp eneg eval
| digit && dec_new && not exp
= toReal2 s (posn+1) (toReal n + 10.0*val) dec_new (dval/10.0) exp eneg eval
| digit && exp
= toReal2 s (posn+1) val dec_new dval exp eneg (n + 10*eval )
| not dec_new && not exp && c == '.'
= toReal2 s (posn+1) val True 1.0 exp eneg eval
| not exp && (c== 'e' || c== 'E')
| dn==0
= val
= val / (10.0 ^ toReal dn)
| digit
= toRealWithDot s (posn+1) (toReal n + 10.0*val) (dn+1)
| c== 'e' || c== 'E'
| posn<len-2 && s.[posn+1] == '-'
= toReal2 s (posn+2) val dec_new dval True (-1) 0
= toRealWithExp s (posn+2) val dn (-1) 0
| posn<len-2 && s.[posn+1] == '+'
= toReal2 s (posn+2) val dec_new dval True (+1) 0
= toRealWithExp s (posn+2) val dn (+1) 0
| posn<len-1
= toReal2 s (posn+1) val dec_new dval True 1 0
// otherwise
= toRealWithExp s (posn+1) val dn 1 0
= 0.0
// otherwise
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = 0<=n && n<=9
digit = c>='0' && c<='9'
toRealWithExp :: !{#Char} !Int !Real !Int !Int !Int -> Real
toRealWithExp s posn val dn eneg eval
| posn == len
# e = eneg*eval-dn
| e>=0
= val * 10.0 ^ toReal e
| e>= -308
= val / 10.0 ^ toReal (~e)
= (val / 5.0 ^ toReal (~e)) / 2.0 ^ toReal (~e)
| digit
= toRealWithExp s (posn+1) val dn eneg (n + 10*eval)
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = c>='0' && c<='9'
entier :: !Real -> Int
entier a
......
StdReal.icl
View file @ 5928340c
......@@ -7,7 +7,7 @@ implementation module StdReal
import StdClass
import StdOverloaded,StdInt,StdArray
from StdBool import &&,||,not
from StdChar import instance == Char, class ==(..)
from StdChar import instance == Char, instance < Char, class ==(..)
instance + Real
where
......@@ -254,41 +254,71 @@ where
// otherwise
= val
where
len
= size s
signedval
= toReal2 s 1 0.0 False 1.0 False 0 0
val
= toReal2 s 0 0.0 False 1.0 False 0 0
first
= s.[0]
toReal2 s posn val dec_new dval exp eneg eval
len = size s
first = s.[0]
signedval = toReal1 s 1 0.0
val = toReal1 s 0 0.0
toReal1 :: !{#Char} !Int !Real -> Real
toReal1 s posn val
| posn == len
= val
| digit
= toReal1 s (posn+1) (toReal n + 10.0*val)
| c == '.'
= toRealWithDot s (posn+1) val 0
| c== 'e' || c== 'E'
| posn<len-2 && s.[posn+1] == '-'
= toRealWithExp s (posn+2) val 0 (-1) 0
| posn<len-2 && s.[posn+1] == '+'
= toRealWithExp s (posn+2) val 0 (+1) 0
| posn<len-1
= toRealWithExp s (posn+1) val 0 1 0
= 0.0
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = c>='0' && c<='9'
toRealWithDot :: !{#Char} !Int !Real !Int -> Real
toRealWithDot s posn val dn
| posn == len
= val*dval*10.0 ^ toReal (eneg*eval)
| digit && not dec_new && not exp
= toReal2 s (posn+1) (toReal n + 10.0*val) dec_new dval exp eneg eval
| digit && dec_new && not exp
= toReal2 s (posn+1) (toReal n + 10.0*val) dec_new (dval/10.0) exp eneg eval
| digit && exp
= toReal2 s (posn+1) val dec_new dval exp eneg (n + 10*eval )
| not dec_new && not exp && c == '.'
= toReal2 s (posn+1) val True 1.0 exp eneg eval
| not exp && (c== 'e' || c== 'E')
| dn==0
= val
= val / (10.0 ^ toReal dn)
| digit
= toRealWithDot s (posn+1) (toReal n + 10.0*val) (dn+1)
| c== 'e' || c== 'E'
| posn<len-2 && s.[posn+1] == '-'
= toReal2 s (posn+2) val dec_new dval True (-1) 0
= toRealWithExp s (posn+2) val dn (-1) 0
| posn<len-2 && s.[posn+1] == '+'
= toReal2 s (posn+2) val dec_new dval True (+1) 0
= toRealWithExp s (posn+2) val dn (+1) 0
| posn<len-1
= toReal2 s (posn+1) val dec_new dval True 1 0
// otherwise
= toRealWithExp s (posn+1) val dn 1 0
= 0.0
// otherwise
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = 0<=n && n<=9
digit = c>='0' && c<='9'
toRealWithExp :: !{#Char} !Int !Real !Int !Int !Int -> Real
toRealWithExp s posn val dn eneg eval
| posn == len
# e = eneg*eval-dn
| e>=0
= val * 10.0 ^ toReal e
| e>= -308
= val / 10.0 ^ toReal (~e)
= (val / 5.0 ^ toReal (~e)) / 2.0 ^ toReal (~e)
| digit
= toRealWithExp s (posn+1) val dn eneg (n + 10*eval)
= 0.0
where
c = s.[posn]
n = toInt c - toInt '0'
digit = c>='0' && c<='9'
entier :: !Real -> Int
entier a
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment