/
contextfn_numbers.go
112 lines (85 loc) · 2.54 KB
/
contextfn_numbers.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
package exec
import (
"math"
"strconv"
"github.com/ChrisTrenkamp/xsel/grammar"
"github.com/ChrisTrenkamp/xsel/grammar/parser/symbols"
)
func init() {
contextFunctions[symbols.NT_Number] = execNumber
contextFunctions[symbols.NT_AdditiveExprAdd] = execAdditiveExprAdd
contextFunctions[symbols.NT_AdditiveExprSubtract] = execAdditiveExprSubtract
contextFunctions[symbols.NT_MultiplicativeExprMultiply] = execMultiplicativeExprMultiply
contextFunctions[symbols.NT_MultiplicativeExprDivide] = execMultiplicativeExprDivide
contextFunctions[symbols.NT_MultiplicativeExprMod] = execMultiplicativeExprMod
contextFunctions[symbols.NT_UnaryExprNegate] = execUnaryExprNegate
}
func execNumber(context *exprContext, expr *grammar.Grammar) error {
numStr := expr.GetString()
numResult, err := strconv.ParseFloat(numStr, 64)
context.result = Number(numResult)
return err
}
func execAdditiveExprAdd(context *exprContext, expr *grammar.Grammar) error {
left, right, err := leftRightIndependentNumber(context, expr)
if err != nil {
return err
}
context.result = Number(left + right)
return nil
}
func execAdditiveExprSubtract(context *exprContext, expr *grammar.Grammar) error {
left, right, err := leftRightIndependentNumber(context, expr)
if err != nil {
return err
}
context.result = Number(left - right)
return nil
}
func execMultiplicativeExprMultiply(context *exprContext, expr *grammar.Grammar) error {
left, right, err := leftRightIndependentNumber(context, expr)
if err != nil {
return err
}
context.result = Number(left * right)
return nil
}
func execMultiplicativeExprDivide(context *exprContext, expr *grammar.Grammar) error {
left, right, err := leftRightIndependentNumber(context, expr)
if err != nil {
return err
}
if right == 0 {
if left == 0 {
context.result = Number(math.NaN())
} else if left > 0 {
context.result = Number(math.Inf(1))
} else {
context.result = Number(math.Inf(-1))
}
return nil
}
context.result = Number(left / right)
return nil
}
func execMultiplicativeExprMod(context *exprContext, expr *grammar.Grammar) error {
left, right, err := leftRightIndependentNumber(context, expr)
if err != nil {
return err
}
if right == 0 {
context.result = Number(math.NaN())
return nil
}
context.result = Number(int(left) % int(right))
return nil
}
func execUnaryExprNegate(context *exprContext, expr *grammar.Grammar) error {
left, err := leftOnlyIndependentResult(context, expr)
if err != nil {
return err
}
leftNum := left.Number()
context.result = Number(-leftNum)
return nil
}