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https://github.com/gorgonia/parser
A simple parser that turns a formulae written in unicode into an ExprGraph
https://github.com/gorgonia/parser
golang gorgonia goyacc parser unicode
Last synced: 3 days ago
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A simple parser that turns a formulae written in unicode into an ExprGraph
- Host: GitHub
- URL: https://github.com/gorgonia/parser
- Owner: gorgonia
- License: mit
- Created: 2018-04-06T08:33:21.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2022-10-08T08:15:32.000Z (about 2 years ago)
- Last Synced: 2024-06-20T10:15:35.623Z (5 months ago)
- Topics: golang, gorgonia, goyacc, parser, unicode
- Language: Go
- Size: 21.5 KB
- Stars: 12
- Watchers: 8
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
[](http://godoc.org/github.com/gorgonia/parser)
[](https://goreportcard.com/report/github.com/gorgonia/parser)
# About
The goal of this project is to parse a mathematical formulae written in unicode and to transpile is into an `ExprGraph` of the Gorgonia project.
## Principle
This parser is generated from a `yacc` file from the subdirectory `src`.
If you want to contribute or add some new functionalities, you may need the `goyacc` tool and then run `go generate` from the `src` dubdirectory.
For a more complete explanation, you can refer to this [blog post](https://blog.owulveryck.info/2017/12/18/parsing-mathematical-equation-to-generate-computation-graphs---first-step-from-software-1.0-to-2.0-in-go.html)
## Available operations
As of today, the parser understands the following opreations on node objects (tensor based):
| Operation | Gorgonia Operation | Symbol | Unicode character |
|--------------------|----------------------------------------------------------------------|---------|-------------------|
| Multiplication | [Mul](https://godoc.org/gorgonia.org/gorgonia#Mul) | · | U+00B7 |
| Hadamard Product | [HadamardProd](https://godoc.org/gorgonia.org/gorgonia#HadamardProd) | * | |
| Addition | [Add](https://godoc.org/gorgonia.org/gorgonia#Add) | + | |
| Substraction | [Sub](https://godoc.org/gorgonia.org/gorgonia#Sub) | - | |
| Pointwise Negation | [Neg](https://godoc.org/gorgonia.org/gorgonia#Neg) | - | |
| Sigmoid | [Sigmoid](https://godoc.org/gorgonia.org/gorgonia#Sigmoid) | σ | U+03C3 |
| Tanh | [Tanh](https://godoc.org/gorgonia.org/gorgonia#Tanh) | tanh | |
| Softmax | [Softmax](https://godoc.org/gorgonia.org/gorgonia#Softmax) | softmax | |
## Example
```go
import (
G "gorgonia.org/gorgonia"
"github.com/gorgonia/parser"
"gorgonia.org/tensor"
)
func main(){
g := G.NewGraph()
wfT := tensor.New(tensor.WithShape(2, 2), tensor.WithBacking([]float32{1, 1, 1, 1}))
wf := G.NewMatrix(g, tensor.Float32, G.WithName("wf"), G.WithShape(2, 2), G.WithValue(wfT))
htprevT := tensor.New(tensor.WithBacking([]float32{1, 1}), tensor.WithShape(2))
htprev := G.NewVector(g, tensor.Float32, G.WithName("ht-1"), G.WithShape(2), G.WithValue(htprevT))
xtT := tensor.New(tensor.WithBacking([]float32{1, 1}), tensor.WithShape(2))
xt := G.NewVector(g, tensor.Float32, G.WithName("xt"), G.WithShape(2), G.WithValue(xtT))
bfT := tensor.New(tensor.WithBacking([]float32{1, 1}), tensor.WithShape(2))
bf := G.NewVector(g, tensor.Float32, G.WithName("bf"), G.WithShape(2), G.WithValue(bfT))
p := parser.NewParser(g)
p.Set(`Wf`, wf)
p.Set(`h`, htprev)
p.Set(`x`, xt)
p.Set(`bf`, bf)
result, _ := p.Parse(`σ(1*Wf·h+ Wf·x+ bf)`)
machine := G.NewLispMachine(g, G.ExecuteFwdOnly())
if err := machine.RunAll(); err != nil {
t.Fatal(err)
}
res := result.Value().Data().([]float32)
}
```
# Caution
* The parser is internally using a `map` and is not concurrent safe.
* The errors are not handle correctly