kilo/vendor/github.com/awalterschulze/gographviz/internal/parser/main.go
Lucas Serven e989f0a25f
init
2019-01-18 02:50:10 +01:00

73 lines
1.9 KiB
Go

//Copyright 2013 GoGraphviz Authors
//
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
//limitations under the License.
//A parser for the DOT grammar.
package parser
import (
"fmt"
"io"
"io/ioutil"
"os"
"github.com/awalterschulze/gographviz/ast"
"github.com/awalterschulze/gographviz/internal/lexer"
)
//Parses a DOT string and outputs the
//abstract syntax tree representing the graph.
func ParseString(dotString string) (*ast.Graph, error) {
return ParseBytes([]byte(dotString))
}
//Parses the bytes representing a DOT string
//and outputs the abstract syntax tree representing the graph.
func ParseBytes(dotBytes []byte) (*ast.Graph, error) {
lex := lexer.NewLexer(dotBytes)
parser := NewParser()
st, err := parser.Parse(lex)
if err != nil {
return nil, err
}
g, ok := st.(*ast.Graph)
if !ok {
panic(fmt.Sprintf("Parser did not return an *ast.Graph, but rather a %T", st))
}
return g, nil
}
//Parses a reader which contains a DOT string
//and outputs the abstract syntax tree representing the graph.
func Parse(r io.Reader) (*ast.Graph, error) {
bytes, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
return ParseBytes(bytes)
}
//Parses a file which contains a DOT string
//and outputs the abstract syntax tree representing the graph.
func ParseFile(filename string) (*ast.Graph, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
g, err := Parse(f)
if err := f.Close(); err != nil {
return nil, err
}
return g, err
}