init

vendor/github.com/awalterschulze/gographviz/internal/parser/main.go

@@ -0,0 +1,72 @@
+//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
+}