From 13bfa731df53edbd6262a69587a6d50442b501f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Mart=C3=AD?= <mvdan@mvdan.cc>
Date: Sat, 16 Jan 2016 09:38:24 +0100
Subject: [PATCH] Initial commit

---
 LICENSE           | 27 ++++++++++++++
 README.md         |  3 ++
 parse.go          | 91 +++++++++++++++++++++++++++++++++++++++++++++++
 sh_test.go        | 31 ++++++++++++++++
 testdata/empty.sh |  0
 5 files changed, 152 insertions(+)
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100644 parse.go
 create mode 100644 sh_test.go
 create mode 100644 testdata/empty.sh

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 000000000..5babf241d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2015, Daniel Martí. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
index 000000000..4f53aeea0
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# sh
+
+A shell parser. Not yet usable.
diff --git a/parse.go b/parse.go
new file mode 100644
index 000000000..f2ef65a59
--- /dev/null
+++ b/parse.go
@@ -0,0 +1,91 @@
+// Copyright (c) 2016, Daniel Martí <mvdan@mvdan.cc>
+// See LICENSE for licensing information
+
+package sh
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+)
+
+const (
+	_ = -iota
+	EOF
+	IDENT
+)
+
+func parse(r io.Reader) error {
+	p := &parser{
+		r: bufio.NewReader(r),
+	}
+	return p.program()
+}
+
+type parser struct {
+	r   *bufio.Reader
+	tok int32
+}
+
+func isIdentChar(r rune) bool {
+	return r == '_' || (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z')
+}
+
+func (p *parser) next() error {
+	r, _, err := p.r.ReadRune()
+	if err == io.EOF {
+		p.tok = EOF
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	if r == ' ' {
+		return p.next()
+	}
+	if isIdentChar(r) {
+		for isIdentChar(r) {
+			r, _, err = p.r.ReadRune()
+			if err != nil {
+				return err
+			}
+		}
+		p.tok = IDENT
+		return nil
+	}
+	p.tok = r
+	return nil
+}
+
+func (p *parser) discardLine() error {
+	if _, err := p.r.ReadBytes('\n'); err != nil {
+		return err
+	}
+	return p.next()
+}
+
+func (p *parser) got(tok int32) bool {
+	if p.tok == tok {
+		p.next()
+		return true
+	}
+	return false
+}
+
+func (p *parser) program() error {
+	if err := p.next(); err != nil {
+		return err
+	}
+	for p.tok != EOF {
+		switch {
+		case p.got('#'):
+			if err := p.discardLine(); err != nil {
+				return err
+			}
+		case p.got(IDENT):
+		default:
+			return fmt.Errorf("unexpected token")
+		}
+	}
+	return nil
+}
diff --git a/sh_test.go b/sh_test.go
new file mode 100644
index 000000000..a09df86de
--- /dev/null
+++ b/sh_test.go
@@ -0,0 +1,31 @@
+// Copyright (c) 2016, Daniel Martí <mvdan@mvdan.cc>
+// See LICENSE for licensing information
+
+package sh
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+	paths, err := filepath.Glob("testdata/*.sh")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, path := range paths {
+		testParse(t, path)
+	}
+}
+
+func testParse(t *testing.T, path string) {
+	f, err := os.Open(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	if err := parse(f); err != nil {
+		t.Fatalf("Error in %s: %v", path, err)
+	}
+}
diff --git a/testdata/empty.sh b/testdata/empty.sh
new file mode 100644
index 000000000..e69de29bb