Merge pull request #3414 from vrothberg/go-modules

Go modules

1 files changed, 362 insertions, 0 deletions

diff --git a/vendor/github.com/ijc/Gotty/parser.go b/vendor/github.com/ijc/Gotty/parser.go
new file mode 100644
index 000000000..a9d5d23c5
--- /dev/null
+++ b/vendor/github.com/ijc/Gotty/parser.go
@@ -0,0 +1,362 @@
+// Copyright 2012 Neal van Veen. All rights reserved.
+// Usage of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package gotty
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var exp = [...]string{
+	"%%",
+	"%c",
+	"%s",
+	"%p(\\d)",
+	"%P([A-z])",
+	"%g([A-z])",
+	"%'(.)'",
+	"%{([0-9]+)}",
+	"%l",
+	"%\\+|%-|%\\*|%/|%m",
+	"%&|%\\||%\\^",
+	"%=|%>|%<",
+	"%A|%O",
+	"%!|%~",
+	"%i",
+	"%(:[\\ #\\-\\+]{0,4})?(\\d+\\.\\d+|\\d+)?[doxXs]",
+	"%\\?(.*?);",
+}
+
+var regex *regexp.Regexp
+var staticVar map[byte]stacker
+
+// Parses the attribute that is received with name attr and parameters params.
+func (term *TermInfo) Parse(attr string, params ...interface{}) (string, error) {
+	// Get the attribute name first.
+	iface, err := term.GetAttribute(attr)
+	str, ok := iface.(string)
+	if err != nil {
+		return "", err
+	}
+	if !ok {
+		return str, errors.New("Only string capabilities can be parsed.")
+	}
+	// Construct the hidden parser struct so we can use a recursive stack based
+	// parser.
+	ps := &parser{}
+	// Dynamic variables only exist in this context.
+	ps.dynamicVar = make(map[byte]stacker, 26)
+	ps.parameters = make([]stacker, len(params))
+	// Convert the parameters to insert them into the parser struct.
+	for i, x := range params {
+		ps.parameters[i] = x
+	}
+	// Recursively walk and return.
+	result, err := ps.walk(str)
+	return result, err
+}
+
+// Parses the attribute that is received with name attr and parameters params.
+// Only works on full name of a capability that is given, which it uses to
+// search for the termcap name.
+func (term *TermInfo) ParseName(attr string, params ...interface{}) (string, error) {
+	tc := GetTermcapName(attr)
+	return term.Parse(tc, params)
+}
+
+// Identify each token in a stack based manner and do the actual parsing.
+func (ps *parser) walk(attr string) (string, error) {
+	// We use a buffer to get the modified string.
+	var buf bytes.Buffer
+	// Next, find and identify all tokens by their indices and strings.
+	tokens := regex.FindAllStringSubmatch(attr, -1)
+	if len(tokens) == 0 {
+		return attr, nil
+	}
+	indices := regex.FindAllStringIndex(attr, -1)
+	q := 0 // q counts the matches of one token
+	// Iterate through the string per character.
+	for i := 0; i < len(attr); i++ {
+		// If the current position is an identified token, execute the following
+		// steps.
+		if q < len(indices) && i >= indices[q][0] && i < indices[q][1] {
+			// Switch on token.
+			switch {
+			case tokens[q][0][:2] == "%%":
+				// Literal percentage character.
+				buf.WriteByte('%')
+			case tokens[q][0][:2] == "%c":
+				// Pop a character.
+				c, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				buf.WriteByte(c.(byte))
+			case tokens[q][0][:2] == "%s":
+				// Pop a string.
+				str, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				if _, ok := str.(string); !ok {
+					return buf.String(), errors.New("Stack head is not a string")
+				}
+				buf.WriteString(str.(string))
+			case tokens[q][0][:2] == "%p":
+				// Push a parameter on the stack.
+				index, err := strconv.ParseInt(tokens[q][1], 10, 8)
+				index--
+				if err != nil {
+					return buf.String(), err
+				}
+				if int(index) >= len(ps.parameters) {
+					return buf.String(), errors.New("Parameters index out of bound")
+				}
+				ps.st.push(ps.parameters[index])
+			case tokens[q][0][:2] == "%P":
+				// Pop a variable from the stack as a dynamic or static variable.
+				val, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				index := tokens[q][2]
+				if len(index) > 1 {
+					errorStr := fmt.Sprintf("%s is not a valid dynamic variables index",
+						index)
+					return buf.String(), errors.New(errorStr)
+				}
+				// Specify either dynamic or static.
+				if index[0] >= 'a' && index[0] <= 'z' {
+					ps.dynamicVar[index[0]] = val
+				} else if index[0] >= 'A' && index[0] <= 'Z' {
+					staticVar[index[0]] = val
+				}
+			case tokens[q][0][:2] == "%g":
+				// Push a variable from the stack as a dynamic or static variable.
+				index := tokens[q][3]
+				if len(index) > 1 {
+					errorStr := fmt.Sprintf("%s is not a valid static variables index",
+						index)
+					return buf.String(), errors.New(errorStr)
+				}
+				var val stacker
+				if index[0] >= 'a' && index[0] <= 'z' {
+					val = ps.dynamicVar[index[0]]
+				} else if index[0] >= 'A' && index[0] <= 'Z' {
+					val = staticVar[index[0]]
+				}
+				ps.st.push(val)
+			case tokens[q][0][:2] == "%'":
+				// Push a character constant.
+				con := tokens[q][4]
+				if len(con) > 1 {
+					errorStr := fmt.Sprintf("%s is not a valid character constant", con)
+					return buf.String(), errors.New(errorStr)
+				}
+				ps.st.push(con[0])
+			case tokens[q][0][:2] == "%{":
+				// Push an integer constant.
+				con, err := strconv.ParseInt(tokens[q][5], 10, 32)
+				if err != nil {
+					return buf.String(), err
+				}
+				ps.st.push(con)
+			case tokens[q][0][:2] == "%l":
+				// Push the length of the string that is popped from the stack.
+				popStr, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				if _, ok := popStr.(string); !ok {
+					errStr := fmt.Sprintf("Stack head is not a string")
+					return buf.String(), errors.New(errStr)
+				}
+				ps.st.push(len(popStr.(string)))
+			case tokens[q][0][:2] == "%?":
+				// If-then-else construct. First, the whole string is identified and
+				// then inside this substring, we can specify which parts to switch on.
+				ifReg, _ := regexp.Compile("%\\?(.*)%t(.*)%e(.*);|%\\?(.*)%t(.*);")
+				ifTokens := ifReg.FindStringSubmatch(tokens[q][0])
+				var (
+					ifStr string
+					err   error
+				)
+				// Parse the if-part to determine if-else.
+				if len(ifTokens[1]) > 0 {
+					ifStr, err = ps.walk(ifTokens[1])
+				} else { // else
+					ifStr, err = ps.walk(ifTokens[4])
+				}
+				// Return any errors
+				if err != nil {
+					return buf.String(), err
+				} else if len(ifStr) > 0 {
+					// Self-defined limitation, not sure if this is correct, but didn't
+					// seem like it.
+					return buf.String(), errors.New("If-clause cannot print statements")
+				}
+				var thenStr string
+				// Pop the first value that is set by parsing the if-clause.
+				choose, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				// Switch to if or else.
+				if choose.(int) == 0 && len(ifTokens[1]) > 0 {
+					thenStr, err = ps.walk(ifTokens[3])
+				} else if choose.(int) != 0 {
+					if len(ifTokens[1]) > 0 {
+						thenStr, err = ps.walk(ifTokens[2])
+					} else {
+						thenStr, err = ps.walk(ifTokens[5])
+					}
+				}
+				if err != nil {
+					return buf.String(), err
+				}
+				buf.WriteString(thenStr)
+			case tokens[q][0][len(tokens[q][0])-1] == 'd': // Fallthrough for printing
+				fallthrough
+			case tokens[q][0][len(tokens[q][0])-1] == 'o': // digits.
+				fallthrough
+			case tokens[q][0][len(tokens[q][0])-1] == 'x':
+				fallthrough
+			case tokens[q][0][len(tokens[q][0])-1] == 'X':
+				fallthrough
+			case tokens[q][0][len(tokens[q][0])-1] == 's':
+				token := tokens[q][0]
+				// Remove the : that comes before a flag.
+				if token[1] == ':' {
+					token = token[:1] + token[2:]
+				}
+				digit, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				// The rest is determined like the normal formatted prints.
+				digitStr := fmt.Sprintf(token, digit.(int))
+				buf.WriteString(digitStr)
+			case tokens[q][0][:2] == "%i":
+				// Increment the parameters by one.
+				if len(ps.parameters) < 2 {
+					return buf.String(), errors.New("Not enough parameters to increment.")
+				}
+				val1, val2 := ps.parameters[0].(int), ps.parameters[1].(int)
+				val1++
+				val2++
+				ps.parameters[0], ps.parameters[1] = val1, val2
+			default:
+				// The rest of the tokens is a special case, where two values are
+				// popped and then operated on by the token that comes after them.
+				op1, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				op2, err := ps.st.pop()
+				if err != nil {
+					return buf.String(), err
+				}
+				var result stacker
+				switch tokens[q][0][:2] {
+				case "%+":
+					// Addition
+					result = op2.(int) + op1.(int)
+				case "%-":
+					// Subtraction
+					result = op2.(int) - op1.(int)
+				case "%*":
+					// Multiplication
+					result = op2.(int) * op1.(int)
+				case "%/":
+					// Division
+					result = op2.(int) / op1.(int)
+				case "%m":
+					// Modulo
+					result = op2.(int) % op1.(int)
+				case "%&":
+					// Bitwise AND
+					result = op2.(int) & op1.(int)
+				case "%|":
+					// Bitwise OR
+					result = op2.(int) | op1.(int)
+				case "%^":
+					// Bitwise XOR
+					result = op2.(int) ^ op1.(int)
+				case "%=":
+					// Equals
+					result = op2 == op1
+				case "%>":
+					// Greater-than
+					result = op2.(int) > op1.(int)
+				case "%<":
+					// Lesser-than
+					result = op2.(int) < op1.(int)
+				case "%A":
+					// Logical AND
+					result = op2.(bool) && op1.(bool)
+				case "%O":
+					// Logical OR
+					result = op2.(bool) || op1.(bool)
+				case "%!":
+					// Logical complement
+					result = !op1.(bool)
+				case "%~":
+					// Bitwise complement
+					result = ^(op1.(int))
+				}
+				ps.st.push(result)
+			}
+
+			i = indices[q][1] - 1
+			q++
+		} else {
+			// We are not "inside" a token, so just skip until the end or the next
+			// token, and add all characters to the buffer.
+			j := i
+			if q != len(indices) {
+				for !(j >= indices[q][0] && j < indices[q][1]) {
+					j++
+				}
+			} else {
+				j = len(attr)
+			}
+			buf.WriteString(string(attr[i:j]))
+			i = j
+		}
+	}
+	// Return the buffer as a string.
+	return buf.String(), nil
+}
+
+// Push a stacker-value onto the stack.
+func (st *stack) push(s stacker) {
+	*st = append(*st, s)
+}
+
+// Pop a stacker-value from the stack.
+func (st *stack) pop() (stacker, error) {
+	if len(*st) == 0 {
+		return nil, errors.New("Stack is empty.")
+	}
+	newStack := make(stack, len(*st)-1)
+	val := (*st)[len(*st)-1]
+	copy(newStack, (*st)[:len(*st)-1])
+	*st = newStack
+	return val, nil
+}
+
+// Initialize regexes and the static vars (that don't get changed between
+// calls.
+func init() {
+	// Initialize the main regex.
+	expStr := strings.Join(exp[:], "|")
+	regex, _ = regexp.Compile(expStr)
+	// Initialize the static variables.
+	staticVar = make(map[byte]stacker, 26)
+}