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author | Valentin Rothberg <rothberg@redhat.com> | 2019-06-24 11:29:13 +0200 |
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committer | Valentin Rothberg <rothberg@redhat.com> | 2019-06-24 13:20:59 +0200 |
commit | d697456dc90adbaf68224ed7c115b38d5855e582 (patch) | |
tree | 5fd88c48b34e7bead0028fa97e39f43f03880642 /vendor/github.com/ijc/Gotty/parser.go | |
parent | a3211b73c62a9fcc13f09305bf629ef507b26d34 (diff) | |
download | podman-d697456dc90adbaf68224ed7c115b38d5855e582.tar.gz podman-d697456dc90adbaf68224ed7c115b38d5855e582.tar.bz2 podman-d697456dc90adbaf68224ed7c115b38d5855e582.zip |
migrate to go-modules
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'vendor/github.com/ijc/Gotty/parser.go')
-rw-r--r-- | vendor/github.com/ijc/Gotty/parser.go | 362 |
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) +} |