func CompileRoot(node lexer.ASTNode) (regexps []Regexp, scope Scope, err error) {
if !node.IsCommandType(0) {
panic("Expecting root node")
}
regexps = make([]Regexp, 0)
scope = NewScope()
for _, child := range node.Children() {
command := child.Command()
switch command.Type {
case lexer.CmdAliasDefinition:
if scope, err = DefineAlias(*child, scope); err != nil {
return regexps, scope, err
}
case lexer.CmdXExpression:
regexp, scope, err := CompileExpression(*child, scope)
if err != nil {
return regexps, scope, err
}
regexps = append(regexps, regexp)
}
}
return regexps, scope, err
}
func DefineAlias(node lexer.ASTNode, scope Scope) (parentScope Scope, err error) {
if !node.IsCommandType(lexer.CmdAliasDefinition) {
panic("Expecting alias definition command")
}
scope.Aliases[node.Command().Comment] = node
return scope, nil
}
func compileExamples(node lexer.ASTNode, scope Scope) (output string, parentScope Scope, err error) {
if !node.IsCommandType(lexer.CmdExample) {
panic("Expecting example command")
}
for _, child := range node.Children() {
command := child.Command()
switch command.Type {
case lexer.CmdExampleMatch:
scope.CurrentRegexp.Examples = append(scope.CurrentRegexp.Examples, NewExample(true, command.Comment, child.Line()))
case lexer.CmdExampleNonMatch:
scope.CurrentRegexp.Examples = append(scope.CurrentRegexp.Examples, NewExample(false, command.Comment, child.Line()))
}
}
return "", scope, nil
}
func compileSelect(node lexer.ASTNode, scope Scope) (output string, parentScope Scope, err error) {
cases := make([]string, len(node.Children()))
for i, child := range node.Children() {
if !child.IsCommandType(lexer.CmdCase) {
return "", scope, child.Line().Error("Only 'Case' statements are valid inside a 'Select' statement")
}
if cases[i], scope, err = compileNodeChildren(*child, scope); err != nil {
return "", scope, err
}
}
// Join the cases with pipes and put it all into a non-capture group
output = fmt.Sprintf("(?:%s)", strings.Join(cases, "|"))
return output, scope, nil
}
func CompileExpression(node lexer.ASTNode, scope Scope) (regexp Regexp, parentScope Scope, err error) {
output := ""
if !node.IsCommandType(lexer.CmdXExpression) {
panic("Compile should be passed an XExpression node only")
}
// List of examples should be isolated in this expression's scope
scope.CurrentRegexp = NewRegexp()
output, scope, err = compileNodeChildren(node, scope)
// The name of the regexp is the comment on the XExpression command
scope.CurrentRegexp.TextName = node.Command().Comment
scope.CurrentRegexp.Source = node.Line().String()
// Run tests on the examples
for _, example := range scope.CurrentRegexp.Examples {
pass := example.Run(output)
if pass {
fmt.Fprintf(os.Stderr, " ✔ Match test passed on %s\n", example.Line.String())
} else {
fmt.Fprintf(os.Stderr, " ✕ Match test failed for\n\t%s\non %s\n", example.Text, example.Line.String())
}
}
scope.CurrentRegexp.RegexpText = output
return scope.CurrentRegexp, scope, err
}
func compileLiteral(node lexer.ASTNode, scope Scope) (output string, parentScope Scope, err error) {
if !node.IsCommandType(lexer.CmdLiteral) {
panic("Expecting literal command")
}
// Directly copy the regexp literal
output = node.Command().Value
// Scan for any capture groups in the literal and increment our reference
literalRegexp, err := syntax.Parse(output, syntax.Perl)
if err != nil {
return output, scope, err
}
numCaptureGroups := len(literalRegexp.CapNames())
// Don't count the full literal regexp as a capture
if numCaptureGroups > 1 {
scope.CurrentRegexp.IncrementCaptureGroup(numCaptureGroups - 1)
}
return output, scope, err
}
func compileNodeChildren(node lexer.ASTNode, scope Scope) (output string, parentScope Scope, err error) {
for _, child := range node.Children() {
childOutput := ""
command := child.Command()
switch child.Command().Type {
case lexer.CmdDescription:
scope.CurrentRegexp.Description = command.Comment
case lexer.CmdLiteral:
if childOutput, scope, err = compileLiteral(*child, scope); err != nil {
return "", scope, child.Line().Error(err.Error())
}
case lexer.CmdAliasCall:
if childOutput, err = callAlias(command.Value, scope); err != nil {
return "", scope, child.Line().Error(err.Error())
}
case lexer.CmdGroup:
if childOutput, scope, err = compileGroup(*child, scope); err != nil {
return "", scope, err
}
case lexer.CmdSelect:
if childOutput, scope, err = compileSelect(*child, scope); err != nil {
return "", scope, err
}
case lexer.CmdExample:
if childOutput, scope, err = compileExamples(*child, scope); err != nil {
return "", scope, err
}
default:
if childOutput, scope, err = compileNodeChildren(*child, scope); err != nil {
return "", scope, err
}
}
output += childOutput
}
return output, scope, nil
}
func compileGroup(node lexer.ASTNode, scope Scope) (output string, parentScope Scope, err error) {
if !node.IsCommandType(lexer.CmdGroup) {
panic("Expected Group node")
}
preventCapture := "?:"
if node.Command().Params == "Capture" {
preventCapture = ""
scope.CurrentRegexp.AddCaptureGroup(node.Command().Comment, "")
}
childOutput, scope, err := compileNodeChildren(node, scope)
if err != nil {
return "", scope, err
}
output = fmt.Sprintf("(%s%s)", preventCapture, childOutput)
return output, scope, err
}