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author | Charlie Stanton <charlie@shtanton.xyz> | 2022-12-24 10:03:56 +0000 |
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committer | Charlie Stanton <charlie@shtanton.xyz> | 2022-12-24 10:03:56 +0000 |
commit | ce2db2bc333ed938ec93d5ad0838f8cb720c4865 (patch) | |
tree | 3478f894bd29875c2d4fb5247577d196883bab8a | |
parent | c19df3ff75e7693e38940f20a5f3b40931be424a (diff) | |
download | subex-ce2db2bc333ed938ec93d5ad0838f8cb720c4865.tar |
Remove the redundant regex implementation
-rw-r--r-- | main/parse.go | 51 | ||||
-rw-r--r-- | main/regexast.go | 92 | ||||
-rw-r--r-- | main/regexstate.go | 48 |
3 files changed, 0 insertions, 191 deletions
diff --git a/main/parse.go b/main/parse.go index 18941f2..59104c1 100644 --- a/main/parse.go +++ b/main/parse.go @@ -21,57 +21,6 @@ func parseReplacement(l *RuneReader) (output []TransducerOutput) { return output } -func parseRegex(l *RuneReader, minPower int) RegexAST { - var lhs RegexAST - r := l.next() - switch r { - case eof: - return nil - case ')', '*', '-', '|', '?', '!': - l.rewind() - return nil - case '(': - lhs = parseRegex(l, 0) - if !l.accept(")") { - panic("Missing matching )") - } - case '.': - lhs = RegexASTAny{} - default: - lhs = RegexASTRune(r) - } - loop: for { - if minPower <= 0 { - next := parseRegex(l, 1) - if next != nil { - lhs = RegexASTConcat{lhs, next} - continue loop - } - } - r := l.next() - switch { - case r == '*' && minPower <= 4: - lhs = RegexASTMaximise{lhs} - case r == '-' && minPower <= 4: - lhs = RegexASTMinimise{lhs} - case r == '!' && minPower <= 4: - lhs = RegexASTTry{lhs} - case r == '?' && minPower <= 4: - lhs = RegexASTMaybe{lhs} - case r == '|' && minPower <= 2: - rhs := parseRegex(l, 3) - if rhs == nil { - panic("Missing regex after |") - } - lhs = RegexASTOr{lhs, rhs} - default: - l.rewind() - break loop - } - } - return lhs -} - func parseSubex(l *RuneReader, minPower int) SubexAST { var lhs SubexAST r := l.next() diff --git a/main/regexast.go b/main/regexast.go deleted file mode 100644 index a5a60c4..0000000 --- a/main/regexast.go +++ /dev/null @@ -1,92 +0,0 @@ -package main - -import ( - "fmt" -) - -type RegexAST interface { - compileWith(next RegexState) RegexState -} - -type RegexASTRune rune -func (ast RegexASTRune) compileWith(next RegexState) RegexState { - return RegexRuneState{ - rune: rune(ast), - next: next, - } -} -func (ast RegexASTRune) String() string { - return string(rune(ast)) -} - -type RegexASTAny struct {} -func (ast RegexASTAny) compileWith(next RegexState) RegexState { - return RegexAnyState{next} -} -func (ast RegexASTAny) String() string { - return "." -} - -type RegexASTConcat struct { - first, second RegexAST -} -func (ast RegexASTConcat) compileWith(next RegexState) RegexState { - return ast.first.compileWith(ast.second.compileWith(next)) -} -func (ast RegexASTConcat) String() string { - return fmt.Sprintf("Concat{%v, %v}", ast.first, ast.second) -} - -type RegexASTOr struct { - first, second RegexAST -} -func (ast RegexASTOr) compileWith(next RegexState) RegexState { - return RegexGroupState{ - ast.first.compileWith(next), - ast.second.compileWith(next), - } -} - -type RegexASTMaximise struct { - content RegexAST -} -func (ast RegexASTMaximise) compileWith(next RegexState) RegexState { - state := &RegexGroupState{ - nil, - next, - } - state.first = ast.content.compileWith(state) - return state -} - -type RegexASTMinimise struct { - content RegexAST -} -func (ast RegexASTMinimise) compileWith(next RegexState) RegexState { - state := &RegexGroupState{ - next, - nil, - } - state.second = ast.content.compileWith(state) - return state -} - -type RegexASTTry struct { - content RegexAST -} -func (ast RegexASTTry) compileWith(next RegexState) RegexState { - return RegexGroupState{ - ast.content.compileWith(next), - next, - } -} - -type RegexASTMaybe struct { - content RegexAST -} -func (ast RegexASTMaybe) compileWith(next RegexState) RegexState { - return RegexGroupState { - next, - ast.content.compileWith(next), - } -} diff --git a/main/regexstate.go b/main/regexstate.go deleted file mode 100644 index 16d5581..0000000 --- a/main/regexstate.go +++ /dev/null @@ -1,48 +0,0 @@ -package main - -type RegexState interface { - eat(char rune) []RegexState - accepting() bool -} - -type RegexNoneState struct {} -func (state RegexNoneState) eat(char rune) []RegexState { - return nil -} -func (state RegexNoneState) accepting() bool { - return true -} - -type RegexAnyState struct { - next RegexState -} -func (state RegexAnyState) eat(char rune) []RegexState { - return []RegexState{state.next} -} -func (state RegexAnyState) accepting() bool { - return false -} - -type RegexRuneState struct { - rune rune - next RegexState -} -func (state RegexRuneState) eat(char rune) []RegexState { - if char == state.rune { - return []RegexState{state.next} - } - return nil -} -func (state RegexRuneState) accepting() bool { - return false -} - -type RegexGroupState struct { - first, second RegexState -} -func (state RegexGroupState) eat(char rune) []RegexState { - return append(state.first.eat(char), state.second.eat(char)...) -} -func (state RegexGroupState) accepting() bool { - return state.first.accepting() || state.second.accepting() -} |