114 lines
3.2 KiB
Go
114 lines
3.2 KiB
Go
// Copyright 2023-2024 Dolthub, Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package utils
|
|
|
|
// TokenType is the type of the token.
|
|
type TokenType uint8
|
|
|
|
const (
|
|
TokenType_Text TokenType = iota
|
|
TokenType_Variable
|
|
TokenType_VariableDefinition
|
|
TokenType_Or
|
|
TokenType_Repeat
|
|
TokenType_OptionalRepeat
|
|
TokenType_ShortSpace
|
|
TokenType_MediumSpace
|
|
TokenType_LongSpace
|
|
TokenType_ParenOpen
|
|
TokenType_ParenClose
|
|
TokenType_OptionalOpen
|
|
TokenType_OptionalClose
|
|
TokenType_OneOfOpen
|
|
TokenType_OneOfClose
|
|
TokenType_EOF
|
|
)
|
|
|
|
// Token represents a token in the synopsis. Unlike with traditional lexers, whitespace is tokenized, with multiple
|
|
// token types for differing lengths, as the whitespace has some significance to the definition.
|
|
type Token struct {
|
|
Type TokenType
|
|
Literal string
|
|
}
|
|
|
|
// IsSpace returns whether the token represents one of the space types.
|
|
func (t Token) IsSpace() bool {
|
|
return t.Type == TokenType_ShortSpace || t.Type == TokenType_MediumSpace || t.Type == TokenType_LongSpace
|
|
}
|
|
|
|
// IsStandardSpace returns whether the token represents a short or medium space, which will not end a statement.
|
|
func (t Token) IsStandardSpace() bool {
|
|
return t.Type == TokenType_ShortSpace || t.Type == TokenType_MediumSpace
|
|
}
|
|
|
|
// IsNewStatement returns whether the token represents one a long space, which will end a statement
|
|
func (t Token) IsNewStatement() bool {
|
|
return t.Type == TokenType_LongSpace
|
|
}
|
|
|
|
// CreatesNewScope returns whether the token creates a new scope.
|
|
func (t Token) CreatesNewScope() bool {
|
|
return t.Type == TokenType_ParenOpen || t.Type == TokenType_OptionalOpen || t.Type == TokenType_OneOfOpen
|
|
}
|
|
|
|
// ExitsScope returns whether the token exits the current scope.
|
|
func (t Token) ExitsScope() bool {
|
|
return t.Type == TokenType_ParenClose || t.Type == TokenType_OptionalClose || t.Type == TokenType_OneOfClose
|
|
}
|
|
|
|
// String returns a string representation of the token.
|
|
func (t Token) String() string {
|
|
switch t.Type {
|
|
case TokenType_Text:
|
|
return t.Literal
|
|
case TokenType_Variable:
|
|
return "$" + t.Literal + "$"
|
|
case TokenType_VariableDefinition:
|
|
return "where $" + t.Literal + "$ is:"
|
|
case TokenType_Or:
|
|
return "|"
|
|
case TokenType_Repeat:
|
|
return "..."
|
|
case TokenType_OptionalRepeat:
|
|
if len(t.Literal) > 0 {
|
|
return "[ " + t.Literal + " ... ]"
|
|
} else {
|
|
return "[ ... ]"
|
|
}
|
|
case TokenType_ShortSpace:
|
|
return " "
|
|
case TokenType_MediumSpace:
|
|
return "\n "
|
|
case TokenType_LongSpace:
|
|
return "\n\n"
|
|
case TokenType_ParenOpen:
|
|
return "("
|
|
case TokenType_ParenClose:
|
|
return ")"
|
|
case TokenType_OptionalOpen:
|
|
return "["
|
|
case TokenType_OptionalClose:
|
|
return "]"
|
|
case TokenType_OneOfOpen:
|
|
return "{"
|
|
case TokenType_OneOfClose:
|
|
return "}"
|
|
case TokenType_EOF:
|
|
return ""
|
|
default:
|
|
panic("unexpected token type")
|
|
}
|
|
}
|