public Parser(Lexer lex)
{
if (lex == null) throw new ArgumentNullException("lex");
this.lex = lex;
this.tok = null;
}
public ListExpr(Token start, Token end, params SExpr[] items)
: base(SExprKind.List, start, end)
{
Items = items;
}
public NullExpr(Token token)
: base(SExprKind.Null, token, token)
{
if (token.Type != TokenType.Null) throw new ArgumentException("token must be of type Null for a NullExpr");
}
public InvocationExpr(Token start, Token end, IdentifierExpr identifier, params SExpr[] parameters)
: base(SExprKind.Invocation, start, end)
{
Identifier = identifier;
Parameters = parameters;
}
public Token Next()
{
// Only read the first char on the first call to Next():
if (c == -2) c = Read();
do
{
// EOF:
if (c == -1 || c == 0) return new Token(pos, TokenType.EOF, null);
// Skip whitespace (commas are whitespace too):
if (c == ' ' || c == '\t' || c == ',' || c == '\n' || c == '\r')
{
c = Read();
continue;
}
// TODO(jsd): comments!
// Curlies and parens are equivalent in this LISP:
if (c == (int)'(' || c == (int)'{')
{
var tok = new Token(lpos, TokenType.ParenOpen, ((char)c).ToString());
c = Read();
return tok;
}
else if (c == (int)')' || c == (int)'}')
{
var tok = new Token(lpos, TokenType.ParenClose, ((char)c).ToString());
c = Read();
return tok;
}
// Square brackets denote plain lists of data, not to be eval'd:
else if (c == (int)'[')
{
var tok = new Token(lpos, TokenType.BracketOpen, ((char)c).ToString());
c = Read();
return tok;
}
else if (c == (int)']')
{
var tok = new Token(lpos, TokenType.BracketClose, ((char)c).ToString());
c = Read();
return tok;
}
// Punctuation:
else if (c == (int)'~')
{
var tok = new Token(lpos, TokenType.Quote, ((char)c).ToString());
c = Read();
return tok;
}
else if (c == '.')
{
var tok = new Token(lpos, TokenType.Dot, ((char)c).ToString());
c = Read();
return tok;
}
else if (c == '/')
{
var tok = new Token(lpos, TokenType.Slash, ((char)c).ToString());
c = Read();
return tok;
}
// Keywords or unquoted strings:
else if (Char.IsLetter((char)c) || c == '_')
{
// Parse an unquoted string ([A-Za-z_][A-Za-z0-9\-_]*):
int spos = lpos;
var sb = new StringBuilder(10);
do
{
sb.Append((char)c);
c = Read();
if (c == -1) break;
} while (Char.IsLetterOrDigit((char)c) || c == '-' || c == '_');
var ident = sb.ToString();
if (String.Equals(ident, "true"))
return new Token(spos, TokenType.Boolean, ident);
else if (String.Equals(ident, "false"))
return new Token(spos, TokenType.Boolean, ident);
else if (String.Equals(ident, "null"))
return new Token(spos, TokenType.Null, ident);
else
return new Token(spos, TokenType.Identifier, sb.ToString());
}
// Quoted string literals:
else if (c == (int)'\'')
{
int spos = lpos;
var sb = new StringBuilder(10);
do
{
c = Read();
if (c == -1) return new Token(pos, TokenType.Error, "Unexpected end");
else if (c == '\'') break;
else if (c == '\\')
{
c = Read();
if (c == -1) return new Token(pos, TokenType.Error, "Unexpected end");
else if (c == '\'') sb.Append('\'');
else if (c == '\\') sb.Append('\\');
else if (c == 'n') sb.Append('\n');
else if (c == 'r') sb.Append('\r');
else if (c == 't') sb.Append('\t');
else return new Token(pos, TokenType.Error, "Unknown backslash escape character '{0}'".F((char)c));
}
else sb.Append((char)c);
} while (true);
c = Read();
return new Token(spos, TokenType.String, sb.ToString());
}
// Raw string literals:
else if (c == (int)'`')
{
int spos = lpos;
var sb = new StringBuilder(10);
do
{
c = Read();
if (c == -1) return new Token(pos, TokenType.Error, "Unexpected end");
// TODO(jsd): Any escape sequences?
else if (c == '`') break;
else sb.Append((char)c);
} while (true);
c = Read();
return new Token(spos, TokenType.String, sb.ToString());
}
// Numerics:
else if (Char.IsDigit((char)c) || c == '-')
{
// Simple/stupid numeric parser [0-9]+(\.[0-9]+)?:
int spos = lpos;
bool hasDecimal = false;
var sb = new StringBuilder(10);
do
{
sb.Append((char)c);
c = Read();
if (c == -1) break;
if (c == '.')
hasDecimal = true;
} while (Char.IsDigit((char)c) || c == '.');
// Determine the type of number by suffix or presence of decimal point:
var type = TokenType.Integer;
if (c == 'd')
{
c = Read();
type = TokenType.Double;
}
else if (c == 'f')
{
c = Read();
type = TokenType.Float;
}
else if (hasDecimal)
{
// Default to decimal type if have a decimal point:
type = TokenType.Decimal;
}
return new Token(spos, type, sb.ToString());
}
else
{
return new Token(lpos, TokenType.Error, "Unexpected character '{0}'".F((char)c));
}
} while (c != -1);
return new Token(pos, TokenType.EOF, null);
}
public ParserError(Token where, string message)
: base(SExprKind.Error, where, where)
{
Message = message;
}
public ScopedIdentifierExpr(Token ident)
: base(SExprKind.ScopedIdentifier, ident, ident)
{
Name = ident;
}
public FloatExpr(Token token, float value)
: base(SExprKind.Float, token, token)
{
if (token.Type != TokenType.Float) throw new ArgumentException("token must be of type Float for a FloatExpr");
Value = value;
}
protected IdentifierExpr(SExprKind kind, Token start, Token end)
: base(kind, start, end)
{
}
public StringExpr(Token token)
: base(SExprKind.String, token, token)
{
if (token.Type != TokenType.String) throw new ArgumentException("token must be of type String for a StringExpr");
Value = token.Text;
}
public DoubleExpr(Token token, double value)
: base(SExprKind.Double, token, token)
{
if (token.Type != TokenType.Double) throw new ArgumentException("token must be of type Double for a DoubleExpr");
Value = value;
}
public StaticMemberIdentifierExpr(Token[] @typeName, Token ident)
: base(SExprKind.StaticMemberIdentifier, @typeName[0], ident)
{
TypeName = @typeName;
Name = ident;
}
public DecimalExpr(Token token, decimal value)
: base(SExprKind.Decimal, token, token)
{
if (token.Type != TokenType.Decimal) throw new ArgumentException("token must be of type Decimal for a DecimalExpr");
Value = value;
}
protected SExpr(SExprKind kind, Token start, Token end)
{
Kind = kind;
StartToken = start;
EndToken = end;
}
public BooleanExpr(Token token, bool value)
: base(SExprKind.Boolean, token, token)
{
if (token.Type != TokenType.Boolean) throw new ArgumentException("token must be of type Boolean for a BooleanExpr");
Value = value;
}
public InstanceMemberIdentifierExpr(Token dot, Token ident)
: base(SExprKind.InstanceMemberIdentifier, dot, ident)
{
Name = ident;
}
void Next()
{
if (hold)
{
hold = false;
return;
}
tok = lex.Next();
if (tok.Type == TokenType.EOF) next = new ParserError(tok, "Unexpected end");
else if (tok.Type == TokenType.Error) next = new ParserError(tok, tok.Text);
else next = tok;
}
public IntegerExpr(Token token, long value)
: base(SExprKind.Integer, token, token)
{
if (token.Type != TokenType.Integer) throw new ArgumentException("token must be of type Integer for an IntegerExpr");
Value = value;
}
public ParserException(Token tok, string message)
: base("MiniLISP error(pos {0}): {1}".F(tok.Position, message))
{
Token = tok;
}
public QuoteExpr(Token start, Token end, SExpr sexpr)
: base(SExprKind.Quote, start, end)
{
SExpr = sexpr;
}