|
private SetPointer ( |
||
| newPosition | The new position of the character pointer ptr. | |
| return | ||
public override Expression Scan(ParseEngine engine)
{
var index = engine.Pointer;
var chars = engine.Characters;
if (ParseEngine.IsIdentifierStart(chars[index]))
{
index++;
while (index < chars.Length && ParseEngine.IsIdentifierPart(chars[index]))
{
index++;
}
var name = new String(chars, engine.Pointer, index - engine.Pointer);
if (engine.UseKeywords)
{
var keyword = engine.Elements.FindKeywordExpression(name, engine);
if (keyword != null)
{
return(keyword);
}
}
var exp = new SymbolExpression(engine, name);
engine.SetPointer(index);
return(exp);
}
return(null);
}
public override Expression Scan(ParseEngine engine)
{
var start = engine.Pointer;
var kw = new LetKeyword(engine.CurrentLine, engine.CurrentColumn, engine.Query);
engine.Advance(Token.Length);
kw.Length = engine.Pointer - start;
engine.Skip();
start = engine.Pointer;
kw.name = engine.Elements.FindExpression<SymbolExpression>().Scan(engine) as SymbolExpression;
if (kw.name == null)
{
engine.AddError(new YAMPVariableNameMissing(engine), kw);
return kw;
}
engine.SetPointer(start);
return kw;
}
public override Expression Scan(ParseEngine engine)
{
var start = engine.Pointer;
var kw = new LetKeyword(engine.CurrentLine, engine.CurrentColumn, engine.Query);
engine.Advance(Token.Length);
kw.Length = engine.Pointer - start;
engine.Skip();
start = engine.Pointer;
kw.name = Elements.Instance.FindExpression <SymbolExpression>().Scan(engine) as SymbolExpression;
if (kw.name == null)
{
engine.AddError(new YAMPVariableNameMissing(engine), kw);
return(kw);
}
engine.SetPointer(start);
return(kw);
}
public override Expression Scan(ParseEngine engine)
{
var start = engine.Pointer;
var chars = engine.Characters;
var ch = chars[start];
var isreal = false;
if (ParseEngine.IsNumber(ch) || (ch == '.' && start + 1 < chars.Length && ParseEngine.IsNumber(chars[start + 1])))
{
var index = start;
var exp = new NumberExpression(engine);
var number = 0.0;
var pow = 0;
if (ch != '.')
{
number += ToDoubleNumber(chars[index++]);
while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]))
{
number *= 10.0;
number += ToDoubleNumber(ch);
index++;
}
}
if (ch == '.')
{
isreal = true;
index++;
if (index < chars.Length && ParseEngine.IsNumber(chars[index]))
{
do
{
number *= 10.0;
number += ToDoubleNumber(chars[index++]);
pow++;
}while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]));
}
}
if (ch == 'e' || ch == 'E')
{
isreal = true;
var epow = 0;
var sign = 1;
index++;
if (index < chars.Length && (chars[index] == '+' || chars[index] == '-'))
{
sign = chars[index] == '-' ? -1 : +1;
index++;
}
while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]))
{
epow *= 10;
epow += ToInt32Number(ch);
index++;
}
pow -= epow * sign;
}
var value = number / Math.Pow(10.0, pow);
if (ch == 'i')
{
exp.value = new ScalarValue(0.0, value);
index++;
}
else if (isreal)
{
exp.value = new ScalarValue(value);
}
else
{
exp.value = new ScalarValue((int)value);
}
exp.Length = index - start;
engine.SetPointer(index);
return(exp);
}
return(null);
}
public override Expression Scan(ParseEngine engine)
{
var chars = engine.Characters;
var start = engine.Pointer;
if (chars[start] == '"' || (chars[start] == '@' && start + 1 < chars.Length && chars[start + 1] == '"'))
{
var index = start;
var exp = new StringExpression(engine);
var escape = false;
var terminated = false;
var sb = new StringBuilder();
if (chars[index] == '@')
{
index += 2;
exp.literal = true;
}
else
{
index++;
}
while (index < chars.Length)
{
if (!literal && !escape && chars[index] == '\\')
{
escape = true;
}
else if (!escape && chars[index] == '"')
{
terminated = true;
index++;
break;
}
else if (escape)
{
switch (chars[index])
{
case 't':
sb.Append("\t");
break;
case 'n':
sb.AppendLine();
break;
case '\\':
case '"':
sb.Append(chars[index]);
break;
default:
engine.SetPointer(index);
engine.AddError(new YAMPEscapeSequenceNotFoundError(engine, chars[index]), exp);
break;
}
escape = false;
}
else
{
sb.Append(chars[index]);
}
index++;
}
if (!terminated)
{
engine.AddError(new YAMPStringNotTerminatedError(engine), exp);
}
exp.value = sb.ToString();
exp.Length = index - start;
engine.SetPointer(index);
return exp;
}
return null;
}
public override Expression Scan(ParseEngine engine)
{
var chars = engine.Characters;
var start = engine.Pointer;
if (chars[start] == '"' || (chars[start] == '@' && start + 1 < chars.Length && chars[start + 1] == '"'))
{
var index = start;
var exp = new StringExpression(engine);
var escape = false;
var terminated = false;
var sb = new StringBuilder();
if (chars[index] == '@')
{
index += 2;
exp.literal = true;
}
else
{
index++;
}
while (index < chars.Length)
{
if (!literal && !escape && chars[index] == '\\')
{
escape = true;
}
else if (!escape && chars[index] == '"')
{
terminated = true;
index++;
break;
}
else if (escape)
{
switch (chars[index])
{
case 't':
sb.Append("\t");
break;
case 'n':
sb.AppendLine();
break;
case '\\':
case '"':
sb.Append(chars[index]);
break;
default:
engine.SetPointer(index);
engine.AddError(new YAMPEscapeSequenceNotFoundError(engine, chars[index]), exp);
break;
}
escape = false;
}
else
{
sb.Append(chars[index]);
}
index++;
}
if (!terminated)
{
engine.AddError(new YAMPStringNotTerminatedError(engine), exp);
}
exp.value = sb.ToString();
exp.Length = index - start;
engine.SetPointer(index);
return(exp);
}
return(null);
}
public override Expression Scan(ParseEngine engine)
{
var start = engine.Pointer;
var chars = engine.Characters;
var ch = chars[start];
var isreal = false;
if (ParseEngine.IsNumber(ch) || (ch == '.' && start + 1 < chars.Length && ParseEngine.IsNumber(chars[start + 1])))
{
var index = start;
var exp = new NumberExpression(engine);
var number = 0.0;
var pow = 0;
if (ch != '.')
{
number += ToDoubleNumber(chars[index++]);
while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]))
{
number *= 10.0;
number += ToDoubleNumber(ch);
index++;
}
}
if (ch == '.')
{
isreal = true;
index++;
if (index < chars.Length && ParseEngine.IsNumber(chars[index]))
{
do
{
number *= 10.0;
number += ToDoubleNumber(chars[index++]);
pow++;
}
while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]));
}
}
if (ch == 'e' || ch == 'E')
{
isreal = true;
var epow = 0;
var sign = 1;
index++;
if (index < chars.Length && (chars[index] == '+' || chars[index] == '-'))
{
sign = chars[index] == '-' ? -1 : +1;
index++;
}
while (index < chars.Length && ParseEngine.IsNumber(ch = chars[index]))
{
epow *= 10;
epow += ToInt32Number(ch);
index++;
}
pow -= epow * sign;
}
var value = number / Math.Pow(10.0, pow);
if (ch == 'i')
{
exp.value = new ScalarValue(0.0, value);
index++;
}
else if (isreal)
exp.value = new ScalarValue(value);
else
exp.value = new ScalarValue((int)value);
exp.Length = index - start;
engine.SetPointer(index);
return exp;
}
return null;
}
