public static List <PageFragment> ParseScript(this ScriptContext context, ReadOnlyMemory <char> text)
{
var to = new List <PageFragment>();
ScriptLanguage scriptLanguage = null;
ReadOnlyMemory <char> modifiers = default;
ReadOnlyMemory <char> prevBlock = default;
int startBlockPos = -1;
var cursorPos = 0;
var lastBlockPos = 0;
const int delim = 3; // '```'.length
while (text.TryReadLine(out var line, ref cursorPos))
{
var lineLength = line.Length;
line = line.AdvancePastWhitespace();
if (line.StartsWith("```"))
{
if (scriptLanguage != null && startBlockPos >= 0 && line.Slice(delim).AdvancePastWhitespace().IsEmpty) //is end block
{
var templateFragments = ScriptTemplate.Language.Parse(context, prevBlock);
to.AddRange(templateFragments);
var blockBody = text.ToLineStart(cursorPos, lineLength, startBlockPos);
var blockFragments = scriptLanguage.Parse(context, blockBody, modifiers);
to.AddRange(blockFragments);
prevBlock = default;
startBlockPos = -1;
scriptLanguage = null;
modifiers = null;
lastBlockPos = cursorPos;
continue;
}
if (line.SafeGetChar(delim).IsValidVarNameChar())
{
line = line.Slice(delim).ParseVarName(out var blockNameSpan);
var blockName = blockNameSpan.ToString();
scriptLanguage = context.GetScriptLanguage(blockName);
if (scriptLanguage == null)
{
continue;
}
modifiers = line.AdvancePastChar('|');
var delimLen = text.Span.SafeCharEquals(cursorPos - 2, '\r') ? 2 : 1;
prevBlock = text.Slice(lastBlockPos, cursorPos - lastBlockPos - lineLength - delimLen);
startBlockPos = cursorPos;
}
}
}
var remainingBlock = text.Slice(lastBlockPos);
if (!remainingBlock.IsEmpty)
{
var templateFragments = ScriptTemplate.Language.Parse(context, remainingBlock);
to.AddRange(templateFragments);
}
return(to);
}
internal static JsStatement[] ParseCodeStatements(this ScriptContext context, ReadOnlyMemory <char> code)
{
var to = new List <JsStatement>();
int startExpressionPos = -1;
var cursorPos = 0;
while (code.TryReadLine(out var line, ref cursorPos))
{
var lineLength = line.Length;
line = line.TrimStart();
var leftIndent = lineLength - line.Length;
line = line.TrimEnd();
var rightIndent = lineLength - leftIndent - line.Length;
if (line.IsEmpty)
{
continue;
}
var firstChar = line.Span[0];
// comments
if (firstChar == '*')
{
if (line.EndsWith("*"))
{
continue;
}
}
// template block statement
if (firstChar == '{' && line.Span.SafeCharEquals(1, '{') && line.Span.SafeCharEquals(2, '#'))
{
var fromLineStart = code.ToLineStart(cursorPos, lineLength).AdvancePastWhitespace();
var literal = fromLineStart.Slice(3);
literal = literal.ParseTemplateScriptBlock(context, out var blockFragment);
blockFragment.OriginalText = fromLineStart.Slice(0, fromLineStart.Length - literal.Length);
to.Add(new JsPageBlockFragmentStatement(blockFragment));
cursorPos = code.Length - literal.Length;
continue;
}
// code block statement
if (firstChar == '#')
{
var fromLineStart = code.ToLineStart(cursorPos, lineLength).AdvancePastWhitespace();
var literal = fromLineStart.Slice(1);
literal = literal.ParseCodeScriptBlock(context, out var blockFragment);
to.Add(new JsPageBlockFragmentStatement(blockFragment));
blockFragment.OriginalText = fromLineStart.Slice(0, fromLineStart.Length - literal.Length);
cursorPos = code.Length - literal.Length;
continue;
}
const int delim = 2; // '}}'.length
// multi-line expression
if (startExpressionPos >= 0)
{
// multi-line end
if (line.EndsWith("}}"))
{
if (code.Span.SafeCharEquals(startExpressionPos, '*'))
{
if (!line.EndsWith("*}}")) // not a closing block comment, continue
{
continue;
}
// ignore multi-line comment
}
else
{
var CRLF = code.Span.SafeCharEquals(cursorPos - 2, '\r') ? 2 : 1;
var exprStr = code.Slice(startExpressionPos, cursorPos - startExpressionPos - rightIndent - delim - CRLF).Trim();
var afterExpr = exprStr.Span.ParseExpression(out var expr, out var filters);
to.AddExpression(exprStr, expr, filters);
}
startExpressionPos = -1;
}
continue;
}
if (firstChar == '{' && line.Span.SafeCharEquals(1, '{'))
{
// single-line {{ expr }}
if (line.EndsWith("}}"))
{
var exprStr = code.Slice(cursorPos - lineLength + leftIndent + delim, lineLength - leftIndent - delim - delim).Trim();
var afterExpr = exprStr.Span.ParseExpression(out var expr, out var filters);
to.AddExpression(exprStr, expr, filters);
continue;
}
// multi-line start
var CRLF = code.Span.SafeCharEquals(cursorPos - 2, '\r') ? 2 : 1;
startExpressionPos = cursorPos - lineLength - CRLF + leftIndent + delim;
continue;
}
else
{
// treat line as an expression statement
var afterExpr = line.Span.ParseExpression(out var expr, out var filters);
afterExpr = afterExpr.AdvancePastWhitespace();
if (!afterExpr.IsEmpty)
{
throw new SyntaxErrorException($"Unexpected syntax after expression: {afterExpr.ToString()}, near {line.DebugLiteral()}");
}
to.AddExpression(line, expr, filters);
}
}
return(to.ToArray());
}