136 lines
3.7 KiB
Go
136 lines
3.7 KiB
Go
package parser
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import (
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"github.com/a-h/parse"
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"github.com/a-h/templ/parser/v2/goexpression"
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)
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var ifExpression ifExpressionParser
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var untilElseIfElseOrEnd = parse.Any(StripType(elseIfExpression), StripType(elseExpression), StripType(closeBraceWithOptionalPadding))
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type ifExpressionParser struct{}
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func (ifExpressionParser) Parse(pi *parse.Input) (n Node, ok bool, err error) {
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var r IfExpression
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start := pi.Index()
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if !peekPrefix(pi, "if ") {
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return r, false, nil
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}
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// Parse the Go if expression.
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if r.Expression, err = parseGo("if", pi, goexpression.If); err != nil {
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return r, false, err
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}
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// Eat " {\n".
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if _, ok, err = parse.All(openBraceWithOptionalPadding, parse.NewLine).Parse(pi); err != nil || !ok {
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err = parse.Error("if: "+unterminatedMissingCurly, pi.PositionAt(start))
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return
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}
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// Once we've had the start of an if block, we must conclude the block.
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// Read the 'Then' nodes.
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// If there's no match, there's a problem in the template nodes.
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np := newTemplateNodeParser(untilElseIfElseOrEnd, "else expression or closing brace")
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var thenNodes Nodes
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if thenNodes, ok, err = np.Parse(pi); err != nil || !ok {
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err = parse.Error("if: expected nodes, but none were found", pi.Position())
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return
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}
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r.Then = thenNodes.Nodes
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// Read the optional 'ElseIf' Nodes.
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if r.ElseIfs, _, err = parse.ZeroOrMore(elseIfExpression).Parse(pi); err != nil {
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return
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}
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// Read the optional 'Else' Nodes.
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var elseNodes Nodes
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if elseNodes, _, err = elseExpression.Parse(pi); err != nil {
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return
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}
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r.Else = elseNodes.Nodes
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// Read the required closing brace.
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if _, ok, err = closeBraceWithOptionalPadding.Parse(pi); err != nil || !ok {
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err = parse.Error("if: "+unterminatedMissingEnd, pi.Position())
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return
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}
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return r, true, nil
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}
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var elseIfExpression parse.Parser[ElseIfExpression] = elseIfExpressionParser{}
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type elseIfExpressionParser struct{}
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func (elseIfExpressionParser) Parse(pi *parse.Input) (r ElseIfExpression, ok bool, err error) {
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start := pi.Index()
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// Check the prefix first.
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if _, ok, err = parse.All(parse.OptionalWhitespace, closeBrace, parse.OptionalWhitespace, parse.String("else if")).Parse(pi); err != nil || !ok {
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pi.Seek(start)
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return
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}
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// Rewind to the start of the `if` statement.
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pi.Seek(pi.Index() - 2)
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// Parse the Go if expression.
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if r.Expression, err = parseGo("else if", pi, goexpression.If); err != nil {
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return r, false, err
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}
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// Eat " {\n".
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if _, ok, err = parse.All(openBraceWithOptionalPadding, parse.NewLine).Parse(pi); err != nil || !ok {
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err = parse.Error("else if: "+unterminatedMissingCurly, pi.PositionAt(start))
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return
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}
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// Once we've had the start of an if block, we must conclude the block.
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// Read the 'Then' nodes.
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// If there's no match, there's a problem in the template nodes.
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np := newTemplateNodeParser(untilElseIfElseOrEnd, "else expression or closing brace")
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var thenNodes Nodes
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if thenNodes, ok, err = np.Parse(pi); err != nil || !ok {
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err = parse.Error("if: expected nodes, but none were found", pi.Position())
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return
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}
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r.Then = thenNodes.Nodes
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return r, true, nil
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}
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var endElseParser = parse.All(
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parse.Rune('}'),
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parse.OptionalWhitespace,
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parse.String("else"),
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parse.OptionalWhitespace,
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parse.Rune('{'),
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parse.OptionalWhitespace)
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var elseExpression parse.Parser[Nodes] = elseExpressionParser{}
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type elseExpressionParser struct{}
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func (elseExpressionParser) Parse(in *parse.Input) (r Nodes, ok bool, err error) {
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start := in.Index()
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// } else {
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if _, ok, err = endElseParser.Parse(in); err != nil || !ok {
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in.Seek(start)
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return
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}
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// Else contents
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if r, ok, err = newTemplateNodeParser(closeBraceWithOptionalPadding, "else expression closing brace").Parse(in); err != nil || !ok {
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in.Seek(start)
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return
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}
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return r, true, nil
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}
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