65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
package cmdlang
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import (
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"io"
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"github.com/alecthomas/participle/v2"
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"github.com/alecthomas/participle/v2/lexer"
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)
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type astLiteral struct {
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Str *string `parser:"@String"`
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}
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type astBlock struct {
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Statements []*astStatements `parser:"LC NL? @@ NL? RC"`
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}
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type astCmdArg struct {
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Literal *astLiteral `parser:"@@"`
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Ident *string `parser:"| @Ident"`
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Var *string `parser:"| DOLLAR @Ident"`
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Sub *astPipeline `parser:"| LP @@ RP"`
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Block *astBlock `parser:"| @@"`
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}
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type astCmd struct {
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Name string `parser:"@Ident"`
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Args []astCmdArg `parser:"@@*"`
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}
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type astPipeline struct {
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First *astCmd `parser:"@@"`
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Rest []*astCmd `parser:"( PIPE @@ )*"`
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}
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type astStatements struct {
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First *astPipeline `parser:"@@"`
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Rest []*astPipeline `parser:"( NL+ @@ )*"` // TODO: also add support for newlines
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}
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type astScript struct {
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Statements *astStatements `parser:"NL* @@ NL*"`
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}
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var scanner = lexer.MustStateful(lexer.Rules{
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"Root": {
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{"Whitespace", `[ \t]+`, nil},
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{"String", `"(\\"|[^"])*"`, nil},
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{"DOLLAR", `\$`, nil},
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{"LP", `\(`, nil},
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{"RP", `\)`, nil},
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{"LC", `\{`, nil},
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{"RC", `\}`, nil},
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{"NL", `[;\n][; \n\t]*`, nil},
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{"PIPE", `\|`, nil},
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{"Ident", `[\w-]+`, nil},
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},
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})
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var parser = participle.MustBuild[astScript](participle.Lexer(scanner),
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participle.Elide("Whitespace"))
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func parse(r io.Reader) (*astScript, error) {
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return parser.Parse("test", r)
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}
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