README
¶
Glean is a parser generator for the Go programming language. It scans .go files to find the rules of a grammar, and writes a parser in Go.
The parser generator can be found in the glean subdirectory of this directory.
Documentation
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Overview ¶
Package glean contains useful utilities for parser generators.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ScanDir ¶
ScanDir searches for grammar rules in the .go files in a directory
Files named *_test.go are ignored. For each rule found, rules.AddRule is called. All the files must belong to the same package; the name of that package is the first returned value.
Types ¶
type Grammar ¶
type Grammar interface {
RuleAdder
ParserWriter
}
A Grammar can accumulate rules and write a parser.
type ParserWriter ¶
type ParserWriter interface {
// ParserWriter writes a grammar parser in Go.
//
// Typically, the caller will write the result into a .go file,
// with a comment marking the file as automatically generated.
//
// The goal argument is the goal symbol that will be the result
// of the parse. The parse function will have the signature
//
// func ([]interface{}) (goal, error)
//
// The packname argument is copied to the package statment in the
// generated code. The prefix is prepended to the names of all
// file-level identifiers; in particular the name of the main
// parse function will be prefix + "Parse".
WriteParser(goal, packname, prefix string) (string, error)
}
A ParserWriter can write a parser (in Go) for a grammar.
type RuleAdder ¶
type RuleAdder interface {
// AddRule adds one rule to the grammar.
//
// Callers should ensure the same name is never used in two calls
// to AddRule.
AddRule(name, target string, items []string) error
}
A RuleAdder can have grammar rules added to it.
Grammar symbols are represented by arbitrary strings. Each rule has a name, which should be unique.
If the intent is to write a parser for the grammar, then the rule names and symbol strings should be valid Go identifiers.
Source Files
Directories
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| Path | Synopsis |
|---|---|
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Package earley contains an implementation of glean.Grammar using a simple Earley-style parser.
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Package earley contains an implementation of glean.Grammar using a simple Earley-style parser. |
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Glean generates parsers for context-free grammars.
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Glean generates parsers for context-free grammars. |
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Package gleanerrors contains types used to report errors from parsers generated by glean.
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Package gleanerrors contains types used to report errors from parsers generated by glean. |