Documentation
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Overview ¶
Package parse implements the elvish parser.
The parser builds a hybrid of AST (abstract syntax tree) and parse tree (a.k.a. concrete syntax tree). The AST part only includes parts that are semantically significant -- i.e. skipping whitespaces and symbols that do not alter the semantics, and is embodied in the fields of each *Node type. The parse tree part corresponds to all the text in the original source text, and is embodied in the children of each *Node type.
Index ¶
- func IsInlineWhitespace(r rune) bool
- func IsWhitespace(r rune) bool
- func ParseAs(src Source, n Node, w io.Writer) error
- func Quote(s string) string
- func QuoteVariableName(s string) string
- func SourceText(n Node) string
- func ValidLHSVariable(p *Primary, allowSigil bool) bool
- type Array
- type Assignment
- type Chunk
- type Compound
- type Error
- type ExprCtx
- type Form
- type Indexing
- type MapPair
- type Node
- type Pipeline
- type Primary
- type PrimaryType
- type Redir
- type RedirMode
- type Sep
- type Source
- type Tree
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func IsInlineWhitespace ¶
IsInlineWhitespace reports whether r is an inline whitespace character. Currently this includes space (Unicode 0x20) and tab (Unicode 0x9).
func IsWhitespace ¶
IsWhitespace reports whether r is a whitespace. Currently this includes inline whitespace characters and newline (Unicode 0xa).
func ParseAs ¶ added in v0.14.0
ParseAs parses the given source as a node, depending on the dynamic type of n, writing deprecation warnings to the given io.Writer if it is not nil. If the error is not nil, it always has type *Error.
func Quote ¶
Quote returns a valid Elvish expression that evaluates to the given string. If s is a valid bareword, it is returned as is; otherwise it is quoted, preferring the use of single quotes.
func QuoteVariableName ¶ added in v0.15.0
QuoteVariableName is like Quote, but quotes s if it contains any character that may not appear unquoted in variable names.
func SourceText ¶ added in v0.14.0
SourceText returns the part of the source text that parses to the node.
func ValidLHSVariable ¶ added in v0.15.0
Types ¶
type Array ¶
type Array struct {
Compounds []*Compound
// When non-empty, records the occurrences of semicolons by the indices of
// the compounds they appear before. For instance, [; ; a b; c d;] results
// in Semicolons={0 0 2 4}.
Semicolons []int
// contains filtered or unexported fields
}
Array = { Space | '\n' } { Compound { Space | '\n' } }
type Assignment ¶
Assignment = Indexing '=' Compound
type Chunk ¶
type Chunk struct {
Pipelines []*Pipeline
// contains filtered or unexported fields
}
Chunk = { PipelineSep | Space } { Pipeline { PipelineSep | Space } }
type Compound ¶
type Compound struct {
ExprCtx ExprCtx
Indexings []*Indexing
// contains filtered or unexported fields
}
Compound = { Indexing }
type Error ¶
Error stores multiple underlying parse errors, and can pretty print them.
func GetError ¶ added in v0.15.0
GetError returns an *Error if the given error has dynamic type *Error, i.e. is returned by one of the Parse functions. Otherwise it returns nil.
type ExprCtx ¶
type ExprCtx int
ExprCtx represents special contexts of expression parsing.
const ( // NormalExpr represents a normal expression, namely none of the special // ones below. It is the default value. NormalExpr ExprCtx = iota // CmdExpr represents an expression used as the command in a form. In this // context, unquoted <>*^ are treated as bareword characters. CmdExpr // LHSExpr represents an expression used as the left-hand-side in either // assignments or map pairs. In this context, an unquoted = serves as an // expression terminator and is thus not treated as a bareword character. LHSExpr // BracedElemExpr represents an expression used as an element in a braced // expression. In this context, an unquoted , serves as an expression // terminator and is thus not treated as a bareword character. BracedElemExpr )
type Form ¶
type Form struct {
Assignments []*Assignment
Head *Compound
Args []*Compound
Opts []*MapPair
Redirs []*Redir
// contains filtered or unexported fields
}
Form = { Space } { { Assignment } { Space } }
{ Compound } { Space } { ( Compound | MapPair | Redir ) { Space } }
type Indexing ¶
type Indexing struct {
ExprCtx ExprCtx
Head *Primary
Indicies []*Array
// contains filtered or unexported fields
}
Indexing = Primary { '[' Array ']' }
type MapPair ¶
type MapPair struct {
Key, Value *Compound
// contains filtered or unexported fields
}
MapPair = '&' { Space } Compound { Space } Compound
type Node ¶
Node represents a parse tree as well as an AST.
type Primary ¶
type Primary struct {
ExprCtx ExprCtx
Type PrimaryType
// The unquoted string value. Valid for Bareword, SingleQuoted,
// DoubleQuoted, Variable, Wildcard and Tilde.
Value string
Elements []*Compound // Valid for List and Labda
Chunk *Chunk // Valid for OutputCapture, ExitusCapture and Lambda
MapPairs []*MapPair // Valid for Map and Lambda
Braced []*Compound // Valid for Braced
// contains filtered or unexported fields
}
Primary is the smallest expression unit.
type PrimaryType ¶
type PrimaryType int
PrimaryType is the type of a Primary.
const ( BadPrimary PrimaryType = iota Bareword SingleQuoted DoubleQuoted Variable Wildcard Tilde ExceptionCapture OutputCapture List Lambda Map Braced )
Possible values for PrimaryType.
func QuoteAs ¶
func QuoteAs(s string, q PrimaryType) (string, PrimaryType)
QuoteAs returns a representation of s in elvish syntax, preferring the syntax specified by q, which must be one of Bareword, SingleQuoted, or DoubleQuoted. It returns the quoted string and the actual quoting.
func (PrimaryType) String ¶
func (i PrimaryType) String() string
type Redir ¶
type Redir struct {
Left *Compound
Mode RedirMode
RightIsFd bool
Right *Compound
// contains filtered or unexported fields
}
Redir = { Compound } { '<'|'>'|'<>'|'>>' } { Space } ( '&'? Compound )
type Sep ¶
type Sep struct {
// contains filtered or unexported fields
}
Sep is the catch-all node type for leaf nodes that lack internal structures and semantics, and serve solely for syntactic purposes. The parsing of separators depend on the Parent node; as such it lacks a genuine parse method.
type Source ¶ added in v0.14.0
Source describes a piece of source code.
func SourceForTest ¶ added in v0.14.0
SourceForTest returns a Source used for testing.
func (Source) IsStructMap ¶ added in v0.14.0
func (src Source) IsStructMap()
IsStructMap marks that Source is a structmap.
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