syntax

Documentation

Overview

Package syntax parses .gpp source: Go grammar plus G++'s extensions — type parameters on methods (v0.1.0), enum declarations and match statements (v0.2.0). It fronts a vendored fork of go/parser (see internal/syntax/parser); the *ast.File it produces is fully stock, with extension constructs occupying their source spans as placeholder nodes and the real structure exposed via Methods, Enums, and Matches.

Index

• Constants
• type CaseClause
• type ClassDecl
• type ClassMember
• type ComposeExpr
• type ComposeKind
• type ConstructorPattern
• type DelegateField
• type EnumDecl
• type File
  • func ParseFile(fset *token.FileSet, path string, src []byte) (*File, error)
  • func (f *File) ComposeFor(bad *ast.BadExpr) (*ComposeExpr, bool)
  • func (f *File) IfFor(bad *ast.BadExpr) (*IfExpr, bool)
  • func (f *File) MatchExprFor(bad *ast.BadExpr) (*MatchExpr, bool)
  • func (f *File) MatchFor(bad *ast.BadStmt) (*MatchStmt, bool)
  • func (f *File) Offset(pos token.Pos) int
  • func (f *File) OutermostExt() []*ast.BadExpr
  • func (f *File) OutermostFlow() (pipes []*PipeExpr, composes []*ComposeExpr)
  • func (f *File) PipeFor(bad *ast.BadExpr) (*PipeExpr, bool)
  • func (f *File) SwitchExprFor(bad *ast.BadExpr) (*SwitchExpr, bool)
  • func (f *File) TryFor(bad *ast.BadExpr) (*TryExpr, bool)
• type GenericMethod
  • func NewMethod(fd *ast.FuncDecl) (*GenericMethod, error)
• type IfExpr
• type InstanceDecl
• type InstanceMember
• type MatchExpr
• type MatchExprArm
• type MatchStmt
• type PatNode
  • func (n PatNode) String() string
• type PatText
  • func ParsePatternText(text string) (PatText, error)
• type Pattern
• type PipeExpr
• type PipeStage
• type QuantityParam
• type SwitchExpr
• type SwitchExprArm
• type TotalFunc
• type TryExpr
• type Variant
• type WildcardPattern

Constants

const (
	ComposeFn      = parser.ComposeFn
	ComposeKleisli = parser.ComposeKleisli
)

Composition operator kinds.

Types

type CaseClause

type CaseClause = parser.CaseClause

Re-exported extension node types; see internal/syntax/parser/ext.go.

type ClassDecl

type ClassDecl = parser.ClassDecl

Re-exported extension node types; see internal/syntax/parser/ext.go.

type ClassMember

type ClassMember = parser.ClassMember

Re-exported extension node types; see internal/syntax/parser/ext.go.

type ComposeExpr

type ComposeExpr = parser.ComposeExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type ComposeKind

type ComposeKind = parser.ComposeKind

Re-exported extension node types; see internal/syntax/parser/ext.go.

type ConstructorPattern

type ConstructorPattern = parser.ConstructorPattern

Re-exported extension node types; see internal/syntax/parser/ext.go.

type DelegateField

type DelegateField = parser.DelegateField

Re-exported extension node types; see internal/syntax/parser/ext.go.

type EnumDecl

type EnumDecl = parser.EnumDecl

Re-exported extension node types; see internal/syntax/parser/ext.go.

type File

type File struct {
	Path      string
	Src       []byte
	Fset      *token.FileSet
	TokFile   *token.File
	AST       *ast.File // stock AST; enum bodies are BadExpr, matches BadStmt
	Methods   []*GenericMethod
	Enums     []*EnumDecl      // source order
	Classes   []*ClassDecl     // source order (v0.5.0)
	Instances []*InstanceDecl  // source order (v0.5.0)
	Delegates []*DelegateField // source order (v0.6.0)

	Quantities []*QuantityParam // source order (v0.7.0)
	Totals     []*TotalFunc     // source order (v0.7.0)
	Matches    []*MatchStmt     // pre-order (nested matches follow their parent)

	// Pipes and Composes are in creation order (extensions nested in a
	// head/left operand precede their encloser); resolve placeholders by
	// pointer via PipeFor/ComposeFor, never by slice position.
	Pipes    []*PipeExpr
	Composes []*ComposeExpr

	// v0.4.0 typed-failure constructs, creation order.
	Tries       []*TryExpr
	IfExprs     []*IfExpr
	SwitchExprs []*SwitchExpr
	MatchExprs  []*MatchExpr
	// contains filtered or unexported fields
}

File is one parsed .gpp file.

func ParseFile

func ParseFile(fset *token.FileSet, path string, src []byte) (*File, error)

ParseFile parses .gpp source. Genuine syntax errors are returned as a scanner.ErrorList.

func (*File) ComposeFor

func (f *File) ComposeFor(bad *ast.BadExpr) (*ComposeExpr, bool)

ComposeFor resolves a placeholder expression to its composition.

func (*File) IfFor

func (f *File) IfFor(bad *ast.BadExpr) (*IfExpr, bool)

IfFor resolves a placeholder expression to its if expression.

func (*File) MatchExprFor

func (f *File) MatchExprFor(bad *ast.BadExpr) (*MatchExpr, bool)

MatchExprFor resolves a placeholder expression to its match expression.

func (*File) MatchFor

func (f *File) MatchFor(bad *ast.BadStmt) (*MatchStmt, bool)

MatchFor resolves a placeholder statement to its match statement.

func (*File) Offset

func (f *File) Offset(pos token.Pos) int

Offset converts a token.Pos within f to a byte offset in f.Src.

func (*File) OutermostExt

func (f *File) OutermostExt() []*ast.BadExpr

OutermostExt lists the expression-extension placeholders whose spans are not contained inside another extension expression's span — the set pass-1 lowering rewrites (nested extensions render recursively inside them). Ordered by source position.

func (*File) OutermostFlow

func (f *File) OutermostFlow() (pipes []*PipeExpr, composes []*ComposeExpr)

OutermostFlow lists the pipelines and compositions whose spans are not contained inside another flow extension's span — the ones pass-1 lowering must rewrite (nested flows render recursively inside them).

func (*File) PipeFor

func (f *File) PipeFor(bad *ast.BadExpr) (*PipeExpr, bool)

PipeFor resolves a placeholder expression to its pipeline.

func (*File) SwitchExprFor

func (f *File) SwitchExprFor(bad *ast.BadExpr) (*SwitchExpr, bool)

SwitchExprFor resolves a placeholder expression to its switch expression.

func (*File) TryFor

func (f *File) TryFor(bad *ast.BadExpr) (*TryExpr, bool)

TryFor resolves a placeholder expression to its try suffix.

type GenericMethod

type GenericMethod struct {
	Decl *ast.FuncDecl // TypeParams present natively (fork keeps them)

	RecvName     string   // receiver identifier as written; "" if absent
	RecvTypeName string   // base named type, e.g. "Stack"
	RecvPointer  bool     // *Stack[T] receiver
	RecvTParams  []string // receiver type parameter names, e.g. ["T"]

	// LBrack and RBrack are byte offsets in Src of the method's type
	// parameter brackets.
	LBrack, RBrack int
}

GenericMethod is a method declaration carrying its own type parameters.

func NewMethod

func NewMethod(fd *ast.FuncDecl) (*GenericMethod, error)

NewMethod builds method info for an ordinary (non-generic) method declaration, e.g. an enum method that lowers like a generic method with zero method type parameters.

type IfExpr

type IfExpr = parser.IfExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type InstanceDecl

type InstanceDecl = parser.InstanceDecl

Re-exported extension node types; see internal/syntax/parser/ext.go.

type InstanceMember

type InstanceMember = parser.InstanceMember

Re-exported extension node types; see internal/syntax/parser/ext.go.

type MatchExpr

type MatchExpr = parser.MatchExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type MatchExprArm

type MatchExprArm = parser.MatchExprArm

Re-exported extension node types; see internal/syntax/parser/ext.go.

type MatchStmt

type MatchStmt = parser.MatchStmt

Re-exported extension node types; see internal/syntax/parser/ext.go.

type PatNode

type PatNode struct {
	Wild    bool   // `_`
	Qual    string // qualifier before '.', e.g. "lib" or "Option"; "" if bare
	Name    string // constructor (or binder) name
	HasArgs bool   // distinguishes None from None()
	Args    []PatNode
}

PatNode is one node of a textual pattern tree.

func (PatNode) String

func (n PatNode) String() string

String renders a PatNode back to pattern text (for witness diagnostics).

type PatText

type PatText struct {
	Binder string // whole-value binder name; "" if absent
	Root   PatNode
	Alts   []PatNode // additional alternatives of a multi-pattern arm (v0.12.0)
}

PatText is a match pattern re-parsed from carrier text (the `//gpp:pattern <verbatim>` lines that thread pattern structure through the resolution fixpoint).

func ParsePatternText

func ParsePatternText(text string) (PatText, error)

ParsePatternText parses "c := Circle(r)", "Add(Lit(a), _)", "_", "opt.Some(v)".

type Pattern

type Pattern = parser.Pattern

Re-exported extension node types; see internal/syntax/parser/ext.go.

type PipeExpr

type PipeExpr = parser.PipeExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type PipeStage

type PipeStage = parser.PipeStage

Re-exported extension node types; see internal/syntax/parser/ext.go.

type QuantityParam

type QuantityParam = parser.QuantityParam

Re-exported extension node types; see internal/syntax/parser/ext.go.

type SwitchExpr

type SwitchExpr = parser.SwitchExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type SwitchExprArm

type SwitchExprArm = parser.SwitchExprArm

Re-exported extension node types; see internal/syntax/parser/ext.go.

type TotalFunc

type TotalFunc = parser.TotalFunc

Re-exported extension node types; see internal/syntax/parser/ext.go.

type TryExpr

type TryExpr = parser.TryExpr

Re-exported extension node types; see internal/syntax/parser/ext.go.

type Variant

type Variant = parser.Variant

Re-exported extension node types; see internal/syntax/parser/ext.go.

type WildcardPattern

type WildcardPattern = parser.WildcardPattern

Re-exported extension node types; see internal/syntax/parser/ext.go.