🪄 Introduction

Introduction to takenoco, a parser combinator library for Go

🧭 Examples

🚀 Getting started

Define the parser:

package csvimport ("errors""strconv"    ."github.com/shellyln/takenoco/base"    ."github.com/shellyln/takenoco/string")var (// Comma and line break characterscellBreakCharacters []stringdocumentParserParserFn)funcinit() {cellBreakCharacters=make([]string,0,len(LineBreakCharacters)+1)cellBreakCharacters=append(cellBreakCharacters,",")cellBreakCharacters=append(cellBreakCharacters,LineBreakCharacters...)documentParser=document()}// Remove the resulting AST.funcerase(fnParserFn)ParserFn {returnTrans(fn,Erase)}// Whitespacesfuncsp()ParserFn {returnerase(ZeroOrMoreTimes(WhitespaceNoLineBreak()))}funcquotedCell()ParserFn {returnTrans(OneOrMoreTimes(FlatGroup(sp(),erase(Seq("\"")),ZeroOrMoreTimes(First(erase(Seq("\"\"")),CharClassN("\""),                    ),                ),First(erase(Seq("\"")),FlatGroup(End(),Error("Unexpected EOF")),                ),sp(),            ),        ),Concat,    )}funccell()ParserFn {returnTrans(ZeroOrMoreTimes(CharClassN(cellBreakCharacters...)),Trim,    )}// Convert AST to array data. (line)funclineTransform(_ParserContext,astsAstSlice) (AstSlice,error) {w:=make([]string,len(asts))length:=len(asts)fori:=0;i<length;i++ {w[i]=asts[i].Value.(string)    }returnAstSlice{{ClassName:"*Line",Type:AstType_Any,Value:w,    }},nil}funcline()ParserFn {returnTrans(FlatGroup(ZeroOrMoreTimes(First(quotedCell(),cell()),erase(Seq(",")),            ),First(quotedCell(),cell()),        ),lineTransform,    )}// Convert AST to array data. (Entire document)funcdocumentTransform(_ParserContext,astsAstSlice) (AstSlice,error) {length:=len(asts)w:=make([][]string,length)fori:=0;i<length;i++ {w[i]=asts[i].Value.([]string)    }fori:=length-1;i>=0;i-- {iflen(w[i])==0||len(w[i])==1&&w[i][0]=="" {w=w[:i]        }else {break        }    }returnAstSlice{{ClassName:"*Document",Type:AstType_Any,Value:w,    }},nil}funcdocument()ParserFn {returnTrans(FlatGroup(ZeroOrMoreTimes(line(),erase(OneOrMoreTimes(LineBreak())),            ),line(),End(),        ),documentTransform,    )}funcParse(sstring) ([][]string,error) {out,err:=documentParser(*NewStringParserContext(s))iferr!=nil {returnnil,err    }else {ifout.MatchStatus==MatchStatus_Matched {returnout.AstStack[0].Value.([][]string),nil        }else {returnnil,errors.New("Parse failed at "+strconv.Itoa(out.SourcePosition.Position))        }    }}

Use the parser:

package mainimport ("fmt""os"    csv"github.com/shellyln/takenoco/_examples/csv")funcmain() {x,err:=csv.Parse("0,1,2,3,4,5,6,7,8,9\n0,1,2,3,4,5,6,7,8,9")iferr!=nil {fmt.Fprintln(os.Stderr,err)os.Exit(-1)    }fmt.Println(x)y:=csv.ToCsv(x)fmt.Println(y)os.Exit(0)}

📦 Build the example app

🪟 Windows prerequirements:

choco install make# or# scoop install make

🔹 Build to native executable

make

🔹 Build to WebAssembly (Go)

make wasm

🔹 Build to WebAssembly (TinyGo; experimental)

🪟 Windows prerequirements:

scoop install tinygoscoop install binaryen

🐧 Linux prerequirements:

🍎 Mac prerequirements:

Build:

make tinywasm

🧩 Contributing

Prerequirements:

go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latestgo install honnef.co/go/tools/cmd/staticcheck@latest

⚖️ License