You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

175 lines
3.8 KiB

package circuitcompiler
import (
"errors"
"io"
"regexp"
"strings"
)
// Parser data structure holds the Scanner and the Parsing functions
type Parser struct {
s *Scanner
buf struct {
tok Token // last read token
lit string // last read literal
n int // buffer size (max=1)
}
}
// NewParser creates a new parser from a io.Reader
func NewParser(r io.Reader) *Parser {
return &Parser{s: NewScanner(r)}
}
func (p *Parser) scan() (tok Token, lit string) {
// if there is a token in the buffer return it
if p.buf.n != 0 {
p.buf.n = 0
return p.buf.tok, p.buf.lit
}
tok, lit = p.s.scan()
p.buf.tok, p.buf.lit = tok, lit
return
}
func (p *Parser) unscan() {
p.buf.n = 1
}
func (p *Parser) scanIgnoreWhitespace() (tok Token, lit string) {
tok, lit = p.scan()
if tok == WS {
tok, lit = p.scan()
}
return
}
// parseLine parses the current line
func (p *Parser) parseLine() (*Constraint, error) {
/*
in this version,
line will be for example s3 = s1 * s4
this is:
val eq val op val
*/
c := &Constraint{}
tok, lit := p.scanIgnoreWhitespace()
c.Out = lit
c.Literal += lit
if c.Literal == "func" {
// format: `func name(in):`
line, err := p.s.r.ReadString(':')
if err != nil {
return c, err
}
// read string inside ( )
rgx := regexp.MustCompile(`\((.*?)\)`)
insideParenthesis := rgx.FindStringSubmatch(line)
varsString := strings.Replace(insideParenthesis[1], " ", "", -1)
c.Inputs = strings.Split(varsString, ",")
return c, nil
}
_, lit = p.scanIgnoreWhitespace() // skip =
c.Literal += lit
// v1
_, lit = p.scanIgnoreWhitespace()
c.V1 = lit
c.Literal += lit
// operator
_, lit = p.scanIgnoreWhitespace()
c.Op = lit
c.Literal += lit
// v2
_, lit = p.scanIgnoreWhitespace()
c.V2 = lit
c.Literal += lit
if tok == EOF {
return nil, errors.New("eof in parseline")
}
return c, nil
}
func existInArray(arr []string, elem string) bool {
for _, v := range arr {
if v == elem {
return true
}
}
return false
}
func addToArrayIfNotExist(arr []string, elem string) []string {
for _, v := range arr {
if v == elem {
return arr
}
}
arr = append(arr, elem)
return arr
}
// Parse parses the lines and returns the compiled Circuit
func (p *Parser) Parse() (*Circuit, error) {
circuit := &Circuit{}
circuit.Signals = append(circuit.Signals, "one")
nInputs := 0
for {
constraint, err := p.parseLine()
if err != nil {
break
}
if constraint.Literal == "func" {
// one constraint for each input
for _, in := range constraint.Inputs {
newConstr := &Constraint{
Op: "in",
Out: in,
}
circuit.Constraints = append(circuit.Constraints, *newConstr)
nInputs++
}
circuit.Inputs = constraint.Inputs
continue
}
circuit.Constraints = append(circuit.Constraints, *constraint)
isVal, _ := isValue(constraint.V1)
if !isVal {
circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.V1)
}
isVal, _ = isValue(constraint.V2)
if !isVal {
circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.V2)
}
if constraint.Out == "out" {
// if Out is "out", put it after first value (one) and before the inputs
if !existInArray(circuit.Signals, constraint.Out) {
signalsCopy := copyArray(circuit.Signals)
var auxSignals []string
auxSignals = append(auxSignals, signalsCopy[0])
auxSignals = append(auxSignals, constraint.Out)
auxSignals = append(auxSignals, signalsCopy[1:]...)
circuit.Signals = auxSignals
circuit.PublicSignals = append(circuit.PublicSignals, constraint.Out)
circuit.NPublic++
}
} else {
circuit.Signals = addToArrayIfNotExist(circuit.Signals, constraint.Out)
}
}
circuit.NVars = len(circuit.Signals)
circuit.NSignals = len(circuit.Signals)
return circuit, nil
}
func copyArray(in []string) []string { // tmp
var out []string
for _, e := range in {
out = append(out, e)
}
return out
}