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More regexp.
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@ncruces
ncruces committed Nov 4, 2024
1 parent 363b12e commit 034b9a3
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Showing 2 changed files with 109 additions and 49 deletions.
130 changes: 85 additions & 45 deletions ext/regexp/regexp.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,11 +32,14 @@ func Register(db *sqlite3.Conn) error {
db.CreateFunction("regexp_instr", 3, flags, regexInstr),
db.CreateFunction("regexp_instr", 4, flags, regexInstr),
db.CreateFunction("regexp_instr", 5, flags, regexInstr),
db.CreateFunction("regexp_instr", 6, flags, regexInstr),
db.CreateFunction("regexp_substr", 2, flags, regexSubstr),
db.CreateFunction("regexp_substr", 3, flags, regexSubstr),
db.CreateFunction("regexp_substr", 4, flags, regexSubstr),
db.CreateFunction("regexp_substr", 5, flags, regexSubstr),
db.CreateFunction("regexp_replace", 3, flags, regexReplace),
db.CreateFunction("regexp_replace", 4, flags, regexReplace))
db.CreateFunction("regexp_replace", 4, flags, regexReplace),
db.CreateFunction("regexp_replace", 5, flags, regexReplace))
}

func load(ctx sqlite3.Context, i int, expr string) (*regexp.Regexp, error) {
Expand Down Expand Up @@ -68,6 +71,7 @@ func regexLike(ctx sqlite3.Context, arg ...sqlite3.Value) {
ctx.ResultError(err)
return // notest
}

text := arg[0].RawText()
ctx.ResultBool(re.Match(text))
}
Expand All @@ -78,10 +82,11 @@ func regexCount(ctx sqlite3.Context, arg ...sqlite3.Value) {
ctx.ResultError(err)
return // notest
}

text := arg[0].RawText()
if len(arg) > 2 {
pos := arg[2].Int()
_, text = split(text, pos)
text = text[skip(text, pos):]
}
ctx.ResultInt(len(re.FindAll(text, -1)))
}
Expand All @@ -92,26 +97,23 @@ func regexSubstr(ctx sqlite3.Context, arg ...sqlite3.Value) {
ctx.ResultError(err)
return // notest
}

text := arg[0].RawText()
var pos, n, subexpr int
if len(arg) > 2 {
pos := arg[2].Int()
_, text = split(text, pos)
pos = arg[2].Int()
}
n := 0
if len(arg) > 3 {
n = arg[3].Int()
}
if len(arg) > 4 {
subexpr = arg[4].Int()
}

var res []byte
if n <= 1 {
res = re.Find(text)
} else {
all := re.FindAll(text, n)
if n <= len(all) {
res = all[n-1]
}
loc := regexFind(re, text, pos, n, subexpr)
if loc != nil {
ctx.ResultRawText(text[loc[0]:loc[1]])
}
ctx.ResultRawText(res)
}

func regexInstr(ctx sqlite3.Context, arg ...sqlite3.Value) {
Expand All @@ -120,35 +122,26 @@ func regexInstr(ctx sqlite3.Context, arg ...sqlite3.Value) {
ctx.ResultError(err)
return // notest
}
pos := 1

text := arg[0].RawText()
var pos, n, end, subexpr int
if len(arg) > 2 {
pos = arg[2].Int()
_, text = split(text, pos)
}
n := 0
if len(arg) > 3 {
n = arg[3].Int()
}

var loc []int
if n <= 1 {
loc = re.FindIndex(text)
} else {
all := re.FindAllIndex(text, n)
if n <= len(all) {
loc = all[n-1]
}
if len(arg) > 4 && arg[4].Bool() {
end = 1
}
if loc == nil {
return
if len(arg) > 5 {
subexpr = arg[5].Int()
}

end := 0
if len(arg) > 4 && arg[4].Bool() {
end = 1
loc := regexFind(re, text, pos, n, subexpr)
if loc != nil {
ctx.ResultInt(loc[end] + 1)
}
ctx.ResultInt(pos + loc[end])
}

func regexReplace(ctx sqlite3.Context, arg ...sqlite3.Value) {
Expand All @@ -157,24 +150,71 @@ func regexReplace(ctx sqlite3.Context, arg ...sqlite3.Value) {
ctx.ResultError(err)
return // notest
}
var head, tail []byte
tail = arg[0].RawText()

text := arg[0].RawText()
repl := arg[2].RawText()
var pos, n int
if len(arg) > 3 {
pos := arg[3].Int()
head, tail = split(tail, pos)
pos = arg[3].Int()
}
if len(arg) > 4 {
n = arg[4].Int()
}

res := text
pos = skip(text, pos)
if n > 0 {
all := re.FindAllSubmatchIndex(text[pos:], n)
if n <= len(all) {
loc := all[n-1]
res = text[:pos+loc[0]]
res = re.Expand(res, repl, text[pos:], loc)
res = append(res, text[pos+loc[1]:]...)
}
} else {
res = append(text[:pos], re.ReplaceAll(text[pos:], repl)...)
}
tail = re.ReplaceAll(tail, arg[2].RawText())
if head != nil {
tail = append(head, tail...)
ctx.ResultRawText(res)
}

func regexFind(re *regexp.Regexp, text []byte, pos, n, subexpr int) (loc []int) {
pos = skip(text, pos)
text = text[pos:]

if n <= 1 {
if subexpr == 0 {
loc = re.FindIndex(text)
} else {
loc = re.FindSubmatchIndex(text)
}
} else {
if subexpr == 0 {
all := re.FindAllIndex(text, n)
if n <= len(all) {
loc = all[n-1]
}
} else {
all := re.FindAllSubmatchIndex(text, n)
if n <= len(all) {
loc = all[n-1]
}
}
}

if 2+2*subexpr <= len(loc) {
loc = loc[2*subexpr : 2+2*subexpr]
loc[0] += pos
loc[1] += pos
return loc
}
ctx.ResultRawText(tail)
return nil
}

func split(s []byte, i int) (head, tail []byte) {
for pos := range string(s) {
if i--; i <= 0 {
return s[:pos:pos], s[pos:]
func skip(text []byte, start int) int {
for pos := range string(text) {
if start--; start <= 0 {
return pos
}
}
return s, nil
return len(text)
}
28 changes: 24 additions & 4 deletions ext/regexp/regexp_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,13 +34,33 @@ func TestRegister(t *testing.T) {
{`regexp_instr('Hello', 'el.')`, "2"},
{`regexp_instr('Hello', '.', 6)`, ""},
{`regexp_substr('Hello', 'el.')`, "ell"},
{`regexp_substr('Hello', 'l', 2, 2)`, "l"},
{`regexp_replace('Hello', 'llo', 'll')`, "Hell"},

// https://www.postgresql.org/docs/current/functions-matching.html
{`regexp_count('ABCABCAXYaxy', 'A.')`, "3"},
{`regexp_count('ABCABCAXYaxy', '(?i)A.', 1)`, "4"},
{`regexp_instr('number of your street, town zip, FR', '[^,]+', 1, 2)`, "23"},
{`regexp_instr('ABCDEFGHI', '(?i)(c..)(...)', 1, 1, 0, 2)`, "6"},
{`regexp_substr('number of your street, town zip, FR', '[^,]+', 1, 2)`, " town zip"},
{`regexp_substr('ABCDEFGHI', '(?i)(c..)(...)', 1, 1, 2)`, "FGH"},
{`regexp_replace('foobarbaz', 'b..', 'X', 1, 1)`, "fooXbaz"},
{`regexp_replace('foobarbaz', 'b..', 'X')`, "fooXX"},
{`regexp_replace('foobarbaz', 'b(..)', 'X${1}Y')`, "fooXarYXazY"},
{`regexp_replace('A PostgreSQL function', '(?i)a|e|i|o|u', 'X', 1, 0)`, "X PXstgrXSQL fXnctXXn"},
{`regexp_replace('A PostgreSQL function', '(?i)a|e|i|o|u', 'X', 1, 3)`, "A PostgrXSQL function"},
// https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/REGEXP_COUNT.html
{`regexp_count('123123123123123', '(12)3', 1)`, "5"},
{`regexp_count('123123123123', '123', 3)`, "3"},
{`regexp_instr('500 Oracle Parkway, Redwood Shores, CA', '[^ ]+', 1, 6)`, "37"},
{`regexp_instr('500 Oracle Parkway, Redwood Shores, CA', '(?i)[s|r|p][[:alpha:]]{6}', 3, 2, 1)`, "28"},
{`regexp_substr('500 Oracle Parkway, Redwood Shores, CA', ',[^,]+,', 3, 1)`, ", Redwood Shores,"},
{`regexp_replace('500 Oracle Parkway, Redwood Shores, CA', '( ){2,}', ' ', 3)`, "500 Oracle Parkway, Redwood Shores, CA"},
{`regexp_instr('1234567890', '(123)(4(56)(78))', 1, 1, 0, 1)`, "1"},
{`regexp_instr('1234567890', '(123)(4(56)(78))', 1, 1, 0, 2)`, "4"},
{`regexp_instr('1234567890', '(123)(4(56)(78))', 1, 1, 0, 4)`, "7"},
{`regexp_substr('500 Oracle Parkway, Redwood Shores, CA', ',[^,]+,')`, ", Redwood Shores,"},
{`regexp_substr('http://www.example.com/products', 'http://([[:alnum:]]+\.?){3,4}/?')`, "http://www.example.com/"},
{`regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 1)`, "123"},
{`regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 4)`, "78"},
{`regexp_substr('123123123123', '1(.)3', 3, 2, 1)`, "2"},
{`regexp_replace('500 Oracle Parkway, Redwood Shores, CA', '( ){2,}', ' ')`, "500 Oracle Parkway, Redwood Shores, CA"},
}

for _, tt := range tests {
Expand Down

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