add phono-pestgros crate

This commit is contained in:
Brent Schroeter 2026-02-13 08:00:23 +00:00
parent 2419880af3
commit a4ffb44f4d
12 changed files with 1337 additions and 11 deletions

142
Cargo.lock generated
View file

@ -364,6 +364,15 @@ dependencies = [
"windows-targets 0.52.6", "windows-targets 0.52.6",
] ]
[[package]]
name = "backtrace-ext"
version = "0.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "537beee3be4a18fb023b570f80e3ae28003db9167a751266b259926e25539d50"
dependencies = [
"backtrace",
]
[[package]] [[package]]
name = "base64" name = "base64"
version = "0.13.1" version = "0.13.1"
@ -1222,7 +1231,7 @@ version = "0.2.24"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "cfe4fbac503b8d1f88e6676011885f34b7174f46e59956bba534ba83abded4df" checksum = "cfe4fbac503b8d1f88e6676011885f34b7174f46e59956bba534ba83abded4df"
dependencies = [ dependencies = [
"unicode-width", "unicode-width 0.2.2",
] ]
[[package]] [[package]]
@ -1756,6 +1765,12 @@ version = "2.11.0"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "469fb0b9cefa57e3ef31275ee7cacb78f2fdca44e4765491884a2b119d4eb130" checksum = "469fb0b9cefa57e3ef31275ee7cacb78f2fdca44e4765491884a2b119d4eb130"
[[package]]
name = "is_ci"
version = "1.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7655c9839580ee829dfacba1d1278c2b7883e50a277ff7541299489d6bdfdc45"
[[package]] [[package]]
name = "is_terminal_polyfill" name = "is_terminal_polyfill"
version = "1.70.1" version = "1.70.1"
@ -1916,6 +1931,36 @@ version = "2.7.6"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273" checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
[[package]]
name = "miette"
version = "7.6.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5f98efec8807c63c752b5bd61f862c165c115b0a35685bdcfd9238c7aeb592b7"
dependencies = [
"backtrace",
"backtrace-ext",
"cfg-if 1.0.3",
"miette-derive",
"owo-colors",
"supports-color",
"supports-hyperlinks",
"supports-unicode",
"terminal_size",
"textwrap",
"unicode-width 0.1.14",
]
[[package]]
name = "miette-derive"
version = "7.6.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "db5b29714e950dbb20d5e6f74f9dcec4edbcc1067bb7f8ed198c097b8c1a818b"
dependencies = [
"proc-macro2",
"quote",
"syn",
]
[[package]] [[package]]
name = "mime" name = "mime"
version = "0.3.17" version = "0.3.17"
@ -2174,6 +2219,12 @@ version = "0.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39" checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
[[package]]
name = "owo-colors"
version = "4.2.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9c6901729fa79e91a0913333229e9ca5dc725089d1c363b2f4b4760709dc4a52"
[[package]] [[package]]
name = "parking" name = "parking"
version = "2.2.1" version = "2.2.1"
@ -2226,20 +2277,22 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
[[package]] [[package]]
name = "pest" name = "pest"
version = "2.8.0" version = "2.8.6"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "198db74531d58c70a361c42201efde7e2591e976d518caf7662a47dc5720e7b6" checksum = "e0848c601009d37dfa3430c4666e147e49cdcf1b92ecd3e63657d8a5f19da662"
dependencies = [ dependencies = [
"memchr", "memchr",
"thiserror 2.0.12", "miette",
"serde",
"serde_json",
"ucd-trie", "ucd-trie",
] ]
[[package]] [[package]]
name = "pest_derive" name = "pest_derive"
version = "2.8.0" version = "2.8.6"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d725d9cfd79e87dccc9341a2ef39d1b6f6353d68c4b33c177febbe1a402c97c5" checksum = "11f486f1ea21e6c10ed15d5a7c77165d0ee443402f0780849d1768e7d9d6fe77"
dependencies = [ dependencies = [
"pest", "pest",
"pest_generator", "pest_generator",
@ -2247,9 +2300,9 @@ dependencies = [
[[package]] [[package]]
name = "pest_generator" name = "pest_generator"
version = "2.8.0" version = "2.8.6"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "db7d01726be8ab66ab32f9df467ae8b1148906685bbe75c82d1e65d7f5b3f841" checksum = "8040c4647b13b210a963c1ed407c1ff4fdfa01c31d6d2a098218702e6664f94f"
dependencies = [ dependencies = [
"pest", "pest",
"pest_meta", "pest_meta",
@ -2260,11 +2313,10 @@ dependencies = [
[[package]] [[package]]
name = "pest_meta" name = "pest_meta"
version = "2.8.0" version = "2.8.6"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7f9f832470494906d1fca5329f8ab5791cc60beb230c74815dff541cbd2b5ca0" checksum = "89815c69d36021a140146f26659a81d6c2afa33d216d736dd4be5381a7362220"
dependencies = [ dependencies = [
"once_cell",
"pest", "pest",
"sha2 0.10.9", "sha2 0.10.9",
] ]
@ -2366,6 +2418,21 @@ dependencies = [
"thiserror 2.0.12", "thiserror 2.0.12",
] ]
[[package]]
name = "phono-pestgros"
version = "0.0.1"
dependencies = [
"bigdecimal",
"chrono",
"pest",
"pest_derive",
"serde",
"serde_json",
"sqlx",
"thiserror 2.0.12",
"uuid",
]
[[package]] [[package]]
name = "phono-server" name = "phono-server"
version = "0.0.1" version = "0.0.1"
@ -3489,6 +3556,27 @@ version = "2.6.1"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292" checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
[[package]]
name = "supports-color"
version = "3.0.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c64fc7232dd8d2e4ac5ce4ef302b1d81e0b80d055b9d77c7c4f51f6aa4c867d6"
dependencies = [
"is_ci",
]
[[package]]
name = "supports-hyperlinks"
version = "3.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e396b6523b11ccb83120b115a0b7366de372751aa6edf19844dfb13a6af97e91"
[[package]]
name = "supports-unicode"
version = "3.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b7401a30af6cb5818bb64852270bb722533397edcfc7344954a38f420819ece2"
[[package]] [[package]]
name = "syn" name = "syn"
version = "2.0.101" version = "2.0.101"
@ -3592,6 +3680,26 @@ dependencies = [
"utf-8", "utf-8",
] ]
[[package]]
name = "terminal_size"
version = "0.4.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "45c6481c4829e4cc63825e62c49186a34538b7b2750b73b266581ffb612fb5ed"
dependencies = [
"rustix",
"windows-sys 0.59.0",
]
[[package]]
name = "textwrap"
version = "0.16.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c13547615a44dc9c452a8a534638acdf07120d4b6847c8178705da06306a3057"
dependencies = [
"unicode-linebreak",
"unicode-width 0.2.2",
]
[[package]] [[package]]
name = "thiserror" name = "thiserror"
version = "1.0.69" version = "1.0.69"
@ -4020,6 +4128,12 @@ version = "1.0.18"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512" checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
[[package]]
name = "unicode-linebreak"
version = "0.1.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3b09c83c3c29d37506a3e260c08c03743a6bb66a9cd432c6934ab501a190571f"
[[package]] [[package]]
name = "unicode-normalization" name = "unicode-normalization"
version = "0.1.24" version = "0.1.24"
@ -4041,6 +4155,12 @@ version = "1.12.0"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493" checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
[[package]]
name = "unicode-width"
version = "0.1.14"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
[[package]] [[package]]
name = "unicode-width" name = "unicode-width"
version = "0.2.2" version = "0.2.2"

View file

@ -19,6 +19,7 @@ futures = "0.3.31"
phono-backends = { path = "./phono-backends" } phono-backends = { path = "./phono-backends" }
phono-models = { path = "./phono-models" } phono-models = { path = "./phono-models" }
phono-namegen = { path = "./phono-namegen" } phono-namegen = { path = "./phono-namegen" }
phono-pestgros = { path = "./phono-pestgros" }
rand = "0.8.5" rand = "0.8.5"
redact = { version = "0.1.11", features = ["serde", "zeroize"] } redact = { version = "0.1.11", features = ["serde", "zeroize"] }
regex = "1.11.1" regex = "1.11.1"

15
phono-pestgros/Cargo.toml Normal file
View file

@ -0,0 +1,15 @@
[package]
name = "phono-pestgros"
edition.workspace = true
version.workspace = true
[dependencies]
bigdecimal = { workspace = true }
chrono = { workspace = true }
pest = { version = "2.8.6", features = ["miette-error"] }
pest_derive = "2.8.6"
serde = { workspace = true }
serde_json = { workspace = true }
sqlx = { workspace = true }
thiserror = { workspace = true }
uuid = { workspace = true }

View file

@ -0,0 +1,71 @@
use bigdecimal::BigDecimal;
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use sqlx::{Postgres, QueryBuilder};
use uuid::Uuid;
/// Enum representing all supported literal types, providing convenience
/// methods for working with them in [`sqlx`] queries, and defining a [`serde`]
/// encoding for use across the application stack.
#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
#[serde(tag = "t", content = "c")]
pub enum Datum {
// BigDecimal is used because a user may insert a value directly via SQL
// which overflows the representational space of `rust_decimal::Decimal`.
// Note that by default, [`BigDecimal`] serializes to JSON as a string. This
// behavior can be modified, but it's a pain when paired with the [`Option`]
// type. String representation should be acceptable for the UI, as [`Datum`]
// values should always be parsed through Zod, which can coerce the value to
// a number transparently.
Numeric(Option<BigDecimal>),
Text(Option<String>),
Timestamp(Option<DateTime<Utc>>),
Uuid(Option<Uuid>),
}
// TODO: Should sqlx helpers be moved to a separate crate?
impl Datum {
// TODO: Can something similar be achieved with a generic return type?
/// Bind this as a parameter to a sqlx query.
pub fn bind_onto<'a>(
self,
query: sqlx::query::Query<'a, Postgres, <sqlx::Postgres as sqlx::Database>::Arguments<'a>>,
) -> sqlx::query::Query<'a, Postgres, <sqlx::Postgres as sqlx::Database>::Arguments<'a>> {
match self {
Self::Numeric(value) => query.bind(value),
Self::Text(value) => query.bind(value),
Self::Timestamp(value) => query.bind(value),
Self::Uuid(value) => query.bind(value),
}
}
/// Push this as a parameter to a [`QueryBuilder`].
pub fn push_bind_onto(self, builder: &mut QueryBuilder<'_, Postgres>) {
match self {
Self::Numeric(value) => builder.push_bind(value),
Self::Text(value) => builder.push_bind(value),
Self::Timestamp(value) => builder.push_bind(value),
Self::Uuid(value) => builder.push_bind(value),
};
}
/// Transform the contained value into a serde_json::Value.
pub fn inner_as_value(&self) -> serde_json::Value {
let serialized = serde_json::to_value(self).unwrap();
#[derive(Deserialize)]
struct Tagged {
c: serde_json::Value,
}
let deserialized: Tagged = serde_json::from_value(serialized).unwrap();
deserialized.c
}
pub fn is_none(&self) -> bool {
match self {
Self::Numeric(None) | Self::Text(None) | Self::Timestamp(None) | Self::Uuid(None) => {
true
}
Self::Numeric(_) | Self::Text(_) | Self::Timestamp(_) | Self::Uuid(_) => false,
}
}
}

View file

@ -0,0 +1,15 @@
use std::error::Error;
use sqlx::{Postgres, QueryBuilder};
use crate::Expr;
#[test]
fn sql_converts_to_query_builder() -> Result<(), Box<dyn Error>> {
let expr = Expr::try_from("3 + 5 < 10")?;
assert_eq!(
QueryBuilder::<'_, Postgres>::from(expr).sql(),
"(($1) + ($2)) < ($3)",
);
Ok(())
}

View file

@ -0,0 +1,76 @@
use std::error::Error;
use crate::{ArithOp, Datum, Expr, FnArgs, InfixOp};
#[test]
fn parses_without_args() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from("now()")?,
Expr::FnCall {
name: vec!["now".to_owned()],
args: FnArgs::Exprs {
distinct_flag: false,
exprs: vec![],
},
}
);
Ok(())
}
#[test]
fn parses_with_args() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from("repeat('hello!', 1 + 2)")?,
Expr::FnCall {
name: vec!["repeat".to_owned()],
args: FnArgs::Exprs {
distinct_flag: false,
exprs: vec![
Expr::Literal(Datum::Text(Some("hello!".to_owned()))),
Expr::Infix {
lhs: Box::new(Expr::Literal(Datum::Numeric(Some(1.into())))),
op: InfixOp::ArithInfix(ArithOp::Add),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(2.into())))),
}
],
},
}
);
Ok(())
}
#[test]
fn schema_qualified() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from(r#"my_schema."MyFunc"('hello!', 1)"#)?,
Expr::FnCall {
name: vec!["my_schema".to_owned(), "MyFunc".to_owned()],
args: FnArgs::Exprs {
distinct_flag: false,
exprs: vec![
Expr::Literal(Datum::Text(Some("hello!".to_owned()))),
Expr::Literal(Datum::Numeric(Some(1.into()))),
],
},
}
);
Ok(())
}
#[test]
fn distinct_aggregate() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from(r#"AGGREGATOR(DISTINCT a."Col 1", b."Col 2")"#)?,
Expr::FnCall {
name: vec!["aggregator".to_owned()],
args: FnArgs::Exprs {
distinct_flag: true,
exprs: vec![
Expr::ObjName(vec!["a".to_owned(), "Col 1".to_owned()]),
Expr::ObjName(vec!["b".to_owned(), "Col 2".to_owned()]),
],
},
}
);
Ok(())
}

View file

@ -0,0 +1,212 @@
//! Based on
//! https://github.com/pest-parser/pest/blob/master/grammars/src/grammars/sql.pest.
//! (Original is dual-licensed under MIT/Apache-2.0.)
//!
//! Postgres largely conforms to the SQLite flavored dialect captured by the
//! original grammar, but its rules for identifiers differ:
//!
//! > SQL identifiers and key words must begin with a letter (a-z, but also
//! > letters with diacritical marks and non-Latin letters) or an underscore
//! > (_). Subsequent characters in an identifier or key word can be letters,
//! > underscores, digits (0-9), or dollar signs ($). Note that dollar signs are
//! > not allowed in identifiers according to the letter of the SQL standard,
//! > so their use might render applications less portable.
//! -- https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
Command = _{ SOI ~ (Query | ExplainQuery | DDL | ACL) ~ EOF }
ACL = _{ DropRole | DropUser | CreateRole | CreateUser | AlterUser | GrantPrivilege | RevokePrivilege }
CreateUser = {
^"create" ~ ^"user" ~ Identifier ~ (^"with")? ~ ^"password" ~ SingleQuotedString ~
AuthMethod?
}
AlterUser = {
^"alter" ~ ^"user" ~ Identifier ~ (^"with")? ~ AlterOption
}
AlterOption = _{ AlterLogin | AlterNoLogin | AlterPassword }
AlterLogin = { ^"login" }
AlterNoLogin = { ^"nologin" }
AlterPassword = { ^"password" ~ SingleQuotedString ~ AuthMethod? }
AuthMethod = { ^"using" ~ (ChapSha1 | Md5 | Ldap) }
ChapSha1 = { ^"chap-sha1" }
Md5 = { ^"md5" }
Ldap = { ^"ldap" }
DropUser = { ^"drop" ~ ^"user" ~ Identifier }
CreateRole = { ^"create" ~ ^"role" ~ Identifier }
DropRole = { ^"drop" ~ ^"role" ~ Identifier }
GrantPrivilege = { ^"grant" ~ PrivBlock ~ ^"to" ~ Identifier }
RevokePrivilege = { ^"revoke" ~ PrivBlock ~ ^"from" ~ Identifier }
PrivBlock = _{ PrivBlockPrivilege | PrivBlockRolePass }
PrivBlockPrivilege = {Privilege ~ (PrivBlockUser | PrivBlockSpecificUser | PrivBlockRole
| PrivBlockSpecificRole | PrivBlockTable | PrivBlockSpecificTable)}
PrivBlockUser = { ^"user" }
PrivBlockSpecificUser = { ^"on" ~ ^"user" ~ Identifier }
PrivBlockRole = { ^"role" }
PrivBlockSpecificRole = { ^"on" ~ ^"role" ~ Identifier }
PrivBlockTable = { ^"table" }
PrivBlockSpecificTable = { ^"on" ~ ^"table" ~ Identifier }
PrivBlockRolePass = { Identifier }
Privilege = _{ PrivilegeRead | PrivilegeWrite | PrivilegeExecute |
PrivilegeCreate | PrivilegeAlter | PrivilegeDrop |
PrivilegeSession | PrivilegeUsage }
PrivilegeAlter = { ^"alter" }
PrivilegeCreate = { ^"create" }
PrivilegeDrop = { ^"drop" }
PrivilegeExecute = { ^"execute" }
PrivilegeRead = { ^"read" }
PrivilegeSession = { ^"session" }
PrivilegeUsage = { ^"usage" }
PrivilegeWrite = { ^"write" }
DDL = _{ CreateTable | DropTable | CreateProc }
CreateTable = {
^"create" ~ ^"table" ~ Identifier ~
"(" ~ Columns ~ "," ~ PrimaryKey ~ ")" ~
Distribution
}
Columns = { ColumnDef ~ ("," ~ ColumnDef)* }
ColumnDef = { Identifier ~ ColumnDefType ~ ColumnDefIsNull? }
ColumnDefIsNull = { NotFlag? ~ ^"null" }
PrimaryKey = {
^"primary" ~ ^"key" ~
"(" ~ Identifier ~ ("," ~ Identifier)* ~ ")"
}
Distribution = { ^"distributed" ~ (Global | Sharding) }
Global = { ^"globally" }
Sharding = { ^"by" ~ "(" ~ Identifier ~ ("," ~ Identifier)* ~ ")"}
DropTable = { ^"drop" ~ ^"table" ~ Identifier }
CreateProc = {
^"create" ~ ^"procedure" ~ Identifier ~
"(" ~ ProcParams? ~ ")" ~ (^"language" ~ ProcLanguage)? ~
((^"as" ~ "$$" ~ ProcBody ~ "$$") | (^"begin" ~ "atomic" ~ ProcBody ~ "end"))
}
ProcParams = { ProcParamDef ~ ("," ~ ProcParamDef)* }
ProcParamDef = { ColumnDefType }
ProcLanguage = { SQL }
SQL = { ^"sql" }
ProcBody = { (Insert | Update | Delete) }
ExplainQuery = _{ Explain }
Explain = { ^"explain" ~ Query }
Query = { (SelectWithOptionalContinuation | Values | Insert | Update | Delete) }
SelectWithOptionalContinuation = { Select ~ (ExceptContinuation | UnionAllContinuation)? }
ExceptContinuation = { ((^"except" ~ ^"distinct") | ^"except") ~ Select }
UnionAllContinuation = { ^"union" ~ ^"all" ~ Select }
Select = {
^"select" ~ Projection ~ ^"from" ~ Scan ~
Join? ~ WhereClause? ~
(^"group" ~ ^"by" ~ GroupBy)? ~
(^"having" ~ Having)?
}
Projection = { Distinct? ~ ProjectionElement ~ ("," ~ ProjectionElement)* }
ProjectionElement = _{ Asterisk | Column }
Column = { Expr ~ ((^"as")? ~ Identifier)? }
Asterisk = { "*" }
WhereClause = _{ ^"where" ~ Selection }
Selection = { Expr }
Scan = { (Identifier | SubQuery) ~ ((^"as")? ~ Identifier)? }
Join = { JoinKind? ~ ^"join" ~ Scan ~ ^"on" ~ Expr }
JoinKind = _{ ( InnerJoinKind | LeftJoinKind ) }
InnerJoinKind = { ^"inner" }
LeftJoinKind = { ^"left" ~ (^"outer")? }
GroupBy = { Expr ~ ("," ~ Expr)* }
Having = { Expr }
SubQuery = { "(" ~ (SelectWithOptionalContinuation | Values) ~ ")" }
Insert = { ^"insert" ~ ^"into" ~ Identifier ~ ("(" ~ TargetColumns ~ ")")? ~ (Values | Select) ~ OnConflict? }
TargetColumns = { Identifier ~ ("," ~ Identifier)* }
OnConflict = _{ ^"on conflict" ~ ^"do" ~ (DoNothing | DoReplace | DoFail) }
DoReplace = { ^"replace" }
DoNothing = { ^"nothing" }
DoFail = { ^"fail" }
Update = { ^"update" ~ Identifier ~ ^"set" ~ UpdateList ~ (UpdateFrom | WhereClause)? }
UpdateList = { UpdateItem ~ ("," ~ UpdateItem)* }
UpdateItem = { Identifier ~ "=" ~ Expr }
UpdateFrom = _{ ^"from" ~ Scan ~ (^"where" ~ Expr)? }
Values = { ^"values" ~ Row ~ ("," ~ Row)* }
Delete = { ^"delete" ~ ^"from" ~ Identifier ~ (^"where" ~ DeleteFilter)? }
DeleteFilter = { Expr }
Identifier = ${ DoubleQuotedIdentifier | UnquotedIdentifier }
DoubleQuotedIdentifier = @{ "\"" ~ ("\"\"" | '\u{01}'..'\u{21}' | '\u{23}'..'\u{10FFFF}')+ ~ "\"" }
UnquotedIdentifier = @{ !(Keyword ~ ("(" | WHITESPACE | "," | EOF)) ~ (UnquotedIdentifierStart ~ UnquotedIdentifierRemainder*) }
UnquotedIdentifierStart = _{ 'a'..'я' | 'A'..'Я' | "_" }
UnquotedIdentifierRemainder = _{ UnquotedIdentifierStart | "$" | ASCII_DIGIT }
Keyword = { ^"left" | ^"having" | ^"not" | ^"inner" | ^"group"
| ^"on" | ^"join" | ^"from" | ^"exists" | ^"except"
| ^"union" | ^"where" | ^"distinct" | ^"between" | ^"option"
| ^"values"}
ExprRoot = _{ &SOI ~ Expr ~ &EOI }
Expr = { ExprAtomValue ~ (ExprInfixOp ~ ExprAtomValue)* }
ExprInfixOp = _{ Between | ArithInfixOp | CmpInfixOp | ConcatInfixOp | And | Or }
Between = { NotFlag? ~ ^"between" }
And = { ^"and" }
Or = { ^"or" }
ConcatInfixOp = { "||" }
ArithInfixOp = _{ Add | Subtract | Multiply | Divide }
Add = { "+" }
Subtract = { "-" }
Multiply = { "*" }
Divide = { "/" }
CmpInfixOp = _{ NotEq | GtEq | Gt | LtEq | Lt | Eq | Lt | In }
Eq = { "=" }
Gt = { ">" }
GtEq = { ">=" }
Lt = { "<" }
LtEq = { "<=" }
NotEq = { "<>" | "!=" }
In = { NotFlag? ~ ^"in" }
ExprAtomValue = _{ UnaryNot* ~ AtomicExpr ~ IsNullPostfix? }
UnaryNot = @{ NotFlag }
IsNullPostfix = { ^"is" ~ NotFlag? ~ ^"null" }
AtomicExpr = _{ Literal | Parameter | Cast | IdentifierWithOptionalContinuation | ExpressionInParentheses | UnaryOperator | SubQuery | Row }
Literal = _{ True | False | Null | Double | Decimal | Unsigned | Integer | SingleQuotedString }
True = { ^"true" }
False = { ^"false" }
Null = { ^"null" }
Decimal = @{ Integer ~ ("." ~ ASCII_DIGIT*) }
Double = @{ Integer ~ ("." ~ ASCII_DIGIT*)? ~ (^"e" ~ Integer) }
Integer = @{ ("+" | "-")? ~ ASCII_DIGIT+ }
Unsigned = @{ ASCII_DIGIT+ }
// TODO: Handle dollar-quoted string literals.
SingleQuotedString = @{ "'" ~ ("''" | (!("'") ~ ANY))* ~ "'" }
Parameter = @{ "$" ~ Unsigned }
// Postgres permits qualified object names with a single identifier
// part, 2 parts plus a function invocation, 3 parts, or 3 parts
// plus a function invocation. For simplicity, assume that an
// arbitrary number of qualifications (e.g. "a.b.c.d[...]") are
// supported.
// TODO: Disallow whitespace where it shouldn't be.
IdentifierWithOptionalContinuation = { Identifier ~ QualifiedIdentifierContinuation* ~ FunctionInvocationContinuation? }
QualifiedIdentifierContinuation = ${ "." ~ Identifier }
FunctionInvocationContinuation = { "(" ~ (CountAsterisk | FunctionArgs)? ~ ")" }
// TODO: Support named argument notation
// (`my_func(name => value)`).
FunctionArgs = { Distinct? ~ (Expr ~ ("," ~ Expr)*)? }
CountAsterisk = { "*" }
ExpressionInParentheses = { "(" ~ Expr ~ ")" }
Cast = { ^"cast" ~ "(" ~ Expr ~ ^"as" ~ TypeCast ~ ")" }
TypeCast = _{ TypeAny | ColumnDefType }
ColumnDefType = { TypeBool | TypeDecimal | TypeDouble | TypeInt | TypeNumber
| TypeScalar | TypeString | TypeText | TypeUnsigned | TypeVarchar }
TypeAny = { ^"any" }
TypeBool = { (^"boolean" | ^"bool") }
TypeDecimal = { ^"decimal" }
TypeDouble = { ^"double" }
TypeInt = { (^"integer" | ^"int") }
TypeNumber = { ^"number" }
TypeScalar = { ^"scalar" }
TypeString = { ^"string" }
TypeText = { ^"text" }
TypeUnsigned = { ^"unsigned" }
TypeVarchar = { ^"varchar" ~ "(" ~ Unsigned ~ ")" }
UnaryOperator = _{ Exists }
Exists = { NotFlag? ~ ^"exists" ~ SubQuery }
Row = { "(" ~ Expr ~ ("," ~ Expr)* ~ ")" }
Distinct = { ^"distinct" }
NotFlag = { ^"not" }
EOF = { EOI | ";" }
WHITESPACE = _{ " " | "\t" | "\n" | "\r\n" }

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//! Unit tests for identifier and object name parsing within expressions.
use crate::{Expr, escape_identifier};
#[test]
fn escaper_escapes() {
assert_eq!(escape_identifier("hello"), r#""hello""#);
assert_eq!(escape_identifier("hello world"), r#""hello world""#);
assert_eq!(
escape_identifier(r#""hello" "world""#),
r#""""hello"" ""world""""#
);
}
#[test]
fn qualified_obj_name_parses() {
assert_eq!(
Expr::try_from(r#""""Hello"", World! 四十二".deep_thought"#),
Ok(Expr::ObjName(vec![
r#""Hello", World! 四十二"#.to_owned(),
"deep_thought".to_owned(),
])),
);
}
#[test]
fn misquoted_ident_fails_to_parse() {
assert!(Expr::try_from(r#""Hello, "World!""#).is_err());
}
#[test]
fn unquoted_ident_lowercased() {
assert_eq!(
Expr::try_from("HeLlO_WoRlD"),
Ok(Expr::ObjName(vec!["hello_world".to_owned()])),
);
}

370
phono-pestgros/src/lib.rs Normal file
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@ -0,0 +1,370 @@
//! Incomplete but useful parser and generator for Postgres flavored SQL
//! expressions and more, based on a modified version of the
//! [official Pest SQL grammar](https://github.com/pest-parser/pest/blob/79dd30d11aab6f0fba3cd79bd48f456209b966b3/grammars/src/grammars/sql.pest).
//!
//! ## Example
//!
//! ```
//! use phono_pestgros::{ArithOp, BoolOp, Datum, Expr, InfixOp};
//!
//! # fn main() -> Result<(), Box<dyn Error>> {
//! let expr = Expr::try_from("3 + 5 < 10")?;
//!
//! assert_eq!(expr, Expr::Infix {
//! lhs: Box::new(Expr::Infix {
//! lhs: Box::new(Expr::Literal(Datum::Numeric(Some(3.into())))),
//! op: InfixOp::ArithInfix(ArithOp::Add),
//! rhs: Box::new(Expr::Literal(Datum::Numeric(Some(5.into())))),
//! }),
//! op: InfixOp::BoolInfix(BoolOp::Lt),
//! rhs: Box::new(Expr::Literal(Datum::Numeric(Some(10.into())))),
//! });
//!
//! assert_eq!(QueryBuilder::try_from(expr).sql(), "(($1) + ($2)) < ($3)");
//! # Ok(())
//! # }
//! ```
use std::{str::FromStr, sync::LazyLock};
use bigdecimal::BigDecimal;
use pest::{
Parser as _,
iterators::{Pair, Pairs},
pratt_parser::PrattParser,
};
use pest_derive::Parser;
pub use crate::datum::Datum;
mod datum;
mod query_builders;
#[cfg(test)]
mod fragment_tests;
#[cfg(test)]
mod func_invocation_tests;
#[cfg(test)]
mod identifier_tests;
#[cfg(test)]
mod literal_tests;
#[cfg(test)]
mod op_tests;
/// Given a raw identifier (such as a table name, column name, etc.), format it
/// so that it may be safely interpolated into a SQL query.
///
/// Note that in PostgreSQL, unquoted identifiers are case-insensitive (or,
/// rather, they are always implicitly converted to lowercase), while quoted
/// identifiers are case-sensitive. The caller of this function is responsible
/// for performing conversion to lowercase as appropriate.
pub fn escape_identifier(identifier: &str) -> String {
// Escaping identifiers for Postgres is fairly easy, provided that the input is
// already known to contain no invalid multi-byte sequences. Backslashes may
// remain as-is, and embedded double quotes are escaped simply by doubling
// them (`"` becomes `""`). Refer to the PQescapeInternal() function in
// libpq (fe-exec.c) and Diesel's PgQueryBuilder::push_identifier().
format!("\"{0}\"", identifier.replace('"', "\"\""))
}
/// Decodes a SQL representation of an identifier. If the input is unquoted, it
/// is converted to lowercase. If it is double quoted, the surrounding quotes
/// are stripped and escaped inner double quotes (double-double quotes, if you
/// will) are converted to single-double quotes. The opposite of
/// [`escape_identifier`], sort of.
///
/// Assumes that the provided identifier is well-formed. Basic gut checks are
/// performed, but they are non-exhaustive.
///
/// `U&"..."`-style escaped Unicode identifiers are not yet supported.
fn parse_ident(value: &str) -> String {
assert!(
!value.to_lowercase().starts_with("u&"),
"escaped Unicode identifiers are not supported"
);
if value.starts_with('"') {
assert!(value.ends_with('"'), "malformed double-quoted identifier");
{
// Strip first and last characters.
let mut chars = value.chars();
chars.next();
chars.next_back();
chars.as_str()
}
.replace(r#""""#, r#"""#)
} else {
// TODO: assert validity with regex
value.to_lowercase()
}
}
/// Decodes a single-quoted string literal. Removes surrounding quotes and
/// replaces embedded single quotes (double-single quotes) with single-single
/// quotes.
///
/// Assumes that the provided identifier is well-formed. Basic gut checks are
/// performed, but they are non-exhaustive.
///
/// `E'...'`-style, dollar-quoted, and other (relatively) uncommon formats for
/// text literals are not yet supported.
fn parse_text_literal(value: &str) -> String {
assert!(value.starts_with('\'') && value.ends_with('\''));
{
// Strip first and last characters.
let mut chars = value.chars();
chars.next();
chars.next_back();
chars.as_str()
}
.replace("''", "'")
}
/// Primary parser and code generation for [`Rule`] types.
#[derive(Parser)]
#[grammar = "src/grammar.pest"]
struct PsqlParser;
/// Secondary parser configuration for handling operator precedence.
static PRATT_PARSER: LazyLock<PrattParser<Rule>> = LazyLock::new(|| {
use pest::pratt_parser::{
Assoc::{Left, Right},
Op,
};
PrattParser::new()
.op(Op::infix(Rule::Or, Left))
.op(Op::infix(Rule::Between, Left))
.op(Op::infix(Rule::And, Left))
.op(Op::prefix(Rule::UnaryNot))
.op(Op::infix(Rule::Eq, Right)
| Op::infix(Rule::NotEq, Right)
| Op::infix(Rule::Gt, Right)
| Op::infix(Rule::GtEq, Right)
| Op::infix(Rule::Lt, Right)
| Op::infix(Rule::LtEq, Right)
| Op::infix(Rule::In, Right))
// Official Pest example overstates the concat operator's precedence. It
// should be lower precedence than add/subtract.
.op(Op::infix(Rule::ConcatInfixOp, Left))
.op(Op::infix(Rule::Add, Left) | Op::infix(Rule::Subtract, Left))
.op(Op::infix(Rule::Multiply, Left) | Op::infix(Rule::Divide, Left))
.op(Op::postfix(Rule::IsNullPostfix))
});
/// Represents a SQL expression. An expression is a collection of values and
/// operators that theoretically evaluates to some value, such as a boolean
/// condition, an object name, or a string dynamically derived from other
/// values. An expression is *not* a complete SQL statement, command, or query.
#[derive(Clone, Debug, PartialEq)]
pub enum Expr {
Infix {
lhs: Box<Expr>,
op: InfixOp,
rhs: Box<Expr>,
},
Literal(Datum),
ObjName(Vec<String>),
FnCall {
name: Vec<String>,
args: FnArgs,
},
Not(Box<Expr>),
Nullness {
is_null: bool,
expr: Box<Expr>,
},
}
impl TryFrom<&str> for Expr {
type Error = ParseError;
fn try_from(value: &str) -> Result<Self, Self::Error> {
// `ExprRoot` is a silent rule which simply dictates that the inner
// `Expr` rule must consume the entire input.
let pairs = PsqlParser::parse(Rule::ExprRoot, value)?;
parse_expr_pairs(pairs)
}
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum InfixOp {
ArithInfix(ArithOp),
BoolInfix(BoolOp),
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum ArithOp {
Add,
Concat,
Div,
Mult,
Sub,
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum BoolOp {
And,
Or,
Eq,
Gt,
Gte,
Lt,
Lte,
Neq,
}
#[derive(Clone, Debug, PartialEq)]
pub enum FnArgs {
CountAsterisk,
Exprs {
/// `true` for aggregator invocations with the `DISTINCT` keyword
/// specified.
distinct_flag: bool,
exprs: Vec<Expr>,
},
}
/// Recursive helper, which does most of the work to convert [`pest`]'s pattern
/// matching output to a usable syntax tree.
fn parse_expr_pairs(expr_pairs: Pairs<'_, Rule>) -> Result<Expr, ParseError> {
PRATT_PARSER
.map_primary(|pair| match pair.as_rule() {
Rule::Expr | Rule::ExpressionInParentheses => parse_expr_pairs(pair.into_inner()),
Rule::Decimal | Rule::Double | Rule::Integer | Rule::Unsigned => Ok(Expr::Literal(
Datum::Numeric(Some(BigDecimal::from_str(pair.as_str()).expect(
"parsed numeric values should always be convertible to BigDecimal",
))),
)),
Rule::SingleQuotedString => Ok(Expr::Literal(Datum::Text(Some(parse_text_literal(pair.as_str()))))),
Rule::IdentifierWithOptionalContinuation => {
let mut name: Vec<String> = vec![];
let mut fn_args: Option<FnArgs> = None;
let inner = pair.into_inner();
for inner_pair in inner {
match inner_pair.as_rule() {
Rule::Identifier => {
name.push(parse_ident(inner_pair.as_str()));
}
Rule::QualifiedIdentifierContinuation => {
let ident_cont = inner_pair.as_str();
assert!(
ident_cont.starts_with('.'),
"QualifiedIdentifierContinuation should always start with the infix dot",
);
name.push(parse_ident({
// Strip leading dot.
let mut chars = ident_cont.chars();
chars.next();
chars.as_str()
}));
}
Rule::FunctionInvocationContinuation => {
fn_args = Some(parse_function_invocation_continuation(inner_pair)?);
}
_ => unreachable!(
"IdentifierWithOptionalContinuation has only 3 valid child rules",
),
}
}
Ok(if let Some(fn_args) = fn_args {
Expr::FnCall { name, args: fn_args }
} else {
Expr::ObjName(name)
})
}
rule => Err(ParseError::UnknownRule(rule)),
})
.map_infix(|lhs, op, rhs| Ok(Expr::Infix {
lhs: Box::new(lhs?),
op: match op.as_rule() {
Rule::Add => InfixOp::ArithInfix(ArithOp::Add),
Rule::ConcatInfixOp => InfixOp::ArithInfix(ArithOp::Concat),
Rule::Divide => InfixOp::ArithInfix(ArithOp::Div),
Rule::Multiply => InfixOp::ArithInfix(ArithOp::Mult),
Rule::Subtract => InfixOp::ArithInfix(ArithOp::Sub),
Rule::And => InfixOp::BoolInfix(BoolOp::And),
Rule::Eq => InfixOp::BoolInfix(BoolOp::Eq),
Rule::Gt => InfixOp::BoolInfix(BoolOp::Gt),
Rule::GtEq => InfixOp::BoolInfix(BoolOp::Gte),
Rule::Lt => InfixOp::BoolInfix(BoolOp::Lt),
Rule::LtEq => InfixOp::BoolInfix(BoolOp::Lte),
Rule::NotEq => InfixOp::BoolInfix(BoolOp::Neq),
Rule::Or => InfixOp::BoolInfix(BoolOp::Or),
rule => Err(ParseError::UnknownRule(rule))?,
},
rhs: Box::new(rhs?),
}))
.map_prefix(|op, child| Ok(match op.as_rule() {
Rule::UnaryNot => Expr::Not(Box::new(child?)),
rule => Err(ParseError::UnknownRule(rule))?,
}))
.map_postfix(|child, op| Ok(match op.as_rule() {
Rule::IsNullPostfix => Expr::Nullness {
is_null: op
.into_inner()
.next()
.map(|inner| inner.as_rule()) != Some(Rule::NotFlag),
expr: Box::new(child?),
},
rule => Err(ParseError::UnknownRule(rule))?,
}))
.parse(expr_pairs)
}
fn parse_function_invocation_continuation(pair: Pair<'_, Rule>) -> Result<FnArgs, ParseError> {
let mut cont_inner_iter = pair.into_inner();
let fn_args = if let Some(cont_inner) = cont_inner_iter.next() {
match cont_inner.as_rule() {
Rule::FunctionArgs => {
let mut distinct_flag = false;
let mut exprs: Vec<Expr> = vec![];
for arg_inner in cont_inner.into_inner() {
match arg_inner.as_rule() {
Rule::Distinct => {
distinct_flag = true;
}
Rule::Expr => {
exprs.push(parse_expr_pairs(arg_inner.into_inner())?);
}
_ => unreachable!(
"only valid children of FunctionArgs are Distinct and Expr"
),
}
}
FnArgs::Exprs {
distinct_flag,
exprs,
}
}
Rule::CountAsterisk => FnArgs::CountAsterisk,
_ => unreachable!(
"only valid children of FunctionInvocationContinuation are FunctionArgs and CountAsterisk"
),
}
} else {
FnArgs::Exprs {
distinct_flag: false,
exprs: vec![],
}
};
assert!(
cont_inner_iter.next().is_none(),
"function should have consumed entire FunctionInvocationContinuation pair",
);
Ok(fn_args)
}
#[derive(Clone, Debug, PartialEq, thiserror::Error)]
#[error("parse error")]
pub enum ParseError {
#[error("unknown rule")]
UnknownRule(Rule),
#[error("pest failed to parse: {0}")]
Pest(pest::error::Error<Rule>),
}
impl From<pest::error::Error<Rule>> for ParseError {
fn from(value: pest::error::Error<Rule>) -> Self {
Self::Pest(value)
}
}

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@ -0,0 +1,30 @@
use std::error::Error;
use crate::{Datum, Expr};
#[test]
fn text_parses() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from("'Hello, World!'")?,
Expr::Literal(Datum::Text(Some("Hello, World!".to_owned())))
);
Ok(())
}
#[test]
fn escaped_quotes_parse() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from("'''Hello, World!'''")?,
Expr::Literal(Datum::Text(Some("'Hello, World!'".to_owned())))
);
Ok(())
}
#[test]
fn numeric_parses() -> Result<(), Box<dyn Error>> {
assert_eq!(
Expr::try_from("1234.56")?,
Expr::Literal(Datum::Numeric(Some("1234.56".parse()?)))
);
Ok(())
}

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//! Unit tests for infix operator parsing within expressions.
use crate::{ArithOp, Datum, Expr, InfixOp};
#[test]
fn add_op_parses() {
assert_eq!(
// https://xkcd.com/3184/
Expr::try_from("six + 7"),
Ok(Expr::Infix {
lhs: Box::new(Expr::ObjName(vec!["six".to_owned()])),
op: InfixOp::ArithInfix(ArithOp::Add),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(7.into())))),
})
);
}
#[test]
fn mult_op_parses() {
assert_eq!(
Expr::try_from("six * 7"),
Ok(Expr::Infix {
lhs: Box::new(Expr::ObjName(vec!["six".to_owned()])),
op: InfixOp::ArithInfix(ArithOp::Mult),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(7.into())))),
})
);
}
#[test]
fn arith_precedence() {
assert_eq!(
Expr::try_from("(1 + 2) * 3 + 4"),
Ok(Expr::Infix {
lhs: Box::new(Expr::Infix {
lhs: Box::new(Expr::Infix {
lhs: Box::new(Expr::Literal(Datum::Numeric(Some(1.into())))),
op: InfixOp::ArithInfix(ArithOp::Add),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(2.into())))),
}),
op: InfixOp::ArithInfix(ArithOp::Mult),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(3.into())))),
}),
op: InfixOp::ArithInfix(ArithOp::Add),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(4.into())))),
})
);
assert_eq!(
Expr::try_from("1 - 2 / (3 - 4)"),
Ok(Expr::Infix {
lhs: Box::new(Expr::Literal(Datum::Numeric(Some(1.into())))),
op: InfixOp::ArithInfix(ArithOp::Sub),
rhs: Box::new(Expr::Infix {
lhs: Box::new(Expr::Literal(Datum::Numeric(Some(2.into())))),
op: InfixOp::ArithInfix(ArithOp::Div),
rhs: Box::new(Expr::Infix {
lhs: Box::new(Expr::Literal(Datum::Numeric(Some(3.into())))),
op: InfixOp::ArithInfix(ArithOp::Sub),
rhs: Box::new(Expr::Literal(Datum::Numeric(Some(4.into())))),
}),
})
})
);
}
#[test]
fn is_null_parses() {
assert_eq!(
Expr::try_from("my_var is null"),
Ok(Expr::Nullness {
is_null: true,
expr: Box::new(Expr::ObjName(vec!["my_var".to_owned()]))
}),
);
}
#[test]
fn is_not_null_parses() {
assert_eq!(
Expr::try_from("my_var is not null"),
Ok(Expr::Nullness {
is_null: false,
expr: Box::new(Expr::ObjName(vec!["my_var".to_owned()]))
}),
);
}
#[test]
fn not_parses() {
assert_eq!(
Expr::try_from("not my_var"),
Ok(Expr::Not(Box::new(Expr::ObjName(vec![
"my_var".to_owned()
])))),
);
}
#[test]
fn repeated_nots_parse() {
assert_eq!(
Expr::try_from("not not my_var"),
Ok(Expr::Not(Box::new(Expr::Not(Box::new(Expr::ObjName(
vec!["my_var".to_owned()]
)))))),
);
}

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//! Assorted utilities for dynamically constructing and manipulating [`sqlx`]
//! queries.
use sqlx::{Postgres, QueryBuilder};
use crate::{ArithOp, BoolOp, Datum, Expr, FnArgs, InfixOp, escape_identifier};
/// Representation of a partial, parameterized SQL query. Allows callers to
/// build queries iteratively and dynamically, handling parameter numbering
/// (`$1`, `$2`, `$3`, ...) automatically.
///
/// This is similar to [`sqlx::QueryBuilder`], except that [`QueryFragment`]
/// objects are composable and may be concatenated to each other.
#[derive(Clone, Debug, PartialEq)]
pub struct QueryFragment {
/// SQL string, split wherever there is a query parameter. For example,
/// `select * from foo where id = $1 and status = $2` is represented along
/// the lines of `["select * from foo where id = ", " and status = ", ""]`.
/// `plain_sql` should always have exactly one more element than `params`.
plain_sql: Vec<String>,
params: Vec<Datum>,
}
impl QueryFragment {
/// Validate invariants. Should be run immediately before returning any
/// useful output.
fn gut_checks(&self) {
assert!(self.plain_sql.len() == self.params.len() + 1);
}
/// Parse from a SQL string with no parameters.
pub fn from_sql(sql: &str) -> Self {
Self {
plain_sql: vec![sql.to_owned()],
params: vec![],
}
}
/// Convenience function to construct an empty value.
pub fn empty() -> Self {
Self::from_sql("")
}
/// Parse from a parameter value with no additional SQL. (Renders as `$n`,
/// where`n` is the appropriate parameter index.)
pub fn from_param(param: Datum) -> Self {
Self {
plain_sql: vec!["".to_owned(), "".to_owned()],
params: vec![param],
}
}
/// Append another query fragment to this one.
pub fn push(&mut self, mut other: QueryFragment) {
let tail = self
.plain_sql
.pop()
.expect("already asserted that vec contains at least 1 item");
let head = other
.plain_sql
.first()
.expect("already asserted that vec contains at least 1 item");
self.plain_sql.push(format!("{tail}{head}"));
for value in other.plain_sql.drain(1..) {
self.plain_sql.push(value);
}
self.params.append(&mut other.params);
}
/// Combine multiple QueryFragments with a separator, similar to
/// [`Vec::join`].
pub fn join<I: IntoIterator<Item = Self>>(fragments: I, sep: Self) -> Self {
let mut acc = QueryFragment::from_sql("");
let mut iter = fragments.into_iter();
let mut fragment = match iter.next() {
Some(value) => value,
None => return acc,
};
for next_fragment in iter {
acc.push(fragment);
acc.push(sep.clone());
fragment = next_fragment;
}
acc.push(fragment);
acc
}
/// Convenience method equivalent to:
/// `QueryFragment::concat(fragments, QueryFragment::from_sql(""))`
pub fn concat<I: IntoIterator<Item = Self>>(fragments: I) -> Self {
Self::join(fragments, Self::from_sql(""))
}
/// Checks whether value is empty. A value is considered empty if the
/// resulting SQL code is 0 characters long.
pub fn is_empty(&self) -> bool {
self.gut_checks();
self.plain_sql.len() == 1
&& self
.plain_sql
.first()
.expect("already checked that len == 1")
.is_empty()
}
}
impl From<Expr> for QueryFragment {
fn from(value: Expr) -> Self {
match value {
Expr::Infix { lhs, op, rhs } => Self::concat([
// RHS and LHS must be explicitly wrapped in parentheses to
// ensure correct precedence, because parentheses are taken
// into account **but not preserved** when parsing.
Self::from_sql("("),
(*lhs).into(),
Self::from_sql(") "),
op.into(),
Self::from_sql(" ("),
(*rhs).into(),
Self::from_sql(")"),
]),
Expr::Literal(datum) => Self::from_param(datum),
Expr::ObjName(idents) => Self::join(
idents
.iter()
.map(|ident| Self::from_sql(&escape_identifier(ident))),
Self::from_sql("."),
),
Expr::Not(expr) => {
Self::concat([Self::from_sql("not ("), (*expr).into(), Self::from_sql(")")])
}
Expr::Nullness { is_null, expr } => Self::concat([
Self::from_sql("("),
(*expr).into(),
Self::from_sql(if is_null {
") is null"
} else {
") is not null"
}),
]),
Expr::FnCall { name, args } => {
let mut fragment = Self::empty();
fragment.push(Self::join(
name.iter()
.map(|ident| Self::from_sql(&escape_identifier(ident))),
Self::from_sql("."),
));
fragment.push(Self::from_sql("("));
match args {
FnArgs::CountAsterisk => {
fragment.push(Self::from_sql("*"));
}
FnArgs::Exprs {
distinct_flag,
exprs,
} => {
if distinct_flag {
fragment.push(Self::from_sql("distinct "));
}
fragment.push(Self::join(
exprs.into_iter().map(|expr| {
// Wrap arguments in parentheses to ensure they
// are appropriately distinguishable from each
// other regardless of the presence of extra
// commas.
Self::concat([
Self::from_sql("("),
expr.into(),
Self::from_sql(")"),
])
}),
Self::from_sql(", "),
));
}
}
fragment.push(Self::from_sql(")"));
fragment
}
}
}
}
impl From<InfixOp> for QueryFragment {
fn from(value: InfixOp) -> Self {
Self::from_sql(match value {
InfixOp::ArithInfix(ArithOp::Add) => "+",
InfixOp::ArithInfix(ArithOp::Concat) => "||",
InfixOp::ArithInfix(ArithOp::Div) => "/",
InfixOp::ArithInfix(ArithOp::Mult) => "*",
InfixOp::ArithInfix(ArithOp::Sub) => "-",
InfixOp::BoolInfix(BoolOp::And) => "and",
InfixOp::BoolInfix(BoolOp::Or) => "or",
InfixOp::BoolInfix(BoolOp::Eq) => "=",
InfixOp::BoolInfix(BoolOp::Gt) => ">",
InfixOp::BoolInfix(BoolOp::Gte) => ">=",
InfixOp::BoolInfix(BoolOp::Lt) => "<",
InfixOp::BoolInfix(BoolOp::Lte) => "<=",
InfixOp::BoolInfix(BoolOp::Neq) => "<>",
})
}
}
impl From<QueryFragment> for QueryBuilder<'_, Postgres> {
fn from(value: QueryFragment) -> Self {
value.gut_checks();
let mut builder = QueryBuilder::new("");
let mut param_iter = value.params.into_iter();
for plain_sql in value.plain_sql {
builder.push(plain_sql);
if let Some(param) = param_iter.next() {
param.push_bind_onto(&mut builder);
}
}
builder
}
}
impl From<Expr> for QueryBuilder<'_, Postgres> {
fn from(value: Expr) -> Self {
Self::from(QueryFragment::from(value))
}
}
/// Helper type to make it easier to build and reason about multiple related SQL
/// queries.
#[derive(Clone, Debug)]
pub struct SelectQuery {
/// Query fragment following (not including) "select ".
pub selection: QueryFragment,
/// Query fragment following (not including) "from ".
pub source: QueryFragment,
/// Query fragment following (not including) "where ", or empty if not
/// applicable.
pub filters: QueryFragment,
/// Query fragment following (not including) "order by ", or empty if not
/// applicable.
pub order: QueryFragment,
/// Query fragment following (not including) "limit ", or empty if not
/// applicable.
pub limit: QueryFragment,
}
impl From<SelectQuery> for QueryFragment {
fn from(value: SelectQuery) -> Self {
let mut result = QueryFragment::from_sql("select ");
result.push(value.selection);
result.push(QueryFragment::from_sql(" from "));
result.push(value.source);
if !value.filters.is_empty() {
result.push(QueryFragment::from_sql(" where "));
result.push(value.filters);
}
if !value.order.is_empty() {
result.push(QueryFragment::from_sql(" order by "));
result.push(value.order);
}
if !value.limit.is_empty() {
result.push(QueryFragment::from_sql(" limit "));
result.push(value.limit);
}
result
}
}
impl From<SelectQuery> for QueryBuilder<'_, Postgres> {
fn from(value: SelectQuery) -> Self {
QueryFragment::from(value).into()
}
}