yyyi_ru/mtgott/src/parser.rs

924 lines
37 KiB
Rust

use std::collections::HashMap;
use crate::charclasses::{is_special_name, is_digit, is_lnspace,
is_normal_word_constituent, is_whitespace};
use std::fmt::{self, Display, Formatter};
use std::error::Error;
#[derive(Debug, PartialEq, Clone)]
pub struct NewLambdaExpression {
pub local_var_array: Vec<usize>,
/* We store all expression trees in giant vector in MTGOTT object.
* We fill this global (to all the files) vector at compile time, and it can be used
* to access expressions (parsed source code) from any dynamically created lambda */
pub expr_id: usize,
}
#[derive(Debug, PartialEq, Clone)]
pub enum Expression {
Root,
Local(usize),
Attribute(Box<Expression>, String),
Get(Box<Expression>, Box<Expression>),
Call(Box<Expression>, Box<Expression>),
Lambda(NewLambdaExpression),
Int(u64),
Str(String),
Arr(Vec<Expression>),
}
#[derive(Debug, PartialEq, Clone)]
pub struct IfSubElement {
pub branches: Vec<Element>,
pub conditions: Vec<Expression>,
}
#[derive(Debug, PartialEq, Clone)]
pub struct ForSubElement {
pub iterable: Expression,
pub core: Element,
// Either "\n", " " or ""
pub separator: String,
}
#[derive(Debug, PartialEq, Clone)]
pub enum SubElement {
Static(String),
// ======== Other are dynamic ========
If(IfSubElement),
// Both for {{}} and {[]}
InsertExpr(Expression),
For(ForSubElement),
Let(Expression, Element),
}
pub type Element = Vec<SubElement>;
#[derive(Debug, PartialEq)]
pub enum Plemege {
Expression(Expression),
/* .0 is argc, .1 is the actual body
* I could compile Element into Expression "on-the-run", but I consider this
* bad for performance + not that good for improving loc count */
Element(usize, Element),
Package(HashMap<String, Plemege>),
}
#[derive(Debug, PartialEq)]
pub enum FileParsingErrorKind {
expected_pack_opening_or_element_opening_or_pack_ending,
expected_pack_opening_or_element_opening_or_eof,
unmatched_pack_ending_tag,
expected_pack_name,
illegal_pack_name,
pack_member_name_already_occupied,
expected_pack_tag_end,
expected_pack_opening_tag_end_or_assignment_operator,
expected_element_name,
incorrect_block_ending_tag_expected_end_element,
illegal_element_name,
expected_argument_name_or_eldef_opening_tag_end,
illegal_argument_name,
repeated_argument_name,
expected_command_name,
incorrect_block_ending_tag_expected_normal,
expected_write_tag_end_after_expression,
expected_roughinsert_tag_end_after_expression,
illegal_command_name,
expected_cmd_tag_end,
expected_variable_name,
illegal_variable_name,
expected_assignment_operator,
expected_cmd_tag_end_after_expression,
expected_comma_or_colon,
expected_colon,
forloop_key_and_val_cant_have_same_name,
incorrect_block_ending_tag_expected_normal_or_lf_gap_nogap_or_forloop,
incorrect_block_ending_tag_expected_normal_or_endif_or_else_or_else_if,
incorrect_block_ending_tag_expected_normal_or_endif,
expected_nonempty_expression,
expected_closing_round_bracket,
cant_start_word_immediately_after_digit,
integer_parsing_error,
expected_attribute_name_after_dot,
illegal_attribute_name,
illegal_lambda_argument_name,
expected_closing_square_bracket,
unmatched_element_ending_tag,
unmatched_magic_block_ending_tag,
recursion_limit_exceeded,
leave_space_between_dollar_argument_and_other_arguments,
cant_use_dollar_in_expression_of_element_without_dollar_argument,
illegal_dollar_level_attribute_name,
expected_round_brackets_open_or_dollar_or_word_or_int_or_string_or_square_bracket_open,
unmatched_double_quotes,
unmatched_closing_square_bracket,
}
use self::FileParsingErrorKind::*;
#[derive(Debug, PartialEq)]
pub struct FileParsingError {
pub kind: FileParsingErrorKind,
pub p1: usize,
pub p2: usize,
}
impl FileParsingError {
fn new(kind: FileParsingErrorKind, p1: usize, p2: usize) -> Self {
Self{kind, p1, p2}
}
}
impl Display for FileParsingErrorKind {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self)
}
}
impl Display for FileParsingError {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
write!(f, "FileParsingError: {} at positions {} to {}", self.kind, self.p1, self.p2)
}
}
impl Error for FileParsingError {}
struct Parser<'a> {
text: &'a str,
p: usize,
/* We can use `this` keyword that refers to current file
* (current file can be either package or element), it does not matter, this_meaning contains expression
* that extracts object representing this file from root.
* Here we abuse the fact that Parser corresponds to one file */
this_meaning: Expression,
source_expr: &'a mut Vec<Expression>
}
impl<'a> Parser<'a> {
fn here(&self)->Option<char> {
self.text[self.p..].chars().next()
}
fn is_ahead(&self, substr: &str)->bool {
self.text[self.p..].starts_with(substr)
}
fn is_char_ahead(&self, ch: char) -> bool {
match self.here() {
Some(cha) => cha == ch,
None => false,
}
}
fn is_digit_ahead(&self) -> bool {
match self.here() {
Some(ch) => is_digit(ch),
None => false,
}
}
fn is_word_ahead(&self) -> bool {
match self.here() {
Some(ch) => is_normal_word_constituent(ch),
None => false,
}
}
fn advance(&mut self) {
self.p += self.text[self.p..].chars().next().unwrap().len_utf8();
}
fn skip_whitespace(&mut self) {
loop {
match self.here() {
Some(ch ) => if !is_whitespace(ch) {
break
} else { self.advance(); }
None => break
}
}
}
fn skip_normal_word(&mut self){
loop {
match self.here() {
Some(ch ) => if !is_normal_word_constituent(ch) {
break
} else { self.advance(); }
None => break
}
}
}
fn next_p(&self) -> usize {
match self.text[self.p..].char_indices().next() {
Some((off, _)) => self.p + off,
None => self.p,
}
}
fn new_unexpected_char_error(&self, kind: FileParsingErrorKind) -> FileParsingError {
FileParsingError::new(kind, self.p, self.next_p())
}
fn parse_pack_plus_ending(
&mut self, top: bool, recc: u32
) -> Result<Plemege, FileParsingError> {
self.check_recursion_limit(recc)?;
let mut res: HashMap<String, Plemege> = HashMap::new();
loop {
self.skip_whitespace();
if self.p == self.text.len() {
return if top {
Ok(Plemege::Package(res))
} else {
Err(self.new_unexpected_char_error(expected_pack_opening_or_element_opening_or_pack_ending))
}
}
if self.is_ahead("{$}") {
return if top {
Err(FileParsingError::new(unmatched_pack_ending_tag, self.p, self.p + 3))
} else {
self.p += 3;
Ok(Plemege::Package(res))
};
} else if self.is_ahead("{$") {
self.p += 2;
self.skip_whitespace();
let p1 = self.p;
self.skip_normal_word();
if self.p == p1 {
return Err(self.new_unexpected_char_error(expected_pack_name))
}
let child_name: &str = &self.text[p1..self.p];
if is_special_name(child_name) {
return Err(FileParsingError::new(illegal_pack_name, p1, self.p))
}
if let Some(_) = res.get(child_name) {
return Err(FileParsingError::new(pack_member_name_already_occupied, p1, self.p))
}
self.skip_whitespace();
if self.is_ahead("$}"){
self.p += 2;
res.insert(String::from(child_name), self.parse_pack_plus_ending(false, recc - 1)?);
} else if self.is_char_ahead('=') {
self.p += 1;
self.skip_whitespace();
res.insert(String::from(child_name), Plemege::Expression(
self.parse_expression(&vec![], &mut vec![],recc - 1)?
));
if !self.is_ahead("$}"){
return Err(self.new_unexpected_char_error(expected_pack_tag_end))
}
self.p += 2;
} else {
return Err(self.new_unexpected_char_error(expected_pack_opening_tag_end_or_assignment_operator))
}
} else if self.is_ahead("{@") {
self.p += 2;
self.skip_whitespace();
let p1 = self.p;
self.skip_normal_word();
if p1 == self.p {
return Err(FileParsingError::new(expected_element_name, p1, self.p))
}
let child_name = &self.text[p1..self.p];
if is_special_name(child_name) {
return Err(FileParsingError::new(illegal_element_name, p1, self.p))
}
if let Some(_) = res.get(child_name) {
return Err(FileParsingError::new(pack_member_name_already_occupied, p1, self.p))
}
let mut arg_names: Vec<&str> = Vec::new();
/* Some functions have $ as their first argument, we will let them have it */
self.skip_whitespace();
if self.is_char_ahead('$') {
arg_names.push("$");
self.p += 1;
if self.is_word_ahead() {
return Err(FileParsingError::new(leave_space_between_dollar_argument_and_other_arguments,
self.p - 1, self.next_p()));
}
}
loop {
self.skip_whitespace();
if self.is_ahead("@}") {
self.p += 2;
break
}
let p1 = self.p;
self.skip_normal_word();
if p1 == self.p {
return Err(FileParsingError::new(expected_argument_name_or_eldef_opening_tag_end, p1, self.p))
}
let arg_name: &str = &self.text[p1..self.p];
if is_special_name(arg_name) {
return Err(FileParsingError::new(illegal_argument_name, p1, self.p))
}
if arg_names.iter().any(|b: &&str| *b == arg_name) {
return Err(FileParsingError::new(repeated_argument_name, p1, self.p))
}
arg_names.push(arg_name);
}
let (child_el, end_cmd): (Element, ReasonOfElementEnd) = self.parse_element_plus_ending_tag(
&arg_names, recc - 1)?;
if !matches!(end_cmd.cmd, BlockEndingTag::END_ELEMENT) {
return Err(FileParsingError::new(incorrect_block_ending_tag_expected_end_element, end_cmd.p1, self.p))
}
res.insert(String::from(child_name), Plemege::Element(arg_names.len(), child_el));
} else {
return Err(self.new_unexpected_char_error(if top {
expected_pack_opening_or_element_opening_or_eof
} else {
expected_pack_opening_or_element_opening_or_pack_ending
}));
}
}
}
}
enum BlockEndingTag {
EOF,
/* This is {@} */
END_ELEMENT,
/* These tags are command tags */
/* {%} */
NORMAL,
LF,
GAP,
NOGAP,
ENDLOOP,
/* Incomplete tag (ony `{% else if` is included */
ELSE_IF,
ELSE,
ENDIF
}
struct ReasonOfElementEnd {
p1: usize,
cmd: BlockEndingTag,
}
fn fix_whitespaces_in_element(subels: &mut Vec<SubElement>) {
let n = subels.len();
if n > 0 {
match &mut subels[0] {
SubElement::Static(org) => {
let mut ta = 0;
for p in 0..org.len(){
if !is_whitespace(org.as_bytes()[p] as char) {
ta = p; break
}
if org.as_bytes()[p] == b'\n' {
ta = p + 1;
}
}
*org = String::from(&org[ta..]);
},
_ => {},
}
match &mut subels[n - 1] {
SubElement::Static(org) => {
while let Some(ch) = org.chars().last() {
if is_whitespace(ch) { org.pop(); } else { break }
}
},
_ => {},
}
}
let mut min_offset = usize::MAX;
for i in 0..subels.len() {
match &mut subels[i] {
SubElement::Static(org) => {
let mut seen_online = i > 0;
let mut line_bg: usize = 0;
for p in 0..org.len() {
let ch = org.as_bytes()[p] as char;
if !is_whitespace(ch) {
if !seen_online {
seen_online = true;
min_offset = std::cmp::min(min_offset, p - line_bg)
}
} else if ch == '\n' {
line_bg = p + 1;
seen_online = false;
}
}
/* This won't cause issues on the .last() because we previously rstripped the last part */
if !seen_online{
min_offset = std::cmp::min(min_offset, org.len() - line_bg)
}
},
_ => {},
}
}
for i in 0..subels.len() {
match &mut subels[i] {
SubElement::Static(org) => {
let mut res: Vec<u8> = Vec::new();
let mut should_ignore_gap = i > 0;
let mut line_bg: usize = 0;
for p in 0..org.len() {
let ch = org.as_bytes()[p];
if ch == b'\n' {
line_bg = p + 1;
should_ignore_gap = false;
/* We handle trailing whitespaces case here */
while let Some(&ch) = res.last() {
if is_lnspace(ch as char) { res.pop(); } else { break }
}
} else if p - line_bg < min_offset && !should_ignore_gap{
continue
}
res.push(ch);
}
*org = String::from_utf8(res).unwrap();
},
_ => {},
}
}
}
impl<'a> Parser<'a> {
/* If BlockEndingCmdTag::ELSE_IF is returned, the ending tag won't be read completely,
* But in other case it would be read to the end */
fn parse_element_plus_ending_tag (
&mut self, arg_names: &Vec<&str>, recc: u32
) -> Result<(Element, ReasonOfElementEnd), FileParsingError> {
self.check_recursion_limit(recc)?;
let mut res: Vec<SubElement> = Vec::new();
let mut tp1 = self.p;
let fin_static = |p: &Parser, tp1: usize, res: &mut Vec<SubElement>| {
res.push(SubElement::Static(String::from(&p.text[tp1..p.p])))
};
/* Fixes whitespaces in static sub-elements */
let finishing_touches = |ree: ReasonOfElementEnd, mut res: Vec<SubElement>|
-> Result<(Element, ReasonOfElementEnd), FileParsingError> {
fix_whitespaces_in_element(&mut res);
Ok((res, ree))
};
loop {
if self.p == self.text.len() {
fin_static(self, tp1, &mut res);
return finishing_touches(ReasonOfElementEnd{p1: self.p, cmd: BlockEndingTag::EOF}, res);
} else if self.is_ahead("{{") {
fin_static(self, tp1, &mut res);
self.p += 2;
if !self.is_ahead("}}") {
let expr: Expression = self.parse_expression(
arg_names, &mut (0..arg_names.len()).collect(), recc)?;
res.push(SubElement::InsertExpr(
Expression::Call(
Box::new(Expression::Attribute(Box::new(Expression::Root), "sanitize".into())),
Box::new(expr))
));
if !self.is_ahead("}}") {
return Err(FileParsingError::new(expected_write_tag_end_after_expression, self.p - 2, self.p));
}
}
self.p += 2;
tp1 = self.p;
} else if self.is_ahead("{[") {
fin_static(self, tp1, &mut res);
self.p += 2;
let expr: Expression = self.parse_expression(
arg_names, &mut (0..arg_names.len()).collect(), recc)?;
res.push(SubElement::InsertExpr(expr));
if !self.is_ahead("]}") {
return Err(FileParsingError::new(expected_write_tag_end_after_expression, self.p - 2, self.p));
}
self.p += 2;
tp1 = self.p;
} else if self.is_ahead("{@}") {
fin_static(self, tp1, &mut res);
self.p += 3;
return finishing_touches(ReasonOfElementEnd{p1: self.p - 3, cmd: BlockEndingTag::END_ELEMENT}, res);
} else if self.is_ahead("{%}") {
fin_static(self, tp1, &mut res);
self.p += 3;
return finishing_touches(ReasonOfElementEnd{p1: self.p - 3, cmd: BlockEndingTag::NORMAL}, res);
} else if self.is_ahead("{%") {
fin_static(self, tp1, &mut res);
/* Might be needed if this is the ENDING cmd tag */
let p1 = self.p;
self.p += 2;
self.skip_whitespace();
let pb = self.p;
self.skip_normal_word();
if pb == self.p {
return Err(self.new_unexpected_char_error(expected_command_name))
}
let cmd = &self.text[pb..self.p];
/* Read space + expect %} and do finishing_touches */
let just_one_thing = |
pelf: &mut Parser, cmd: BlockEndingTag, res: Vec<SubElement>
| -> Result<(Element, ReasonOfElementEnd), FileParsingError> {
pelf.skip_whitespace();
if !pelf.is_ahead("%}") {
return Err(pelf.new_unexpected_char_error(expected_cmd_tag_end));
}
pelf.p += 2;
finishing_touches(ReasonOfElementEnd{p1, cmd}, res)
};
match cmd {
"lf" => return just_one_thing(self, BlockEndingTag::LF, res),
"gap" => return just_one_thing(self, BlockEndingTag::GAP, res),
"nogap" => return just_one_thing(self, BlockEndingTag::NOGAP, res),
"else" => {
self.skip_whitespace();
let ps = self.p;
self.skip_normal_word();
if ps == self.p {
return just_one_thing(self, BlockEndingTag::ELSE, res)
} else if &self.text[ps..self.p] != "if" {
return Err(FileParsingError::new(illegal_command_name, pb, self.p))
}
return finishing_touches(ReasonOfElementEnd{p1, cmd: BlockEndingTag::ELSE_IF}, res);
}
"endif" => return just_one_thing(self, BlockEndingTag::ENDIF, res),
"endloop" => return just_one_thing(self, BlockEndingTag::ENDLOOP, res),
"for" => res.push(self.parse_let(arg_names, recc - 1)?),
"if" => res.push(self.parse_if(arg_names, recc - 1)?),
"let" => res.push(self.parse_let(arg_names, recc - 1)?),
_ => return Err(FileParsingError::new(illegal_command_name, pb, self.p)),
}
tp1 = self.p;
} else {
self.advance();
}
}
}
fn parse_expression_at_cmd_tag_end(
&mut self, arg_names: &Vec<&str>, recc: u32
) -> Result<Expression, FileParsingError> {
self.check_recursion_limit(recc)?;
let expr: Expression = self.parse_expression(arg_names, &mut (0..arg_names.len()).collect(), recc - 1)?;
if !self.is_ahead("%}"){
return Err(self.new_unexpected_char_error(expected_cmd_tag_end_after_expression));
}
self.p += 2;
Ok(expr)
}
/*
* It parses expr %} block {% else if expr %} block {% else %} block {%} */
fn parse_if(
&mut self, arg_names: &Vec<&str>, recc: u32
) -> Result<SubElement, FileParsingError> {
self.check_recursion_limit(recc)?;
let mut conditions: Vec<Expression> = Vec::new();
let mut blocks: Vec<Element> = Vec::new();
loop {
let expr = self.parse_expression_at_cmd_tag_end(arg_names, recc - 1)?;
let (inner_block, ending_tag) = self.parse_element_plus_ending_tag(arg_names, recc - 1)?;
conditions.push(expr);
match ending_tag.cmd {
BlockEndingTag::ELSE | BlockEndingTag::NORMAL | BlockEndingTag::ENDIF |
BlockEndingTag::ELSE_IF => blocks.push(inner_block),
_ => return Err(FileParsingError::new(
incorrect_block_ending_tag_expected_normal_or_endif_or_else_or_else_if, ending_tag.p1, self.p)),
}
if matches!(ending_tag.cmd, BlockEndingTag::ELSE) {
let (else_block, the_end) = self.parse_element_plus_ending_tag(arg_names, recc - 1)?;
if !matches!(the_end.cmd, BlockEndingTag::NORMAL | BlockEndingTag::ENDIF){
return Err(FileParsingError::new(incorrect_block_ending_tag_expected_normal_or_endif, the_end.p1, self.p));
}
blocks.push(else_block);
break
} else if matches!(ending_tag.cmd, BlockEndingTag::NORMAL | BlockEndingTag::ENDIF) {
break
}
}
Ok(SubElement::If(IfSubElement{branches: blocks, conditions}))
}
fn parse_let(&mut self, arg_names: &Vec<&str>, recc: u32) -> Result<SubElement, FileParsingError> {
self.check_recursion_limit(recc)?;
self.skip_whitespace();
let p1 = self.p;
self.skip_normal_word();
if p1 == self.p {
// Ironically, these symbols are actually constants
return Err(FileParsingError::new(expected_variable_name, p1, self.p));
}
let new_variable_name = &self.text[p1..self.p];
if is_special_name(new_variable_name){
return Err(FileParsingError::new(illegal_variable_name, p1, self.p));
}
self.skip_whitespace();
if !self.is_char_ahead('=') {
return Err(self.new_unexpected_char_error(expected_assignment_operator));
}
self.p += 1;
let expr = self.parse_expression_at_cmd_tag_end(arg_names, recc - 1)?;
let mut arg_names_extended = arg_names.clone();
arg_names_extended.push(new_variable_name);
let (inner_block, ending) = self.parse_element_plus_ending_tag(&arg_names_extended, recc - 1)?;
if !matches!(ending.cmd, BlockEndingTag::NORMAL) {
return Err(FileParsingError::new(incorrect_block_ending_tag_expected_normal, ending.p1, self.p));
}
Ok(SubElement::Let(expr, inner_block))
}
fn parse_for_new_variable(&mut self) -> Result<(&'a str, usize), FileParsingError> {
self.skip_whitespace();
let t1 = self.p;
self.skip_normal_word();
if t1 == self.p {
return Err(self.new_unexpected_char_error(expected_variable_name));
}
let name = &self.text[t1..self.p];
if is_special_name(name) {
return Err(FileParsingError::new(illegal_variable_name, t1, self.p));
}
Ok((name, t1))
}
fn parse_for(&mut self, arg_names: &Vec<&str>, recc: u32) -> Result<SubElement, FileParsingError> {
self.check_recursion_limit(recc)?;
let mut arg_names_extended = arg_names.clone();
let (name1, _) = self.parse_for_new_variable()?;
arg_names_extended.push(name1);
self.skip_whitespace();
let mut name2= if self.is_char_ahead(',') {
self.p += 1;
let (name, pt2) = self.parse_for_new_variable()?;
if name == name1 {
return Err(FileParsingError::new(forloop_key_and_val_cant_have_same_name, pt2, self.p))
}
name
} else { "" };
arg_names_extended.push(name2);
if !self.is_char_ahead(':'){
return Err(self.new_unexpected_char_error(
if name2.len() > 0 { expected_colon } else { expected_comma_or_colon }
));
}
self.p += 1;
let expr = self.parse_expression_at_cmd_tag_end(arg_names, recc - 1)?;
let (inner_block, ending) = self.parse_element_plus_ending_tag(
&arg_names_extended, recc - 1)?;
let separator: String = String::from(match ending.cmd {
BlockEndingTag::NOGAP => "",
BlockEndingTag::GAP => " ",
BlockEndingTag::NORMAL | BlockEndingTag::LF | BlockEndingTag::ENDLOOP => "\n",
_ => return Err(FileParsingError::new(
incorrect_block_ending_tag_expected_normal_or_lf_gap_nogap_or_forloop, ending.p1, self.p)),
});
Ok(SubElement::For(ForSubElement{iterable: expr, core: inner_block, separator}))
}
/* Checks for ]} }} and %}. May actually return NoneOfThose */
fn is_tag_end_ahead(&self) -> bool {
["]}", "}}", "%}", "$}"].iter().any(|s| self.is_ahead(s))
}
fn fn_parse_expression_l2_trail(
&mut self, arg_names: &Vec<&str>, mut from: Expression,
used_local_consts: &mut Vec<usize>, recc: u32
) -> Result<Expression, FileParsingError> {
self.check_recursion_limit(recc)?;
loop {
self.skip_whitespace();
from = if self.is_char_ahead('.') {
self.p += 1;
self.skip_whitespace();
let attrp1 = self.p;
self.skip_normal_word();
if attrp1 == self.p {
return Err(self.new_unexpected_char_error(expected_attribute_name_after_dot));
}
let attr_name = &self.text[attrp1..self.p];
if is_special_name(attr_name) {
return Err(FileParsingError::new(illegal_attribute_name, attrp1, self.p));
}
Expression::Attribute(Box::new(from), String::from(attr_name))
} else if self.is_char_ahead('[') {
self.p += 1;
let sub_expr = self.parse_expression(arg_names, used_local_consts, recc - 1)?;
self.skip_whitespace();
if !self.is_char_ahead(']') {
return Err(self.new_unexpected_char_error(expected_closing_square_bracket))
}
self.p += 1;
Expression::Get(Box::new(from), Box::new(sub_expr))
} else {
break
}
}
Ok(from)
}
/* Suppose we use some toplevel name in expression. There is a chance it is a local constant.
* If so, we search for its index I in arg_names and if name_in_expr belongs to arg_names
* we return the index of number I in used_local_consts (pushing I to the right if needed).
* If name_in_expr is not a local constant, we return None */
fn expression_parsing_include_local_const(
arg_names: &Vec<&str>, used_local_consts: &mut Vec<usize>, name_in_expr: &str
) -> Option<usize> {
match arg_names.iter().rposition(|&n| n == name_in_expr) {
Some(i) => {
let lci = match used_local_consts.iter().position(|iig| *iig == i) {
Some(lci) => lci,
None => {used_local_consts.push(i); used_local_consts.len() - 1},
};
Some(lci)
}
None => None
}
}
/* l1 expression = l2 space l2 space ... space l2 */
fn parse_expression_l2(
&mut self, arg_names: &Vec<&str>,
used_local_consts: &mut Vec<usize>, recc: u32
) -> Result<Option<Expression>, FileParsingError> {
self.check_recursion_limit(recc)?;
self.skip_whitespace();
if self.is_tag_end_ahead() {
Ok(None)
} else if self.is_char_ahead('(') {
self.p += 1;
let expr = self.parse_expression(arg_names, used_local_consts, recc - 1)?;
self.skip_whitespace();
if !self.is_char_ahead(')') {
return Err(self.new_unexpected_char_error(expected_closing_round_bracket))
}
self.p += 1;
Ok(Some(expr))
} else if self.is_digit_ahead() {
let p1 = self.p;
loop {
if self.is_digit_ahead() {
self.p += 1;
} else if self.is_word_ahead() {
return Err(self.new_unexpected_char_error(cant_start_word_immediately_after_digit))
} else {
return match self.text[p1..self.p].parse::<u64>() {
Ok(v) => Ok(Some(Expression::Int(v))),
Err(_) => Err(FileParsingError::new(integer_parsing_error, p1, self.p)),
};
}
}
} else if self.is_word_ahead() {
let p1 = self.p;
self.skip_normal_word();
let toplevel_name = &self.text[p1..self.p];
let p2 = self.p;
self.skip_whitespace();
if self.is_char_ahead(':') {
if is_special_name(toplevel_name) {
return Err(FileParsingError::new(illegal_lambda_argument_name, p1, p2))
}
self.p += 1;
let argument_iig = arg_names.len();
let mut arg_names_extended = arg_names.clone();
arg_names_extended.push(toplevel_name);
let mut used_by_lambda: Vec<usize> = Vec::new();
let lambda_body = self.parse_expression(
&arg_names_extended, &mut used_by_lambda, recc - 1)?;
for iig in &used_by_lambda {
if !used_local_consts.contains(iig) && *iig != argument_iig {
used_local_consts.push(*iig);
}
}
let expr_id = self.source_expr.len();
self.source_expr.push(lambda_body);
Ok(Some(Expression::Lambda(NewLambdaExpression{
local_var_array: used_by_lambda.iter().map( |iig| -> usize {
if *iig == argument_iig {
usize::MAX // We assume usize::MAX never appears as an actual index in used_local_consts
} else {
used_local_consts.iter().position(|iig_of_this| iig_of_this == iig).unwrap()
}
}).collect(), expr_id})))
} else if toplevel_name == "this" {
Ok(Some(self.fn_parse_expression_l2_trail(
arg_names, self.this_meaning.clone(), used_local_consts, recc - 1)?))
} else {
let bg: Expression = match Self::expression_parsing_include_local_const(
arg_names, used_local_consts, toplevel_name
) {
Some(n) => Expression::Local(n),
None => Expression::Attribute(Box::new(Expression::Root), toplevel_name.into()),
};
Ok(Some(self.fn_parse_expression_l2_trail(arg_names, bg, used_local_consts, recc - 1)?))
}
} else if self.is_char_ahead('$') {
self.p += 1;
let bg_dollar: Expression = match Self::expression_parsing_include_local_const(
arg_names, used_local_consts, "$"
) {
Some(n) => Expression::Local(n),
None => return Err(self.new_unexpected_char_error(cant_use_dollar_in_expression_of_element_without_dollar_argument)),
};
let bg: Expression = if self.is_word_ahead() {
let p1 = self.p;
self.skip_normal_word();
let dollar_level_name = &self.text[p1..self.p];
if is_special_name(dollar_level_name) {
return Err(FileParsingError::new(illegal_dollar_level_attribute_name, p1, self.p));
}
Expression::Attribute(Box::new(bg_dollar), dollar_level_name.into())
} else { bg_dollar };
Ok(Some(self.fn_parse_expression_l2_trail(arg_names, bg, used_local_consts, recc - 1)?))
} else if self.is_char_ahead('"'){
self.p += 1;
let sb = self.p;
loop {
match self.here() {
Some(ch ) => if ch == '"' { break } else { self.advance(); }
None => return Err(self.new_unexpected_char_error(unmatched_double_quotes))
}
}
let se = self.p;
self.p += 1;
Ok(Some(Expression::Str(String::from(&self.text[sb..se]))))
} else if self.is_char_ahead('['){
self.p += 1;
self.skip_whitespace();
let mut res: Vec<Expression> = Vec::new();
loop {
if self.is_char_ahead(']') {
self.p += 1;
break;
} else {
res.push(self.parse_expression(arg_names, used_local_consts, recc - 1)?);
if self.is_char_ahead(',') {
self.p += 1;
self.skip_whitespace();
} else if self.is_char_ahead(']') {
self.p += 1;
break
} else {
return Err(self.new_unexpected_char_error(unmatched_closing_square_bracket))
}
}
}
Ok(Some(Expression::Arr(res)))
} else {
Ok(None)
}
}
fn parse_expression(
&mut self, arg_names: &Vec<&str>,
used_local_consts: &mut Vec<usize>, recc: u32
) -> Result<Expression, FileParsingError> {
self.check_recursion_limit(recc)?;
let mut e1: Expression = self.parse_expression_l2(arg_names, used_local_consts, recc - 1)?
.ok_or(self.new_unexpected_char_error(expected_round_brackets_open_or_dollar_or_word_or_int_or_string_or_square_bracket_open))?;
loop {
let arg_expr: Option<Expression> = self.parse_expression_l2(arg_names, used_local_consts,recc - 1)?;
if matches!(arg_expr, None) { break }
e1 = Expression::Call(Box::new(e1), Box::new(arg_expr.unwrap()));
}
Ok(e1)
}
fn check_recursion_limit(&self, recc: u32) -> Result<(), FileParsingError> {
if recc == 0 { Err(self.new_unexpected_char_error(recursion_limit_exceeded)) } else { Ok(() )}
}
}
/* file_path is a path without extension and separated by '/' */
pub fn make_expression_for_this(file_path: &str) -> Expression {
file_path.split("/").fold(Expression::Root, |b, s| {
Expression::Attribute(Box::new(b), String::from(s))
})
}
/* Parses a file treating it like a package (where other packages and elements could be located)
* file_path is a path of file, separated by '/' and without mtgott extension */
pub fn parse_one_file_packed(
text: &str, file_path: &str, source_expr: &mut Vec<Expression>,
) -> Result<Plemege, FileParsingError> {
let mut parser: Parser = Parser{text, p: 0, this_meaning: make_expression_for_this(file_path), source_expr};
parser.parse_pack_plus_ending(true, 150)
}
pub fn parse_one_file_simplified(
text: &str, file_path: &str, source_expr: &mut Vec<Expression>,
) -> Result<Plemege, FileParsingError> {
let mut parser: Parser = Parser{text, p: 0, this_meaning: make_expression_for_this(file_path), source_expr};
let (el, tt): (Element, ReasonOfElementEnd) = parser.parse_element_plus_ending_tag(&vec!["$"], 150)?;
match tt.cmd {
BlockEndingTag::EOF => Ok(Plemege::Element(1, el)),
BlockEndingTag::END_ELEMENT => Err(FileParsingError::new(unmatched_element_ending_tag, tt.p1, parser.p)),
_ => Err(FileParsingError::new(unmatched_magic_block_ending_tag, tt.p1, parser.p)),
}
}