extern/kalker
1
0
Fork 0
mirror of https://github.com/PaddiM8/kalker.git synced 2025-01-06 13:39:17 +01:00
Code Issues Packages Projects Releases Wiki Activity

Allow multiplication with parenthesis without star symbol

Browse Source
This commit is contained in:
PaddiM8 2020-12-13 23:16:47 +01:00
parent 4f02a0f0a3
commit 483e82fb03
1 changed files with 20 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
kalk/src/parser.rs
View File

@ -30,6 +30,7 @@ pub struct Context {
/// When a unit declaration is being parsed, this value will be set
/// whenever a unit in the expression is found. Eg. unit a = 3b, it will be set to Some("b")
unit_decl_base_unit: Option<String>,
parsing_identifier_stmt: bool,
}
impl Context {
@ -41,6 +42,7 @@ impl Context {
angle_unit: DEFAULT_ANGLE_UNIT.into(),
parsing_unit_decl: false,
unit_decl_base_unit: None,
parsing_identifier_stmt: false,
};
parse(&mut context, crate::prelude::INIT).unwrap();
@ -128,7 +130,9 @@ fn parse_stmt(context: &mut Context) -> Result<Stmt, CalcError> {
fn parse_identifier_stmt(context: &mut Context) -> Result<Stmt, CalcError> {
let began_at = context.pos;
context.parsing_identifier_stmt = true;
let primary = parse_primary(context)?; // Since function declarations and function calls look the same at first, simply parse a "function call", and re-use the data.
context.parsing_identifier_stmt = false;
// If `primary` is followed by an equal sign, it is a function declaration.
if let TokenKind::Equals = peek(context).kind {
@ -159,7 +163,7 @@ fn parse_identifier_stmt(context: &mut Context) -> Result<Stmt, CalcError> {
Err(CalcError::Unknown)
} else {
// It is a function call, not a function declaration.
// It is a function call or eg. x(x + 3), not a function declaration.
// Redo the parsing for this specific part.
context.pos = began_at;
Ok(Stmt::Expr(Box::new(parse_expr(context)?)))
@ -257,10 +261,14 @@ fn parse_factor(context: &mut Context) -> Result<Expr, CalcError> {
|| match_token(context, TokenKind::Percent)
|| match_token(context, TokenKind::Identifier)
|| match_token(context, TokenKind::Literal)
|| match_token(context, TokenKind::OpenParenthesis)
{
// If the token is an identifier, assume it's multiplication. Eg. 3y
// If the token is an identifier, literal, or open parenthesis,
// assume it's multiplication. Eg. 3y or (3x + 2)(2 + 3)
let op = match peek(context).kind {
TokenKind::Identifier | TokenKind::Literal => TokenKind::Star,
TokenKind::Identifier | TokenKind::Literal | TokenKind::OpenParenthesis => {
TokenKind::Star
}
_ => advance(context).kind,
};
@ -380,8 +388,15 @@ fn parse_identifier(context: &mut Context) -> Result<Expr, CalcError> {
}
}
let parse_as_var_instead = match_token(context, TokenKind::OpenParenthesis)
&& !context.parsing_identifier_stmt
&& !context.symbol_table.contains_fn(&identifier.value);
// Eg. sqrt(64)
if match_token(context, TokenKind::OpenParenthesis) {
// If the function doesn't exist, parse it as a variable and multiplication instead.
// Although, if the parse_identifier_stmt function called this function,
// parse it as a function anyway, since it might be creating one.
if !parse_as_var_instead && match_token(context, TokenKind::OpenParenthesis) {
advance(context);
let mut parameters = Vec::new();
@ -398,7 +413,7 @@ fn parse_identifier(context: &mut Context) -> Result<Expr, CalcError> {
}
// Eg. x
if context.symbol_table.contains_var(&identifier.value) {
if parse_as_var_instead || context.symbol_table.contains_var(&identifier.value) {
Ok(Expr::Var(identifier.value))
} else if context.parsing_unit_decl {
context.unit_decl_base_unit = Some(identifier.value);