sigil_stitch/
code_node.rs

1//! Tree-based intermediate representation for code generation.
2//!
3//! `CodeNode` is the internal IR used by [`CodeBlock`](crate::code_block::CodeBlock).
4//! Each node is self-contained — type references, names, and nested blocks are
5//! stored inline rather than in a separate argument vector. This enables natural
6//! tree traversal for import collection, structural transformation, and rendering.
7
8use crate::code_block::{Arg, CodeBlock, FormatPart, Specifier};
9use crate::type_name::TypeName;
10
11/// A single node in the code generation tree.
12///
13/// Each variant is self-contained: a type reference is `CodeNode::TypeRef(TypeName)`,
14/// not a separate format tag plus a positional argument.
15#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
16#[non_exhaustive]
17pub enum CodeNode {
18    /// Literal text (no interpolation).
19    Literal(String),
20    /// A type reference with import tracking (was `%T` + `Arg::TypeName`).
21    TypeRef(TypeName),
22    /// A name identifier (was `%N` + `Arg::Name`).
23    NameRef(String),
24    /// A string literal value, rendered with language-specific quoting
25    /// (was `%S` + `Arg::StringLit`).
26    StringLit(String),
27    /// An inline literal string (was `%L` + `Arg::Literal`).
28    InlineLiteral(String),
29    /// A nested code block (was `%L` + `Arg::Code`).
30    Nested(CodeBlock),
31    /// A comment line. Rendered as `{prefix} {text}{suffix}` using the
32    /// language's comment syntax.
33    Comment(String),
34    /// Soft line break point (`%W`). In direct mode emits a space; in pretty
35    /// mode becomes `BoxDoc::softline()`.
36    SoftBreak,
37    /// Increase indent level (`%>`).
38    Indent,
39    /// Decrease indent level (`%<`).
40    Dedent,
41    /// Statement begin marker (`%[`). Triggers `ensure_indent()`.
42    StatementBegin,
43    /// Statement end marker (`%]`). Emits `;` if the language uses semicolons.
44    StatementEnd,
45    /// Hard newline.
46    Newline,
47    /// Block open delimiter. Carries the control-flow condition text (e.g.,
48    /// `"if x > 0"`, `"for i in range(10)"`). At render time the renderer calls
49    /// `lang.block_open_for(condition)` — if it returns `Some(s)`, emit `s`;
50    /// otherwise fall back to `lang.block_syntax().block_open`.
51    /// Empty string means no condition (e.g., a bare `{ }` block).
52    BlockOpen(String),
53    /// Terminal block close delimiter. Carries the condition from the matching
54    /// `begin_control_flow` call. At render time the renderer calls
55    /// `lang.block_close_for(condition)` — if it returns `Some(s)`, emit `s`;
56    /// otherwise fall back to `lang.block_syntax().block_close`.
57    /// Emits: closer + newline.
58    BlockClose(String),
59    /// Non-terminal block close before a branch keyword (`else`, `elif`, `catch`).
60    /// Like `BlockClose` but emits closer + space (not newline) so the branch
61    /// keyword continues on the same line (e.g., `} else {`).
62    /// Suppressed when `block_syntax().close_on_transition` is `false`
63    /// (Lua, Bash — where `else`/`elif` sit between opener and closer).
64    BranchClose(String),
65    /// A sequence of nodes (for grouping, e.g. a statement or control flow block).
66    Sequence(Vec<CodeNode>),
67}
68
69/// Convert legacy `(FormatPart, Arg)` parallel vectors into `Vec<CodeNode>`.
70///
71/// Used by `CodeBlockBuilder::add()` which still calls `parse_format()` to get
72/// `Vec<FormatPart>`, then zips with args into self-contained nodes.
73pub(crate) fn parts_args_to_nodes(parts: &[FormatPart], args: &[Arg]) -> Vec<CodeNode> {
74    let mut nodes = Vec::with_capacity(parts.len());
75    let mut arg_index = 0;
76
77    for part in parts {
78        let node = match part {
79            FormatPart::Literal(text) => CodeNode::Literal(text.clone()),
80            FormatPart::Arg(spec) => {
81                let arg = &args[arg_index];
82                arg_index += 1;
83                match (spec, arg) {
84                    (Specifier::Type, Arg::TypeName(tn)) => CodeNode::TypeRef(tn.clone()),
85                    (Specifier::Name, Arg::Name(n)) => CodeNode::NameRef(n.clone()),
86                    (Specifier::StringLit, Arg::StringLit(s)) => CodeNode::StringLit(s.clone()),
87                    (Specifier::Literal, Arg::Literal(s)) => CodeNode::InlineLiteral(s.clone()),
88                    (Specifier::Literal, Arg::Code(block)) => CodeNode::Nested(block.clone()),
89                    _ => CodeNode::Literal(String::new()),
90                }
91            }
92            FormatPart::Wrap => CodeNode::SoftBreak,
93            FormatPart::Indent => CodeNode::Indent,
94            FormatPart::Dedent => CodeNode::Dedent,
95            FormatPart::StatementBegin => CodeNode::StatementBegin,
96            FormatPart::StatementEnd => CodeNode::StatementEnd,
97            FormatPart::Newline => CodeNode::Newline,
98            FormatPart::BlockOpen(s) => CodeNode::BlockOpen(s.clone()),
99            FormatPart::BlockClose(s) => CodeNode::BlockClose(s.clone()),
100            FormatPart::BranchClose(s) => CodeNode::BranchClose(s.clone()),
101        };
102        nodes.push(node);
103    }
104
105    nodes
106}
107
108#[cfg(test)]
109mod tests {
110    use super::*;
111    use crate::code_block::CodeBlock;
112    use crate::type_name::TypeName;
113
114    #[test]
115    fn test_literal_conversion() {
116        let parts = vec![FormatPart::Literal("hello".to_string())];
117        let args = vec![];
118        let nodes = parts_args_to_nodes(&parts, &args);
119        assert_eq!(nodes.len(), 1);
120        assert!(matches!(&nodes[0], CodeNode::Literal(s) if s == "hello"));
121    }
122
123    #[test]
124    fn test_type_ref_conversion() {
125        let tn = TypeName::primitive("string");
126        let parts = vec![
127            FormatPart::Literal("x: ".to_string()),
128            FormatPart::Arg(Specifier::Type),
129        ];
130        let args = vec![Arg::TypeName(tn)];
131        let nodes = parts_args_to_nodes(&parts, &args);
132        assert_eq!(nodes.len(), 2);
133        assert!(matches!(&nodes[0], CodeNode::Literal(s) if s == "x: "));
134        assert!(matches!(&nodes[1], CodeNode::TypeRef(_)));
135    }
136
137    #[test]
138    fn test_nested_block_conversion() {
139        let inner = CodeBlock::of("inner()", ()).unwrap();
140        let parts = vec![FormatPart::Arg(Specifier::Literal)];
141        let args = vec![Arg::Code(inner)];
142        let nodes = parts_args_to_nodes(&parts, &args);
143        assert_eq!(nodes.len(), 1);
144        assert!(matches!(&nodes[0], CodeNode::Nested(_)));
145    }
146
147    #[test]
148    fn test_structural_nodes() {
149        let parts = vec![
150            FormatPart::Indent,
151            FormatPart::StatementBegin,
152            FormatPart::Literal("x".to_string()),
153            FormatPart::StatementEnd,
154            FormatPart::Newline,
155            FormatPart::Dedent,
156        ];
157        let nodes = parts_args_to_nodes(&parts, &[]);
158        assert_eq!(nodes.len(), 6);
159        assert!(matches!(nodes[0], CodeNode::Indent));
160        assert!(matches!(nodes[1], CodeNode::StatementBegin));
161        assert!(matches!(nodes[3], CodeNode::StatementEnd));
162        assert!(matches!(nodes[4], CodeNode::Newline));
163        assert!(matches!(nodes[5], CodeNode::Dedent));
164    }
165
166    #[test]
167    fn test_soft_break_conversion() {
168        let parts = vec![
169            FormatPart::Literal("a".to_string()),
170            FormatPart::Wrap,
171            FormatPart::Literal("b".to_string()),
172        ];
173        let nodes = parts_args_to_nodes(&parts, &[]);
174        assert_eq!(nodes.len(), 3);
175        assert!(matches!(nodes[1], CodeNode::SoftBreak));
176    }
177
178    #[test]
179    fn test_block_open_close_conversion() {
180        let parts = vec![
181            FormatPart::BlockOpen("if x".to_string()),
182            FormatPart::BlockClose("if x".to_string()),
183            FormatPart::BranchClose("if x".to_string()),
184        ];
185        let nodes = parts_args_to_nodes(&parts, &[]);
186        assert_eq!(nodes.len(), 3);
187        assert!(matches!(&nodes[0], CodeNode::BlockOpen(s) if s == "if x"));
188        assert!(matches!(&nodes[1], CodeNode::BlockClose(s) if s == "if x"));
189        assert!(matches!(&nodes[2], CodeNode::BranchClose(s) if s == "if x"));
190    }
191
192    #[test]
193    fn test_mixed_args_conversion() {
194        let tn = TypeName::primitive("number");
195        let parts = vec![
196            FormatPart::Literal("let ".to_string()),
197            FormatPart::Arg(Specifier::Name),
198            FormatPart::Literal(": ".to_string()),
199            FormatPart::Arg(Specifier::Type),
200            FormatPart::Literal(" = ".to_string()),
201            FormatPart::Arg(Specifier::StringLit),
202        ];
203        let args = vec![
204            Arg::Name("x".to_string()),
205            Arg::TypeName(tn),
206            Arg::StringLit("hello".to_string()),
207        ];
208        let nodes = parts_args_to_nodes(&parts, &args);
209        assert_eq!(nodes.len(), 6);
210        assert!(matches!(&nodes[1], CodeNode::NameRef(s) if s == "x"));
211        assert!(matches!(&nodes[3], CodeNode::TypeRef(_)));
212        assert!(matches!(&nodes[5], CodeNode::StringLit(s) if s == "hello"));
213    }
214}
sigil_stitch/code_node.rs

sigil_stitch/
code_node.rs
