diff options
Diffstat (limited to 'language-web/src/main/js/language/indentation.ts')
-rw-r--r-- | language-web/src/main/js/language/indentation.ts | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/language-web/src/main/js/language/indentation.ts b/language-web/src/main/js/language/indentation.ts new file mode 100644 index 00000000..78f0a750 --- /dev/null +++ b/language-web/src/main/js/language/indentation.ts | |||
@@ -0,0 +1,87 @@ | |||
1 | import { TreeIndentContext } from '@codemirror/language'; | ||
2 | |||
3 | /** | ||
4 | * Finds the `from` of first non-skipped token, if any, | ||
5 | * after the opening keyword in the first line of the declaration. | ||
6 | * | ||
7 | * Based on | ||
8 | * https://github.com/codemirror/language/blob/cd7f7e66fa51ddbce96cf9396b1b6127d0ca4c94/src/indent.ts#L246 | ||
9 | * | ||
10 | * @param context the indentation context | ||
11 | * @returns the alignment or `null` if there is no token after the opening keyword | ||
12 | */ | ||
13 | function findAlignmentAfterOpening(context: TreeIndentContext): number | null { | ||
14 | const { | ||
15 | node: tree, | ||
16 | simulatedBreak, | ||
17 | } = context; | ||
18 | const openingToken = tree.childAfter(tree.from); | ||
19 | if (openingToken === null) { | ||
20 | return null; | ||
21 | } | ||
22 | const openingLine = context.state.doc.lineAt(openingToken.from); | ||
23 | const lineEnd = simulatedBreak == null || simulatedBreak <= openingLine.from | ||
24 | ? openingLine.to | ||
25 | : Math.min(openingLine.to, simulatedBreak); | ||
26 | const { cursor } = openingToken; | ||
27 | while (cursor.next() && cursor.from < lineEnd) { | ||
28 | if (!cursor.type.isSkipped) { | ||
29 | return cursor.from; | ||
30 | } | ||
31 | } | ||
32 | return null; | ||
33 | } | ||
34 | |||
35 | /** | ||
36 | * Indents text after declarations by a single unit if it begins on a new line, | ||
37 | * otherwise it aligns with the text after the declaration. | ||
38 | * | ||
39 | * Based on | ||
40 | * https://github.com/codemirror/language/blob/cd7f7e66fa51ddbce96cf9396b1b6127d0ca4c94/src/indent.ts#L275 | ||
41 | * | ||
42 | * @example | ||
43 | * Result with no hanging indent (indent unit = 2 spaces, units = 1): | ||
44 | * ``` | ||
45 | * scope | ||
46 | * Family = 1, | ||
47 | * Person += 5..10. | ||
48 | * ``` | ||
49 | * | ||
50 | * @example | ||
51 | * Result with hanging indent: | ||
52 | * ``` | ||
53 | * scope Family = 1, | ||
54 | * Person += 5..10. | ||
55 | * ``` | ||
56 | * | ||
57 | * @param context the indentation context | ||
58 | * @param units the number of units to indent | ||
59 | * @returns the desired indentation level | ||
60 | */ | ||
61 | function indentDeclarationStrategy(context: TreeIndentContext, units: number): number { | ||
62 | const alignment = findAlignmentAfterOpening(context); | ||
63 | if (alignment !== null) { | ||
64 | return context.column(alignment); | ||
65 | } | ||
66 | return context.baseIndent + units * context.unit; | ||
67 | } | ||
68 | |||
69 | export function indentBlockComment(): number { | ||
70 | // Do not indent. | ||
71 | return -1; | ||
72 | } | ||
73 | |||
74 | export function indentDeclaration(context: TreeIndentContext): number { | ||
75 | return indentDeclarationStrategy(context, 1); | ||
76 | } | ||
77 | |||
78 | export function indentPredicateOrRule(context: TreeIndentContext): number { | ||
79 | const clauseIndent = indentDeclarationStrategy(context, 1); | ||
80 | if (/^\s+(;|\.)/.exec(context.textAfter) !== null) { | ||
81 | return clauseIndent - 2; | ||
82 | } | ||
83 | if (/^\s+(~>)/.exec(context.textAfter) !== null) { | ||
84 | return clauseIndent - 3; | ||
85 | } | ||
86 | return clauseIndent; | ||
87 | } | ||